Ginkgo biloba extract reverses CCI4-induced liver fibrosis in rats

AIM: To study the reversing effect of Ginkgo biloba extract (GbE) on established liver fibrosis in rats. METHODS: Following confirmation of CCI4-induced liver fibrosis, GbE or saline was administrated to the rats for 4 weeks. The remaining rats received neither CCI 4 norGbE as normal control. The four groups were compared in terms of serum enzymes, tissue damage, expression of αSMA and tissue inhibitor-1 of metalloproteinase (TIMP-1) and metalloproteinase-1 (MMP-1). RESULTS: Compared with saline-treated group, liver fibrosis rats treated with GbE had decreased serum total bilirubin (P<0.01) and aminotransferase levels (P<0.01) and increased levels of serum albumin (P<0.01). Microscopic studies revealed that the livers of rats receiving GbE showed allieviation in fibrosis (P<0.05) as well as expression of αSMA (P<0.01). The liver collagen and reticulum contents were lower in rats treated with GbE than saline-treated group (P<0.01). RT-PCR revealed that the level of TIMP-1 decreased while the level of MMP-1 increased in GbE group. CONCLUSION: Administration of GbE improved CCI4-induced liver fibrosis. It is possibly attributed to its effect of inhibiting the expression of TIMP-1 and promoting the apoptosis of hepatic stellate cells.

Protective effects of Ginkgo biloba extract on the ethanol-induced gastric ulcer in rats

AIM: To evaluate the preventive effect of Ginkgo bilobaextract (GbE) on ethanol-induced gastric mucosal injuries in rats.METHODS: Female Wistar albino rats were used for the studies. We randomly divided the rats for each study into five subgroups: normal control, experimental control, and three experimental groups. The gastric ulcers were induced by instilling 1 mL 50% ethanol into the stomach. We gaveGbE 8.75, 17.5, 26.25 mg/kg intravenously to the experimental groups respectively 30 min prior to the ulcerative challenge. We removed the stomachs 45 min later. The gastric ulcers,gastric mucus and the content of non-protein sulfhydryl groups (NP-SH), malondialdehyde (MDA), c-Jun kinase (JNK) activity in gastric mucosa were evaluated. The amount of gastric juice and its acidity were also measured. RESULTS: The findings of our study are as follows: (1)GbE pretreatment was found to provide a dose-dependent protection against the ethanol-induced gastric ulcers in rats; (2) the GbE pretreatment afforded a dose-dependent inhibition of ethanol-induced depletion of stomach wall mucus, NP-SH oontents and increase in the lipid peroxidation (increase MDA) in gastric tissue; (3) gastric ulcer induced by ethanolproduced an increase in JNK activity in gastric mucosawhich also significantly inhibited by pretreatment with GbE;and (4) GbE alone had no inhibitory effect on gastric secretionin pylorus-ligated rats.CONCLUSION: The finding of this study showed that GbE significantly inhibited the ethanol-induced gastric lesions in rats. We suggest that the preventive effect of GbE may be mediated through: (1) inhibition of lipid peroxidation;(2) preservation of gastric mucus and NP-SH; and (3)blockade of cell apoptosis.