In vitro evaluation of the cytotoxicity and eye irritation potential of preservatives widely used in cosmetics

Abstract

The consumption of cosmetics has been increasing every year and is expected to reach $675 billion by 2020 at an estimated growth rate of 6.4% per year. Exposure to skin irritants is the major cause of non-immunological inflammation of the skin. Therefore, the safety evaluation of cosmetic preservatives should be increased. Thus, the present work aimed to evaluate the cytotoxicity as the viability endpoint and the eye irritation potential of preservatives used in cosmetics. Cytotoxicity assays were performed using MTT and NRU in human keratinocytes (HaCaT), human dermal fibroblasts, adult (HDFa), and human hepatoma cells (HepG2). The eye irritation potential was evaluated using the Hen's Egg Test-chorioallantoic membrane (HET-CAM). The evaluated preservatives were methylparaben (MP), propylparaben (PP), phenoxyethanol (PE), and a mixture of methylchloroisothiazolinone and methylisothiazolinone (CMI/MI). All preservatives showed cytotoxic potential within the permitted concentrations for use in cosmetic products. In the HET-CAM test, PE and CMI/MI, MP, and PP were classified as severe, moderate, and poor irritants, respectively. Our results indicate that proper safety evaluations are required to ensure the beneficial properties of preservatives on cosmetic products without exceeding exposure levels that would result in adverse health effects for consumers.

In Vitro Evaluation of Mangostanin as an Antimicrobial and Biocompatible Topical Antiseptic for Skin and Oral Tissues

“…These results are consistent with our previous study, which demonstrated the lack of the cytotoxicity effect of modified HA combined with MGTN on the 3D model of the gingival tissue equivalent (Munar-Bestard et al; Mangostanin hyaluronic acid hydrogel as an effective biocompatible alternative to chlorhexidine, 2023; manuscript submitted for publication). In addition, in the commercial 3D model of oral mucosa epithelium, the treatment with HA 0.05% MGTN gel showed low IL-1α levels, contrary to the positive control or to the gels containing CHX, thus showing excellent biocompatibility with tissues, as observed for the Betadine and Prontosan gels, whereas Crystalmina gel that contains 1% CHX exhibited a higher cytotoxicity, in concordance with the literature. − The lack of effect in cell viability induced by the positive control on the 3D model of human epidermis can be explained by the keratinized external layer of this tissue and/or to the relatively low SDS concentration used in this assay, evidencing the low sensibility of the 3D model of human epidermis tissue for MTT . In contrast, comparing the effects of HA with 0.05% MGTN with the commercial periodontal gels, we observed that the commercial periodontal gels containing 0.2% CHX exhibited a higher cytotoxicity in the 3D oral mucosa model, in line with CHX effects .…”

Microspheres Based on Blends of Chitosan Derivatives with Carrageenan as Vitamin Carriers in Cosmeceuticals

“…Cell-based testing systems have a few advantages over other methods for the validation of efficacy because they are cost-effective, adaptable for high throughputs, and yield results considerably faster than conventional in vivo methods [56]. Multiple mechanisms and cell types are involved in the induction of skin toxicological responses, e.g., skin irritation involves resident epidermal cells, dermal fibroblasts, and endothelial cells, as well as invading leukocytes that interact with each other under the control of a network of cytokines and lipid mediators [57]. Therefore, two kinds of cell types have been selected for this study, human fibroblasts and keratinocytes.…”

Antimicrobial Properties Related to Anti-Acne and Deodorant Efficacy of Hedychium coronarium J. Koenig Extracts from Pulsed Electric Field Extraction

“…The hen's egg test-chorioallantoic membrane (HET-CAM) is a reliable alternative method for determining the risk of chemical irritation [41,42]. It has been used to evaluate the irritation potential of various cosmetic ingredients, particularly those related to the eyes, or even facial care that has the possibility to irritate the eyes.…”