Diarrhea is one of the leading causes of morbidity and mortality among children under the age of five years in the developing world. Opportunistic bacteria have been identified as the major cause of diarrhea in HIV infected patients. Treatment of these emerging and re-emerging strains of diarrhea causing bacteria has become difficult due to their increased tolerant to the present available antibiotics. There is need to identify and develop alternative drugs, which are effective, affordable and easily accessible to diarrhea patients. However, there is no record in the literature of the antibacterial activity of these plants. The objective of this study was to enhance understanding of the efficacy of ethno-medical materials in the management of diarrhea. Antibacterial activity was evaluated by determination of Minimum Inhibition Concentration and the Minimum Bactericidal Concentration of the plant extracts against the diarrhea causing bacterial. Phytochemical screening for bioactive compounds was undertaken using standard qualitative methods. Maytenus putterlickoides (roots) and Senna spectabilis (leaves) were active against Salmonela typhi, Shigella flexineriae and Shigella Dysenteriae with zone of inhibition ranging 9.2-15.8 mm. Olinia usambarensis (leaves) had antimicrobial activity against several bacterial isolates with zone of inhibition ranging 9-15 mm. Alkaloids, tannins, anthrocyanins, triterpenes and steroids, saponins, flavanoids, coumarins and reducing sugars were present in the three plant extracts. These phytochemicals account for the antibacterial activity of the extracts against the bacterial strains.

Plant products are used as the primary health care in developing countries due to their availability and affordability compared to conventional methods. It is estimated that more than 80% of the world's population use herbal preparations in the management and treatment of diseases. Herbal products are now readily available in supermarkets and drug stores. The therapeutic value of these herbal products is believed to be due to the presence of bioactive elements present in the plant parts. Toxicity studies should, however be carried to ascertain the safety of the herbal preparation. In this study, safety studies were carried out through biochemical assays, histopathology and hematological tests. The plant extracts led to changes in body weight, hematological and histopathological changes like increase in lymphocyte number. High dose of orally administered Olinia usambarensis also caused microcytic hypochromic anemia. Senna spectabilis and Olinia usambarensis revealed intense infiltration of inflammatory cells causing necrosis and loss of cellular details of the kidney. This study will enhance understanding of the safety of ethno-medical materials in the management of diarrhea caused by bacterial pathogens.