Natural skin sensitizer carvacrol in oregano oil induces itch sensation and dermatitis through activation of warm temperature-sensitive Ca2+permeable TRPV3 channels

Natural bioactive compound carvacrol is the main ingredient of oregano oil that is commonly and widely used as cosmetic raw material and food seasoning. Oregano oil is also known to cause many side effects, such as pruritus, skin redness and dermatitis. However, the molecular identity underlying the side effects of oregano oil on skin remains largely unknown. In this study we found that carvacrol causes pruritus and atopic dermatitis by directly activating warm-temperature sensitive Ca2+ permeable TRPV3 channel abundantly expressed in the keratinocytes of the skin. Conversely, we have also identified a natural compound osthole that selectively inhibit TRPV3 and attenuate chronic pruritus and atopic dermatitis in rodent models. Our findings identify the cutaneous TRPV3 channel as biosensor critical for inducing side effects of natural products commonly used in cosmetology or traditional phytotherapy. Thus, topical inhibition of TRPV3 may lead to development of skin care products for cosmetic or pharmaceutical industry.