Recherche de l’extrait de Codiaeum variegatum possédant de fortes propriétés antioxydantes et anti-inflammatoires

Codiaeum variegatum commonly known as garden croton, is a medicinal plant used for the treatment of amoebiasis in Cameroon and some Asian countries. The present study aimed to explore some biological properties such as antioxidant, and anti-inflammatory, which may be relevant for the valorization of this plant. Aqueous, hydroethanolic 70/30 (v/v) and ethanolic extracts were tested for the antioxidant activity using DPPH radical scavenging, iron reduction power and lipid peroxidation inhibition assays. The anti-inflammatory activity was investigated via the inhibition of nitric oxide (NO) production on isolated mice macrophages activated by Saccharomycces cerevisiae, the inhibition of 5-lipoxygenase activity, the inhibition of BSA denaturation and the activation of two lysosomal enzymes involved in phagocytosis. The phytochemical composition of the plant extracts was assayed using standard methods. It results that the ethanolic extract (EE) exhibited the best DPPH scavenging activity (IC50=77.04 µg extract/mol of DPPH), lower than that of ascorbic acid (8.98 µg extract/mol of DPPH). In addition EE also showed good ferric reducing power (EC50=543.6 µg/mL), and lipid peroxidation inhibition (IC50=21.52 µg/mL). On the other hand, the hydroethanolic extract (HE) shown a good anti-inflammatory activity via strong inhibition of NO production (IC50=8.80 µg/mL) with non significative difference with that of baicalin (IC50=6.77 µg/mL) ; a good inhibition of BSA denaturation (IC50=205.9 µg/mL) ; and also an efficiency in inhibition of 5-lipoxygenase activity. Furthermore, the activities of acid phosphatase and alkaline phosphatase increased in the presence of HE (EC50=10.03 µg/mL and EC50=0.274 µg/mL respectively). Taken together, these results demonstrated that hydroethanolic and ethanolic stem extracts of C. variegatum have good antioxidant and anti-inflammatory potential which are complementary to the anti-amoebic activity of this medicinal plant. Therefore it can be used for the formulation of alternative medicines in order to reduce the oxidant and inflammatory status which occurred during amoebiasis.