Open Access

Cerebrospinal fluid levels of inflammation, oxidative stress and NAD+are linked to differences in plasma carotenoid concentrations

  • Jade Guest1, 2,
  • Ross Grant1, 2, 3Email author,
  • Manohar Garg4,
  • Trevor A Mori5,
  • Kevin D Croft5 and
  • Ayse Bilgin6
Journal of Neuroinflammation201411:117

https://doi.org/10.1186/1742-2094-11-117

Received: 18 December 2013

Accepted: 27 May 2014

Published: 1 July 2014

Abstract

Background

The consumption of foods rich in carotenoids that possess significant antioxidant and inflammatory modulating properties has been linked to reduced risk of neuropathology. The objective of this study was to evaluate the relationship between plasma carotenoid concentrations and plasma and cerebrospinal fluid (CSF) markers of inflammation, oxidative stress and nicotinamide adenine dinucleotide (NAD+) in an essentially healthy human cohort.

Methods

Thirty-eight matched CSF and plasma samples were collected from consenting participants who required a spinal tap for the administration of anaesthetic. Plasma concentrations of carotenoids and both plasma and cerebrospinal fluid (CSF) levels of NAD(H) and markers of inflammation (IL-6, TNF-α) and oxidative stress (F2-isoprostanes, 8-OHdG and total antioxidant capacity) were quantified.

Results

The average age of participants was 53 years (SD = 20, interquartile range = 38). Both α-carotene (P = 0.01) and β-carotene (P < 0.001) correlated positively with plasma total antioxidant capacity. A positive correlation was observed between α-carotene and CSF TNF-α levels (P = 0.02). β-cryptoxanthin (P = 0.04) and lycopene (P = 0.02) inversely correlated with CSF and plasma IL-6 respectively. A positive correlation was also observed between lycopene and both plasma (P < 0.001) and CSF (P < 0.01) [NAD(H)]. Surprisingly no statistically significant associations were found between the most abundant carotenoids, lutein and zeaxanthin and either plasma or CSF markers of oxidative stress.

Conclusion

Together these findings suggest that consumption of carotenoids may modulate inflammation and enhance antioxidant defences within both the central nervous system (CNS) and systemic circulation. Increased levels of lycopene also appear to moderate decline in the essential pyridine nucleotide [NAD(H)] in both the plasma and the CSF.

Keywords

Brain Carotenoid Inflammation NAD+ Oxidative stress

Background

Neuroinflammation and oxidative stress have emerged as key players in the complex interplay between environmental and biological factors involved in the development of neurodegenerative disease [1, 2]. Under normal homeostatic conditions both immune and oxidative activity are largely transitory due to inherent negative feedback mechanisms including increased production of anti-inflammatory cytokines and enhanced endogenous antioxidant (that is glutathione peroxidase, catalase or superoxide dismutase) activity. During periods of chronic disease however, these processes can be continuously activated often amplifying each other in a positive feed forward cycle, causing cell death, tissue dysfunction and disease [3, 4].

Neuroinflammation is a well-established feature of the pathology associated with most neurodegenerative disorders [57]. During various stages of disease the activity of microglia and astrocytes are markedly increased resulting in altered production of important signalling molecules such as cytokines [8, 9]. Secretion of the inflammatory cytokines TNF and IL-6 are reportedly up-regulated within the central nervous system (CNS) of a number of neurodegenerative disorders including Alzheimer’s disease (AD) [10]. While elevated levels of TNF and IL-6 have been found to induce neuronal apoptosis and tau protein phosphorylation respectively [1114], observations that IL-6 and TNF inhibit glutamate and β-amyloid (Aβ) toxicity respectively also indicate potentially neuroprotective roles [15, 16]. At lower concentrations TNF has also been shown to be involved in synaptic scaling, cell signalling and a number of behavioural and autonomic processes, leading some to consider this cytokine as a neuromodulator [1722]. Likewise, physiological levels of IL-6 have been shown to possess neuromodulatory properties, enhancing the differentiation of neurons and expression and function of the neuronal adenosine A1 receptor, an important modulator of synaptic transmission [23, 24]. Evidence is thus emerging that cytokines such as TNF and IL-6 can elicit either positive modulatory or toxic effects in the CNS that is likely dependent on their level of expression.

While the complex pathological and physiological roles of inflammatory cytokines in the CNS are yet to be fully understood, it is relatively well established that elevated levels of each of these cytokines directly promote oxidative stress [2527]. The brain, and neurons in particular, are especially vulnerable to oxidative stress as a consequence of their poor antioxidant protection, high oxygen demand and high levels of both polyunsaturated fatty acids and transition metals [28]. The term ‘oxidative stress’, describes a significant imbalance between antioxidant defences and the bodies’ formation of reactive nitrogen (RNS) and/or oxygen species (ROS) [29]. Accumulation of RNS/ROS may result in a variety of detrimental effects such as protein oxidation, lipid peroxidation and DNA damage [2]. Failure to repair this damage, particularly to the DNA, has been demonstrated to cause genomic instability and neuronal apoptosis and is associated with the development of several neuropathologies [2, 3032].

In order to maintain cellular integrity and homeostasis after oxidative assault, a number of repair processes exist including activation of the nicotinamide adenine dinucleotide (NAD+) dependent DNA nick sensor poly(ADP-ribose) polymerase-1 (PARP) [33]. Importantly PARP activation in response to DNA damage catalyses the successive cleavage of the ADP-ribose moiety from NAD+ resulting in the formation of poly(ADP-ribose) subunits. In the context of low-to-moderate DNA damage this process facilitates DNA repair. However, over-activation of PARP, due to excessive DNA damage, can result in neuronal death as a consequence of decreased ATP production following critical depletion of NAD+[34]. In order to preserve cellular energy and concomitantly PARP activity, adequate levels of NAD+ must be maintained.

While age is the major risk factor for the development of most neurodegenerative disorders [35, 36], a number of lifestyle choices have been linked to either promotion or prevention of pathogenesis by increasing or decreasing oxidative stress and inflammation. Carotenoids, a family of phytochemicals synthesised by plants, that are responsible for the red, orange, and yellow pigments of fruit and vegetables, have been the subject of increased attention as a result of their antioxidant and inflammatory modulating properties. Importantly, serum carotenoids have been shown to be positively associated with brain carotenoid levels and can be considered a reliable predictor of brain carotenoid concentrations [37].

Within the brain, carotenoids are thought to exert a variety of protective effects. In a cell culture model of AD, lycopene was shown to efficiently attenuate Aβ-induced ROS formation, improve neuron viability and decrease the rate of apoptosis [38]. Low serum levels of lycopene, β-carotene, lutein and zeaxanthin have also been linked to impaired cognitive function and AD [3942]. Lutein supplementation has also been shown to prevent erythrocyte lipid peroxidation in humans and has been suggested as a potential therapy for the prevention of dementia [43].

