Blackcurrant Improves Diabetic Cardiovascular Dysfunction by Reducing Inflammatory Cytokines in Type 2 Diabetes Mellitus Mice

Diabetic cardiovascular dysfunction is a representative complication of diabetes. Inflammation associated with the onset and exacerbation of type 2 diabetes mellitus (T2DM) is an essential factor in the pathogenesis of diabetic cardiovascular complications. Diabetes-induced myocardial dysfunction is characterized by myocardial fibrosis, which includes structural heart changes, myocardial cell death, and extracellular matrix protein accumulation. The mice groups in this study were divided as follows: Cont, control (db/m mice); T2DM, type 2 diabetes mellitus mice (db/db mice); Vil.G, db/db + vildagliptin 50 mg/kg/day, positive control, dipeptidyl peptidase-4 (DPP-4) inhibitor; Bla.C, db/db + blackcurrant 200 mg/kg/day. In this study, Bla.C treatment significantly improved the homeostatic model evaluation of glucose, insulin, and insulin resistance (HOMA-IR) indices and diabetic blood markers such as HbA1c in T2DM mice. In addition, Bla.C improved cardiac function markers and cardiac thickening through echocardiography. Bla.C reduced the expression of fibrosis biomarkers, elastin and type IV collagen, in the left ventricle of a diabetic cardiopathy model. Bla.C also inhibited TD2M-induced elevated levels of inflammatory cytokines in cardiac tissue (IL-6, IL-1β, TNF-α, and TGF-β). Thus, Bla.C significantly improved cardiac inflammation and cardiovascular fibrosis and dysfunction by blocking inflammatory cytokine activation signals. This showed that Bla.C treatment could ameliorate diabetes-induced cardiovascular complications in T2DM mice. These results provide evidence that Bla.C extract has a significant effect on the prevention of cardiovascular fibrosis, inflammation, and consequent diabetes-induced cardiovascular complications, directly or indirectly, by improving blood glucose profile.