Phytochemical Screening and Antimicrobial Properties of Carissa edulis Extracts Obtained from Kaimosi Forest, Vihiga County, Kenya

Medicinal plants still play an important role in human and animal healthcare. About 60% of the world’s population and 80% of Africa’s population depend on herbal medicine for their primary healthcare. In Vihiga county Kenya, C. edulis has been reported to manage several human disease conditions such as epilepsy, headache, toothache, cough, chest complaints, sickle cell anemia, gonorrhea, syphilis and rabies among others. Its therapeutic efficacy is attributed to numerous phytochemicals present in its extracts. In this study, a phytochemical analysis was carried out in the roots, leaves and bark extracts, antimicrobial effects on Escherichia coli and staphylococcus aureus laboratory cultures determined. The extracts were modified by grinding and ethanol used as solvent in the extraction. Different concentrations of 25%, 50%, 75% and 100% of plant extracts were used in the analysis and sterile distilled water used as the control. Data on zone growth inhibition was subjected to analysis of variance and the means were separated and compared using least significant differences at p≤ 0.05 by use of SAS statistical package. The results showed the presence of an array of phytochemicals in the leaves, bark and roots of the plant. The bark for example tested positive for tannins, saponins, flavanoids, terpenoids, glycosides and sterols while the leaves and roots tested negative for saponins and flavanoids respectively. The leaves exhibited the greatest inhibition against Escherichia coli with a mean diameter of 7.57mm and all the three parts exhibited a significant difference. The different concentrations also showed that inhibition increased with increase in concentration. The mean inhibition diameter at 100% was 8.96 while at 25% it was 7.21.