In vitro activity: HC-030031 is a substituted theophylline derivative. Potent and selective TRPA1 inhibitor. HC-030031 can block both inward and outward currents elicited by AITC or formalin rapidly and reversibly and also blocks the activation of TRPA1 by N-methylmaleimide and by electrophillic prostaglandins. It does not block currents mediated by TRPV1, TRPV3, TRPV4 hERG, or NaV1.2 channels.
Kinase Assay: Cells were plated in 384-well plates. Cells were loaded with 1 μM Fluo-4 and 0.05% pluronic acid for 1 h at room temperature. Formalin-selectivity experiments were run with 0.003% formalin. Agonist EC50 curves used 0–25 μM AITC or 0–0.017% formalin. IC50 curves for TRPA1 antagonists were constructed by using 0.625–40 μM antagonist in the presence of 5 μM AITC or 0.001% formalin using data collected 3 min after agonist addition. Data were collected by using a Hamamatsu FDSS 6000 fluorescence-based plate reader and analyzed using IGOR Pro.
Cell Assay: HC-030031 selectively inhibited TRPA1 activation by cinnamaldehyde and allyl isothiocyanate (AITC) in vitro [2]. HC-030031 inhibited the AITC- and formalin-induced Ca2+ increase in TRPA1-expressing cells. | 
