PHYTOCHEMICAL SCREENING AND ANTIMICROBIAL ACTIVITY OF THUJA OCCIDENTALIS SEEDS EXTRACTS AGAINST THE ISOLATED COMMON SKIN INFECTING MICROORGANISMS

摘要

Objective: This study represents the first attempt to investigate the antimicrobial activity of Thuja occidentalis seeds extracts against the isolated skin infecting microorganisms. Methods: T. occidentalis seeds were powdered and extracted continuously by Soxhlet apparatus using 96% ethanol to obtain the total crude ethanolic extract. The extracts with increasing polarity were successively prepared with petroleum ether, chloroform, ethyl acetate, and methanol using the Soxhlet apparatus. The extracts were screened for their phytochemical constituents. Their antimicrobial activity against standards microorganism and the isolated skin infecting microorganisms was evaluated using the agar diffusion method. Results: The result revealed the presence of flavonoids, alkaloids, terpenoids, tannins and cardiac glycosides. The antimicrobial activity result showed that Escherichia coli , Pseudomonas aeroginosa , Staphylococcus aureus , Bacillus subtilis and Candida albicans were found to be sensitive to the extracts of T. occidentalis seeds with inhibition zones range between 20±0.57-12±1.25 mm. The isolated skin infecting microorganisms; Staphylococcus aureus and Staphylococcus epidermidis were found to be highly susceptible to the extracts of T. occidentalis seeds with inhibition zones of 28±1.02-22±0.45 mm and minimum inhibitory concentration (MIC) values of 6.25 mg/ml. Conclusion: From the results it concludes, T. occidentalis seeds extracts had a considerable level of antimicrobial activity. They are more effective towards gram-positive than gram-negative bacteria. Hence, the active principles present in the extracts are particularly powerful effective against the skin infected isolated bacteria. In conclusion, there is a proportional increasing in the antimicrobial activity with increase of the solvents polarity. This may attribute to the fact that the chemical constituents responsible for the antimicrobial activity are of high polarity, such as tannins.