Nephroprotective Effects of Ginger against Oxidative Stress

Abstract

There have been growing indications of Zingiber officinale (ginger) acting as a nephroprotectant with antioxidant and anti-inflammatory effects. The extent and reproducibility of such effects in models of kidney injury, however, are unknown. The purpose of this systematic review and meta-analysis was to undertake a quantification of the impact of ginger on both renal performance and the levels of oxidative stress in experimental rat models of kidney injury. An extensive literature search was conducted to identify the preclinical research conducted on the actions of ginger supplementation in rat models of renal injury caused by diabetes, ethanol toxicity, exposure to cadmium, or ischemia/reperfusion. The information regarding the biomarkers of renal functions and antioxidant was extracted. Standardized mean differences (Hedges’ g) were pooled as the mean difference using a random-effects model. Between-study heterogeneity and risk of bias were measured according to the pre-established guidelines of preclinical meta-analysis. Quantitative synthesis showed that ginger therapy was indeed able to significantly change the renal functions through decreased serum creatinine, urea, blood urea nitrogen, cystatin C, and albuminuria when compared to injured controls. Meanwhile, ginger also augmented the antioxidant capacities of the kidneys notably, such as superoxide dismutase, catalase, and glutathione peroxidase. Although the heterogeneity between studies was moderate, sensitivity analyses revealed that the pooled estimates were strong, and no significant publication bias was found. This meta-analysis comprises unified preclinical studies that show that Zingiber officinale possesses considerable nephroprotective effects in various experimental kidney injury models, mainly by inhibiting the occurrence of oxidative stress. These results indicate the possible clinical translationability of ginger as a complementary therapeutic modality to protect against AKI and emphasize the necessity of properly designed clinical trials.