Effect of moxa smoke produced during combustion of Aiye (Folium Artemisiae Argyi) on behavioral changes in mice inhaling the smoke

Abstract

OBJECTIVETo evaluate the effects that inhalation of the combustion products of the traditional Chinese herb Aiye (Folium Artemisiae Argyi) has on the central nervous system. METHODSForty Kunming mice (half male) were randomly assigned (n = 10/group) to a control group (C) or one of three moxa smoke concentration groups (% opacity): low (L1; 0.4%), medium (M1; 2%), and high (H1; 15%). Mice in the latter three groups were exposed to moxa smoke in a dynamic gas exposure cabinet for 20 min per day for 7 days. Mice in control group were placed in the same cabinet without any intervention. For the sleep experiments, another 50 mice were divided into five groups of 10 mice each: a saline-injected control group, L1 + pentobarbital sodium (PS)-injected group, M1 +PS group, H1 (15%) + PS group, and a positive control group (10 mg/kg, chlorpromazine, p.o.). The weight, general activities, locomotor activities, rotarod performance, sleep duration, and sleeping rate induced by a subthreshold dose of pentobarbital sodium were recorded in the mice, and the composition of moxa smoke was analyzed using headspace gas chromatography (GC-HS). RESULTSA low concentration of smoke significantly decreased the frequency of locomotor activities and the time for which the mice remaining on the rotarod; however, a high smoke concentration significantly prolonged the pentobarbital-induced sleeping time and sleeping rate. CONCLUSIONThe concentration-dependent relaxing effects of moxa smoke on the Central Nervous System (CNS) were confirmed. Moreover, GC-HS analysis showed that the component present in the highest concentration in moxa smoke was eucalyptol, an essential oil well recognized for its soothing effects on the CNS. This may therefore be accountable for the sedative effects of moxa smoke.