Wetungu Martin W., Matasyoh, J. C, Kinyanjui, T
The plant Tarchonanthus camphoratus belongs to the Asteraceae family. Its common name is wild sage or camphor bush. It is widely distributed, but has similar medicinal use throughout its range. It is taken orally or applied externally to relieve bronchitis, asthma, headache, inflammation, chilblains or abdominal pains. The aim of the study was to assess the antimicrobial activity of the extracts from the leaves of this plant. A powdered sample of the leaves weighing 500 g was sequentially extracted with hexane (1.5 L), dichloromethane (1.5 L) and methanol (3 x 1.5 L). The methanolic extract was partitioned between equal volumes (250 ml each) of distilled water and n-butanol. The n-butanol fraction was concentrated under reduced pressure followed by addition of diethyl ether, precipitating 20 g of a dry crude extract. The extract was successively fractionated using hexane, dichloromethane, chloroform, ethyl acetate, acetone, ethanol and methanol yielding 1.6 g, 1.4 g, 1.6 g, 7.0 g, and 1.4 g, 2 g and 4 g respectively of samples soluble in each solvent. Phytochemical tests revealed the presence of terpenoids in hexane, dichloromethane, and chloroform fractions. Ethyl acetate fraction contained terpenoids and phenolics. Tannins, phenolics and flavonoids were present in the acetone and ethanol fractions while tannins, phenolics and saponins were present in the methanol fraction. Antimicrobial activity tests of the extracts soluble in various solvents were then performed on Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, Salmonella typhi, Candida albicans and Bacillus spp. Ethyl acetate fraction was active against E. coli, P. mirabilis, K. pneumoniae, S. typhi, and Bacillus spp while the methanol fraction was active against E. coli, K. pneumoniae, S. typhi, and Bacillus spp. Minimum Inhibitory Concentration of Ethyl acetate fraction was 80 mg/ml, 67 mg/ml, 57 mg/ml and 200 mg/ml for E. coli, P. mirabilis, Bacillus spp and S. typhi respectively. The inhibitory bioactivity against a variety of bacteria validates the traditional usage of the plant as a remedy for various conditions.
Wetungu Martin W., Matasyoh, J. C, Kinyanjui, T. Antimicrobial activity of solvent extracts from the leaves of Tarchonanthus camphoratus (Asteraceae). J Pharmacogn Phytochem 2014;3(1):123-127.