Extraction of anti-hyperglycaemic bioactive compounds from Phyllanthus niruri L. through solvent mixture design: In vitro and in vivo evaluation

Abstract

BackgroundSpecies within Phyllanthus genus exhibit a diverse range of experimentally validated pharmacological activities. Notably, Phyllanthus niruri Linneo(Phyllanthaceae), commonly referred to as stonebreaker, is a native Central and South American species with a rich history of use in traditional ethnomedicine for treating gastrointestinal and renal disorders. PurposeThe aim of this study was to investigate the application of various solvent mixtures to optimize the extraction of anti-hyperglycemic secondary metabolites from P. niruri. MethodsTo optimize the extraction of anti-hyperglycemic compounds from P. niruri, a solvent mixture design strategy was employed. The optimized extracts were subjected to chemical characterization using spectrophotometric methods and HPLC-DAD analysis. Also, the influence of edaphoclimatic conditions on the composition of extracts was investigated. The anti-hyperglycaemic potential of the extracts was evaluated through both in vitro and in vivo assays. The in vitro studies included enzyme inhibition assays targeting α-glucosidase from two sources (yeast and pig). For in vivo studies, a rat model with oral starch overload was used to confirm the anti-hyperglycaemic activity of the extracts. ResultsAn optimal solvent mixture (70 % methanol and 30 % ethyl acetate) was found as effective for extracting compounds with anti-hyperglycemic potential from P. niruri. All the extracts obtained using this solvent inhibited both, yeast and pig α-glucosidase, with greater selectivity for inhibiting the yeast-derived enzyme. Extracts from aerial parts (AP) exhibited the strongest inhibitory activity. These extracts contained phenolic compounds, specifically flavonoids, but no condensed tannins were detected. Chromatographic analysis of profile revealed a major peak consistent with corilagin. In vivo studies using a dose of 500 mg kg-1 demonstrated that this extract significantly reduced blood sugar levels after starch overload in rats. ConclusionThis study demonstrates the importance of selecting appropriate solvent mixtures to extract bioactive compounds with anti-hyperglycemic properties from P. niruri. Our findings support the traditional use of this plant as a anti-hyperglycaemic agent in ethnomedicine.