Activités antibactériennes des combinaisons d’Extraits Bruts et des Fractions Actives de Dissotis multiflora Triana (Melastomataceae) et Paullinia Pinnata (Sapindaceae).

Abstract

Dissotis multiflora Triana (Mélastomaceae) and Paullinia pinnata(Sapindaceae) are two medicinal plants used in the West Region of Cameroon for the treatment of infectious diseases without scientific support. This work was undertaken to the evaluate the antibacterial activity for the combination of the ethanolic extract and the actives fractions of leaves of Dissotis multiflora and Paullinia pinnata on six pathogenic bacterial strains among which were five in Gram-negative bacteria (Escherichia coli, Salmonella typhi, Klebsiella pneumoniae, Shigella flexneri and Proteus mirabilis) and one Gram positive (Bacillus cereus).A phytochemical screening was per formed according to the standard methods. The well-variant of the diffusion test and microdilution assay were used for the evaluation of antibacterial activities. Qualitative phytochemical analysis reveals the presence of alkaloids, polyphenols, saponins, alcaloïdes, anthraquinones, anthocyanes, tanins and steroids. The susceptibility test on solid medium the two crude extractshave inhibit all the strains with the diameter ranged from 8.33 ± 1.24 (K. pneumonia) ranged to13.67 ± 1.64 mm (S. typhi) from P. pinnata and10.33 ± 1.2 (K. Pneumoniae) ranged to21.5 ± 0.4 mm (S. typhi) from D. multIflora. Furthrmore the active fractions show that the CMI ranged to (48 μg/ml) from S. typhiand(390, 62 μg/ml) from P. mirabilis respectively from the fractions F1A/M (7/3) and F1A/M (3/7) for D. multiflora.So the CMI ranged to 97 (B. cereus)from 390,62 μg/ml (E. coli, S. flexneri, S. typhi and P. mirabilis)F2A/M (7/3) to P.pinnata. About the combinations of the two crude extracts the combination 5:5 and 6:4 have presented synergic effect on E. coli and B. cereus so an indifferent effect has noted to P. mirabilis and S. typhi with an antagonism on K. Pneumoniae and S. flexneri. About the fractions the combination6:4 from thefractions F1A/M (7/3) / F2A/M (7/3) the D. multiflora and P. pinnata have presented a synergic on all the strains tested in exception ofS. typhi where had noted an indifferent effect so that the combinations F1A/M (3/7) and F2A/M (7/3) the D. multiflora and P. pinnata have an antagonist effecton B. cereus, an synergic effect on P. mirabilis and indifferent effect on S. flexneri. In exception,the combinations 4 :6 and 8 :2 all of another have presented an synergic effect on K. Pneumoniae. These results confirm the traditional utilisation from these plants in the treatment of the infectious diseases.