ASSESSEMENT OF ANTIBACTERIAL ACTIVITIES OF FRUIT EXTRACT OF AFRAMOMUM MELEGUETA (SCHUMANN) ON SELECTED BACTERIAL PATHOGENS ISOLATED FROM INFECTED WOUNDS

Abstract

An infected wound is a localized defect or excavation of the skin or underlying soft tissue in which pathogenic organisms have invaded into viable tissue surrounding the wound. This work is aimed at assessing the in-vitro and in-vivo antibacterial activities of Ethanol (Polar) and N-hexane (Non-Polar) fruits extracts of Aframomum melegueta on selected bacterial pathogens isolated from wounds. Agar disc diffusion method was used for the antibiotics susceptibility screening, while agar well diffusion method was used for the in-vitro susceptibility screening of the plant extracts. The antibacterial activities of the extracts were tested against the isolated bacteria at 100 mg/ml, 200 mg/ml, 300 mg/ml and 400 mg/ml concentrations. The in-vivo susceptibility screening was carried out using standard method on albino rats. A total of 225 wound samples were collected from patients attending State Specialist Hospital, Akure, Ondo State. A total of 152 bacteria which include Proteus vulgaris, Pseudomonas aeruginosa, Klebsiella pneumonia and Escherichia coli were isolated from wound samples. S. aureus had the highest occurrence rate of 33.6% while P. vulgaris had the lowest occurrence rate of 7.2%. The Phytochemical evaluation of the fruit extracts of A. melegueta showed the presence of saponin, flavonoids, alkaloids and tannins in both Ethanol and N-hexane fruit extract. The in-vitro susceptibility test showed that S. aureus, E. coli and P. aeruginosa were sensitive to ethanol extract at 100 mg/ml. S. aureus showed the highest zone of inhibition of 16.22±0.02 mm, while all the other bacterial isolates were resistant at concentration of 100 mg/ml. All the bacteria isolates were resistant to the N-hexane extract at concentration of 100 mg/ml except S. aureus showing a zone of inhibition of 10.03±0.03 mm. The bacterial isolates were all sensitive to both Ethanol and N-hexane extracts at concentration 400 mg/ml except P. vulgaris which was only sensitive to Ethanol extract at concentration 400 mg/ml (6.24+0.03 mm) and resistant to N-hexane extract at all concentrations. The minimum inhibitory concentrations (MIC) ranged from 50mg/ml – 400mg/ml for ethanol extract and 100mg/ml – 300mg/ml for N-hexane extract. The minimum bactericidal concentration (MBC) ranged from 200mg/ml – 400mg/ml for Ethanol extract and 300mg/ml – 400mg/ml for N-hexane extract. The histopathological and hematological analysis showed that the fruit extracts of Aframomum melegueta had no toxicological effect on the experimental rats. Hematological parameter of the rats treated with the extracts showed an increase in the packed cell volume (PCV) (39.00±2.00c) and a decrease in the white blood cell (WBC) (10.70±1.20b) compared to the untreated mice with a PCV of 33.00±2.00b and WBC of 19.57±2.10b Histopathological analysis of the treated rat showed a normal architecture of the liver and kidney. This research has established that A. melegueta has antibacterial activities due to its high content of phytonutrients such as alkaloids, flavonoids and bioactive compounds such as caryophellene, n-Decanoic acid e.t.c.