Effects ofPapaver rhoeas. Extract on the Development and Expression of Tolerance to Morphine-Induced Locomotor Activity in Mice

Abstract

In the current study, effects of a water-alcohol extract of Papaver rhoeas L.(Papaveraceae) on the acquisition and expression of morphine-induced behavioral tolerance in mice was investigated. Subcutaneous (s.c.) administration of morphine (50 mg=kg) induced locomotor activity in animals. Reduction of locomotor behavioral response in mice pretreated with morphine (50 mg=kg, twice daily for 3 days) alone indicates that tolerance had been developed. Extract (25, 50, and 100 mg=kg, i.p.) administration, 30 min before each of three daily doses of morphine, augmented the development of tolerance. Moreover, intraperitoneal administration of the plant extract (25, 50, and 100 mg=kg) 30 min before the test inhibited the expression of morphine-induced behavioral tolerance. The results indicate that administration of the extract of Papaver rhoeas induces different effects on the acquisition and expression of morphine-induced behavioral tolerance in mice.

Papaver Rhoeas L. Hydroalcoholic Extract Exacerbates Forced Swimming Test-Induced Depression in Mice

“…In this study, the PR extract did not appear to have any inducing or inhibiting effect on the mice’s motor activity in either gender. Previous studies did not report any motor-activity effect for the extract either, and in our previous study, the extract showed no effect on the animals’ mobility in and of itself ( Sahraei et al, 2006a ; Sahraei et al, 2007 ). The extract therefore appears to be unable to affect animals’ motor activity function, an effect which is easily discernible with morphine ( Sahraei et al, 2006a ).…”

“…Numerous studies have been conducted on the various effects of PR extract, and the present study also showed that the extract of this plant has major depression-inhibiting effects. Previous studies have shown that PR extract has immense effects on numerous animal models, including physical and mental morphine-dependence ( Pourmotabbed et al, 2004 ; Sahraei et al, 2006b ), morphine responsiveness and behavioral tolerance ( Sahraei et al, 2007 ), and tolerance to the analgesic effects of morphine (Shams et al, 2008). Recent studies, however, have shown the effect of this plant in inhibiting the metabolic effects of stress in male mice ( Mirzaie et al, 2013 ).…”

“…The effective compounds in Papaver rhoeas L. hydroalcoholic extract to reduce depression have not identified yet. However, previous researchers have shown that the extract contain anthocyanin, which might reduce depression through interactions with dopamine receptors and their subsequent inhibition ( Sahraei et al, 2007 ). It should be noted that presynaptic dopamine D 2 receptors are positioned on dopamine terminals, and their inhibition increases the release of dopamine, which is an effective neurotransmitter in reducing depression ( MacDonald, 1997 ; Mann, 2005 ).…”

Pharmacological Properties of Papaver rhoaes L.

“…Psychological dependence is defined as a desire for repeated use of abused drugs despite their adverse side effects. Psychological dependence is considered as the main reason for relapse to drug abuse [13]. Several animal models have been developed to study this phenomenon including conditioned place preference (CPP) and self-administration [14].…”

“…Considering the findings of these studies, it is clear that the extract of the PR may be used as anti-euphoric drug in the human and we suggest that some clinical trials in this regard may be useful. It must be noted that since the biological properties of different abused drugs shown similarities [13], the effects of the extract on other abused drugs such as cocaine and nicotine may be similar to morphine.…”