Phytochemical investigation and anti-microbial activity of Clausena anisata (Willd), Hook

Clausena anisata belongs to the family Rutaceae, a shrub widely used in West Africa for the treatment of bacterial and fungal infections of the skin including boils, ringworm and eczema. The study was designed to evaluate the antimicrobial activity and phytochemical screening of ethanol leaf extract of C. anisata (CLE).

Antimicrobial activity of CLE was investigated using agar well diffusion and micro-dilution methods against four Gram-positive bacteria (Bacillus substilis NCTC 10073, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Bacillus thuringiensis ATCC 13838) and two Gram-negative bacteria (Pseudomonas aeruginosa ATCC 4853, Proteus vulgaris ATCC 4175) and a clinical isolate of Candida albicans.

CLE was active against all test organisms with minimum inhibitory concentration (MIC), range of 0.5 to 7.0 mg/mL against Gram-positive bacteria, 2.5 to 1.0 mg/mL against Gram-negative bacteria and 5.5mg/mL against C. albicans. The MICs of the methanol fraction of CLE were 0.6 mg to 5.0/mL and 1.0 to 3.0 mg/mL for Gram-positive and Gram-negative bacteria respectively. Chloroform fraction had MIC of 3.0 to 7.5 mg/mL and 2.0 to 6.5 mg/mL for Gram-positive and Gram-negative bacteria, respectively and petroleum ether fraction had 4.5 to 8.0 mg/mL for Gram-positive and Gram-negative bacteria. The CLE exhibited static action against all test organisms within a range of 0.5 to 22.0 mg/mL. Phytochemical screening of C. anisata revealed the presence of tannins, flavonoids, steroids, saponins, glycosides and alkaloids. HPLC finger-printing of the CLE and its fractions were determined.

These results may justify the medicinal uses of C. anisata for the treatment of microbial infections.