Chemopreventive effect of selenium and Chinese medicinal herbs on N ‐nitrosobis(2‐oxopropyl)amine‐induced hepatocellular carcinoma in Syrian hamsters

Background/Aims: Oxidative DNA damage by reactive oxygen species is involved in the process of liver carcinogenesis. To test the hypothesis that a remedy containing Scutellaria baicalensis Georgi (Sb) and Bupleurum scorzonerifolfium Willd (Bs) (Sb/Bs remedy) modulates hepatic neoplastic growth, BOP ( N ‐nitrosobis(2‐oxopropyl)amine)‐induced liver cancers in hamsters were established. Methods: Parameters such as survival rate, tumour area, tumour foci, 8‐hydroxydeoxyguanosine (8‐OHdG), caspase‐3, transforming growth factor (TGF‐β1) and tumour necrosis factor‐α (TNF‐α) were measured after Sb/Bs remedy treatment during BOP‐induced carcinogenesis. Results: The results showed that the Sb/Bs remedy and its constituents Sb and Bs suppressed the tumour area in BOP‐induced liver tumours. Because selenium (Sel) is toxic at a high dose (10 mg/kg), with a low survival rate (0%), the combination of Sb/Bs remedy and low‐dose Sel (1 mg/kg) was found to decrease the tumour area and the number of tumour foci while increasing serum TNF‐α and TGF‐β1, but not IL‐6 levels. Besides, the Sb/Bs remedy, when combined with low‐dose Sel, not only decreased the expression of 8‐OHdG and increased caspase‐3 expression within the glutathione S ‐transferase placental form‐positive tumour foci but also increased tumour apoptosis in BOP‐induced hamsters. Conclusions: We conclude that low‐dose Sel has a chemoprevention effect on BOP‐induced liver tumours and such an effect was more enhanced when combined with Sb/Bs treatment.