Antioxidant and Antibacterial Activities of the Essential Oils of Synedrella nodiflora, Mikania cordata and Melanthera scandensthree Plants of the Ivorian Flora

Aims: The objective of this work is to contribute to the valorization of medicinal and aromatic plants of the Ivorian flora. We propose to evaluate the antioxidant and antibacterial activities of the essential oil (EO) of three species used in traditional medicine.

Study Design: Valorization of aromatic and medicinal plants and essential oil.

Methodology: The antioxidant potential of the extracts was evaluated using the Blois method. The antibacterial activity of the different oils at different concentrations was determined for each bacterial strain, by the technique of macro-dilution in solid medium (diffusion in wells).The minimum inhibitory concentration (MIC) and The Minimum Bactericidal Concentration (MBC) were determined. MBC / MIC ratios were calculated. When this ratio is less than 4, the extract is considered to be bactericidal. When it is 4, the extract is considered bacteriostatic.

Results: The antioxidant activity has pointed out the poor antioxidant power of the essential oil(EO) extracted. The EC50 values vary from 15 µg/mL to 32 µg/mg. The antibacterial tests have shown that the samples exert an inhibitory effect on Gram (+) bacteria. The diameters of the inhibition zones vary between 14 and 25 mm for the extracts against 35 mm for the gentamycin. The MBC/MIC is 2 for the gentamycin and 4 for all the EO combined versus the resistant S. aureus methicillin. Therefore, the essential oil has shown a bacteriostatic effect on this strain. As far as S. aureus CIP 483 is concerned, the MBC/MIC has given 1 for the gentamycin, 2 for M. scandens. The EO extract of M. scandens has a bactericidal action against this bacteria strain.

Conclusion: All the essential oils have less antioxidant activity than that of vitamin C.

The antibacterial activity of EO has given satisfactory results on all Gram (+) bacteria. Melanthera scandens Essential Oil shows antibacterial potential against Staphylococcus aureus CIP 483.