Contribution à l’étude -in vitro-, des activités biologiques des saponines de Chenopodium quinoa Willd.

Abstract

The aim of this work is to focus on the medicinal properties of saponins from Chenopodium quinoa Willd seeds, an annual herbaceous plant recently introduced to Algeria. Their extraction was carried out by two methods: alcoholic (MeOH / BuOH) and aqueous, then the determination of total saponin content by the vanillin-sulfuric acid method, followed by biological activity tests -in vitro- (antimicrobial activity, inhibition of protein denaturation and hemolytic test). The assay shows the highest saponin content in the MeOH extract 876.5 ± 0.063 μg eq DG / mg DE, followed by the extract AQ 728.2 ± 0.111 μg eq DG / mg DE and BuOH extract 150 ± 0,029 μg eq DG/mg DE. The antimicrobial activity by the broth macro-dilution method after the alkaline treatment of the extracts in which the MeOH extract shows an activity against all the strains, particularly the Gram-positive ones, the AQ extract exerts an activity against 3 strains out of 5 tested. Whereas, the result of inhibition of protein denaturation is ranked in descending order: BuOH extract 85% ± 0.00%, MeOH extract 76.67% ± 1.44, AQ extract 70,10% ± 0.36. The result of the haemolytic test reveals a strong hemolysis 45.61% at the lowest concentration for the BuOH extract, while the MeOH extract and the AQ extract are slightly haemolytic with 19.35% and 12.32 % respectively. The saponins of Chenopodium quinoa Willd seeds could be exploited for therapeutic purposes, particularly in the field of combating microbial infection.