Camphor activates some of the transient receptor potential (TRP) channels such as TRPV1, TRPV3, TRPM8
, and inhibits TRPA1, causing warm sensation, excitation, and desensitization of sensory nerves, relieving the pain, itch and irritation in the applied area.
Specific substances such as Menthol and Camphor are higher in percentage that is 2.6% and 4.73% respectively,1 they attenuate the excitability of nerve membranes and of the specific itch mediating C-fibers and A-fibers.2 Both substances act by attaching to the transient receptor potential (TRP) receptor, but the main mechanism of action by which topical menthol reduces pruritus is by attaching onto the cold receptor TRPM8
which then goes and reaches the A-delta fibers and hence giving a cooling sensation.2 While camphor attaches onto the warm receptor TRPV3.3 Furthermore, menthol also helps in providing general anaesthesia by being a positive modulator of GABA type a receptor.
reported that FA and Z-ligustilide which is another major component of Angelica sinensis, have a synergistic effect on cold-induced vasospasm by regulating cold-sensing proteins TRPM8
and TPRA1 (41).
To find evidence of this adaptation, the researchers took a closer look at TRPM8
, a gene that codes for the only known receptor that enables a person to detect and respond to cool and cold temperatures.
Romano et al., "Colon carcinogenesis is inhibited by the TRPM8
antagonist cannabigerol, a Cannabis-derived non-psychotropic cannabinoid," Carcinogenesis, vol.
Other Possible Therapeutic Targets: Transient Receptor Potential Ankyrin-1 (TRPA1) and Transient Receptor Potential Melastatin-8 (TRPM8
Cortright, "Increased TRPA1, TRPM8
, and TRPV2 expression in dorsal root ganglia by nerve injury," Biochemical and Biophysical Research Communications, vol.
(39) Menthol has been shown to help regulate cold and pain sensation through the TRPM8
Lp1, Lp2, Lp3, Lp4, and Lp5 had e< [10.sup.-15] and coverage >40% to mammalian TRPM2 (Lp1), TRPM8
(Lp2), TRPP1 (Lp3), and TRPP2 (Lp4 and Lp5), as well as Xenopus laevis TRPM8
and TRPA1 are responsive to cold temperature.
The roles of iPLA2, TRPM8
and TRPA1 in chemically induced cold hypersensitivity.