Collectively, these reports indicate that higher carotenoid levels may mitigate against the development of an oxidative-inflammatory state and thereby reduce tissue damage within the CNS. While evidence from cell culture, animal and limited post-mortem brain tissue studies support this hypothesis, to date no study has investigated this putative association in the CNS of a healthy human cohort. Therefore the objective of this study was to evaluate the relationship between plasma concentrations of carotenoids and plasma and cerebrospinal fluid (CSF) markers of inflammation, oxidative stress and NAD+ in an essentially healthy human cohort.

Methods

Ethics statement

This study was conducted in accordance with the Helsinki declaration. Ethical approval was obtained from the Human Research Ethics Committee, Sydney Adventist Hospital (EC00141, project number 2011-005). Written informed consent was obtained from all participants prior to commencement.

Participants

Male (n = 10) and female (n = 28) participants, who required a spinal tap for the administration of anaesthetic as part of routine care (that is prior to surgery), were recruited at Sydney Adventist Hospital, Australia as part of a larger health study [44]. The average age of participants was 53 years (SD = 20, interquartile range = 38). Participants were excluded from the cohort if they were smokers or had a confirmed diagnosis of a neurological/neurodegenerative disorder or CNS infection. In total thirty-eight CSF and matched blood samples were collected from consenting participants considered in general good health.

Sample collection

CSF and blood samples (fasting ≥ ten hours) were collected by an anaesthetist no longer than 30 minutes apart. Blood was collected into heparinised tubes from a superficial vein on an upper limb, prior to the administration of fluids or anaesthetics. CSF samples were collected via standard lumber puncture prior to injection of anaesthetics. Samples were centrifuged for 10 minutes at 1,800 rpm and stored at −194°C within 1 hour of collection, for a maximum of 12 months, until analysis. Samples intended for F2-isoprostane analysis where stored in the presence of a glutathione/butylated hydroxytoluene preservative.

Biochemical analysis

Total nicotinamide adenine dinucleotide (NAD(H)) concentrations were measured spectrophotometrically using a thiazolyl blue microcycling assay established by Bernofsky and Swan [45], and adapted to a 96-well plate format by Grant and Kapoor as previously described [46, 47].

IL-6, TNF-α, total antioxidant capacity (TAC) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) were measured using a standardised commercial solid phase sandwich enzyme-linked immunosorbent assay (ELISA) (Human IL6 High Sensitivity ELISA Kit, Abcam, Cambridge, MA, USA; Human TNF-α UltraSensitive, Invitrogen Corporation, Camarillo, CA, USA; Antioxidant Assay Kit, Cayman Chemical Company, Ann Arbor, MI, USA; Highly Sensitive 8-OHdG Check, Japan Institute for the Control of Ageing, Shizuoka Japan).

Total F2-isoprostanes were measured by gas chromatography-mass spectrometry (GC-MS) using electron capture negative ionisation according to a modification in the method of Mori et al. as previously described [48, 49].

Plasma carotenoids were measured using high-performance liquid chromatography according to the method established by Barua and colleagues and previously described (Figure 1) [50, 51].
Figure 1

An example chromatograph of plasma carotenoids as measured by HPLC.

Statistical analysis

Statistical analyses were performed using SPSS version 16.0 for Windows (SPSS Inc., Chicago, IL, USA). Data is presented as means ± standard deviation (SD) unless otherwise stated. The Pearson correlation coefficient and multiple linear regression, controlling for age and gender, was used to identify significant relationships between carotenoids, [NAD(H)], and markers of oxidative stress and inflammation. Normality was assessed using histogram, Shapiro-Wilk and Kolmogorov-Smirnov analysis. Because some carotenoids (lutein and zeaxanthin, β-cryptoxanthin, lycopene, total carotenoids) and both plasma and CSF IL-6 showed slightly skewed distributions, analyses were performed using base-10 log-transformed data. Adjusted and non-adjusted P-values are provided throughout with test significance set at P-value ≤ 0.05.

Results

The mean plasma concentrations of individual carotenoid pigments are presented in Table 1.
Table 1

Mean plasma carotenoid concentrations

Carotenoid

Mean (ng/mL) ± SD

Lutein and zeaxanthin

538.24 ± 338.15

β-cryptoxanthin

59.54 ± 54.91

Lycopene

218.86 ± 176.80

α-carotene

15.19 ± 14.92

β-carotene

80.46 ± 82.13

Total carotenoids

935.02 ± 474.95

Association between carotenoids and inflammatory cytokines

A significant inverse association was observed between plasma levels of lycopene and plasma IL-6 (P < 0.001, r = −0.53, n = 34) (Figure 2A). This association remained even after controlling for age and gender (P = 0.02, R2 = 0.21). An increase in lycopene of 1% was associated, on average, with a 0.54% decrease in plasma IL-6. Higher plasma total carotenoid concentrations were also associated with lower levels of plasma IL-6 (P = 0.01, r = −0.44, n = 34) (Figure 2B), however this relationship did not remain statistically significant after controlling for age and gender (P = 0.06). No associations were found between plasma IL-6 and any other individual carotenoid.
Figure 2

Association between carotenoids and reduced levels of peripheral and central IL-6. (A) Inverse association between plasma lycopene and plasma IL-6 levels. A significant inverse association exists between plasma lycopene and plasma IL-6 (P = 0.02, R2 = 0.21, n = 34). Comparisons were made using multiple linear regression controlling for age and gender. (B) Inverse association between plasma total carotenoids and plasma IL-6 levels. A significant inverse association exists between total plasma carotenoids and plasma IL-6 (P = 0.01, r = −0.44, n = 34), however this relationship does not remain statistically significant after controlling for age and gender (P = 0.06). Comparisons were made using the Pearson correlation coefficient and multiple linear regression controlling for age and gender. (C) Inverse association between plasma β-cryptoxanthin and cerebrospinal fluid (CSF) IL-6 levels. A significant inverse association exists between plasma β-cryptoxanthin and CSF levels of IL-6 (P = 0.04, R2 = 0.45, n = 36). Comparisons were made using multiple linear regression controlling for age and gender. (D) Inverse association between total carotenoids and CSF IL-6 levels. A significant inverse association exists between plasma total carotenoids and CSF levels of IL-6 (P = 0.01, r = −0.44, n = 36), however this relationship does not remain statistically significant after controlling for age and gender (P = 0.06). Comparisons were made using the Pearson correlation coefficient and multiple linear regression controlling for age and gender.

