Antimicrobial Activities of African Medicinal Spices and Vegetables

This chapter reports the antimicrobial potential of spices and vegetable found in Africa. Herein, methods used for antimicrobial screening are critically reviewed. The main classes of plant antimicrobials as well as the preliminary phytochemical screening methods of secondary metabolites are compiled. Herein, we have also reviewed and discussed the cutoff points to define the significance of antimicrobial agents. In addition, we proposed new threshold values for extracts from edible parts of plants as follows: highly active extracts [minimal inhibitory concentration (MIC) below 100 μg/mL], significantly active (100 ≤ MIC ≤ 512 μg/mL), moderately active (512 2048 μg/mL), and not active (MIC > 10 mg/mL). On this basis, we have reported the antimicrobial potency of African medicinal spices and vegetables belonging to Annonaceae, Apiaceae, Brassicaceae, Gnetaceae, Lamiaceae, Liliaceae, Moraceae, Pedaliaceae, Piperaceae, Solanaceae, Tiliaceae, Rutaceae, Zingiberaceae, etc. The role of some African spices and vegetable as antibiotic-potentiating agents was also discussed as well as their ability to fight bacterial multidrug resistance.