Phytochemical Screening, Determination of Total Phenolic Content and Antimicrobial Activities of Leaf Extracts of Foeniculum Vulgare (Wollago).

Abstract

Foeniculum vulgare (Mill.) is a weed of cultivated or disturbed grounds, common in grassland areas of Ethiopia. Foeniculum vulgare, known by local name “wollago” has a long history of herbal uses as both food and medicine in Jimma Oromo society, Oromia regional state, Ethiopia. The main objective of this study was to investigate phytochemicals, total phenolic content and antimicrobial activities of Foeniculum vulgare leaf extract. The extraction was done by maceration method. The obtained result was 57.93 ± 0.67, 46.56 ± 0.56, 41.79 ± 1.33, 17.59 ± 0.26% for methanol, acetone, chloroform and petroleum ether extracts respectively. Qualitative analysis disclosed the presence of alkaloids, terpenoids and phenols. TPC was determined using Folin Ciocalteu method. The maximum absorption wavelength (765 nm) and contact time between the extracts or standard and the reagent (30 – 45 min) were experimentally justified and used. The determined total phenolic content was 107.37 ± 0.24, 60.27 ± 0.12, 31.63 ± 0.08 and 20.10 ± 0.63 mg/g of the dry weight of extract expressed as gallic acid equivalents for methanol, acetone, chloroform and petroleum ether extracts respectively. The antimicrobial activities of petroleum ether, acetone, chloroform and methanol extract of plant leaf of Foeniculum vulgare against pathogenic bacteria and Candida albicans were investigated. The results of antibacterial activity of Foeniculum vulgare carried out by disc diffusion method with concentration of 37.5, 75 and 150 mg/mL. The results showed that the highest concentration of methanol, acetone, chloroform and petroleum ether extract (150 mg/ml) had maximum effect on Staphylococcus aureus (Gram positive) with a diameter of inhibition zone 19.6 ± 0.47, 16.5 ± 0.5, 11.25 ± 0.85 and 14.2 ± 0.99 mm respectively. The lowest concentration of methanol, acetone, chloroform and petroleum ether extract (37.5 and 75 mg/mL) showed significant effect on the Bacillus cereus, Staphylococcus aureus, Streptococcus pyogen but no inhibition zone was observed against E. coli. The highest concentration (150 mg/mL) of methanol, acetone, chloroform and petroleum ether extract against C. albicans with inhibition zone 16.07 ± 1.1, 13.3 ± 0.6, 11.5 ± 0.34, 15.25 ± 0.5 mm respectively. The current study supports the claims of use of Foeniculum vulgare leaf as traditional medicine for the treatment of infectious diseases caused by bacterial and fungal pathogens.