Ethnobotany and Antimicrobial Activity of the Selected Medicinal Plants Used for the Management of Microbial Infections in Pemba Island, Tanzania.

Abstract

Introduction: Microbial infections are among the most life-threatening factors worldwide, killing millions of people annually. The high number of deaths is partly due to the antimicrobial resistance of some microbes to available antimicrobial agents on the market. On the other hand, local communities have used medicinal plants to manage microbial-related infections for a long time, but most of these plants are not well documented or even evaluated. This study aims to contribute to the documentation and evaluation of medicinal plants reported to be used for microbial infection management. The data recorded may be used for further research in the discovery of new antimicrobial agents, thereby saving the lives of people in the future.

Methodology: An ethnobotanical survey was conducted to collect data from 42 local informants through semi-structured interviews in Pemba Island. The plants with higher fidelity levels were selected for antimicrobial assays whereby disc diffusion and microdilution methods were used.

Results:  A total of 117 plants belonging to 48 families were reported for use in the management of microbial infection conditions. Fever scored the highest Informant consensus factor (ICF) of 0.76 showing a high degree of agreement on the potential plants used for fever. Azadirachta indica scored the highest Fidelity Level (FL) of 100% for fever showing the potentiality of the particular plant species. This study evaluated plant species commonly used for the management of microbial infections in vitro for antimicrobial activity against bacteria and fungi strains. Results obtained show that the zones of inhibition for the active plant species ranged between 9.5mm and 18mm. The MICs of the active plant species ranged from 0.625mg/mL to 2.5mg/mL.

Conclusion:  The findings show that most of the medicinal plant species used by the Pemba community have notable activity against S. aureus, E. coli, and K. Pneumoniae which are human pathogens.