Taurine attenuates nitric oxide- and reactive oxygen intermediate- dependent hepatocyte injury

Objective: To evaluate the potential role of the semi-amino acid taurine in the prevention of hepatocyte (HC) apoptosis and necrosis mediated by nitric oxide (NO) and reactive oxygen intermediates. Designs isolated rat HCs were cultured with lipopolysaccharide (LPS), antioxidants, taurine, and sodium nitroprusside to examine the effect of these agents on HC injury. Results: Lipopolysaccharide, in the presence of antioxidants, led to HC apoptosis, while LPS alone failed to induce HC apoptosis. Taurine significantly attenuated LPS plus antioxidant-mediated HC apoptosis, and this correlated with taurine-mediated NO inhibition. Taurine also significantly reduced LPS-mediated hepatocellular enzyme release and HC necrosis, and this correlated with HC free radical and peroxynitrite inhibition. However, taurine did not prevent sodium nitroprusside-mediated HC apoptosis and necrosis. Conclusions: Taurine attenuates HC apoptosis and necrosis through inhibition of both NO and reactive oxygen intermediate. While taurine acts directly as an antioxidant, its effects on NO may occur at the messenger RNA level. Our findings indicate a potential prophylactic and therapeutic role for this amino acid during systemic inflammatory response syndrome.