An increase in plasma β-cryptoxanthin levels was associated with a decrease in CSF IL-6 (P = 0.04, r = −0.34, n = 36) (Figure 2C). This association remained even after controlling for age and gender (P = 0.04, R2 = 0.45). An increase in β-cryptoxanthin by 1% was associated, on average, with a 0.33% decrease in CSF IL-6. Higher plasma total carotenoids were also associated with reduced levels of CSF IL-6 (P = 0.01, r = −0.44, n = 36) however this relationship did not remain statistically significant after controlling for age and gender (P = 0.06) (Figure 2D). A trend between increased plasma lycopene levels and reduced concentrations of CSF IL-6 was observed, however this was not statistically significant (P = 0.22). No associations were found between CSF IL-6 and any other individual carotenoid.

An increase in plasma α-carotene was associated with an increase in CSF TNF-α (P = 0.01, r = 0.185, n = 36) (Figure 3). This association remained even after controlling for age and gender (P = 0.02, R2 = 0.10). A ten-fold increase in α-carotene was associated with a small 0.003 pg/mL increase in CSF TNF-α. A positive trend between β-carotene and CSF TNF-α was also observed, however this did not reach statistical significance (P = 0.17). No associations were found between CSF TNF-α and any other individual carotenoid.
Figure 3

Positive association between cerebrospinal fluid (CSF) TNF-α and plasma α-carotene. A significant positive association exists between plasma α-carotene and CSF TNF-α (P = 0.02, R2 = 0.10, n = 36). Comparisons were made using multiple linear regression controlling for age and gender.

Association between carotenoids and markers of oxidative stress

A significant positive association was observed between both α-carotene (P = 0.01, r = 0.43, n = 33) and β-carotene (P < 0.001, r = 0.59, n = 33) and the total antioxidant capacity (TAC) in plasma (Figure 4). These relationships remained even after controlling for age and gender (P = 0.01, R2 = 0.14; P < 0.001, R2 = 0.32 respectively). A 1 ng/mL increase in α-carotene or β-carotene was associated with a 0.15 or 0.04 nmol/mg protein increase in plasma TAC respectively. When controlling for age and gender, higher plasma levels of lycopene also tended to correspond with reduced levels of plasma F2-isoprostanes, however this did not quite reach statistical significance (P = 0.06). An apparent inverse trend between CSF F2-isoprostane levels and plasma β-cryptoxanthin (P = 0.16), α-carotene (P = 0.14) and β-carotene (P = 0.20) was observed, though these did not reach statistical significance. No further associations were apparent between CSF F2-isoprostane and plasma levels of any individual carotenoid. No associations were observed between CSF 8-OHdG concentrations and plasma levels of any individual carotenoid.
Figure 4

Positive association between plasma total antioxidant capacity (TAC) and (A) plasma α-carotene (B) plasma β-carotene. (A) A significant positive association exists between plasma α-carotene and plasma TAC (P = 0.01, R2 = 0.14, n = 33). Comparisons were made using multiple linear regression controlling for age and gender. (B) A significant positive association exists between plasma β-carotene and plasma TAC (P < 0.001, R2 = 0.32, n = 33). Comparisons were made using multiple linear regression controlling for age and gender.

Association between carotenoids and both peripheral and central [NAD(H)]

A significant positive association was found between lycopene and both plasma (P < 0.01, r = 0.50, n = 38) and CSF (P < 0.01, r = 0.50, n = 37) [NAD(H)] (Figure 5). These relationships remained even after controlling for age and gender (P < 0.001, R2 = 0.31; P < 0.001, R2 = 0.21 respectively). A 1% increase in lycopene was associated, on average, with a 0.20% increase in plasma [NAD(H)]. Likewise a ten-fold increase in lycopene was associated with a 48.4 μg/mL increase in CSF [NAD(H)].
Figure 5

Association between carotenoids and increased levels of peripheral and central [NAD(H)]. (A) A significant positive association exists between lycopene and plasma [NAD(H)] (P < 0.001, R2 = 0.31, n = 38). Comparisons were made using multiple linear regression controlling for age and gender. (B) A significant positive association exists between lycopene and CSF [NAD(H)] (P < 0.001, R2 = 0.21, n = 37). Comparisons were made using multiple linear regression controlling for age and gender. (C) A significant positive association exists between total carotenoids and plasma [NAD(H)] (P = 0.03, R2 = 0.12, n = 37). Comparisons were made using multiple linear regression controlling for age and gender.

After controlling for age and gender a positive association between total carotenoids and plasma NAD(H) levels was also observed (P = 0.03, R2 = 0.12, n = 37) (Figure 5C). A 1% increase in total carotenoids was associated, on average, with a 0.21% increase in plasma [NAD(H)]. Plasma total carotenoids were positively associated with CSF [NAD(H)] (P = 0.05, r = 0.33, n = 37), however this did not remain statistically significant after controlling for age and gender. No associations were found between plasma [NAD(H)], CSF [NAD(H)] and any other individual carotenoid.

Discussion

Neuroinflammation and oxidative stress are established pathological features of most neurodegenerative disorders. While the consumption of foods rich in carotenoids, known to possess antioxidant and inflammatory modulating properties, has been linked to a reduced risk of cognitive decline [40], surprisingly there is limited research on the effect of carotenoids on neuroinflammation and oxidative stress. To our knowledge this is the first study to investigate the association between peripheral carotenoid concentrations and CNS markers of oxidative stress and inflammation in humans without CNS pathology.

As expected, high plasma lycopene and total carotenoid concentrations were associated with reduced plasma IL-6 levels. This is consistent with epidemiologic studies reporting carotenoid concentrations to be inversely associated with peripheral markers of inflammation [52]. While further research into the mechanism of carotenoid mediated inflammation is required, it has been demonstrated that a variety of carotenoids, including lycopene and lutein inhibit cytokine production via suppressing ROS stimulated NF-κβ activation [5356].

While major contributors to plasma TAC are uric acid and albumin [57], the positive correlation observed between plasma TAC and both α-carotene and β-carotene indicate that these carotenoids contribute to peripheral antioxidant defences. However, their capacity to mitigate against both lipid and DNA damage in vivo is questionable as no inverse associations were observed between carotenes and either plasma F2-isoprostane or 8-OHdG respectively. Previous evidence for an association between the carotenes and markers of lipid and DNA oxidative damage is mixed, with some studies showing a significant protective effect and others finding no significant association [5861]. For example van den Berg and colleagues reported that while a three-week plant-based diet increased serum levels of carotenoids, including α-carotene and β-carotene, and increased TAC, consistent with results from this study, no effects were observed on any plasma marker of oxidative damage to lipids, proteins and DNA [61].

