Study Of The Protective Effect Of Pomegranate Seed Extract On Acute Liver Injury And Its Mechanism

[Objective] To study the protective effect of pomegranate seed extracts on acute liver injury, and explore its mechanism.[Methods] In vitro chemistry experiments, prussianBlue method, pyrogallol autoxidation method, o-phenanthroline-Fe2+ oxidation method were used to evaluate the antioxidant capacity of pomegranate seed extract (40% polyphenols), compared with polygonum cuspidatum extract (50% resveratrol), red clover extract (20% isoflavones), coffee bean extract (50% chlorogenic acid) and vitamin C (99.99%). In animal experiments,40 male Kuming mice were divided into 5 groups randomly as follows:Group A(normal group) and Group B(model group) which oral administrated with distilled water; Group C, D, E were oral administrated with pomegranate seed extract at a dose of 200mg/kg.d, 400mg/kg.d and 600mg/kg.d, respectively. All the mice were treated as above for seven consecutive days prior to 0.2% of CC14 injection (10mL/kg) intraperitoneally for Group B, C, D and E to induce actue liver injury. Sixteen hours later, the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), the malondialdehyde (MDA) and superoxide dismutase (SOD) in mouse liver sections were determined. In vitro cell experiments, human embryo liver L-02 cells were treated with pomegranate seed extract at a concentration of 12.5μg/mL,25μg/mL, 50μg/mL, 100μg/mL and 200μg/mL, respectively, for 4 hours. Followed by being treated by lOmmol/L CC14 for 1 hour to induce the cell injury. The cell viability and ALT, AST, LDH levels in cell culture supernate were exmained, as well as the SOD activity and MDA level in cell.[Results] Vitro chemical experiments showed that the total oxidation resistance is ranked as:polygonum cuspidatum extract, pomegranate seed extract, vitamin C, red clover extract, coffee bean extract; The ability to scavenge Hydroxyl radical, from high to low, was ranked as:polygonum cuspidatum extract (EC50= 0.126mg/mL), pomegranate seed extract (EC50=0.138mg/mL), Vitamin C (EC50= 0.167mg/mL), red clover extract (EC50=0.282mg/mL), coffee bean extract (EC50= 0.552mg/mL); The ability to scavenge Superoxide anion, from high to low, was ranked as: polygonum cuspidatum extract (EC50=0.020mg/mL), vitamin C (EC50= 0.023mg/mL), pomegranate seed extract (EC50= 0.027mg/mL), red clover extract (EC50= 0.040mg/mL), coffee bean extract (EC50= 0.051mg/mL). Animal experiments founded that pomegranate seed extracts could protect mice from acute liver injury induced by carbon tetrachloride, by dereasing the serum ALT, AST and liver MDA concentration and increasing the liver SOD activity.Vitro cell experiments showed that pomegranate seed extracts could protect human embryo liver L-02 cells from actue oxidative damage induced by carbon tetrachloride. The level of ALT, AST, LDH and MDA in pomegranate extracts groups were significantly lower than those of CCl4 model group (P＜0.05), while the cell viability and SOD activity were higher than those of CC14 model group (P<0.05). A significant linear dose-response relationship was observed in the range of 12.5μg/mL-200μg/mL of pomegranate seed extracts, and the 200μg/ml had the most significant protective effect.[Conclusion] Chemical experiments showed that antioxidant activity of pomegranate seed extract is better than coffee extract, red clover extract; animal experiments and cell experiments showed that pomegranate seed extract can preventive protection to protect mice liver from acute liver injury induced by carbon tetrachloride, the mechanism may contribute to its antioxidant activity. Pomegranate seed extracts may have broad development prospects in the development and application of health functional food.