Small yellow ginger extract: Preparation, characterization, antioxidant properties, and protective activities against alcohol-induced HepG2 cell injury

Small yellow ginger (Zingiber officinale Roscoe) is a traditional medicinal and edible plant. In this study, response surface methodology was used to optimize the preparation process of small yellow ginger extract using total polyphenols content as an indicator, and the chemical composition, antioxidant capacity and protective effects of the extract on alcohol-induced injury in HepG2 cells were investigated. The results implied that the best conditions to reach the highest value of total polyphenols content (10.59 mg GAE/g) were an extraction time of 32 min, ethanol concentration of 71 % v/v, solid-liquid ratio of 1:19 g/mL, and temperature of 60 ℃. The 67 main components were identified by UPLC-MS/MS. The extract exhibited excellent DPPH and ABTS radical scavenging effects (IC₅₀ of 0.11 mg/mL and 28.83 μg/mL, respectively) and ORAC values (758.36 μmol TE/g lyophilized powder). The CAA assay indicated that the extract possessed potent antioxidant activity (46.22 μg/mL) against HepG2 cells. Furthermore, the extract exhibited a significant protective effect on ethanol-induced HepG2 cell injury. This study provides a scientific basis for the development of functional foods and natural antioxidants based on small yellow ginger and promotes its application in the prevention and treatment of alcoholic liver disease.