Appetite stimulation via partial agonism of cannabinoid type 1 receptors by Δ9tetrahydrocannabinol (Δ9THC) is well documented and can be modulated by non-Δ9THC phytocannabinoids. Δ9THC concentrations sufficient to elicit hyperphagia induce changes to both appetitive (reduced latency to feed) and consummatory (increased meal one size and duration) behaviours. Here, we show that a cannabis extract containing too little Δ9THC to stimulate appetite can induce hyperphagia solely by increasing appetitive behaviours. Twelve, male Lister hooded rats were presatiated before treatment with a low-Δ9THC cannabis extract (0.5, 1.0, 2.0 and 4.0 mg/kg). Hourly intake and meal pattern data were recorded and analyzed using one-way analyses of variance followed by Bonferroni post-hoc tests. The cannabis extract significantly increased food intake during the first hour of testing (at 4.0 mg/kg) and significantly reduced the latency to feed versus vehicle treatments (at doses ≥1.0 mg/kg). Meal size and duration were unaffected. These results show only the increase in appetitive behaviours, which could be attributed to non-Δ9THC phytocannabinoids in the extract rather than Δ9THC. Although further study is required to determine the constituents responsible for these effects, these results support the presence of non-Δ9THC cannabis constituent(s) that exert a stimulatory effect on appetite and likely lack the detrimental psychoactive effects of Δ9THC.
[Show abstract][Hide abstract] ABSTRACT: The herb Cannabis sativa (C. sativa) has been used in China and on the Indian subcontinent for thousands of years as a medicine. However, since it was brought to the UK and then the rest of the western world in the late 19th century, its use has been a source of controversy. Indeed, its psychotropic side effects are well reported but only relatively recently has scientific endeavour begun to find valuable uses for either the whole plant or its individual components. Here, we discuss evidence describing the endocannabinoid system, its endogenous and exogenous ligands and their varied effects on feeding cycles and meal patterns. Furthermore we also critically consider the mounting evidence which suggests non-Δ(9) tetrahydrocannabinol phytocannabinoids play a vital role in C. sativa-induced feeding pattern changes. Indeed, given the wide range of phytocannabinoids present in C. sativa and their equally wide range of intra-, inter- and extra-cellular mechanisms of action, we demonstrate that non-Δ(9) tetrahydrocannabinol phytocannabinoids retain an important and, as yet, untapped clinical potential.
Phytotherapy Research 02/2011; 25(2):170-88. DOI:10.1002/ptr.3375 · 2.66 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cannabinoid type 1 receptor-mediated appetite stimulation by Δ⁹tetrahydrocannabinol (Δ⁹THC) is well understood. Recently, it has become apparent that non-Δ⁹THC phytocannabinoids could also alter feeding patterns. Here, we show definitively that non-Δ⁹THC phytocannabinoids stimulate feeding. Twelve male, Lister-Hooded rats were prefed to satiety prior to administration of a standardized cannabis extract or to either of two mixtures of pure phytocannabinoids (extract analogues) comprising the phytocannabinoids present in the same proportions as the standardized extract (one with and one without Δ⁹THC). Hourly intake and meal pattern data were recorded and analysed using two-way analysis of variance followed by one-way analysis of variance and Bonferroni post-hoc tests. Administration of both extract analogues significantly increased feeding behaviours over the period of the test. All three agents increased hour-one intake and meal-one size and decreased the latency to feed, although the zero-Δ⁹THC extract analogue did so to a lesser degree than the high-Δ⁹THC analogue. Furthermore, only the analogue containing Δ⁹THC significantly increased meal duration. The data confirm that at least one non-Δ⁹THC phytocannabinoid induces feeding pattern changes in rats, although further trials using individual phytocannabinoids are required to fully understand the observed effects.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND AND PURPOSE Endocannabinoid systems are strongly implicated in the physiological control of appetite and eating behaviour, with cannabinoid CB(1) receptor agonists and antagonists, respectively, increasing or decreasing food intake. This study examined the acute actions of the putative endocannabinoid noladin ether on food intake and eating motivation, assessing how it affects the amount of work expended by animals to obtain food. EXPERIMENTAL APPROACH Non-deprived male rats were injected systemically with noladin ether to assess its acute effects on ad libitum feeding of a standard laboratory diet. Additionally, the effects of noladin on lever pressing for palatable food were determined using a progressive ratio (PR) operant paradigm. KEY RESULTS Noladin dose dependently increased 2 h food intake, with a significant effect over 1 h after a dose of 0.5 mg·kg(-1). In the PR test, this hyperphagic dose of noladin ether promoted sustained high rates of responding and significantly increased the total number of lever presses and break-point. These latter effects were prevented by pretreatment with 1.0 mg·kg(-1) of the selective CB(1) antagonist surinabant (SR147778), that alone had no effect on responding. CONCLUSIONS AND IMPLICATIONS This is the first report of hyperphagia induced by acute noladin administration, and the first description of behavioural actions in rats. Consistent with prevailing notions about the role of endocannabinoids in appetite, a hyperphagic dose of noladin markedly increased efforts expended by animals to obtain food. Thus, noladin exerts a specific action on eating motivation; possibly promoting eating by increasing the incentive value of food.
British Journal of Pharmacology 02/2012; 166(6):1815-21. DOI:10.1111/j.1476-5381.2012.01888.x · 4.84 Impact Factor
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