Effect of infusion extract prepared from red nutshell of Pistachio on morphine withdrawal syndrome in rat

Many kinds of the plant species can decrease naloxone-precipitated withdrawal syndrome in experimental morphine-dependent models. In this study, we tried to examine the effect of infusion obtained from red nutshell of pistachio (Pistacia vera) on withdrawal signs after administration of naloxone in morphine-dependent male rats.Methods and Materials: A total of 42 male NMRI rats were used in this study. Animals were made dependent by chronic administration of morphine during 14 days in their drinking water. Naloxone (2 mg/kg) was injected intraperitoneally (i.p.) to rats in order to produce behavioral parameters of withdrawal syndrome for 20 min including diarrhea, writhing and ejaculation. Weight loss was noticed 24 h after administration of naloxone. In control group (n=10), only naloxone was injected after dependency in 15th day. While, in other groups (n=8), morphine-treated rats have been received an infusion of nutshell of pistachio (25, 50, 100 and 200 mg/kg; i.p.), 30 min before naloxone administration. There were some withdrawal signs such as diarrhea, writhing and weight loss in all dependent rats after administration of naloxone. The number of writhing in infusion pretreated rats [25 (P<0.05), 50 (P<0.05) and 100 mg/kg (P<0.01) groups] significantly decreased in comparison with control group. Diarrhea in all infusion pretreated groups (P<0.01) and weight loss in 50 (P<0.05) and 100 mg/kg (P<0.01) infusion pretreated groups decreased significantly. The most dramatic decrease in morphine withdrawal signs has been seen in 100 mg/kg infusion pretreated rats (P<0.01). The results indicate that an infusion of the red nutshell of pistachio (Pistacia Vera) can be effective (dose-dependently) on morphine withdrawal syndrome. However, high dose of this infusion has a toxic effect and future studies should be about mechanisms, pharmacokinetic and pharmacodynamic properties of the red nutshell infusion of pistachio.