摘要
Abstract
Objective To investigate the analgesic effect of mangiferin (MGF) on sciatic nerve in rats with neuropathic pain and to explore the potential mechanism.Methods Sixty rats were randomly divided into five groups:Sham group,model group,MGF 25 mg/kg group,MGF 50 mg/kg group and MGF 100 mg/kg group.Thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) were detected before surgery and on day 1,10 and 20 after surgery.The content of nitric oxide (NO) and the activity of endothelial nitric oxide synthase (eNOS) were detected by ELISA,the levels of malondialdehyde (MDA),superoxide dismutase (SOD),glutathione peroxidase (GSH) and catalase (CAT) were also detected on day 20 after surgery,and eNOS protein expression was valued by Western blotting.Results On day 1,dayl0 and day20,TWL and MWT in model group were significantly down-regulated,compared with Sham group [(13.1 ± 1.2) vs (6.7 ± 0.8),(13.6 ± 1.3) vs (6.9 ± 0.7),(13.7 ± 1.3) vs (6.8 ± 0.9),P ＜ 0.05],[(43.6 ± 3.9) vs (35.2 ± 3.7),(44.2 ± 4.1) vs (35.4 ± 3.8),(44.5 ± 4.9) vs (35.6 ± 3.7),P ＜ 0.05].There was no significant difference in TWL and MWT between the MGF group and model group on day 1,while TWL and MWT in MGF 25 mg/kg group,MGF 50 mg/kg group and MGF 100 mg/kg group were markedly up-regulated on day 10 and day 20.ELISA results demonstrated that the content of MDA in MGF group was significantly down-regulated,and the contents of SOD,GSH and CAT in MGF groups were markedly up-regulated,compared with the model group.Besides,the NO contents [(40.2 ± 3.9),(33.6 ± 3.4) and (29.9 ± 3.1) ng/mg] and the eNOS activities [(105.7 ± 5.3),(89.3 ± 4.7) and (80.2 ± 5.1) μmol/g] in MGF 25 mg/kg,50 mg/kg and 100 mg/kg groups were significantly down-regulated,compared with the model group [(58.9 ± 4.3) ng/mg and (148.2 ± 6.9) μ mol/g,P ＜ 0.05].Western blotting indicated that the protein expression of eNOS in MGF group [(17.1 ± 1.3),(14.2 ± 1.1) and (12.8 ± 1.3)] was markedly down-regulated,compared with the model group (22.6 ± 2.8).Conclusion MGF can relieve the neuropathic pain induced by sciatic nerve ligation,and the molecular mechanism may be related to the anti-oxidative stress and anti-inflammation.关键词
芒果苷/神经病理性疼痛/氧化应激/大鼠Key words
Mangiferin/neuropathic pain/oxidative stress/rats分类
生物科学
