The protective antioxidant activity of ginger extracts (Zingiber Officinale) in acute kidney injury: A systematic review and meta-analysis of animal studies

Zingiber officinale (Ginger) is considered an herbal medicinal plant with antioxidant features. This study attempted to perform a meta-analysis of the data obtained from previously conducted animal studies on the protective antioxidant effect of ginger extracts on acute kidney injury. This literature search was conducted using some databases, including PubMed, Embase, and Scopus published up to August 2021, by searching relevant keywords. Thereafter, the pooled effect size was estimated using the random effect model. The SYRCLE's risk of bias tool was then conducted to assess the quality of the obtained studies. The source of heterogeneity among these studies was detected using meta-regression and subgroup analyses. Finally, the meta-analysis on 17 eligible articles revealed that ginger extract supplementation significantly increased SOD (SMD = 5.451 U/mg protein; 95 % CI: 2.099, 8.804; P = 0.005), CAT (SMD = 2.912 U/mg protein; 95 % CI: 0.583, 5.241; P = 0.024), GSH (SMD = 3.400 mu g/mg protein; 95 % CI: 1.941,4.859; P < 0.001), and TAC (SMD = 5.923 mmol/L; 95 % CI: 0.900,10.947; P = 0.005). In addition, Ginger extracts decreased MDA (SMD =-3.069 nmol/g tissue; 95 % CI:-5.971,-0.166; P = 0.005). However, no significant effect was noticed in terms of both GPx (SMD = 1.096 U/ mg protein; 95 % CI:-0.699, 2.891; P = 0.177), and GST (SMD = 0.199 U/g protein; 95 % CI:-6.558, 6.957; P = 0.911). Therefore, the results of the meta-analysis support the convincing evidence regarding the protective antioxidant activity of ginger extracts in animals with acute kidney injury.