Abstract

COMPARATIVE STUDY OF COMMON ANTIBIOTICS AND SOME NIGERIAN MEDICINAL PLANTS FOR ANTIBACTERIAL ACTIVITY

¹Adonu Cyril C*, ¹ Eze Chinelo C , ¹Ugwueze Mercy E and ²Ugwu Kenneth O

ABSTRACT

The antibacterial activities of methanol leaf extracts of Psidium guajava, Carica papaya, Vernonia amygdalina ,Indigofera tinctora, Rauwolfia vomitoria, Myrianthus arboreus, Pterocarpus soyaauxii and Persea americana were compared with those of common antibiotics. The pulverized leaves of all the plants were extracted with methanol in a Soxhlet apparatus. The extracts were concentrated and evaporated to dryness using rotary evaporator at an optimum temperature of between 40 and 45ᵒC to avoid denaturation of the active ingredients. Antimicrobial screening of these extracts and multidisc antibiotics was carried out using agar diffusion techniques and antibiograms of all the clinical isolates were prepared and used for comparison. The extracts from Rauwolfia vomitoria, Myrianthus arboreus, and Persea americana had no activity against the test bacteria. At potency of 1000 microgramme, the extracts from Psidium guajava, Carica papaya, Vernonia amygdalina and ,Indigofera tinctora produced inhibition zone diameters(IZDs) greater than a good number of the antibiotics. These active plants could serve as a promising source of future antimicrobials to ameliorate the damaging effects of infections caused by resistant bacteria.

Keywords: Antibacterial activity, Antibiotics, Antibiogram, Medicinal plants, Psidium guajava, Carica papaya.,