In vitro antifungal, antibacterial activities and nutritional value of nine Cameroonian edible vegetables

The high medicinal potential of plants, including edible vegetables, is well documented. Vegetables can afford significant health benefits to consumers, depending on their medicinal properties and nutritional value. This study analysed the antimicrobial activity and nutrient contents of nine commonly consumed Cameroonian vegetables and spices for which such information is at present limited. The antimicrobial activity of the methanol extracts of the vegetables was evaluated by disc diffusion and microdilution methods against three tomato fungi and two pathogenic bacteria species. The inhibition zones against fungi ranged from 10-21 mm; Irvingia gabonensis and Apium graveolens showed the highest zones with dose-dependent activity against Fusarium solani and F. oxysporum. The inhibition zones against bacteria ranged from 8-12 mm with Allium porrum having the highest inhibition zone (12 mm). Irvingia gabonensis seeds had the lowest minimum inhibitory concentration (MIC) of 6.25 mg/mL against F. solani and also had the lowest MIC of 2 mg/mL against S. aureus. Proximate composition and mineral analysis were carried out on the most active antimicrobial vegetables, I. gabonensis seeds and A. graveolens. I. gabonensis seeds were rich in lipids (69.90 ±0.14%) while A. graveolens leaves were rich in protein (35.35 ±0.49%). For macro minerals, phosphorous had the highest concentration in I. gabonensis seeds (359.67 ±1.89 mg/100 g) and A. graveolens leaves (622.14 ±2.69 mg/100 g). Iron content was the highest of micro minerals in I. gabonensis seeds (276.51 ±1.41 mg/100 g) while zinc concentration was the highest in A. graveolens leaves (16.86 ±0.27 mg/100 g). This study has shown that three of the nine Cameroonian vegetables, I. gabonensis seeds, Apium graveolens and A. porrum, may potentially offer both antimicrobial and nutritional benefits to consumers. Consequently, further studies should be conducted to ascertain the effect of cooking and other factors in order to maximize these benefits.