ABSTRACT
Effect of sodium chloride extract of Dacryodes edulis (African pear) and Chrysophyllum albidum (African star apple) seeds on enteric pathogens (Escherichia coli (ATCC25922); Salmonella typhi (clinical strain); Klebsiella pneumoniae (clinical strain); Pseudomonas spp. (ATCC4853); Enterococcus faecalis (ATCC29212) and Staphylococcus aureus (ATCC25923) were investigated using agar well diffusion and micro broth dilution methods. Results revealed that the extracts have antimicrobial activity against the test organisms. In agar well diffusion method, the extracts were most effective at concentration 100 mg/ml as inhibition zone diameter (IZD) values ranges from 16.5 mm to 23 mm for African pear seed extract and 16.5 mm to 21.9 mm for African star apple seed extract. In the broth dilution method, the extracts were bacteriostatic at lower concentration and bactericidal at higher concentration against all test organisms. Sodium chloride extract of African pear seed shows minimum inhibitory concentration (MIC) values ranges from 1.5625 mg/ml to 50 mg/ml and minimum bactericidal concentration (MBC) values ranges from 6.25 mg/ml to 50 mg/ml respectively while sodium chloride extract of African star apple seed shows MIC values ranges from 6.25 mg/ml to 50 mg/ml and MBC values ranges from 25 mg/ml to 100 mg/ml respectively. In liquid broth medium, sodium chloride extract of African pear seed exhibited the highest activity against Pseudomonas as the least MIC (1.5625 mg/ml) and MBC (6.25 mg/ml) were recorded against the test organism. It is concluded that the sodium chloride extract of African pear and African star apple seeds showed potential antimicrobial activity of MIC and MBC ≤ 100 mg/ml, thus they have antimicrobial activity against enteric pathogens. Hence, sodium chloride will be useful for extracting bioactive agents in African pear and African star apple seeds, thus this will help reduce the cost of extraction and incidence of intestinal diseases.
ABSTRACT
The aim of this work was to determine the chemical profile and assess in vitro the antibacterial activity of the leaves, resin and stem-barks of Dacryodes edulis. The essential oils were analyzed simultaneously by Gas Chromatography and Gas Chromatography coupled to Mass Spectrometry. Agar diffusion well and microdilution methods were used to assay the antibacterial activity. The resin essential oil contained p-cymene (30.32%), α-thujene (28.58%), α-phellandrene (27.14%) and β-phellandrene (10.16%) as the main components; the stem-barks essential oil had as abundant components p-cymene (35.14%), trans-carveol (22.60%), α-thujene (14.86%), β-phellandrene (8.65%) and β-elemene (5.22%). The leaves essential oil was distinct with elemol (29.22%), caryophyllene oxide (15.26%), trans-carveol (11.80%) and spathulenol (6.28%) as major components. The leaves essential oil was the most active with MIC and MBC value of 18.75 mg/mL on B. cereus; the most susceptible strain. The stem-barks essential oil had a MIC of 50 mg/mL and MBC of 100 mg/mL on all the strains meanwhile the resin essential oil had a bacteriostatic effect at 200 mg/mL. Based on these results, it emanates that the essential oils of D. edulis represent a potential source of antibacterial substances.