Beneficial effect of myricetin on renal functions in streptozotocin-induced diabetes

Abstract

Myricetin is a naturally occurring flavonoid that is known to decrease plasma glucose levels in diabetes; however, its influence on renal functions has not yet been determined. This study investigated the effect of myricetin on structural and functional changes occurring in diabetic nephropathy. Male Albino Wistar rats were divided into three groups: normoglycemic, diabetic and myricetin-treated diabetic. Diabetes was induced by intraperitoneal (ip) injection of streptozotocin (50 mg/kg), and rats having fasting blood glucose (FBG) levels greater than 200 mg/dl were included in the study. Treatment of myricetin (6 mg/day ip) was initiated 16 weeks after diabetes was confirmed. Light microscopy was performed on hematoxylin-eosin- and Masson's trichrome-stained sections to evaluate the effect of myricetin on structural changes in the kidney, while creatinine clearance, blood urea nitrogen (BUN), kidney weight, urine volume and protein were measured to assess kidney functions. Activities of glutathione peroxidase (GPx) and xanthine oxidase (XO) were also measured in renal tissues obtained from all experimental groups. Myricetin treatment significantly decreased glomerulosclerosis and reduced BUN, urinary volume and protein excretion, which was profoundly increased in diabetic rats. Decreased creatinine clearance measured in diabetic rats was significantly increased following myricetin treatment. Myricetin also restored altered renal activities of GPx and XO, which were decreased and increased in diabetic rats, respectively. In conclusion, myricetin improved altered renal functions and restored renal activities of GPx and XO in diabetic rats. Obtained data suggest that myricetin could be of therapeutic potential in diabetic nephropathy.

Seasonal variation of the main individual phenolics and juglone in walnut (Juglans regia) leaves

“…Myricetin is another important dietary flavonoid, which occurs mainly in blackcurrants, black grapes, cranberries, bilberries, broad beans, red wine and grape juice (Hertog et al, 1992) but walnuts too are a rich dietary source (Cosmulescu et al, 2010;Cosmulescu & Trandafir, 2011b;Stampar et al, 2006). Myricetin is reported to have beneficial effects on renal functions (Ozcan et al, 2012) or a promising agent for the chemoprevention of skin cancer (Kang et al, 2011). The highest levels of myricetin were recorded in July 15th samples of Valcor leaves (248.99 mg/100 g FW), while the lowest were found in samples taken on June 1st from the Muscelean cultivar (54.14 mg/100 g FW).…”

Increased Small Dense LDL and Decreased Paraoxonase Enzyme Activity Reveals Formation of an Atherogenic Risk in Streptozotocin-Induced Diabetic Guinea Pigs

“…Increased oxidative stress and altered antioxidant-protective mechanisms reported in type 1 diabetic animal models [35, 36] can lead to reduced PON1 due to inhibition of the enzyme by its substrates, lipid peroxides [37]. This may provide a mechanism by which decreased PON1 activity promotes atherosclerosis and increased risk for vascular complications in type 1 diabetes.…”

Optimization of ultrasound-assisted hydroalcoholic extraction of phenolic compounds from walnut leaves using response surface methodology

“…Myricetin is an important dietary flavonoid, with a potent antioxidant and free-radical scavenging activity. Several studies have demonstrated that myricetin exhibits beneficial effects on bone health (Hsu et al 2007), on renal functions (Ozcan et al 2012) or in the chemoprevention of skin cancer (Kang et al 2011). Extremely high contents of myricetin were found also in walnuts (456.5 mg/100 g FW) by Lugasi et al (2003).…”