Antimicrobial And Antioxidant Activities Of Some Nigerian Medicinal Plants

Abstract

Ten Nigerian plants suggested from their ethnomedical uses to possess antimicrobial and antioxidant activities were studied for their anti-microbial and anti-oxidant properties. Antimicrobial activity was tested against Escherichia coli NCTC 10418, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Candida albicans, Candida pseudotropicalis and Trichophyton rubrum (clinical isolate). Trichilia heudelotti leaf extract showed both antibacterial and antifungal activities and was the most active against all the strains of bacteria tested. Boerhavia diffusa, Markhamia tomentosa and T. heudelotti leaf extracts inhibited the gram negative bacteria E.coli and P. aeruginosa strains whereas those of M. tomentosa, T. heudelotti and Sphenoceutrum jollyamum root inhibited at least one of the fungi tested. At a concentration of 312 µg/ml, hexane and chloroform fractions of T. heudelotti extract inhibited 6 and 14% of the fifty mult-idrug resistant bacteria isolates from clinical infectins, respectively. At ≤ 5mg/ml, the CHCl 3 (64%) and aqueous (22%) fractions of T. heudelotti and those of CHCl 3 (34%) and EtOAC (48%) of M. tomentosa gave the highest inhibition that was stronger than their corresponding methanol extracts. The corresponding EC 50 of the extracts on M. acuminata, T. heudelotti, E. senegalensis and M. tomentosa were 4.00, 6.50, 13.33, and 16.50 ig/ml using the TLC staining and 1,1-dipheyl-2-picry-hydrazyl (DPPH) free radical scavenging assay. Therefore, leaf extracts of M. tomentosa and T. heudelotti, especially the latter, possess strong antimicrobial and antioxidant activities and should be further investigated. These activities justified the ethnomedical uses of these plants.

Phytochemical and antimicrobial studies of four species of <i>Cola</i> Schott & Endl. (Sterculiaceae)

“…An important occurrence is that none of the extracts was effective against Staphylococcus aureus. This is in contrast to the observations in some other studies where the tested plants were more active against Grampositive bacteria (Aladesanmi et al, 2007;Ajaiyeoba and Fadare, 2006;Isu, 2005;Onocha et al, 2003). Generally, the antifungal activities of the extracts as reported in the results were stronger and more pronounced than the antibacterial activities.…”

Antifungal and antibacterial activities of different extracts ofHarungana madagascariensisstem bark

“…In a recent study of microbes' susceptibility tests, it was indicated that the susceptibility profile of synthetic and common antibiotics on most of the microbes tested in this study showed a very high level of antibiotic resistance by the clinical and environmental microbes (Aladesanmi et al, 2007). There was a high level of antibiotic resistance to the commonly used antibiotics such as penicillin V (100%), cephalothin (98%), tetracycline (82%), and amoxicillin + potassium clavulanate-(Augmentin ® ) (77%).…”

In Vitro Anthelmintic Efficacy of Fractions from Plumbago zeylanica L (Family- Plumbaginnaceae) Root Extract

“…Root powder of Plumbago zeylanica (238g) was also extracted by maceration in 1.5 liters of ethanol for three day on an electrical shaker (shake speed 220 at room temprature). Both the extracts were filtered using What man No1 filter paper and the filtrate was concentrated by rotary evaporator at room temperature and further with vacuum pump [18,23,24].…”