Antimicrobial activity of glycyrrhiza uralensis fischer and morus alba bark extract

The purpose of preservatives is to prevent microbial contamination in cosmetics. Parabens were believed that one of the most reliable forms of preservatives. Whether they have been the victim of media or not, the fear of parabens has been triggered among people. In order to meet the consumer’s growing desire to the natural cosmetic product, we screened natural preservatives and conducted an experiment of antimicrobial activity with Glycyrrhiza uralensis fischer extract, Morus alba bark extract and 1,2-hexanediol which is also classified as a humectant. MIC (minimum inhibitory concentration) tests were carried out. It showed that the MIC of Glycyrrhiza uralensis fischer extract against Escherichia coil., Pseudomonas aeruginosa., Staphylococcus aureus. were 2.5, 6, 10%, respectively. The MIC of Morus alba bark extract against Escherichia coil., Pseudomonas aeruginosa., Staphylococcus aureus. were 2, 5, 6%, respectively. Based on these results, we formulated an ample styled emulsion containing 3 natural ingredients such as 3% of 1,2-hexanediol, 10% of Glycyrrhiza uralensis fischer extract, and 5% of Morus alba bark extract. And a challenge test was followed. 99.9% killing of Escherichia coil., Pseudomonas aeruginosa. and Staphylococcus aureus. within 7 days was achieved. From this study, we concluded that the combined three natural ingredients system successfully inhibit the growth of the three microorganisms and could be used as a good alternative of cosmetic preservatives with natural claims.