Preparation-dependent antioxidant efficacy of Pistacia khinjuk stocks: links between phenolic composition and in vivo biological activity.

In this study, preparation-dependent differences in antioxidant and hepatoprotective bioactivity of Pistacia khinjuk Stocks were investigated. Phenolic profiling and antioxidant capacity analyses were integrated with in vivo biochemical and oxidative stress assessments in a rat model of ethanol-induced oxidative stress. LC-MS analysis revealed that the extract was enriched in gallic acid, rutin hydrate, and homovanillic acid, whereas the coffee form contained higher levels of ellagic acid, luteolin, and isoquercitrin. The extract form most effectively enhanced GPx (glutathione peroxidase) and GST (glutathione S-transferase) activities and reduced ALT (alanine aminotransferase) and LDH (lactate dehydrogenase) levels, whereas the coffee preparation increased catalase activity and reduced AST (Aspartate aminotransferase) and lipid peroxidation. Despite its lower total polyphenol content, the coffee form exhibited notable antioxidant effects, suggesting that processing-induced transformations may influence functional bioactivity. Overall, compositional differences translated into preparation-dependent biological responses, indicating that the antioxidant efficacy of P. khinjuk varies with preparation method.