Evaluation of Hypoglycemic and Genotoxic Effect of Polyphenolic Bark Extract from Quercus sideroxyla

Abstract

Quercus sideroxyla is a wood species whose bark has phenolic compound and should be considered to be bioactive; the hypoglycemic and genotoxic properties of Q. sideroxyla bark were evaluated in this study. Total phenolic compound was determined in crude extract (CE) and organic extract (OE). The OE has the highest amount of phenols (724.1 ± 12.0 GAE/g). Besides, both CE and OE demonstrated effect over the inhibition of α-amylase in vitro. Hypoglycemic activity was assessed by glucose tolerance curve and the area under curve (UAC); OE showed the highest hypoglycemic activity. In addition, diabetes was induced by streptozotocin (65 mg/kg) and the extracts (50 mg/kg) were administered for 10 days; OE showed hypoglycemic effect compared with diabetic control and decreased hepatic lipid peroxidation. Acute toxicity and genotoxicity were evaluated in CE; results of acute toxicity did not show any mortality. Besides, the comet assay showed that CE at a dose of 100 mg/kg did not show any genotoxic effect when evaluated at 24 h, whereas it induced slight damage at 200 mg/kg, with the formation of type 1 comets.

Aqueous Bark Extract ofCeiba speciosa(A. St.-Hill) Ravenna Protects against Glucose Toxicity inCaenorhabditis elegans

“…C. elegans contains many key metabolic-related components such as oxidative stress and insulin signaling pathways, making it a useful platform to improve our understanding of complex diseases such as metabolic syndrome [ 13 ]. Glucose is the main energy source and key regulator of animal metabolism; however, a chronic abundance of glucose will have deleterious effects on cellular and tissue functions [ 28 ]. Carbohydrate excess activates several lipogenic enzymes contributing to deregulation in lipid metabolism and insulin resistance development [ 29 ].…”

Antioxidants in Oak (Quercus sp.): Potential Application to Reduce Oxidative Rancidity in Foods

“…Because of this, studies have been carried out to address this problem. The toxicity of Q. crassifolia , Q. infectoria, and Q. sideroxyla have been tested in rats, administered by subacute oral [ 74 ], acute via enema [ 86 ], and acute via gavage [ 87 ], respectively. The Q. crassifolia extract showed toxic effects at a repeatedly administered dose of 33 mg/kg bw/day and with an NOAEL (No Observed Adverse Effect Level) of 11 mg/kg bw/day, while the Q. infectoria extract dose of 10 g/kg showed no adverse effects on animal behavior, proposing that the maximum tolerated dose is above this value.…”