Étude ethnobotanique, phytochimique et écotoxicologique de Ocimum gratissimum Linn ( Lamiaceae) à Cotonou

Abstract

Objective: The use of Ocimum gratissimum Lamiaceae (African Basil) is widespread in Benin. This study evaluated whether the virtues attributed to this plant are focused on rational basis and that its consumption is without adverse consequences for human health. Methodology and Results: An ethnobotanical study targeting leaves from vegetable vendors in the three major markets (Dantokpa; Saint Michel; Vêdoko), some herbalists, health workers and consumers was conducted in Cotonou the capital city of Benin. A phytochemical study based on differential precipitation reactions was carried out, supplemented by the determination of heavy metals (lead, cadmium) and some nutrients by molecular absorption spectrophotometry. The investigations revealed several uses of Ocimum gratissimum Linn (Lamiaceae) i.e medicinal, food, ritual, chemical and ornamental. It contains phytochemicals compound such as phenolic; nitrogen; steroids; terpenes; mucilage; derived cyanogenic and several nutrients (protein; Nitrogen; Iron; Zinc; Copper). The results also reveal the presence of heavy metals (lead, cadmium) in concentrations above the WHO standards. Conclusion and implementation of the results: The results of phytochemical and nutritional analyzes confirmed the empirical uses identified in the ethnobotanical study. This plant is a remedy in the prevention and treatment of certain diseases, an excellent dietary supplement, and an alternative to chemical control. The presence of Trace of Elements Metals with concentrations higher than the WHO standards reflects a potential risk to human health. It is urgent for the central state, the social partners and the scientific community to rethink the production of Ocimum gratissimum Linn of acceptable phytosanitary quality in order to guarantee to the population the safe use of this Medicinal Plant with leafy vegetables, Health and Sustainable Development.