Protective effect of yacon leaves decoction against early nephropathy in experimental diabetic rats

• Published in: Food and chemical toxicology 2012-05, Vol.50 (5), p.1704-1715
• Main Authors: Honoré, Stella M., Cabrera, Wilfredo M., Genta, Susana B., Sánchez, Sara S.
• Format: Article
• Language: English
• Subjects: Actins - metabolism; albumins; Animals; Asteraceae - chemistry; basement membrane; Biological and medical sciences; blood glucose; Blotting, Western; body weight; collagen; Collagen Type III - metabolism; Collagen Type IV - metabolism; creatinine; Diabetes; Diabetes Mellitus, Experimental - complications; Diabetes. Impaired glucose tolerance; Diabetic Nephropathies - physiopathology; Diabetic Nephropathies - prevention & control; diabetic nephropathy; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; excretion; fibronectins; Fibronectins - metabolism; genetic markers; hyperglycemia; hypertrophy; immunoblotting; Immunohistochemistry; insulin; Kidney; Kidney - metabolism; Kidney - physiopathology; kidneys; Laminin - metabolism; leaves; Male; mechanism of action; Medical sciences; morbidity; mortality; oral administration; patients; Plant Extracts - therapeutic use; Plant Leaves - chemistry; protective effect; Rats; Rats, Wistar; reverse transcriptase polymerase chain reaction; Smallanthus sonchifolius; Streptozocin; TGF/Smad signaling; toxicology; urine; Yacon
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2012.02.073

[Display omitted] ► Leaves decoction of Smallanthus sonchifolius (yacon) is a protective agent against renal damage during diabetes. ► Altered renal parameters were normalized in yacon decoction-treated diabetic rats. ► Yacon decoction alleviates early glomerulosclerosis in diabetes through TGF-β/Smad inhibition. ► The results might promote a better understanding for the molecular mechanisms of yacon decoction actions during diabetes. Nephropathy is the most common cause of morbidity and mortality in diabetic patients. Prevention of this complication has a major relevance. Smallanthus sonchifolius (yacon) leaves have been shown to ameliorate hyperglycemia in streptozotocin-induced diabetic rats. We examined the beneficial effects of yacon leaves decoction on diabetic nephropathy and explored the possible underlying action mechanism. Streptozotocin-diabetic rats were orally administered 10% yacon leaves water decoction (70mg dry extract/kg body weight) once a day for 4weeks. Biochemical parameters in blood and urine were analyzed and immunohistochemistry staining, western immunoblotting and qRT-PCR were assessed. Yacon decoction significantly decreased high blood glucose level in diabetic rats and improved insulin production. Diabetic-dependent alterations in urinary albumin excretion, creatinine clearance, kidney hypertrophy and basement membrane thickening were attenuated by yacon decoction. These findings were associated with a marked decrease in TGF-β1/Smad2/3 signaling. The expression of molecular markers of diabetic nephropathy such as collagen IV, laminin-1, fibronectin and collagen III were also diminished in the yacon-treated group compared to control diabetic group. These results suggest that yacon leaves decoction is a protective agent against renal damage in diabetic nephropathy, whose action can be mediated by TGF-β/Smads signals.