Anti-Shigellosis Activity of<i>Cola anomala</i>Water/Ethanol Pods Extract on<i>Shigella flexneri-</i>Induced Diarrhea in Rats

Abstract

This study was undertaken to evaluate the activities of water/ethanol <i>Cola anomala</i> pods extract. <i>In vitro</i> antimicrobial susceptibility was determined by the disk diffusion method; the minimum inhibitory concentration and minimum bactericidal concentration were determined by agar dilution technique. <i>In vivo</i>, shigellosis was induced in healthy Wistar albino rats by oral administration of <i>Shigella flexneri</i> inoculum, 12 × 10⁸ CFU/mL. At the onset of diarrhea, infected and normal control animals were subdivided into various groups treated with distilled water, with water/ethanol <i>Cola anomala</i> pods extract at 25, 50, or 100 mg/kg, or with ciprofloxacin, 2.5 mg/kg. After one-week treatment, rats were sacrificed, and blood and colon were collected. Blood was used for blood cell count. A portion of the colon served for histological studies while homogenate from the remaining part was centrifuged and the supernatant was collected for the determination of NO, PGE₂, IL-1<i>β</i>, and TNF-<i>α</i> levels. <i>In vitro</i>, water/ethanol <i>Cola anomala</i> pods extract showed to be bactericidal, with a minimum inhibitory concentration of 2.0 mg/mL and a minimum bactericidal concentration of 3.0 mg/mL. In diarrheic rats, the extract significantly (<i>P</i> < 0.01) increased the white blood cells and significantly (<i>P</i> < 0.01) decreased stool <i>Shigella</i> density from the first to the seventh day of treatment. It partially restored the structure of eroded intestine epithelium and prevented weight loss; the dose dependently and significantly (<i>P</i> < 0.001) decreased NO, IL-1<i>β</i>, and TNF-<i>α</i> production in the colon and was found to have no significant effect on PGE₂ production. These results support the use of this plant in traditional medicine in the treatment of gastrointestinal ailments.