Inhibition of thermal induced protein denaturation of extract/fractions of <i>Withania somnifera</i> and isolated withanolides

<div><p>This study describes the <i>in vitro</i> inhibition of protein denaturation of extract/fractions of <i>Withania somnifera</i> and isolated withanolides including 20β hydroxy-1-oxo(22<i>R</i>)-witha-2,5,24 trienolide (<b>1</b>), (20<i>R</i>,22<i>R</i>-14α,20α)-dihydroxy-1-oxowitha-2,5,16,24 tetraenolide (<b>2</b>). The results showed that the extract/fractions of the plant evoked profound inhibitory effect on thermal-induced protein denaturation. The chloroform fraction caused the most dominant attenuation of 68% at 500 μg/mL. The bioactivity-guided isolation from chloroform fraction led to the isolation of compounds <b>1</b> and <b>2</b> that showed profound protein inhibition with 78.05% and 80.43% effect at 500 μg/mL and thus strongly complimented the activity of extract/fractions. In conclusion, extract/fractions of <i>W. somnifera</i> possessed strong inhibition of protein denaturation that can be attributed to these isolated withanolides.</p></div

Biofunctional properties of <i>Eruca sativa</i> Miller (rocket salad) hydroalcoholic extract

<p><i>Eruca sativa</i> Miller is a worldwide common alimentary plant (rocket leaves). The aim of this study was to correlate the potential <i>in vitro</i> scavenging activity of the <i>E. sativa</i> hydroalcoholic extract (HAE) with its <i>in vivo</i> hypoglycaemic effect. In DDPH free radical (DFR) and ferric-reducing antioxidant power assays, HAE in a concentration dependent manner (25–100 μg/mL) displayed a strong scavenging activity with maximum effect of 88% and 75% at 100 μg/mL, respectively. Daily administration of HAE (50 mg/kg; p.o.) in the <i>in vivo</i> model of alloxan-induced diabetic rabbits for 28 days showed significant reduction in glycaemia, also supported by recovery of body weight. In conclusion, our results give preliminary information on the potential use of this plant as a nutraceutical, useful to control and/or prevent a hyperglycaemic status.</p