Brazilin Ameliorates Diabetic Nephropathy and Inflammation in db/db Mice

Hyperglycemia and inflammation play important roles in the pathogenesis of diabetic nephropathy (DN). Brazilin might be an effective pharmacological agent against hyperglycemia and inflammation. In our present study, we explored whether brazilin mitigated pathological progression, inflammation, and extracellular matrix (ECM) accumulation in a mouse model of diabetic nephropathy. Brazilin reduced aggravated biochemical indices of DN (proteinuria and the serum glucose level) and renal hypertrophy. Brazilin also improved renal morphology and inhibited macrophage infiltration, as manifested by different pathological staining methods. Brazilin reduced the levels of pro-inflammatory cytokines and CD68, a macrophage marker, in the kidney cortex, as revealed by both RT-PCR and western blotting experiments. Furthermore, brazilin significantly downregulated the serum levels of pro-inflammatory cytokines and chemokines. Interestingly, brazilin significantly upregulated the levels of the anti-inflammatory factor IL-10, and prevented ECM accumulation. Brazilin reduced nuclear translocation of the NF-κB p65 subunit both in vitro and in vivo. Thus, brazilin might be a useful treatment for DN, through mitigating hypoglycemia, inflammation, and ECM accumulation.