Cosmetic safety assessment has undergone a major shift with the global move away from animal testing. The European Union led this change, fully banning the marketing of cosmetics tested on animals by 2013. This has prompted over 40 countries to adopt similar regulations, driving demand for reliable non-animal testing methods. While validated alternatives exist for endpoints like skin and eye irritation, systemic toxicity remains challenging due to its biological complexity.
Next-Generation Risk Assessment (NGRA) strategies, particularly the Threshold of Toxicological Concern (TTC), have gained traction for evaluating the systemic safety of ingredients with limited toxicity data. Another credible route for botanical ingredients is the documented history of safe use in foods. Althaea rosea flower extract (ARFE), also known as hollyhock, is used in both food and cosmetics, but its systemic safety in topical applications remained unverified. This study applied both the TTC approach and a food-consumption-based comparison to evaluate ARFE’s systemic safety profile in cosmetics.
Key Findings
• Forty-eight constituents were identified in ARFE; 92.6% are commonly found in foods or considered nutritional components.
• No genotoxic concerns were found for any constituents, including luteolin, after detailed in silico evaluation.
• All constituents’ estimated systemic exposure doses (SEDs) were below their respective TTC thresholds, supporting ARFE’s systemic safety at cosmetic use levels.
• Initial concerns about naringin and luteolin exceeding TTC limits were resolved after refined dermal absorption modeling showed reduced SEDs within safe margins at up to 2% cosmetic concentrations.
• Daily intake of ARFE through tea was estimated at 66.67 mg/kg/day, while cosmetic exposure ranged from 0.0045 to 5.380 mg/kg/day—up to 317 times lower—indicating negligible systemic risk from cosmetic use.
This study provides strong evidence for the systemic safety of Althaea rosea flower extract in cosmetic applications using a dual approach: the TTC method and safe food consumption history. The research demonstrates the practical application of NGRA in assessing complex botanical ingredients without animal testing. Notably, refined dermal absorption estimates helped resolve key safety questions for compounds like luteolin and naringin.
Despite limitations such as possible trace constituents not captured in the review and metabolic differences between oral and topical exposure, the findings validate ARFE’s safe use in cosmetics. This study also serves as a model for assessing other botanicals and contributes to the advancement of non-animal safety methodologies in the cosmetic industry.
Link to the study: https://www.mdpi.com/2079-9284/12/4/133
