Antihyperglycaemic activity of two species of Phyllanthus

Abstract

Phyllanthus niruri L. (rompepiedra) and P. sellowianus (sarandí blanco), are native species of Central and South America. In ethnopharmacology, P. niruri is used as a diuretic, while P. sellowianus is used as a hypoglycemic. The aim of the works was to evaluate the inhibitory potential of these extracts on α-glucosidase enzymes (APG) from different sources. Aerial Parts (APn) and Roots (Rn) of P. niruri collected in Corrientes-Capital, along with Leaves (Ls), Stem Bark (SBs), and Roots (Rs) of P. sellowianus from Corrientes-Monte Caseros, were employed for this research. The extracts were prepared with methanol: ethyl acetate (7:3) and dried using a rotary evaporator. Antihyperglycemic efficacy was studied based on the ability of the extracts to inhibit APG activity. Results were quantified in terms of inhibition ratios (Ir), with acarbose as positive control. Additionally, phytochemistry and the HPLC-DAD profiles of the extracts were evaluated. In the Saccharomyces cerevisiae APG inhibition assay, extracts from both species outperformed the acarbose. The most active extracts were SBs: Ir=318.69, Ls: Ir=277.93 and APn: Ir=251.67. However, during the pig APG inhibition assay, all extracts exhibited lower potency (Ir<1). Leaf extract (L) from P. sellowianus had the greatest inhibitory activity (Ir=0.0875), followed by SB and AP extracts from P. niruri (Ir=0.0819). All extracts showed a high polyphenolic content, while only in R and SB condensed tannins were detected. Chromatographic analysis of active extracts revealed a major peak with a retention time of 25min and λmax=220 and 276 nm. Our findings highlight the higher inhibitory activity of P. sellowianus compared to P. niruri extracts and emphasize the inhibitory influence of extracts from both species on alpha-glucosidases, with a higher affinity towards the yeast enzyme. These results have important implications for the design of future screening protocols to assess the antihyperglycaemic potential.