A number of carotenoids, including β-cryptoxanthin, lycopene and β-carotene, are thought to cross the blood brain barrier and modulate inflammation [62, 37]. In this study a novel inverse association between β-cryptoxanthin and CSF IL-6 was observed. Similarly an increase in total carotenoids was also associated with reduced CSF IL-6 levels. This is consistent with in vitro work by others showing that β-cryptoxanthin significantly attenuates both the release and transcription of various cytokines [63, 64]. Astaxanthin, another member of the carotenoid xanthophyll family, has also been shown to decrease IL-6 mRNA in activated microglia [65].

In contrast to the inverse associations observed between carotenoids and IL-6, an increase in plasma α-carotene was associated with a statistically significant increase in CSF TNF-α. A positive, though not statistically significant trend was also observed between β-carotene and CSF TNF-α. While evidence of the moderating effect of carotenoids on inflammation is growing, consistent with results from this study, a small number of in vitro and ex vivo studies have reported that β-carotene can increase the secretion of TNF-α from monocytes and macrophages [66, 67]. Although no known studies have investigated the potential for α-carotene to likewise promote TNF-α secretion, the structural similarity between both carotene types suggest this possibility and is consistent with the data presented in this manuscript, though further research is required to verify this observation.

TNF-α is a multifunctional, pleiotropic cytokine initially identified as a potent regulator of cellular activity during an immune response. Although traditionally considered toxic and known to initiate neuronal apoptosis when elevated [13] in healthy brain tissue under non-inflammatory conditions, physiological TNF-α levels below approximately 20 (pg/mL) appear to have positive neuromodulatory activity [17, 6872]; being involved in synaptic scaling, cell signalling and a number of behavioural and autonomic processes [1721]. Under certain circumstances TNF-α has also displayed neuroprotective properties such as preventing Aβ toxicity [15]. While the role of TNF-α in normal brain function is yet to be fully elucidated, considered together, these studies indicate that physiological levels of TNF-α, as observed in this study (2.69 pg/mL ± 0.68 SD) may play a role in maintaining neural homeostasis. Therefore, our finding of a positive association between the carotenes and TNF-α levels (within the lower physiological range) likely do not reflect increased inflammation, but rather promotion of the healthy neuromodulatory function of TNF-α.

There is a growing interest in understanding the role and mechanism of the carotenoids as inhibitors of oxidative stress. Indeed evidence suggests that the ability of carotenoids to combat oxidative stress does not solely rely on their capacity to quench free radicals. Recently lycopene, a potent singlet oxygen (1O2) quencher [73], has been reported to restore PARP activity after deltamethrin-induced testicular injury in rats [74]. Further Apo-10′ lycopenoic acid, a lycopene metabolite, has been shown in murine models to increase sirtuin 1 (SIRT1) mRNA and protein levels [75]. Importantly, both PARP and SIRT1 use NAD+ as the primary substrate for their activities. We report for the first time a significant positive association between lycopene and both plasma and CSF NAD(H) levels, which remained even after controlling for age and gender. While further investigation is required, we postulate that by quenching ROS, lycopene reduces DNA damage, preventing PARP over-activation, and hence preservation of central NAD+ stores.

NAD+ is a ubiquitous molecule that is necessary for a number of vital cellular processes. In addition to its role in classical energy production and many cellular reactions as a redox couple, NAD+ also serves, as previously mentioned, as a substrate for the sirtuin and PARP family of enzymes and the immune linked NAD+ glycohydrolases (CD38) [7678]. As a group, these NAD+ dependent enzymes help modulate circadian rhythms, insulin secretion, genomic stability and cell longevity [7983]. As NAD(H) levels impact at least PARP and SIRT1 activity, our observation that lycopene correlates with increased NAD(H) availability within the brain suggests that consumption of this carotenoid may improve cell metabolic and genomic stability, decreasing an individuals’ susceptibility to neurodegenerative disease. This is of potential significant relevance in light of observations by others that higher levels of NAD+ correlate with reduced synaptic loss and increased neuronal viability [84, 85], and the need to find effective strategies to maintain cell function in the aging brain.

While the observations reported in this study are statistically valid, it is recognised that these associations have been obtained from a modest number of matched whole blood and CSF samples, potentially limiting sensitivity. As a result, some relationships may have been obscured; for example, although no statistically significant association between carotenoids and specific biomarkers of lipid and DNA damage was found, a number of expected inverse trends were observed that may have reached statistical significance if sample numbers were increased. In addition, some observed associations did not remain significant after controlling for age and gender (for example, between CSF IL-6 and serum total carotenoids) which may yet prove significant in a larger cohort study. In the case of age, this may also reflect the relative inability of carotenoids to exert enough anti-inflammatory effect on their own to combat the known age associated acceleration in inflammation and oxidative stress [47, 86]. Nevertheless the reported associations in this study are generally consistent with the limited number of previously published observations and represent the first data linking carotenoid levels with changes in [NAD(H)] and inflammatory/oxidative stress markers in the healthy CNS.

Conclusion

An extensive body of evidence now indicates that oxidative stress and inflammation play a central role in the development of neurodegenerative disorders. While the consumption of foods rich in carotenoids have been linked to a reduced risk of this type of neuropathology, limited research is available detailing their association with inflammation and oxidative stress levels within the human CNS. This study provides evidence for the first time that plasma carotenoids may modulate CSF levels of inflammatory cytokines in healthy humans and reports a link between increased plasma carotenoid concentrations and reduced oxidative activity. We also provide novel evidence that lycopene may influence levels of the essential pyridine nucleotide NAD(H) in both the plasma and the CSF. This data therefore suggests that higher carotenoid intake may assist in the maintenance of brain health, however further research (both cross-sectional and longitudinal) is required to confirm this proposition.

Abbreviations

8-OHdG: 

8-hydroxy-2′-deoxyguanosine

Aβ: 

beta amyloid

AD: 

Alzheimer’s disease

ATP: 

adenosine triphosphate

CD38: 

cluster of differentiation

CNS: 

central nervous system

CSF: 

cerebrospinal fluid

ELISA: 

Enzyme-Linked Immunosorbent Assay

IL-6: 

interleukin-6

GC-MS: 

gas chromatography-mass spectrometry

HPLC: 

high performance liquid chromatography

NAD+

nicotinamide adenine dinucleotide

NAD(H): 

total nicotinamide adenine dinucleotide

Nam: 

nicotinamide

NF-κβ: 

nuclear factor-κβ

1O2

singlet oxygen

PARP: 

poly(ADP-ribose) polymerase-1

RNS: 

reactive nitrogen species

ROS: 

reactive oxygen species

SIRT1: 

sirtuin 1

TAC: 

total antioxidant capacity

TNF-α: 

tumour necrosis factor alpha

Declarations

Acknowledgements

This study was supported by a grant to R Grant and J Guest from the BUPA Health Foundation. We would like to thank the anaesthetists of Sydney Adventist Hospital who kindly assisted in the collection of all samples.

