Chiranthodendron Pentadactylon Larreat 'Mexican Tree of the Little Hands' (Sterculiaceae), A Powerful Antioxidant, And its Effect in Experimental Diabetic Nephropathy

Ethnopharmacological relevance:&nbsp;Chiranthodendron pentadactylon commonly known in Mexico as 'tree of the little hands', where its flower’s infusion is used for treat heart attacks and diabetes, chronic-degenerative diseases related to oxidative stress and inflammation, due to its flavonoids content with scientific supported antioxidant and anti-inflammatory properties such as catechins, whose help to reduce oxidative impact on the body organs; however, its possible beneficial effects due to its antioxidant effect over diabetic nephropathy remains unknown to date, being this the first cause of end-stage of renal disease in diabetic patients worldwide.<br><br>Aim of the study: Present work sought to evaluate therefore the antioxidant effect of methanolic extract of C. pentadactylon flowers, on the nephropathy of streptozotocin-induced diabetic rats.<br><br>Materials and methods: Methanolic extract was obtained from C. pentadactylon dried flowers, and preliminary chemical screening was performed in thin layer chromatography to identify metabolites. Antioxidant potential in vitro of extract was determined by inhibition of DPPH radical and total phenolic content; then antioxidant effect in vivo of the extract was evaluated in streptozotocin-induced diabetic rats administered by intragastric route at 100 and 200 mg/kg body weight for 6 weeks; plasma glucose and creatinine levels, food, and water consumption, as well as daily urinary volume collected to quantify proteinuria, were measured periodically, in all experimental animals. Renal hypertrophy ratios as renal weight mg/body weight g, and protein/DNA were also evaluated. Finally, oxidative stress biomarkers such as lipid peroxidation rate and antioxidant enzymes activity were measured in renal tissue.<br><br>Results: Methanolic extract showed that of its total chemical composition, 20% corresponded to total phenolic content (205.27 mg equivalents of gallic acid/g of extract) and showed a median inhibitory concentration value of 18.05 µg/mL over DPPH radical, compared to quercetin (5.91 µg/mL), since by thin layer chromatography flavonoids were detected. For in vivo study endpoint, extract at both doses showed a significant decrease in protein/DNA ratio in renal tissue of diabetic rats, reaching levels statistically like healthy rats; same moderate decreasing behavior were observed for urine’s protein levels and plasma creatinine in extract-treated diabetic rats, compared to those with diabetes and untreated, reaching values shown by healthy animals only for creatinine parameter. Finally, best antioxidant effect was exerted by dose of 100 mg/kg, which significantly increased catalase activity and decreased lipid peroxidation in kidney tissue compared to those un-treated diabetic rats, even in greater proportion than in diabetic rats administered with vitamin E; while dose of 200 mg/kg also showed antioxidant effect but in a smaller proportion although statistically similar to vitamin E. In the rest of the evaluated parameters, treatment with the extract did not modify the course of the physiological and biochemical alterations caused by experimental diabetes.<br><br>Conclusions: Six-week daily administration of C. pentadactylon methanolic flower’s extract during experimental diabetes induced by streptozotocin improves renal function, through antioxidant enzyme activity stimulation which prevents lipid peroxidation in renal tissue without causing adverse side effects.