Etudes de la phytochimie et de l’activité antimicrobienne in vitro des feuilles de Moringa oleifera (Moringaceae)

Résumé

Moringa oleifera leaves are used in Burkina Faso since as  vegetable. But, in the last few years, a particular attention has been drawn to this tree for its nutritional and pharmaceutical values. To know more about the leaves of this tree, we undertook phytochemical and antimicrobial studies.

The phytochemical studies have been conducted on Moringa oleifera leaves harvested in Gourcy, North-West of  Burkina Faso. The results revealed that the leaves were rich in micronutrients notably in Calcium (15,08g/kg mat.sèche), Magnesium (6,88g/kg), Copper (8,13g/kg), Zinc (26,59g/kg), Iron (677,77g/kg),  Manganese (62,93g/kg), vitamines A (39mg/100g mat.sèche), B1 (3,10mg/100g), B2 (10,2mg/kg), C (210mg/kg) and essential amino acids indispensable to a person’s bodily functions. The phytochemical screening revealed the high level of the leaves in phenolic coumponds (flavonoids and tannins), in sterols and  triterpens, all of them, chemical coumpounds with antimicrobial effects. Aqueous extracts have been tested against 17 bacterial strains (clinical isolates) obtained from pus, blood, stools, urines, and also against strains from American Type Collection Culture (Salmonella, Staphylococcus, Streptococcus, Escherichia coli, Proteus, Pseudomonas, klesiella). The extracts have also been tested against strains of fungi notably Candida albicans. The results have showed that the aqueous extract was effective against all the strains that have been tested, most of the MIC ranging from 3.12 to 1.56 mg/ml. The extracts have revealed  even more effective against all the tested Candida albicans strains than the bacteria, thus justifying the successful use of  Moringa oleifera leaves for the treatment of many infectious diseases.

Key words : Moringa oleifera –micronutrients– phenolic compounds - antimicrobial