Achyrocline satureioides Hydroalcoholic Extract as a Hypoallergenic Antimicrobial Substitute of Natural Origin for Commonly Used Preservatives in Cosmetic Emulsions.

Achyrocline satureioides is a South American herb used in traditional medicine to treat a wide range of ailments. The healing and antimicrobial effects of this plant have already been covered by many studies, which have confirmed its beneficial effects on human health. In this study, the antimicrobial effect of A. satureioides hydroalcoholic extract against Escherichia coli ATCC10536, Staphylococcus aureus ATCC25923, Staphylococcus epidermidis ATCC12228 and Lactobacillus acidophilus INCQS00076 was determined. The cytotoxicity of the extract was tested on human HaCaT keratinocytes showing very favourable effects on the proliferation and renewal of keratinocytes. According to the results of the HPLC and GC-MS analyses, the lyophilized extract contained only a minimal amount of fragrance allergens. The extract was then used in two cosmetic formulations, and one of them showed a significant synergistic interaction with other cosmetic components. We suggest the use of A.satureioides hydroalcoholic extract as a suitable antimicrobial component of natural origin for cosmetic preparations as a substitute for commonly used preservatives that can cause skin irritation and as a material with its own biological activity.