Portulaca oleracea L. (Purslane) extracts display antioxidant and hypoglycaemic effects

Purslane (Portulaca oleracea L.) is a member of the family Portulacaceae. Due to its many health benefits, it is listed in a World Health Organization database. The aim of this work is to investigate the purslane extracts for their chemical profile and bioactivity. In this study, two different solvents (MeOH/H2O and EtOH) were applied to fresh and dried leaves. The extracts were analysed using HPLC-DAD. Phenolic acids (caffeic acid, p-coumaric acid and ferulic acid) and flavonoids (apigenin, kaempferol, luteolin, quercetin, isorhamnetin, kaempferol-3-O-glucoside and rutin) were identified in all samples. Quercetin and p-coumaric acid were the most abundant compounds. Total antioxidant activity was measured by using the ABTS and DPPH tests, and the ferric reducing antioxidant power (FRAP) assay. Hypoglycaemic properties were investigated via the inhibition of carbohydrate-hydrolysing enzymes, alpha-amylase and alpha-glucosidase. Fresh hydroalcoholic purslane extract exhibited the highest radical scavenging potential in both ABTS and DPPH test (IC50 values of 52.86 and 66.98 mu g/mL, respectively), whereas dried hydroalcoholic purslane extract showed the highest alpha-glucosidase inhibitory potential (IC50 value of 45.05 mu g/mL). Collectively these data show the health properties of this widely consumed salad plant.