ABSTRACT Medicinal plant essential oils (lemon grass, cumin, chamomile, green tea, peppermint, thyme and wheat germ) were evaluated to their efficiency as nature preservatives on microbiological quality of cosmetic products. Antibacterial activity of the tested medicinal plant oils against pathogenic bacteria namely Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Salmonella spp. isolated from the tested cosmetic samples were studied. All the tested medicinal plant oils, except green tea and wheat germ oils, had broad spectrum of antibacterial activity against all tested pathogenic bacteria . The maximum antibacterial activity was observed with lemon grass oil compared to oils, which gave 30 mm inhibition zone followed by cumin, peppermint, chamomile and thyme oils. The effect of medicinal plant oil additions (0.25, 0.5 and 1.0 mg/ml) to cosmetic samples against microbial contamination of cosmetic samples was studied. Separately additions of all the tested medicinal plants oils (0.25%) to the tested cosmetic samples caused a dramatic decreases in total microbial counts. Pathogenic bacteria not detected after the incubation periods at 37±2 °C. In addition, the rate of microbial count decreasing was influenced by the type and concentration of tested medicinal plant oil. Lemon grass, cumin and peppermint oils were the most efficient medicinal plant oils against microbial contamination. Results showed that using of tested medicinal plants oils (Lemon grass cumin, peppermint, chamomile and thyme) as natural preservatives markedly contributed in decreasing of microbial contamination of cosmetic products, instead of chemosynthetic preservatives which have harmful side effects on human body. |
