ANTIMICROBIAL AND PHYTOCHEMICAL STUDIES ON EXTRACTS OF BUCHOLZIA CORIACEA SEEDS
G. A. Awemu,1 A.U.D. Aniekan,1 A.M. Odiegwu2, K.O. Adimabua,3
1 Department of Pharmaceutical and Medicinal Chemistry, Madonna University, Elele, Nigeria
2 Department of Nursing Science, Madonna University, Elele, Nigeria
3 Department of Public Health, Madonna University, Elele, Nigeria
The in vitro antimicrobial activity of crude methanol and aqueous extracts of the seeds of Bucholzia coriacea were investigated. The extracts exhibited antimicrobial activities against Escherichia coli, klebsiella pneumonia, Bacillus subtilis, Staphylococcus aureus, Salmonella typhii, Bacillus cereus and Pseudomonas aeruginosa. The minimum inhibitory concentration (MIC) of the ethanol extract was between 0.50 – 6.00 mgml-1 while the minimum bactericidal concentration ranged from 2.0 – 10.0. The methanol and water extracts exhibited antifungal activity against Candida albicans and Aspergillus niger with zones of inhibition of 7.50 and 2.80mm for Candida albicans; and 6.0 and 2.0 for Aspergillus niger. Phytochemical screening revealed the presence of tannins, saponins, terpenoids, cardiac glycosides and alkaloids in the ethanolic and water extracts. The ability of the ethanol extract of Bucholzia coriacea seeds to inhibit the growth of bacteria and fungi is an indication of its broad spectrum antimicrobial potential which justifies its utilization in traditional medicine in treatment of infections.
Antimicrobial agents are among the most commonly used and misused classes of drugs leading to the emergence of drug resistance fuelling an ever increasing need for new drugs ( Abdullahi et al, 2010; Chambers, 2006). To overcome the problem of antibiotic resistance, medicinal plants have been extensively studied as alternative treatments for infective diseases, as they inhibit the growth of pathogens or kill them and have no or least toxicity to host cells ( G. Sahgal et al, 2009).
Bucholzia coriacea belongs to the family Capparacea and is widely distributed in the rain forests of Ivory Coast, Cameroon, Liberia, Nigeria and Gabon (Ajaiyeoba et al, 2003). It is a medium sized evergreen tree or shrub with large, glossy, leathery leaves that are arranged spirally and clustered with conspicuous cream white flowers in racemates at the end of the branches. Its bark is smooth, dark brown or dark green while the slashes are deep red ( Dela Veau , et al, 1973). The seed is commonly called wonderful kola or elephant kola in Nigeria. The leaves and stem bark in various formulations exhibit anthelminthic, antimicrobial, antifungal and cytotoxic effects on microorganisms (Ajaiyeoba et al, 2003). Despite the various applications of the plant in ethnomedicine, very little scientific evaluation of the seed extracts have been carried out. The present study was therefore undertaken to evaluate the antimicrobial effects and phytochemical profile of the methanolic and aqueous extracts of Bucholzia coriacea seeds.
MATERIALS AND METHODS
PLANT MATERIAL AND EXTRACTION
Bucholzia coriacea pods were harvested in the forest at Elele, Rivers State of Nigeria and its identity authenticated by a taxonomist at the Department of Pharmacognosy, Faculty of Pharmacy, Madonna University, Elele, where a voucher specimen was deposited. The fresh seeds were removed from their pods, sliced into tiny particles to facilitate drying and shade dried for fourteen days. The dried seeds were pulverized using an electric mill. A 250 g of the powder was extracted by maceration in ethanol for forty eight hours. The extract was filtered using Whatman no. 1 filter paper and concentrated using a rotary evaporator. The resultant extract was stored in a refrigerator at 4oC. For the aqueous extract, 250 g of the powered seed was extracted through cold maceration with water as the solvent for forty eight hours. The resultant extract was concentrated with a rotary evaporator and stored in a refrigerator at 40C.