The renal effects of blood glucose-lowering plant-derived extracts in diabetes mellitus--an overview.

Diabetes mellitus, a disorder characterized by chronic hyperglycemia and excessive urine excretion, is associated with complications such as atherosclerosis, cardiac dysfunction, and nephropathy. Renal disease, which develops through a number of metabolic pathways in diabetes, is characterized by functional as well as structural abnormalities of the kidney. The most common cause of end-stage renal disease (ESRD) is diabetic nephropathy, which accounts for significant morbidity and mortality. Current conventional diabetes therapy using blood glucose-lowering medications has limitations in averting the development of renal diseases. The onset of diabetic nephropathy is associated with a progressive rate of decline in renal function, urinary albumin excretion, and glomerular filtration rate (GFR). Diabetes mellitus treatment should therefore aim to intervene on promoters of the decline in renal function in diabetes to avert adverse outcomes. Preventing the pathogenesis of nephropathy with therapeutic interventions based on specific alterations in kidney function represents a plausible approach. Cumulative evidence suggests that some herbal extracts with hypoglycaemic properties may have beneficial effects on some processes associated with a decline in renal function, as well as reduce the severity of nephropathy in diabetic experimental animals. On the other hand, some herbal extracts may be hazardous in diabetes, as reports indicate impairment of renal function. This review outlines current evidence supporting plant extracts with the potential of averting progressive renal diabetic complications as well as the nephrotoxicity of some herbal extracts.