Calendula officinalis Protection Against Cytotoxicity Effects of Personal Care Products on HaCaT Human Skin Cells

Abstract

Background: Human skin is normally exposed to ionizing and UV radiations and on occasions it may also be subjected to beauty products or drugs that the host uses; all of which can generate reactive oxygen species (ROS). Objective: In this study, Calendula officinalis extract, which contains antioxidant compounds, was examined for its protective effects against the products that generate ROS- induced cytotoxic activity towards human skin cells. Methodology: The protection against cytotoxicity by Calendula officinalis extract was investigated in vitro using a dose-response on HaCaT human skin cells. The proprietary aqueous calendula extract C from biodynamically grown plant was examined. Protection against cytotoxicity was measured via the methyl tetrazolium cytotoxicity (MTT) assay. Cells were exposed to the calendula extracts for 48h before being exposed to personal care products consisting of two head lice treatments -Lice Breaker (Permethrin 1% w/w) and Organix Pyrethrum treatment (4 g/L Pyrethrins, 16 g/LPiperonyl Butoxide) and two beauty products -Nivea Visage Q10 plus Anti-Wrinkle face moisturizer + TiO2; and Nivea Visage Q10 Plus Anti-Wrinkle face moisturizer (without TiO2) for 1h. Results: The effect of different concentrations of calendula extract on HaCaT human skin cells in vitro was explored. Doses of 1% (v/v) [1.4 mg dry weight equiv/ml] or less showed no toxicity. Cells were also exposed to the calendula extract for 48 hours before being exposed to the four personal care products for 1h. using the MTT cytotoxicity assay; it was observed that extract of Calendula officinalis gave time-dependent and concentrationdependent protection against harmful products that induce cell killing. Pre-incubation with the calendula extract for 48 hours significantly increased survival relative to the population without the extract by 30% and 47.4%, respectively, following treatment with personal care products. Conclusion: This study demonstrates that calendula extract contains bioactive and free radical scavenging compounds that significantly protect against personal care products that generate oxidative stress cytotoxicity in a human skin cell culture model.