Studies on the potential antioxidant properties of Senecio stabianus Lacaita (Asteraceae) and its inhibitory activity against carbohydrate-hydrolysing enzymes

This study showed for the first time the antioxidant and hypoglycaemic properties of the methanol, n-hexane and ethyl acetate extracts from Senecio stabianus Lacaita, a plant that belongs to the Asteraceae family. The antioxidant activities were carried out using two different in vitro assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH) test and 2,2\u2032-azinobis(3- ethylbenzthiazoline-6-sulphonate) (ABTS) test. The ethyl acetate extract showed the highest activity with inhibitory concentration 50% (IC 50) values of 35.5 and 32.7 \u3bcg mL -1 on DPPH test and ABTS test, respectively. This activity may be related to a good total phenol and flavonoid content. All extracts were also tested for their potential inhibitory activity of \u3b1-amylase and \u3b1-glucosidase digestive enzymes. The n-hexane extract exhibited the highest \u3b1-amylase inhibition with an IC 50 value of 0.21 mg mL -1. Through bioassay-guided fractionation processes seven fractions (A-G) were obtained and tested. Based on the phytochemical analysis, the activity of n-hexane extract may be related to the presence of monoterpenes and sesquiterpenes

In vitro antioxidant effect and inhibition of alpha-amylase of two varieties of Amaranthus caudatus seeds

This study reports on the biological properties, antioxidant and antidiabetic, of two varieties of Amaranthus caudatus seeds, Oscar blanco and Victor red. Oil, squalene and phenolic contents were also determined. Seeds of both investigated varieties were found to possess very different levels of squalene (2.2% in Oscar blanco variety and 7.5% in Victor red variety). Although the antioxidant activity of A. caudatus var. Oscar blanco and A. caudatus var. Victor red statistically did not differ significantly from each other (IC50 values of ethyl acetate extracts were 0.50 mg/ml and 0.62 mg/ml, respectively), significant differences were noticed in relation to antidiabetic activity (inhibition of a-amylase, EC 3.2.1.1) of methanolic extracts that showed 50.5% for A. caudatus var. Oscar blanco and 28% for A. caudatus var. Victor red at concentration of 25m g/ml

Radical scavenging , total antioxidant capacity and antiproliferative activity of phenolic extracts from extra virgin olive oil by cultivar ‘Frantoio’

The beneficial health effects of extra virgin olive oil are due to both its high content of monounsaturated fatty acids and its high content of phenolic compounds, which have recently attracted research interest. In this context, the aim of this work was to examine the in vitro antioxidant and antiproliferative activities of the phenolic extract obtained from extra virgin olive oil from O. europea cultivar Frantoio (samples 1-4), one of the main varieties cultivated in Italy. The total phenolic content was determined by Folin-Ciocalteu method and instead the phenolic profile was obtained by HPLC coupled to a diode array detector and mass spectrometry. Extra virgin olive oil extracts exhibited high antioxidant activity through different mechanisms of action and these activities are related to the phenolic content. Sample 3 demonstrated the strongest free radical scavenging activity with IC50 value of 56.5 g/mL. The reducing ability measured with FRAP assay revealed that samples ranged from 91.3 to 156 M Fe(II)/g. The same interesting trend was observed with Trolox equivalent antioxidant capacity value. Moreover, the virgin olive oils showed a good oxidative stability ranging between 19 to 32 h. Antiproliferative activity evaluated by SRB assay revealed that phenolic extracts from the cultivar Frantoio showed a strong antiproliferative activity against CORL-23 cell line with an IC50 value of 14.5 and 55.9 g/mL for samples 3 and 1, respectively, and these results are comparable to the positive control vinblastine. Overall, these results showed that extra virgin olive oils from the cultivar Frantoio, may represent an interesting source of phenolic compounds as functional components that could be consumed in diets and/or used for the elaboration of functional food and pharmaceutical industrie