β-carotene exhibits antioxidant and antiapoptotic properties to prevent ethanol-induced cytotoxicity in isolated rat hepatocytes

The study was designed to evaluate the effects of 1 μM β-carotene on antioxidant status in ethanol-treated rat hepatocytes and investigate possible anti-apoptotic mechanisms of β-carotene in protecting ethanol-induced cytotoxicity. The isolated rat hepatocytes were incubated for 48 h in a medium with or without alcohol (100 mM) and β-carotene (1 μM) using the following groups: the control (C), β-carotene (CB), ethanol (E), and ethanol + β-carotene (EB) groups. The cell viability, antioxidative status, cytochrome P450 2E1 (CYP2E1) and caspase expressions in hepatocytes were measured. The E group demonstrated lower cell viability, glutathione (GSH) levels, and lipid peroxide accumulation in rat hepatocytes; meanwhile, CYP2E1, caspase-3, and caspase-9 expressions increased. In contrast, cell viability, GSH levels, and glutathione reductase (GRD) activity significantly increased while lipid peroxides and expressions of CYP2E1, casapse-3, and caspase-9 decreased in the EB group. The results suggest that ethanol treatment decreases cell viability in rat hepatocytes via induced oxidative stress. 1 μM β-carotene decreased oxidative stress and prevented ethanol-induced cell death by inhibiting caspase-9 and caspase-3 expression.