Enhancing antidiabetic bioactivity of purslane leaf extract (Portulaca oleracea L.) through synthesis of nanoemulsion: In vitro and in vivo evidence

Purslane plant (Portulaca oleracea) is a type of herbal plant that can be used in traditional diabetes treatment because it has the highest content of the quercetin found in the leaves which plays a role in inhibiting the α-amylase enzyme. However, it is less active due to limitations in drug solubility and delivery. Therefore, we developed a nanoemulsion of purslane leaf extract as an antidiabetic in vitro through α-amylase enzyme inhibition and in vivo through alloxan induction. The nanoemulsion was made using virgin coconut oil as the oil phase, polysorbate as the surfactant, propylene glycol as the cosurfactant, and phosphate buffer as the water phase with purslane leaf extract masses of 0.005, 0.01, 0.02, and 0.04 grams. The physical stability tests of nanoemulsions carried out were organoleptic tests, percent transmittance tests, viscosity tests, pH tests, solubility tests, emulsification time tests, cycling tests, particle size tests, and zeta potential. The smallest nanoemulsion particle size in the F2 formulation was 10.53±0.20 nm. However, the results of antidiabetic activity obtained an IC50 value of inhibition of purslane leaf extract nanoemulsion against α- amylase enzyme which was better than purslane leaf extract, which was 1225.38 ppm, while the IC50 value of purslane leaf extract was 7904.61 ppm. In vivo analysis reveals purslane leaf extract nanoemulsion significantly reduces the sugar blood level on alloxan-induced mice models compare to the extract. This result indicates that nanoemulsion enhancing the antidiabetic activity and potentially applied for drug development.