Ginger (Zingiber Officinale Roscoe) Extract Protects the Heart Against Inflammation and Fibrosis in Diabetic Rats

Background: Fibrosis and inflammation in the heart of patients with diabetes mellitus alongside increased production of free radicals and collagen are together known as diabetic cardiomyopathy. Ginger rhizome has antidiabetic, antioxidant and anti-inflammatory effects. Thus, we investigated the effect of ginger extract on diabetes-induced cardiomyopathy in streptozotocin-induced diabetic rats.

Methods: Animals were divided into 7 groups: control; diabetic; diabetic treated with different doses of ginger extract of 100, 200 and 400 mg/kg; metformin (200 mg/kg); and metformin-valsartan (200 and 30 mg/kg, respectively). Serum levels of glucose, aspartate aminotransferase, lactate dehydrogenase and creatine kinase-muscle/brain were measured. Fibrosis and inflammation were determined by histologic assessment. Gene expression of transforming growth factor (TGF)-β1, TGF-β3 and angiotensin II type 1 receptor was evaluated by real-time polymerase chain reaction in heart tissue.

Results: Serum glucose level in all treated groups, except for the ginger extract 100-mg/kg group, was significantly lower than in the diabetic group. Serum levels of aspartate aminotransferase, lactate dehydrogenase and creatine kinase-muscle/brain were significantly reduced in all treated groups compared with the diabetic group. In the study of fibrosis, collagen amount in the heart tissue of all treated groups, except the ginger extract 100-mg/kg group, was significantly lower than in the diabetic group. Inflammatory cell infiltrates were decreased, and disarrangement was improved in cardiac tissues of all treated groups compared with the diabetic group. Expression of angiotensin II type 1 receptor and TGF-β1 and TGF-β3 genes in all treated groups downregulated compared with the diabetic group.

Conclusions: Treatment by ginger extract reduced myocardial fibrosis and inflammation in the course of diabetic cardiomyopathy, possibly through regulation of the expression of genes involved in the SMAD/TGF-β pathway.

Keywords: cardiomyopathie; cardiomyopathy; diabetes; diabète; fibrose; fibrosis; gingembre; ginger; inflammation.