Résumé:
This study focuses on the phytochemical characterization and the evaluation of the
antioxidant and anti-inflammatory activities of Gymnemasylvestre leaves collected from the
Mostaganem region (Algeria). Gymnemasylvestre is a well-known medicinal plant
traditionally used for its antidiabetic and metabolic-regulating properties. The primary
objective of this research is to identify bioactive compounds and assess their biological
potential through various in vitro assays.
Qualitative phytochemical screening revealed the presence of several classes of secondary
metabolites, including polyphenols, flavonoids Quantitative determinations were performed
using standard spectrophotometric methods:
Total polyphenol content was measured using the Folin–Ciocalteu method and
expressed as mg gallic acid equivalents (GAE) per gram of extract.
Total flavonoid content was determined by the aluminum chloride method and
expressed as mg quercetin equivalents (QE) per gram.
The antioxidant activity of the leaf extracts was assessed using two complementary methods:
The DPPH radical scavenging assay (2,2-diphenyl-1-picrylhydrazyl) to evaluate free
radical neutralization capacity.
The FRAP assay (Ferric Reducing Antioxidant Power) to measure the reducing power
of the extracts.
The results indicated that methanolic extracts exhibited higher levels of phenolic compounds
and stronger antioxidant activity compared to aqueous extracts. A positive correlation was
observed between polyphenol/flavonoid content and antioxidant efficacy, confirming the
significant role of these compounds in oxidative stress reduction.
Additionally, the anti-inflammatory activity was evaluated in vitro using protein denaturation
inhibition assays, specifically targeting bovine serum albumin (BSA) and protease enzymes.
The findings revealed dose-dependent inhibition, highlighting a notable anti-inflammatory
effect, particularly in methanolic extracts.
In conclusion, Gymnema sylvestre leaves from the Mostaganem region are rich in bioactive
phytochemicals and demonstrate significant antioxidant and anti-inflammatory potential.
These findings support the traditional use of the plant and underscore its promise as a natural
source for therapeutic and nutraceutical applications.