Authors’ Affiliations

(1)
Australasian Research Institute, Sydney Adventist Hospital
(2)
School of Medical Sciences, Faculty of Medicine, University of New South Wales, Wallace Wurth Building
(3)
Sydney Medical School, University of Sydney
(4)
School of Biomedical Sciences and Pharmacy, University of Newcastle
(5)
School of Medicine and Pharmacology, Royal Perth Hospital Unit, University of Western Australia
(6)
Faculty of Science, Macquarie University

References

  1. Glass CK, Saijo K, Winner B, Marchetto MC, Gage FH: Mechanisms underlying inflammation in neurodegeneration. Cell. 2010, 140: 918-934.PubMed CentralView ArticlePubMedGoogle Scholar
  2. Lin MT, Beal MF: Mitochondrial dysfunction and oxidative stress in neurodegenerative diseases. Nature. 2006, 443: 787-795.View ArticlePubMedGoogle Scholar
  3. Rawdin BJ, Mellon SH, Dhabhar FS, Epel ES, Puterman E, Su Y, Burke HM, Reus R, Rosser R, Hamilton SP, Nelson JC, Wolkowitz OM: Dysregulated relationship of inflammation and oxidative stress in major depression. Brain Behav Immun. 2013, 31: 143-152.PubMed CentralView ArticlePubMedGoogle Scholar
  4. Il’yasova D, Ivanova A, Morrow JD, Cesari M, Pahor M: Correlation between two markers of inflammation, serum C-reactive protein and interleukin 6, and indices of oxidative stress in patients with high risk of cardiovascular disease. Biomarkers. 2008, 13: 41-51.View ArticlePubMedGoogle Scholar
  5. Furney SJ, Kronenberg D, Simmons A, Güntert A, Dobson RJ, Proitsi P: Combinatorial markers of mild cognitive impairment conversion to Alzheimers disease - cytokines and MRI measures together predict disease progression. J Alzheimers Dis. 2011, 26 (Suppl 3): 395-405.PubMedGoogle Scholar
  6. Collins LM, Toulouse A, Connor TJ, Nolan YM: Contributions of central and systemic inflammation to the pathophysiology of Parkinson’s disease. Neuropharmacology. 2012, 62: 2154-2168.View ArticlePubMedGoogle Scholar
  7. Evans MC, Couch Y, Sibson N, Turner MR: Inflammation and neurovascular changes in amyotrophic lateral sclerosis. Mol Cell Neurosci. 2013, 53: 3-41.View ArticleGoogle Scholar
  8. Sudduth TL, Schmitt FA, Nelson PT, Wilcock DM: Neuroinflammatory phenotype in early Alzheimer’s disease. Neurobiol Aging. 2013, 34: 1051-1059.PubMed CentralView ArticlePubMedGoogle Scholar
  9. Boissonneault V, Filali M, Lessard M, Relton J, Wong G, Rivest S: Powerful beneficial effects of macrophage colony-stimulating factor on β-amyloid deposition and cognitive impairment in Alzheimer’s disease. Brain. 2009, 132: 1078-1092.View ArticlePubMedGoogle Scholar
  10. Forloni G, Mangiarotti F, Angeretti N, Lucca E, De Simoni MG: β-amyloid fragment potentiates IL-6 and TNF-α secretion by LPS in astrocytes but not in microglia. Cytokine. 1997, 9: 759-762.View ArticlePubMedGoogle Scholar
  11. Wood JA, Wood PL, Ryan R, Graff-Radford NR, Pilapil C, Robitaille Y, Quirion R: Cytokine indices in Alzheimer’s temporal cortex: no changes in mature IL-1 beta or IL-1 RA but increases in the associated acute phase proteins IL-6, alphy-2-macroglobulin and C-reactive protein. Brain Res. 1993, 629: 245-252.View ArticlePubMedGoogle Scholar
  12. Morimoto K, Horio J, Satoh H, Sue L, Beach T, Arita S, Tooyama I, Konishi Y: Expression profiles of cytokines in the brains of Alzheimer’s disease (AD) patients compared to the brains of non-demented patients with and without increasing AD pathology. J Alzheimers Dis. 2011, 25: 59-76.PubMed CentralPubMedGoogle Scholar
  13. Talley AK, Dewhurst S, Perry SW, Dollard SC, Gummuluru S, Fine SM, New D, Epstein LG, Gendelman HE, Gelbard HA: Tumor necrosis factor alpha-induced apoptosis in human neuronal cells: protection by the antioxidant N-acetylcysteine and the genes bcl-2 and crmA. Mol Cell Biol. 1995, 15: 2359-2366.PubMed CentralView ArticlePubMedGoogle Scholar
  14. Quintanilla RA, Orellana DI, González-Billault C, Maccioni RB: Interleukin-6 induces Alzheimer-type phosphorylation of tau protein by deregulating the cdk5/p35 pathway. Exp Cell Res. 2004, 295: 245-257.View ArticlePubMedGoogle Scholar
  15. Barger S, Horster D, Furukawa K, Goodman Y, Krieglstein J, Mattson M: Tumor necrosis factors alpha and beta protect against APP toxicity: evidence for involvement of a kB-binding factor and attenuation of peroxide and Ca21 accumulation. Proc Natl Acad Sci U S A. 1995, 92: 9328-9332.PubMed CentralView ArticlePubMedGoogle Scholar
  16. Liu Z, Qiu YH, Li B, Ma SH, Peng YP: Neuroprotection of interleukin-6 against NMDA-induced apoptosis and its signal-transduction mechanisms. Neurotox Res. 2011, 19: 484-495.View ArticlePubMedGoogle Scholar
  17. Vitkovic L, Bockaert J, Jacque C: ‘Inflammatory’ cytokines: neuromodulators in normal brain?. J Neurochem. 2000, 74: 457-471.View ArticlePubMedGoogle Scholar
  18. Raison CL, Borisov AS, Woolwine BJ, Massung B, Vogt G, Miller AH: Interferon-α effects on diurnal hypothalamic-pituitary-adrenal axis activity: relationship with proinflammatory cytokines and behaviour. Mol Psychiatr. 2010, 15: 535-547.View ArticleGoogle Scholar
  19. Shoham S, Davenne D, Cady AB, Dinarello CA, Krueger JM: Recombinant tumor necrosis factor and interleukin 1 enhance slow-wave sleep. Am J Physiol. 1987, 253: R142-R149.PubMedGoogle Scholar
  20. Stellwagen D, Malenka RC: Synaptic scaling mediated by glial TNF-[alpha]. Nature. 2006, 440: 1054-1059.View ArticlePubMedGoogle Scholar
