In vitro inhibitory effects of Hypoxis hemerocallidea and Pentanisia prunelloides on α-amylase, α-glucosidase and pancreatic lipase activities associated with obesity-related metabolic disorders.

Abstract

Obesity is a complex metabolic disorder associated with dysregulated lipid metabolism and impaired adipose tissue function, resulting in the development of various chronic diseases such as diabetes mellitus. Plant-based therapeutic strategies, targeting the inhibition of digestive enzymes, have gained increasing attention as potential safe alternatives to synthetic drugs. This study investigated the inhibitory effect of root and leaf extracts of Hypoxis hemerocallidea Fisch., C.A.Mey. & Avé-Lall. and Pentanisia prunelloides (Klotzsch ex Eckl. & Zeyh.) Walp, against α-amylase, α-glucosidase, and pancreatic lipase, and related these activities to metabolite profiles to explore their potential relevance in obesity-associated metabolic dysfunctions. The results showed that H. hemerocallidea leaves exhibited a strong inhibitory activity against pancreatic lipase (98.68%) and α-glucosidase (98.10%), while α-amylase was considerably lower (11.71%). In P. prunelloides, both roots and leaves showed a strong α-glucosidase inhibitory activity of 99.02% and 96.38%, respectively. Moderate α-Amylase inhibitory activity was observed in the roots of H. hemerocallidea (53.14%), and P. prunelloides (50.63%), with the inhibition levels comparable to the lipase standard inhibitor acarbose (55.65%). Metabolite profiling using liquid chromatography-mass spectrometry (LC-MS) analysis revealed diverse putatively identified bioactive metabolites, including flavonoids, phenolic acids, phenolic glycosides, proanthocyanidins, saponins, terpenoids, and xanthones. Correlation and multivariate analyses suggested potential associations between metabolite abundance and enzyme inhibitory activities. Collectively, these findings suggest that both plant species possess substantial metabolite diversity and promising in vitro enzyme inhibitory activities, with H. hemerocallidea exhibiting comparatively stronger inhibitory activity. However, no compound isolation, cytotoxicity assessment, and in vivo validation was performed; therefore, the findings should be considered preliminary and require further pharmacological and mechanistic investigation.