Abstract

Hexalobus crispiflorus A. Rich., synonym Hexalobus grandiflorus Benth, is a plant in the Central African pharmacopoeia, widely used in the treatment of skin diseases and diabetes. The present study is a contribution to the qualitative and quantitative analysis and evaluation of the antioxidant activity of this plant. Preliminary phytochemical tests carried out on the different crude extracts of H. crispiflorus revealed the presence of flavonoids, anthocyanins, tannins, saponosides, triterpenes and sterols, followed by confirmation by thin layer chromatography. Quantitative analysis showed that the hydroethanolic extracts (50%) of H. crispiflorus have a high content of total polyphenols and flavonoids 955.11 ± 0.76 µg AG/g Ms and 779.85 ± 7.93 µg Eq Quer/g Ms, respectively. Hydroethanolic extract remains the best solvent for extraction of phenolic compounds. The evaluation of the free radical scavenging capacity using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical trapping method on 96-well microplates showed that only the hydroethanolic (50%, 80%) and aqueous extracts had a moderate percentage of inhibition 17.94, 19.47 and 39.85%, respectively, but this was still low compared to the reference molecule, ascorbic acid (89.4%). The results obtained could justify the therapeutic virtues of this species in the treatment of various pathologies.

Key words: Hexalobus crispiflorus A. Rich, extracts, qualitative and quantitative composition, antioxidant activity.