Fig. 1
From: Procyanidins attenuate neuropathic pain by suppressing matrix metalloproteinase-9/2
PC directly inhibited the chronic constrictive injury (CCI)-induced activation of matrix metalloproteinase (MMP)-9 and MMP-2. a Mechanical allodynia was significantly induced after CCI surgery. Mechanical pain threshold was tested by Von Frey Hairs. b–d MMP-9 and MMP-2 activity were significantly increased at 14 days after CCI injury. The lumbar spinal cords (L1–L6) were collected and analyzed 14 days after the CCI operation. Gelatin zymography was performed to determine MMPs’ activity. Representative bands and a data summary (n = 4) are shown. e–g PC directly reduced MMP-9 and MMP-2 activity of the spinal cord collected from CCI mice in vitro. The lumbar spinal cords (L1–L6) from mice treated CCI operation for 14 days were separated and homogenized. The same sample was loaded into each well of precast gels for gelatin zymography. After electrophoresis, the gels were cut into pieces. Each piece has three electrophoresis lanes on it and was then incubated in buffer with or without PC (10−6, 10−5, or 10−4 mol/L). Then, the gel pieces were stained with 1% Coomassie brilliant blue in the same box and captured in the same image. h–j PC directly reduced MMP-9 and MMP-2 activity of the spinal cord collected from normal mice in vitro. The same sample was loaded into each well of precast gels for gelatin zymography. After electrophoresis, the gel pieces were incubated in buffer with or without PC (10−7, 10−6, 10−5, or 10−4 mol/L). Significant difference was revealed following one-way ANOVA (*P < 0.05, **P < 0.01; Bonferroni post hoc tests)