EFFECTS OF HUA-KHAO-YEN EXTRACT (DIOSCOREA MEMBRANACEA PIERRE)IN HEPATOCELLULAR CARCINOMA-INDUCED RAT

Abstract

Hepatocellular carcinoma (HCC) is the most common liver cancer in adults. The lack of effective treatment for HCC is still problematic and leads to a high mortality rate. Sorafenib (SF) is an orally administered drug currently approved to treat advanced HCC patients. However, it mediates many of the side effects. Owing to the common usage of the rhizomes of Hua-Khao-Yen, Dioscorea membranacea Pierre (DM), a medicinal herbal plant, is an alternative medicine for treatment of various cancers in Thailand. Therefore, the present study aimed to demonstrate the anticancer effect of the DM extract in HCC-bearing rats. In this study, such anti-cancer properties of DM extract were demonstrated through the gross morphology, histopathology, and liver enzymes aspects. In addition the mechanisms of DM for treatment of HCC were explored by using a proteomics assay and quantitative real-time PCR. The six groups of rats were set: (1) control rats; (2) control rats receiving DM extract at 40 mg/kg; (3) HCC rats; (4) HCC rats receiving DM extract at 4 mg/kg; (5) HCC rats receiving DM extract at 40 mg/kg, and (6) HCC rats receiving SF at 30 mg/kg. It was found that the HCC-bearing rats were present macroscopically with various sizes of hepatic nodules and microscopically with thick hepatic cell cords, or pseudoglandular patterns together with abnormal scaffolds of reticulin stain. The HCC rats with DM treatment showed significantly decreased cancer areas and reticulin expression compared with the untreated group. Even though treatment of HCC rats with SF yielded the lowest cancer areas, it also caused a rising level of liver enzymes and a low level of albumin in serum. With proteomics analysis the mechanisms of DM extract were shown to exert via inhibiting proteins involved in proliferation and angiogenesis pathways. In DM-treated HCC rats down-regulation of PDGFRA, VEGFR1, and MSK2 proteins were detected in comparison to HCC rats without any treatment, suggesting less cancer cell proliferation and less neovascularization. The HCC-bearing rats treated with DM extract also caused the up-regulation of a tumor suppressor, NEMO protein, in the liver. Moreover, HCC-bearing rats treated with DM extract caused a higher expression of BIK and DIABLO proteins but a lower expression of PARP1 compared with the non-treated HCC rats indicating the apoptotic effects of the extract. The alteration of the related-gene expressions revealed by quantitative real-time PCR were in similar trend of changes in the protein profile. Last but not least, the HCC rats treated with DM showed a decrease in malondialdehyde (MDA) level, suggesting lower lipid peroxidation compared to the nontreated HCC group. The findings suggest that DM extract could reduce cancer in HCC-induced rats. It has an antioxidant effect and exerts an anti-cancer effect on HCC-induced rats through VEGF/PDGF, and the apoptosis signaling pathway.

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