Studies of Phyto-compounds with Antibacterial Properties from Stem Bark of Combretum lamprocarpum (Diels)

Abstract

Combretum lamprocarpum (C. lamprocarpum) stem bark was investigated in an attempt to identify chemical substances of medicinal value to enable scientific validation of the plant in the treatment of diseases caused by pathogenic microorganisms. The plant’s stem bark, after collection, identification, Air-drying and pulverization, was subjected to cold extraction with n-hexane, dichloromethane (DCM), ethyl acetate and methanol successively in that order. The extracts obtained were subjected to phytochemical screening, thin-layer chromatography (TLC) and antimicrobial studies using standard procedures. The preliminary phytochemical screening of the crude extracts revealed the presence of flavonoids, tannins, glycosides, steroids, triterpenoids, anthraquinones, and alkaloids. The TLC of the extracts showed eight, five, three and two prominent bands in the n-hexane, DCM, ethyl acetate and methanol extracts, respectively. The antimicrobial effects of the crude extracts were tested against eight microorganisms, namely: Methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, Streptococcus pyogenes, Corynebacterium ulcerans, Escherichia coli, Proteus vulgaris, Proteus mirabilis, and Pseudomonas aeruginosa. The antimicrobial studies indicated that the extracts possess significant activity against Methicillin-resistant Staphylococcus aureus, Corynebacterium ulcerans, Escherichia coli and Pseudomonas aeruginosa (with zones of inhibition ranging from 22mm to 28mm and MIC ranges: 2.5-40mg/ml). The presence of the phytochemical constituents with similar and/or distinct therapeutic activities, coupled with the result of the antibacterial assay, indicated that the plant stem bark could be used in the treatment of the ailments acclaimed in ethno-medicine.