Chemopreventive effect of modified zengshengping on oral cancer in a hamster model and assessment of its effect on liver

Abstract

Ethnopharmacological relevance Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors, seriously compromising patients’ quality of life. Previous studies showed that Zengshengping (ZSP), a popular traditional Chinese medicine, has certain inhibiting effects on both oral precancerous lesions and OSCC. However, few reports underlined ZSP side effects such as liver toxicity, which limit its long-term application.Aim of the study was to evaluate the chemopreventive effect of a modified ZSPs formula on oral cancer in a hamster model. Its effect on hamster liver was also assessed.Materials and Methods The original medicine (ZSP-1) and other two formulas slightly different and called ZSP-2 and ZSP-3 were prepared ahead of time. DMBA (0.5%) was topically applied for 6 weeks to induce a premalignant lesion on hamsters’ cheek pouch, then ZSP-1/2/3 were intragastrically administered for 8 weeks. Hamster treated with DMBA + each of the ZSPs represented the ZSP-1/2/3 groups, while those without ZSP-1/2/3 treatment represented the DMBA group. To assess the effect of ZSPs in the liver, intragastric administration of ZSP-1/2/3 was carried out to other groups of hamsters for 12 weeks and the blood was collected every two weeks to detect the hepatic function. Some of the hamsters were sacrificed at the end of 12 weeks, while the remaining animals were sacrificed after other 4 weeks to estimate the effect of ZSP-1/2/3 withdrawal on the liver.Results showed that tumor development in the ZSP-1/2/3 groups was less than that in DMBA group. BrdU, CD31 and COX-2 expression in the hyperplastic tissues was significantly lower in the ZSP-1/2/3 groups than that in the DMBA group. In addition, VEGF and COX-2 expression in ZSP-1/2/3 groups was lower while caspase-9 and p53 expression was higher than those in the DMBA group. Finally, PTEN expression in ZSP-1/2/3 groups was higher than that in the DMBA group. As regard the effect in the liver, ALP in the ZSP-1/2/3 groups was higher than that in the control group treated with an intragastric administration of ddH2O. After 4 weeks of withdrawal, the hamsters of the ZSP-3 group did not recover from the increase in ALP. Histopathology showed the presence of inflammatory lesions in each group after 12 weeks, especially in the ZSP-1/3 groups, and the number of apoptotic cells in the ZSP-3 group was higher than that in the other groups, without any recovery after withdrawal of the drug. At 12 weeks, the MDA in the ZSP-1 group was higher than that in the control group and the ZSP-2 group, but the difference disappeared after drug withdrawal because the MDA in the ZSP-1/3 groups decreased.Conclusions ZSP-2 possessed a chemopreventive effect against oral cancer by inhibiting inflammation, proliferation of tumor cells, generation of microvessels and by promoting tumor cell apoptosis. In addition, hepatotoxicity of ZSP-2, which might be related to oxidative stress injury, was reduced to some extent.