Suppression of LPS-induced IL-6 expression in vivo by compound HAK-2. C57/B6 mice (5 months old) were injected intraperitoneally (i.p.) with saline (control group, n = 6) or with 1 mg LPS/kg body weight (LPS group, n = 6). Compound HAK-2 (10 mg/kg body weight) was co-injected i.p. with LPS (LPS + HAK-2 group, n = 8). After 2 hours treatment, samples from hippocampus (A), cortex (B) and plasma (C) were prepared and analyzed by qRT-PCR and ELISA, respectively. Data obtained were normalized by means of mRNA level of 3 reference genes (glyceraldehyde 3-phosphate dehydrogenase, glucose-6-phosphate dehydrogenase and hypoxanthine-guanine phosphoribosyltransferase). Results are shown as induction factors compared to those of saline-treated mice (given as factor 1). Statistically significant differences between LPS group and LPS + HAK-2 group were calculated using the unpaired t-test (*p < 0.05; **p < 0.01; ***p < 0.001).