Fig. 5

Effects of borneol, 2-methylisoborneol, fenchyl alcohol, and camphor on AITC-induced hTRPA1 current in HEK293T cells. a–d Representative AITC (20 μM)-induced hTRPA1 currents that were inhibited by borneol (1 mM, a), 2-methylisoborneol (1 mM, c), fenchyl alcohol (1 mM, c), or camphor (1 mM, d) in the absence of extracellular Ca²⁺. e Dose-dependent inhibition of AITC (20 μM)-induced hTRPA1 current by 1,8 cineole, camphor, borneol, 2-methyl isoborneol, or fenchyl alcohol. Half-maximal inhibitory concentrations (IC₅₀) values are 3.43 ± 0.58, 1.26 ± 0.32, 0.20 ± 0.06, 0.12 ± 0.03, and 0.32 ± 0.06 mM for 1,8-cineole, camphor, borneol, 2-methylisoborneol, and fenchyl alcohol, respectively (n = 5–10)