Survival and growth of escherichia coli and shigella spp in water treated with croton oligandrus hutch extracts. (euphorbiaceae): reduction of diarrhea diseases in yaoundé (center - cameroon)

Infectious diarrhea of bacterial aetiology are responsible for about 4 millions deaths each year. Conventional medicine use for its treatment, has been facing microbial resistance; thus requires the use of alternative therapeutic measures. This study seeks to estimate the antibacterial activities of the ethanolic and aqueous extracts of Croton oligandrus Hutch against two sensitive bacterial str ains (Escherichia coli and Shigella spp.), isolated from well water in Yaoundé, Cameroon. 300 g each of the powder, were separately extracted in 3L of water and ethanol for 48 hours; and the retrieved concentrate were subjected to qualitative phytochemical screening. The antibacterial activity were tested using the surface spread out and disk diffusion methods.
The phytochemical screening of both the aqeous and ethanolic extracts revealed in common saponosides, alkaloids, tannins and polyphenols, while cardiac glycosides, resins, flavonoids, catechic tannins, quinones and mucilages were present only in the ethanolic extract. The ethanolic and aqueous extracts at dose 2000 mg/mL, significantly inhibited (98.04-100%) Shigella spp. and E. coli. Complete inhibition of E. coli was observed at doses of 1000 and 2000 mg/mL, with the ethanolic extract. At, 3 hours, the lowest inhibition potential were observed for both extracts at dose 500 mg/mL, against E. coli and Shigella spp., strains. At doses 500-2000 mg/mL, the diameter of inhibition for Shigella spp. varied from 15-25 mm (very sensitive to extremely sensitive) for the ethanolic extract and 10-16 mm (very sensitive to extremely sensitive) for the aqueous extract. At the same doses, the diameter of inhibition for E. coli, varied from 16-21 for the aqueous extract and 10-23 for the ethanolic extract.
All the studied microorganisms were sensible to the different extracts with the ethanolic extract demonstrating greater anti-diarrheal activity on both strains compared to the aqueous extract.