Ginger Supplementation Attenuated Mitochondrial Fusion and Improved Skeletal Muscle Size in Type 2 Diabetic Rats

Abstract

Background/aim: Oxidative stress, regulated by SOD2 and mitochondrial dynamics, contributes to muscle atrophy in diabetes. Ginger root extract (GRE) reduces oxidative stress. However, its effect on oxidative stress, mitochondrial dynamics, and muscle atrophy is not known in the diabetic muscle. This study examined the effect of GRE on intramuscular oxidative stress, mitochondrial dynamics, and muscle size in diabetic rats.

Materials and methods: Twenty-six male Sprague-Dawley rats were randomly divided into control diet (CON; n=10), high-fat diet with one dose of 35 mg/kg streptozotocin (HFD; n=9), and high-fat diet with one dose of 35 mg/kg streptozotocin and 0.75% w/w GRE (GRE; n=7) fed for seven weeks. Subsequently, the muscle was analyzed for cross-sectional area (CSA), H₂O₂ concentration, and DRP-1, MFN2, Parkin, PINK1, SOD2 mRNA. Additionally, the protein levels of SOD2, DRP-1, DRP-1^ser616, LC3AB, MFN2, OPA1, Parkin, and PINK1 were analyzed. CSA, H₂O₂ concentration, and gene and protein expression levels were analyzed using a one-way ANOVA. Correlations among intramuscular H₂O₂, CSA, and SOD2 protein were assessed using Pearson's bivariate correlation test.

Results: In the soleus, the GRE group had a greater CSA and lower intramuscular H₂O₂ concentration compared to the HFD group. Compared to the HFD group, the GRE group had higher SOD2 and DRP-1 mRNA levels and lower MFN2 and total OPA1 protein levels. H₂O₂ concentration was negatively correlated with CSA and positively correlated with SOD2.

Conclusion: GRE attenuated intramuscular H₂O₂, mitochondrial fusion, and muscle size loss. These findings suggest that GRE supplementation in diabetic rats reduces oxidative stress, which may contribute to muscle size preservation.

Keywords: Mitochondrial dynamics; mitophagy; oxidative stress.