Etude de l’activité biologique de l’extrait d’une plante médicinale.

Abstract

This work aims to identify the main chemical groups present in Eucalyptus citriodora leaves as well as the evaluation of the antioxidant and antibacterial activities of its methanolic and aque-ous extracts. The results of the phytochemical study showed the presence of phenols, flavo-noids, tannins, terpenoids, carbohydrates, quinones, saponins, steroids and proteins. Quantita-tive analysis showed the richness of the extracts in polyphenols with contents of 62.38 to 200.64 μg EAG /mg of sample; the high content was obtained by methanol. The antioxidant power revealed that both extracts exhibit antioxidant properties; where the methanolic extract exhibits excellent ability to neutralize the free radicals DPPH. Concerning the antibacterial activity test, the results showed significant activity of the aqueous and methanolic extracts against Pseudo-monas aeruginosa and Bacillus subtilis. For Staphylococcus aureus, both extracts revealed a relatively weak effect. On the other hand, Escherichia coli was resistant to both extracts. The obtained results indicate that the methanolic and aqueous extracts of Eucalyptus citriodora leaves are rich in bioactive compounds, exhibiting strong antioxidant activity and antibacterial efficacy that varies depending on the bacterial strains.