Thujone inhibits the function of α7-nicotinic acetylcholine receptors and impairs nicotine-induced memory enhancement in one-trial passive avoidance paradigm.

Thujone inhibits the function of α7-nicotinic acetylcholine receptors and impairs nicotine-induced memory enhancement in one-trial passive avoidance paradigm. Toxicology. 2017 Apr 07;: Authors: Sultan A, Yang KS, Isaev D, Nebrisi EE, Syed N, Khan N, Howarth CF, Sadek B, Oz M Abstract Effects of thujone, a major ingredient of absinthe, wormwood oil and some herbal medicines, were tested on the function of α7 subunit of the human nicotinic acetylcholine (α7 nACh) receptor expressed in Xenopus oocytes using the two-electrode voltage-clamp technique. Thujone reversibly inhibited ACh (100μM)-induced currents with an IC50 value of 24.7μM. The effect of thujone was not dependent on the membrane potential and did not involve Ca(2+)-dependent Cl(-) channels expressed endogenously in oocytes. Inhibition by thujone was not reversed by increasing ACh concentrations. Moreover, specific binding of [(125)I] α-bungarotoxin was not altered by thujone. Further experiments in SH-EP1 cells expressing human α7 nACh receptor indicated that thujone suppressed choline induced Ca(2+) transients in a concentration-dependent manner. In rat hippocampal CA3-dentate gyrus synapses, nicotine-induced enhancement of long-term potentiation was also inhibited by thujone. Furthermore, the results observed in in-vivo one-trial passive avoidance paradigm show that thujone (1.25mg/kg, i.p.) significantly impaired nicotine-induced enhancement of learning and memory ...
Source: Toxicology - Category: Toxicology Authors: Tags: Toxicology Source Type: research