  21. Eder J: Tumour necrosis factor alpha and interleukin 1 signalling: do MAPKK kinases connect it all?. Trends Pharmacol Sci. 1997, 8: 319-322.View ArticleGoogle Scholar
  22. McCoy M, Tansey MG: TNF signaling inhibition in the CNS: implications for normal brain function and neurodegenerative disease. J Neuroinflammation. 2008, 5: 45.PubMed CentralView ArticlePubMedGoogle Scholar
  23. Satoh T, Nakamura S, Taga T, Matsuda T, Hirano T, Kishimoto T, Kaziro Y: Induction of neuronal differentiation in PCI2 cells by B-cell stimulatory factor 2/interleukin 6. Mol Cell Biol. 1998, 8: 3546-3549.View ArticleGoogle Scholar
  24. Biber K, Pinto-Duarte A, Wittendorp MC, Dolga AM, Fernandes CC, Von Frijtag Drabbe Künzel J, Keijser JN, de Vries R, Ijzerman AP, Ribeiro JA, Eisel U, Sebastião AM, Boddeke HWGM: Interleukin-6 upregulates neuronal adenosine a1 receptors: implications for neuromodulation and neuroprotection. Neuropsychopharmacol. 2008, 33: 2237-2250.View ArticleGoogle Scholar
  25. Wassmann S, Stumpf M, Strehlow K, Schmid A, Schieffer B, Böhm M, Nickenig G: Interleukin-6 induces oxidative stress and endothelial dysfunction by overexpression of the angiotensin II type 1 receptor. Circ Res. 2004, 94: 534-541.View ArticlePubMedGoogle Scholar
  26. Petit-Frère C, Clingen PH, Grewe M, Krutmann J, Roza L, Arlett CF, Green MHL: Induction of interleukin-6 production by ultraviolet radiation in normal human epidermal keratinocytes and in a human keratinocyte cell line is mediated by DNA damage. J Invest Dermatol. 1998, 111: 354-359.View ArticlePubMedGoogle Scholar
  27. Suematsu N, Tsutsui H, Wen J, Kang D, Ikeuchi M, Ide T, Hayashidani S, Shiomi T, Kubota T, Hamasaki N, Takeshita A: Oxidative stress mediates tumor necrosis factor-alpha-induced mitochondrial DNA damage and dysfunction in cardiac myocytes. Circulation. 2003, 107: 1418-1423.View ArticlePubMedGoogle Scholar
  28. Halliwell B: Oxidative stress and neurodegeneration: where are we now?. J Neurochem. 2006, 97: 1634-1658.View ArticlePubMedGoogle Scholar
  29. Sies H: Introductory remarks. Oxidative Stress. 1985, London: Academic, 1-8.View ArticleGoogle Scholar
  30. Nunomura A, Perry G, Aliev G, Hirai K, Takeda A, Balraj EK, Jones PK, Ghanbari H, Wataya T, Shimohama S, Chiba S, Atwood CS, Petersen RB, Smith MA: Oxidative damage is the earliest event in Alzheimer disease. J Neuropathol Exp Neurol. 2001, 60: 759-767.View ArticlePubMedGoogle Scholar
  31. Dexter DT, Carter CJ, Wells FR, Javoy-Agid F, Agid Y, Lees A, Jenner P, Marsden CD: Basal lipid peroxidation in substantia nigra is increased in Parkinson’s disease. J Neurochem. 1989, 52: 381-389.View ArticlePubMedGoogle Scholar
  32. Rothstein JD: Current hypotheses for the underlying biology of amyotrophic lateral sclerosis. Ann Neurol. 2009, 65 (Suppl 1): 3-9.View ArticleGoogle Scholar
  33. Sun F, Gobbel G, Li W, Chen J: Molecular mechanisms of DNA damage and repair in ischemic neuronal injury. Mech Ageing Dev. 2012, 133: 186-194.View ArticleGoogle Scholar
  34. Alano CC, Garnier P, Ying W, Higashi Y, Kauppinen TM, Swanson RA: NAD+ depletion is necessary and sufficient for poly(adp-ribose) polymerase-1-mediated neuronal death. J Neuro. 2010, 30: 2967-2978.View ArticleGoogle Scholar
  35. Evans DA, Funkenstein HH, Albert MS, Scherr PA, Cook NR, Chown MJ, Hebert LE, Hennekens CH, Taylor JO: Prevalence of Alzheimer’s disease in a community population of older persons. Higher than previously reported. JAMA. 1989, 262: 2551-2556.View ArticlePubMedGoogle Scholar
  36. Moghal S, Rajput AH, D’Arcy C, Rajput R: Prevalence of movement disorders in elderly community residents. Neuroepidemiology. 1994, 3: 175-178.View ArticleGoogle Scholar
  37. Johnson EJ, Vishwanathan R, Scott TM, Schalch W, Wittwer J, Hausman DB, Davey A, Johnson MA, Green RC, Gearing M, Poon LW: Serum carotenoids as a biomarker for carotenoid concentrations in the brain. FASEB. 2011, 25: s344.2.Google Scholar
  38. Qu M, Chen C, Li M, Peo L, Chu F, Yang J, Yu Z, Wang D, Zhou Z: Protective effects of lycopene against amyloid β-induced neurotoxicity in cultured rat cortical neurons. Neurosci Lett. 2011, 505: 286-290.View ArticlePubMedGoogle Scholar
  39. Warsama Jama J, Launer LJ, Witteman JCM, Den Breeijen JH, Breteler MMB, Grobbee DE, Hofman A: Dietary antioxidants and cognitive function in a population-based sample of older persons: the Rotterdam study. Am J Epidemiol. 1996, 144: 275-280.View ArticleGoogle Scholar
  40. Johnson EJ, Vishwanathan R, Johnson MA, Hausman DB, Davey A, Scott TM, Green RC, Miller LS, Gearing M, Woodard J, Nelson PT, Chung HY, Schalch W, Wittwer J, Poon LW: Relationship between serum and brain carotenoids, α-tocopherol, and retinol concentrations and cognitive performance in the oldest old from the Georgia centenarian study. J Aging Res. 2013, article ID 951786Google Scholar
  41. Akbaraly NT, Faure H, Gourlet V, Favier A, Berr C: Plasma carotenoid levels and cognitive performance in an elderly population: results of the EVA Study. J Gerontol Biol. 2007, 62: 308-316.View ArticleGoogle Scholar
  42. Kiko T, Nakagawa K, Tsuduki T, Suzuki T, Arai H, Miyazawa T: Significance of lutein in red blood cells of Alzheimer’s disease patients. J Alzheimers Dis. 2012, 28: 593-600.PubMedGoogle Scholar
