Abstract
Pyrazinamide (PZA) is an anti-tuberculosis drug known to causes liver injury. phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) signaling protects against liver injury by promoting cellular antioxidant defenses and reducing intracellular reactive oxygen species (ROS) and lipid peroxidation. The regulatory mechanisms and functions of PI3K/Akt signaling during the hepatotoxicity of PZA are however not fully understood. Rats were administered PZA or/and the PI3K activator (740Y-P) for 7 days. The levels of serum parameters were examined via standard enzymatic techniques and the pathological status of the liver was confirmed by H & E staining. The levels of lipid peroxidation and antioxidant production were determined using commercial kits. Liver apoptosis was assessed by TUNEL staining. The expression of apoptosis-related proteins and PI3K/Akt signaling were assessed by western blot analysis. PZA treatment significantly increased serum alanine transaminase, aspartate transaminase, gamma-glutamyl transpeptidase and tall bilirubin leading to liver damage in rats. PZA also facilitated lipid peroxidation and suppressed antioxidant defenses. PZA led to apoptotic induction in rat liver cells through the downregulation of Bcl-2 and the upregulation of Bax and caspase-3. PZA also dramatically inhibited PI3K/Akt signaling in rat liver cells. We further verified that PI3K/Akt signaling in response to 740Y-P could attenuate hepatic injury, lipid peroxidation and apoptosis in rat liver cells in response to PZA. We reveal that PZA-induced liver injury in rats occurs through PI3k/Akt signaling, the recovery of which prevents liver injury in rat models.