The Role of TRPV1 Channel in Cosmetic Safety Evaluation

Irritation is one of the most concerning aspects for both customs and the industry. In recent years, the transient receptor potential vanilloid type 1 (TRPV1) channel has raised great attention worldwide and is characterized as one of the most well-known pain-inducing receptors nowadays. This study focuses on the relationship between the sense of sting raised by surfactants and the TRPV1 channel. Twenty-six surfactants commonly used in the cosmetic industry were tested on both native HaCaT cells and stable TRPV1-overexpressing HaCaT cells for assessing their ability to cause Ca²⁺ influxes through the TRPV1 channel. The results showed that anionic surfactants with smaller counterions (for example, ammonium ions) seemed to have cytotoxicity, which may cause nonspecific Ca²⁺ influxes. The rest of the anionic surfactants, amphoteric surfactants, and natural plant extraction surfactants with different characteristics could result in different outcomes. Specifically, traditional anionic surfactants, with their higher hydrocarbon chain R between C₁₂ and C₁₈, were more likely to activate specific Ca²⁺ influxes. On the opposite, amino acid-based surfactants and nonionic surfactants were more likely to be mild on both native HaCaT cells and stable TRPV1-overexpressing HaCaT cells than other categories.