  43. Nakagawa K, Kiko T, Hatade K, Sookwong P, Arai H, Miyazawa T: Antioxidant effect of lutein towards phospholipid hydroperoxidation in human erythrocytes. British J Nutr. 2009, 102: 1280-1284.View ArticleGoogle Scholar
  44. Guest J, Garg M, Bilgin A, Grant R: Relationship between central and peripheral fatty acids in humans. Lipids Health Dis. 2013, 12: 79-87.PubMed CentralView ArticlePubMedGoogle Scholar
  45. Bernofsky C, Swan M: An improved cycling assay for nicotinamide adenine dinucleotide. Anal Biochem. 1973, 53: 452-458.View ArticlePubMedGoogle Scholar
  46. Grant RS, Kapoor V: Murine glial cells regenerate NAD+, after peroxide induced depletion, using either nicotinic acid, nicotinamide, or quinolinic acid as substrates. J Neurochem. 1998, 70: 1759-1763.View ArticlePubMedGoogle Scholar
  47. Massudi H, Grant R, Braidy N, Guest J, Farnsworth B, Grant R: Age-associated changes in oxidative stress and NAD+ metabolism in human tissue. PLoS One. 2012, 7: e42357.PubMed CentralView ArticlePubMedGoogle Scholar
  48. Mori TA, Croft KD, Puddey IB, Beilin LJ: An improved method for the measurement of urinary and plasma F2-isoprostanes using gas chromatography-mass spectrometry. Anal Biochem. 1999, 268: 117-125.View ArticlePubMedGoogle Scholar
  49. Barden AE, Corcoran TB, Mas E, Durand T, Galano J-M, Roberts LJ, Paech M, Muchatuta NA, Phillips M, Mori TA: Is there a role for isofurans and neuroprostanes in pre-eclampsia and normal pregnancy?. Antioxid Redox Signal. 2012, 16: 165-169.PubMed CentralView ArticlePubMedGoogle Scholar
  50. Barua AB, Kostic D, Olsen J: New simplified procedures for the extraction and simultaneous high performance liquid chromatographic analysis of retinol, tocopherols and carotenoids in human serum. J Chrom. 1993, 617: 257-264.View ArticleGoogle Scholar
  51. Burrows TL, Warren JM, Colyvas K, Garg ML, Collins CE: Validation of overweight children’s fruit and vegetable intake using plasma carotenoids. Obesity. 2009, 17: 162-168.View ArticlePubMedGoogle Scholar
  52. Ghashut RA, McMillan DC, Kinsella J, Duncan A, Talwar D: Quantitative data on the magnitude of the systemic inflammatory response and its effect on carotenoids status based on plasma measurements. ESPEN J. in pressGoogle Scholar
  53. Kim GY, Kim JH, Ahn SC, Lee HJ, Moon DO, Lee CM, Park YM: Lycopene suppresses the lipopolysaccharide-induced phenotypic and functional maturation of murine dendritic cells through inhibition of mitogen-activated protein kinases and nuclear factor-kappa&UF062. Immunology. 2004, 113: 203-211.PubMed CentralView ArticlePubMedGoogle Scholar
  54. Armoza A, Haim Y, Basiri A, Wolak T, Paran E: Tomato extract and the carotenoids lycopene and lutein improve endothelial function and attenuate inflammatory NF-κβ signaling in endothelial cells. J Hypertens. 2012, 31: 521-529.View ArticleGoogle Scholar
  55. Bai SK, Lee SJ, Na HJ, Ha KS, Han JA, Lee H, Kwon YG, Chung CK, Kim YM: β-carotene inhibits inflammatory gene expression in lipopolysaccharide-stimulated macrophages by suppressing redox-based NF-κβ activation. Exp Mol Med. 2005, 37: 323-334.View ArticlePubMedGoogle Scholar
  56. Kim JH, Na HJ, Kim CK, Kim JY, Ha KS, Lee H, Chung HT, Kwon HJ, Kwon YG, Kim YM: The non-provitamin A carotenoid, lutein, inhibits NF-kappaβ-dependent gene expression through redox-based regulation of the phosphatidylinositol 3-kinase/PTEN/Akt and NF-kappaβ-inducing kinase pathways: role of H2O2 in NF-kappaβ activation. Free Radic Biol Med. 2008, 45: 885-896.View ArticlePubMedGoogle Scholar
  57. Sies H: Total antioxidant capacity: appraisal of a concept. J Nutr. 2007, 137: 1493-1495.PubMedGoogle Scholar
  58. Moreno JM, Leets I, Puche RJ, Salazar AM, Papale JF, Alvarado G, Garcia-Casal MN: Low dose β-carotene supplementation diminishes oxidative stress in type 2 diabetics and healthy individuals. J Pharm Nutr Sci. 2013, 3: 206-214.Google Scholar
  59. Hughes KJ, Mayne ST, Blumberg JB, Ribaya-Mercado JD, Johnson EJ, Cartmel B: Plasma carotenoids and biomarkers of oxidative stress in patients with prior head and neck cancer. Biomark Insights. 2009, 4: 17-26.PubMed CentralPubMedGoogle Scholar
  60. Hininger IA, Meyer-Wenger A, Moser U, Wright A, Southon S, Thurnham D, Chopra M, Van Den Berg H, Olmedilla B, Favier AE, Roussel AM: No significant effects of lutein, lycopene or β-carotene supplementation on biological markers of oxidative stress and LDL oxidizability in healthy adult subjects. J Am Coll Nutr. 2001, 20: 232-238.View ArticlePubMedGoogle Scholar
  61. van den Berg R, van Vliet T, Brorkmans WMR, Cnubben NH, Vaes WH, Roza L, Haenen GR, Bast A, van den Berg H: A vegetable/fruit concentrate with high antioxidant capacity has no effect on biomarkers of antioxidant status in male smokers. J Nutr. 2001, 131: 1722-1747.Google Scholar
  62. Unno K, Sugiura M, Ogawa K, Takabayashi F, Toda M, Sakuma M: β-Cryptoxanthin, plentiful in Japanese mandarin orange, prevents age-related cognitive dysfunction and oxidative damage in senescence- accelerated mouse brain. Biol Pharm Bull. 2011, 34: 311-317.View ArticlePubMedGoogle Scholar
  63. Nishigaki M, Yamamoto T, Ichioka H, Honjo KI, Yamamoto K, Oseko F, Kita M, Mazda O, Kanamura N: β-cryptoxanthin regulates bone reabsorption related-cytokine production in human periodontal ligament cells. Arch Oral Biol. 2013, 58: 880-886.View ArticlePubMedGoogle Scholar
