抄録
Parabens are commonly added in pharmaceutical, cosmetic and food products because of their wide antibacterial properties, low toxicity, inertness and chemical stability although the molecular mechanism of their antibacterial effect is not fully understood. Allyl isothiocyanate, cinnamaldehyde and allicin have strong antibacterial activities and are known to activate TRPA1 ion channel, which belongs to the TRP super family and is involved in nociception. Here we show that methyl p-hydroxybenzoate (methyl paraben) activates TRPA1 in both HEK293 cells expressing TRPA1 and in mouse sensory neurons with an EC50 value of 4.4 mM, an easily attainable concentration in methyl paraben-containing products. Furthermore, methyl paraben caused pain-related behaviors in mice similar to those caused by allyl isothiocyanate, which was blocked by the TRP channel blocker, ruthenium red. These results indicate methyl paraben is able to activate TRPA1 and can cause pain sensation. As such, methyl paraben provides a useful tool for investigating TRPA1 function and development of antinociceptive agents acting on TRPA1. [J Physiol Sci. 2007;57 Suppl:S99]
