| Summary: | 碩士 === 中興大學 === 獸醫病理學研究所 === 95 === Toona sinensis Roem is a perennial deciduous tree of the family Meliaceae. Almost all part of T. sinensis, including seeds, bark, root bark, petioles, and leaves, show medicinal effect. Leaves of T. sinensis exhibite anti-inflammatory, anti-doting, lowing plasma glucose in diabetic rats. In addition, it also improves the activity of human sperm, and induces apoptosis of leukemia cells. The aim of this study was to evaluate the inhibition effect of TSL-1 in chemical-induced hepatoma in rats, and the cytotoxicity in HepG2 cells and the anti-mutagenicity in Ames test. In vivo assay, rats were intraperitoneally injected a single dose of diethylnitrosamine (DEN) (200 mg/kg) on the first day, then given acetylaminofluorene (2-AAF) 200 mg/kg in diet on week 2, and supplemented with TSL-1(0.1, 0.5 and 1 g/kg) for 8 weeks. A one-third hepatectocy was performed on the third week in all rats. Results revealed that TSL -1 significantly inhibited the degrees of 2AAF-induced hepatoma in rats, decreased the elevation of AST, ALT and GGT in serum, lessened the area of preneoplastic GGT foci and glutathion S-transferase placental (GST-P) in liver tissuse and lowered the lipid peroxidation of malondialdehyde (MDA), but increased the antioxidant activities of GSH and SOD in liver homogenous tissues. In vitro, the cytotoxicity of TSL-1 toward HepG2 cells was measured by using the MTT and Trypan blue assays. The results showed that TSL-1 had a dose-related cytotoicity effect on HepG2 cells, and the LC50 of TSL-1 was 0.7 mg/ml in the 24 hours incubation. Altnough TSL-1 could induce apoptotic effect on HepG2 cells but mainly via necrosis pathway. Furthermore, the antimutagenicity of TSL-1 was determined in the Ames test of TA98 and TA100. Results that TSL-1 exhibited more than 70% inhibition of AAF-induced mutagenicitiys in TA98 and TA100. In conclusion TSL-1 could inhibit the degree of 2AAF-induced hepatoma in rats, and might be related to its strong antioxidant and anti-genetic activities. Howerver, the real mechanism of TSL-1 needs to eluadate in the future
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