  64. Katsuura S, Imamura T, Bando N, Yamanishi R: β-Carotene and β-cryptoxanthin but not lutein evoke redox and immune changes in RAW264 murine macrophages. Mol Nutr Food Res. 2009, 53: 1396-1405.View ArticlePubMedGoogle Scholar
  65. Kim YH, Koh HK, Kim DS: Down-regulation of IL-6 production by astaxanthin via ERK-, MSK-, and NF-κβ-mediated signals in activated microglia. Int Immunopharmacol. 2010, 10: 1560-1572.View ArticlePubMedGoogle Scholar
  66. Hughs DA, Wright AJA, Finglas PM, Peerless ACJ, Bailey AL, Astley SB, Pinder AC, Southon S: The effect of β-carotene supplementation on the immune function of blood monocytes from healthy male nonsmokers. J Lab Clin Med. 1997, 129: 309-317.View ArticleGoogle Scholar
  67. Yeh S-L, Wang H-M, Chen P-Y, Wu T-Z: Interactions of β-carotene and flavonoids on the secretion of pro-inflammatory mediators in an in vitro system. Chem-Biol Interact. 2009, 179: 386-393.View ArticlePubMedGoogle Scholar
  68. Tarkowski E, Blennoe K, Wallin A, Tarkowski A: Intracerebral production of tumor necrosis factor-α local neuroprotective agent, in Alzheimer disease and vascular dementia. J Clin Immunol. 1999, 19: 223-230.View ArticlePubMedGoogle Scholar
  69. Tarkowski E, Tullberg M, Fredman P, Wikkelso C: Correlation between intrathecal sulfatide and TNF-α levels in patients with vascular dementia. Geriatr Cogn Disord. 2003, 15: 207-211.View ArticleGoogle Scholar
  70. Tang R-B, Lee B-H, Chung R-L, Chen S-J, Wong T-T: Interleukin-1β and tumor necrosis factor-α in cerebrospinal fluid of children with bacterial meningitis. Child Nerv Sys. 2001, 17: 453-456.View ArticleGoogle Scholar
  71. Kwon KY, Jeon B-C: Cytokine levels in cerebrospinal fluid and delayed ischemic deficits in patients with aneurysmal subarachnoid haemorrhage. J Korean Med Sci. 2001, 16: 774-780.PubMed CentralView ArticlePubMedGoogle Scholar
  72. Perry SW, Dewhurst S, Bellizzi MJ, Gelbard HA: Tumor necrosis factor-alpha in normal and diseased brain: conflicting effects via intraneuronal receptor crosstalk?. J NeuroVirol. 2002, 8: 611-624.View ArticlePubMedGoogle Scholar
  73. Di Mascio P, Kaiser S, Sies H: Lycopene as the most efficient biological carotenoid singlet oxygen quencher. Arch Biochem Biophys. 1989, 274: 532-538.View ArticlePubMedGoogle Scholar
  74. Ismail MF, Mohamed HM: Modulatory effect of lycopene on deltamethrin-induced testicular injury in rats. Cell Biochem Biophys. 2013, 65: 425-432.View ArticlePubMedGoogle Scholar
  75. Chung J, Koo K, Lian F, Hu KQ, Ernst H, Wang XD: Apo-10′-lycopenoic acid, a lycopene metabolite, increases sirtuin 1 mRNA and protein levels and decreases hepatic fat accumulation in ob/ob mice. J Nutr. 2012, 142: 405-410.PubMed CentralView ArticlePubMedGoogle Scholar
  76. D’Amours D, Desnoyers S, D’Silva I, Poirier GG: Poly(ADP-ribosyl)ation reactions in the regulation of nuclear functions. Biochem J. 1999, 342: 249-268.PubMed CentralView ArticlePubMedGoogle Scholar
  77. Zhao X, Allison D, Condon B, Zhang F, Gheyi T, Zhang A, Ashok S, Russell M, MacEwan I, Qian Y, Jamison JA, Luz JG: The 2.5 Å crystal structure of the SIRT1 catalytic domain bound to nicotinamide adenine dinucleotide (NAD+) and an indole (EX527 analogue) reveals a novel mechanism of histone deacetylase inhibition. J Med Chem. 2013, 56: 963-969.View ArticlePubMedGoogle Scholar
  78. Szarkowska L, Erecinska M: Energy-linked reduction of the mitochondrial nicotinamide-adenine. Acta Biochim Pol. 1965, 2: 179-186.Google Scholar
  79. Finkel T, Deng CX, Mostoslavsky R: Recent progress in the biology and physiology of sirtuins. Nature. 2009, 460: 587-591.PubMed CentralView ArticlePubMedGoogle Scholar
  80. Liang F, Kume S, Koya D: SIRT1 and insulin resistance. Nat Rev Endocrinol. 2009, 5: 367-373.View ArticlePubMedGoogle Scholar
  81. Nakahata Y, Sahar S, Astarita G, Kaluzova M, Sassone-Corsi P: Circadian control of the NAD+ salvage pathway by CLOCK-SIRT1. Science. 2009, 324: 654-657.View ArticlePubMedGoogle Scholar
  82. Ramsey KM, Yoshino J, Brace CS, Abrassart D, Kobayashi Y, Marcheva B, Hong HK, Chong JL, Buhr ED, Lee C, Takahashi JS, Imai S, Bass J: Circadian clock feedback cycle through NAMPT mediated NAD+ biosynthesis. Science. 2009, 324: 651-654.PubMed CentralView ArticlePubMedGoogle Scholar
  83. Schreiber V, Dantzer F, Ame JC, de Murcia G: Poly(ADP-ribose): novel functions for an old molecule. Nat Rev Mol Cell Biol. 2006, 7: 517-528.View ArticlePubMedGoogle Scholar
  84. Deleglise B, Lassus B, Soubeyre V, Alleaume-Butaux A, Hjorth JJ, Vignes M, Schneider B, Brugg B, Viovy J-L, Peyrin J-M: Synapto-protective drugs evaluation in reconstructed neuronal network. PLoS One. 2013, 8: e71103.PubMed CentralView ArticlePubMedGoogle Scholar
  85. Won SJ, Choi BY, Yoo BH, Sohn M, Ying W, Swanson RA, Suh SW: Prevention of traumatic brain injury-induced neuron death by intranasal delivery of nicotinamide adenine dinucleotide. J Neurotrauma. 2012, 29: 1401-1409.View ArticlePubMedGoogle Scholar
  86. Guest J, Grant R, Mori TA, Croft KD: Changes in oxidative damage, inflammation and [NAD(H)] with age in cerebrospinal fluid. PLoS One. 2014, 9: e85335.PubMed CentralView ArticlePubMedGoogle Scholar

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