Effect of mouse recombinant leptin on ethanol elicited damage in the mouse hepatocellular carcinoma cell lines

A BSTRACT Obesity is associated with hepatocellular carcinoma (HCC). Leptin, an anti-obesity hormone exerts potent modulatory properties both in vivo and in vitro. We have previously shown the reduction of lipotoxicity with leptin in vivo. The aim of this study was to evaluate the effect of leptin on ethanol induced fibrogenesis and apoptosis in mouse hepatocellular carcinoma (HCC) cell lines. Mouse HCC cell lines were treated for 48 h with and without ethanol (500 mM) and leptin (31.2 nM), subsequently analyzed for cell proliferation, flow cytometry, biochemical and molecular studies. Ethanol exposure significantly reduced the cell viability as evidenced by 3-(4,5 dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay (P<0.05). Moreover, ethanol treated cells significantly lowered DNA synthesis as evidenced by thymidine incorporation (P<0.05) and increased DNA fragmentation. Ethanol incubation also significantly increased the % of apoptotic cells (P<0.05). These results were compared with that of untreated control cell lines. Leptin co-treatment with ethanol significantly enhanced (P<0.05) cell viability and DNA synthesis, whereas significantly (P<0.05) decreased apoptotic cells and DNA ladder formation. In addition, ethanol exposure significantly (P<0.05) increased cytokine (TNFα), reactive oxygen species (ROS),TBARS and mRNA expressions of caspase-3, procollagen type I, MMP 2, MMP 9 and TIMP-1 compared to untreated control mouse HCC cell lines. Leptin co-administration significantly (P<0.05) down regulated the above indices when compared to ethanol alone exposed mouse HCC cell lines. Furthermore, ethanol exposure significantly (P<0.05) lowered antioxidant enzymes activities. Leptin co-administration along with ethanol significantly (P<0.05) improved antioxidant enzymes activities. Thus, our experimental data provide evidence that leptin treatment to ethanol exposed mouse HCC cell lines results in attenuating fibrogenesis and apoptosis, thereby warranting further population based mechanistic studies