1.α-Terpineol attenuates morphine-induced physical dependence and tolerance in mice: role of nitric oxide.
Parvardeh S1, Moghimi M1, Eslami P2, Masoudi A1. Iran J Basic Med Sci. 2016 Feb;19(2):201-8.
OBJECTIVES: Dependence and tolerance to opioid analgesics are major problems limiting their clinical application. α-Terpineol is a monoterpenoid alcohol with neuroprotective effects which is found in several medicinal plants such as Myrtus communis, Laurus nobilis, and Stachys byzantina. It has been shown that some of these medicinal plants such as S. byzantina attenuate dependence and tolerance to morphine. Since α-terpineol is one of the bioactive phytochemical constituent of these medicinal plants, the present study was conducted to investigate the effects of α-terpineol on morphine-induced dependence and tolerance in mice.
2.α-Terpineol Induces Gastric Retention of Liquids by Inhibiting Vagal Parasympathetic Pathways in Rats.
da Silva MT1, Marques RB2, Batista-Lima FJ3, Soares MA3, Dos Santos AA3, Magalhães PJ3, de Assis Oliveira F2, de Castro Almeida FR2. Planta Med. 2016 Apr 28. [Epub ahead of print]
α-Terpineol is a monoterpene with smooth muscle relaxant properties. In this study, its effects on the gastric emptying rate of awake rats were evaluated with emphasis on the mode by which it induces gastrointestinal actions. Administered by gavage, α-terpineol (50 mg/kg) delayed gastric emptying of a liquid test meal at 10 min postprandial. Hexamethonium or guanethidine did not interfere with the retarding effect induced by α-terpineol, but atropine and L-NG-nitroarginine methyl ester abolished it. In vagotomized rats, α-terpineol did not delay gastric emptying. In isolated strips of gastric fundus, concentration-effect curves in response to carbamylcholine were higher in magnitude after treatment with the monoterpene. α-Terpineol (1 to 2000 µM) relaxed sustained contractions induced by carbamylcholine or a high K+ concentration in a concentration-dependent manner. This relaxing effect was not affected by the presence of L-NG-nitroarginine methyl ester, 1 H-[1, 2, 4]oxadiazolo[4,3-a]quinoxalin-1-one, tetraethylammonium, or atropine.