Nicotinic Activity of Arecoline, the Psychoactive Element of "Betel Nuts", Suggests a Basis for Habitual Use and AntiInflammatory Activity

作者：Papke Roger L^*; Horenstein Nicole A; Stokes Clare

来源：PLos One, 2015, 10(10): e0140907.

DOI：10.1371/journal.pone.0140907

Habitual chewing of "betel nut" preparations constitutes the fourth most common human self-administration of a psychoactive substance after alcohol, caffeine, and nicotine. The primary active ingredient in these preparations is arecoline, which comes from the areca nut, the key component of all such preparations. Arecoline is known to be a relatively nonselective muscarinic partial agonist, accounting for many of the overt peripheral and central nervous system effects, but not likely to account for the addictive properties of the drug. We report that arecoline has activity on select nicotinic acetylcholine receptor (nAChR) subtypes, including the two classes of nAChR most related to the addictive properties of nicotine: receptors containing alpha 4 and beta 2 subunits and those which also contain alpha 6 and beta 3 subunits. Arecoline is a partial agonist with about 6-10% efficacy for the alpha 4* and alpha 6* receptors expressed in Xenopus oocytes. Additionally, arecoline is a silent agonist of alpha 7 nAChR; while it does not activate a7 receptors when applied alone, it produces substantial activation when co-applied with the positive allosteric modulator PNU-120696. Some alpha 7 silent agonists are effective inhibitors of inflammation, which might account for anti-inflammatory effects of arecoline. Arecoline's activity on nAChR associated with addiction may account for the habitual use of areca nut preparations in spite of the well-documented risk to personal health associated with oral diseases and cancer. The common link between betel and tobacco suggests that partial agonist therapies with cytisine or the related compound varenicline may also be used to aid betel cessation attempts.

• 出版日期2015-10-21