Can raisins ameliorate hypercholesterolemia-inducednephropathy? What is the evidence?

BackgroundMany drugs that lower circulating cholesterol levels are available, but they arefrequently associated with severe side effects.AimThis study was conducted to investigate the possible protective effect of raisinsagainst a high-cholesterol-diet-induced nephropathy using biochemical andhistopathological examination.Materials and methodsThis experimental study was performed on 30 male Wistar rats randomly divided intofour groups: group I served as the control group and was fed a standard diet alongwith saline; group II was fed a standard diet along with 0.5 g of raisins; group III wasfed a high-cholesterol diet (HCD); and group IV was fed the HCD along with 0.5 gof raisins through a nasogastric tube for 13 weeks. The kidneys were processed forhistopathological examination using light and electron microscopes. The data wereanalyzed using statistical package for the social sciences (version 16).ResultsIngestion of raisins along with the HCD significantly decreased blood glucose,insulin, cholesterol, triglycerides, low-density lipoprotein, and creatinine levels,whereas it increased the high-density lipoprotein level. Mesangial expansion,glomerular capillary congestion, and fibrosis decreased in the rats fed HCD andraisins compared with those fed only the HCD. Raisins significantly reducedmesangial cell activation evident by α-smooth muscle actin, podocyte injury indicatedby desmin, and glomerular inflammation denoted by a number of monocytes, whereasit increased endothelial nitric oxide synthase expression in glomerular capillaries. Theultrastructural findings confirmed these results.ConclusionRaisins protect the kidney from hypercholesterolemia-induced injury. Consumptionof raisins or its pharmaceutical preparations is advised, particularly for those whoconsume a high-fat diet.