Figure 1.

Possible molecular targets for phytochemicals as local anesthetic agents. When locally applied to peripheral tissues, quercetin inhibits the development of both generator potentials and action potentials in the peripheral terminal of primary afferents after nociceptive stimulation via the inhibition of mechanosensitive ionic channels (acid-sensing ion channel [ASIC] and transient receptor potential ankyrin 1 [TRPA1]), voltage-gated sodium (Nav) channels, and the facilitation of voltage-gated potassium (Kv) channels. The potency of quercetin is almost equal to that of Nav channel blockers, such as the commonly used local anesthetics, e.g., lidocaine. Cav = voltage-gated calcium, TG = trigeminal ganglion, SpVc = trigeminal spinal nucleus caudalis.