Study of phenolic compounds of Phyllanthus amarus and their α-glucosidase enzyme inhibitory activity assessment

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Résumé

The access to diabetes care remains limited in low-income countries, leading populations to rely on
medicinal plants. In Burkina Faso, Phyllanthus amarus is traditionally used against diabetes. This study
aimed to identify its chemical constituents and evaluate the antidiabetic potential of aqueous,
hydroethanolic, and decocted extracts from leafy stems. Indeed, total phenolic compounds and total
flavonoids were determined by the Folin-Ciocalteu and aluminum trichloride methods respectively. For
antioxidant capacity, the DPPH free radicals scavenging method was used. The antihyperglycemic
potential of the various extracts was estimated by monitoring their inhibitory effect on α-glucosidase
enzyme activity. Qualitative tests and thin-layer chromatography revealed flavonoids, tannins, lignans,
terpenes, coumarins, saponins, and alkaloids. The decoction contained the highest levels of phenolic
compounds (656.938±7.616 μg EGA/mg) and flavonoids (770.569±9.333 μg EQ/mg), as well as the
strongest antioxidant activity (IC50 = 14.737±0.199 µg/mL). Hydroethanolic and decocted extracts
showed significant inhibition of α-glucosidase with IC50 values of 64.102±2.342 µg/mL and
44.302±0.627 µg/mL, respectively, outperforming acarbose (265.892±7.263 µg/mL). These findings
highlight the diversity of phytochemicals and the notable biological activities of Phyllanthus amarus,
supporting its traditional use in Burkina Faso and other African countries for diabetes management.

Mots-clés

Phyllanthus amarus, phytochemistry, pharmacognosy, antioxidant, diabetes