Assessment of Systemic Safety of Althaea rosea Flower Extract for Use in Cosmetics: Threshold of Toxicological Concern and History of Safe Consumption Approaches

Althaea rosea flower extract (ARFE) is widely used as a food and cosmetic ingredient. However, the systemic safety of ARFE for use in cosmetics has not been confirmed, yet. Here, we adopted the threshold of toxicological concern (TTC) and history of safe food consumption approaches to evaluate the systemic safety of ARFE as a cosmetic ingredient. A systematic literature review identified 48 chemical constituents in ARFE, 92.6% of which are common food components. Through a literature review, 48 chemical constituents of ARFE were identified. To exclude the potential genotoxicity issues, in silico predictions of an in vitro AMES test and additional literature reviews were performed, demonstrating that all the chemical constituents of ARFE have no genotoxicity issues. To evaluate the systemic toxicity of ARFE, a comparison with the dietary intake of ARFE was performed. The daily dietary intake of ARFE through tea products was estimated to be 66.67 mg/kg/day. Since exposure to ARFE through cosmetic use ranges from 0.0045 to 5.380 mg/kg/day, which is far lower than dietary intake, it is unlikely to pose any additional health risk. The TTC approach along with in silico predictions of dermal absorption also revealed that systemic exposure doses (SEDs) of all the chemical constituents are below TTC thresholds, further supporting its systemic safety for use in cosmetics.