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

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.

Spirulina (arthrospira) protects against valproic acid-induced neural tube defects in mice.

Valproic acid (VPA) is a potent inducer of neural tube defects in human and mouse, its teratogenicity is associated with its potential to generation of free radicals and increase oxidative stress. Furthermore, spirulina (SP) has shown pharmacological properties against teratogenicity, which are attributed to its antioxidant potential. Accordingly, the present study was performed to investigate the influence of SP on the teratogenicity of VPA in imprinting control region mice and the possible mechanisms of action. VPA (sodium valproate) was administered intraperitoneally to mice on gestation day (GD) 8 at a dose of 600 mg/kg. SP was given orally at 125, 250, and 500 mg/kg daily from GD0 through GD18. The most common finding in fetuses with VPA exposure was exencephaly. SP decreased the incidence of this and other malformations and increased levels of superoxide dismutase, catalase, and glutathione peroxidase. In conclusion, these results illustrate the protective action of SP through its antioxidant activity against VPA-induced teratogenicity.

Antiobesity and hypoglycaemic effects of aqueous extract of Ibervillea sonorae in mice fed a high-fat diet with fructose.

Obesity, type II diabetes, and hyperlipidaemia, which frequently coexist and are strongly associated with oxidative stress, increase the risk of cardiovascular disease. An increase in carbohydrate intake, especially of fructose, and a high-fat diet are both factors that contribute to the development of these metabolic disorders. In recent studies carried out in diabetic rats, authors reported that Ibervillea sonorae had hypoglycaemic activity; saponins and monoglycerides present in the plant could be responsible for the effects observed. In the present study, we determined the effects of an aqueous I. sonorae extract on a murine model of obesity and hyperglycaemia, induced by a high-calorie diet, and the relationship of these effects with hepatic oxidation. A high-fat diet over a period of 8 weeks induced weight gain in the mice and increased triglycerides and blood glucose levels. Simultaneous treatment with I. sonorae aqueous extracts, at doses of 100, 200, and 400 mg/kg, decreased triglycerides and glycaemia levels, prevented an increase in body weight in a dose-dependent manner, and decreased hepatic lipid oxidation at a dose of 200 mg/kg. These data suggest that the aqueous extract from I. sonorae root prevents obesity, dyslipidaemia, and hyperglycaemia induced by a hypercaloric diet; however, high doses may induce toxicity.