Chlorella vulgaris Menunjukkan Kesan Antioksidan dan Antitumor Terhadap Kanser Hepar dalam Kajian in vivo dan in vitro(Chlorella vulgaris Exhibited Antioxidant and Antitumour Effects against LiverCancer in in vivo and in vitro Studies)

The unicellular green microalgae Chlorella vulgaris (ChV) has been reported to have beneficial effects on various diseases including cancer. The main objectives of this study were to determine and evaluate the antioxidant and antitumour properties of ChV against liver cancer cells, both in vivo and in vitro. The antioxidant effect of hot water extract of ChV was demonstrated by DPPH assay which exhibited a high percentage of free radical scavenging activity. In in vivo studies, male Wistar rats (200-250 g) were divided into eight groups according to the diet given: control group (normal diet), liver cancer (choline deficient diet + 0.1% ethionine in drinking water to induce liver cancer), abbreviated as CDE group, ChV group with three different doses (50, 150 and 300 mg/kg body weight), and CDE group treated with three different doses of ChV. Rats were killed at 0, 4, 8 and 12 weeks of experiment and blood and tissue samples were taken from the rats in all groups for the determination of cellular proliferation and apoptosis. ChV at all doses reduced the percentage of liver tumour incidence (the preneoplastic nodules) in the CDE (liver cancer) rats when compared to the CDE rats alone. The percentage of hepatocyte proliferation was significantly higher (p 0.05) in CDE rats when compared to control which however was inhibited by ChV at all doses. Meanwhile, the percentage of apoptotic cells in the CDE rats increased significantly (p 0.05) compared to control which was further increased when treated with higher dosage of ChV (300 mg/kg body wt). The antitumour effects of hot water extract of ChV in in vitro studies were determined by observing the changes in the proliferation and apoptosis rate in liver cancer cell line, HepG2. ChV reduced (p 0.05) the proliferation rate of HepG2 cells in dose-dependent manner. The IC50 value was recorded at 1.6 mg/ml. Apoptosis was induced by ChV, as indicated by TUNEL analysis which was supported further by Western blot analysis indicating increased expression of P53 and pro-apoptotic proteins BAX, and Caspase-3. From these findings, it can be suggested that ChV has great potential as an antioxidant with the ability to exert antitumour effects against liver cancer.