The Effects of Methanolic Pith and Peel Extracts of Citrus Paradisi (grapefruit) on Some Bacterial Pathogens

Medicinal plants are the natural resources in developing drugs. The recent increase in antibiotic resistance has led to technical advancements which includes the use of natural products from medicinal plants in the treatment of bacteria and bacterial-related infections. Citrus paradisi was used in this study. The methanol extracts of the Citrus paradisi pith and peel were evaluated for their antibacterial activities against seven bacterial isolates using agar well diffusion method, the activities of some conventional antibiotics were also examined. The powdered fruit parts (pith and peel) were extracted using Soxhlet extraction method. The phytochemical analysis report revealed that the methanol extracts of both the pith and the peel of Citrus paradisi are very rich in akaloids, terpenoids, phenol, glycoside, tannin and flavonoids. The methanol extracts of Citrus paradisi pith and peel were also examined for their antibacterial activities against the test organisms. The pith extract had a higher antibacterial activity in comparison with the peel extract. The antibacterial activities of both extracts were higher on the Gram negative bacteria than the Gram positive bacteria. The highest mean inhibition zone diameter was recorded at 100mg/ml against Pseudomonas aeruginosa (31mm) and Staphylococcus aureus (29.5mm) using pith extract of Citrus paradisi. There was a significant difference in mean zone diameters of Citrus paradisi pith extract among the bacteria tested (p