Toona sinensis Roem (Meliaceae) leaf extract alleviates liver fibrosis via reducing TGFβ1 and collagen

Toona sinensis Roem (TS) leaf tea as a health food for the improvement of blood sugar and hypertension has been demonstrated. Thioacetamide (TAA), a hepatotoxin, causes the progression of liver fibrosis. In this study, we tested the effects of TS leaf on TAA-induced liver injury. TAA (200 mg/kg Bwt/3 days, i.p.) treated rats were orally administrated with TS leaf extract (1 g/kg Bwt/10 days) three times. After 30 days treatment, the morphological data showed that TS leaf extract given to TAA-treated rats had less liver fibrosis. The GOT/GPT, collagen 1 and collagen 3 mRNAs of livers in TAA-treated rats were elevated when compared to normal rats. The improvements of GOT/GPT, collagen 1 and collagen 3 mRNAs were shown in the TS leaf extract given to TAA-treated rats. TS leaf extract given to TAA-treated rats showed higher levels of cytochrome P450 (1A1, 2A and reductase) than those of TAA-treated rats. Compared to the TAA-treated group, TGFβ1 mRNA (RT-PCR) was decreased with an increase of TGFβR1 protein (western blot) in the TS leaf extract given to TAA-treated rats. The decreased tendency of FGFR2 was found in the TS leaf extract given to TAA-treated rats. The result implies that TS leaf possesses beneficial effects on liver injury through increments of detoxification and the metabolic pathway.