[Show abstract][Hide abstract] ABSTRACT: Reviewed here is the existing evidence for the effects of ginseng extracts and isolated ginsenosides relevant to cognition in humans. Clinical studies in healthy volunteers and in patients with neurological disease or deficit, evidence from preclinical models of cognition, and pharmacokinetic data are considered. Conditions under which disease modification may indirectly benefit cognition but may not translate to cognitive benefits in healthy subjects are discussed. The number of chronic studies of ginseng effects in healthy individuals is limited, and the results from acute studies are inconsistent, making overall assessment of ginseng's efficacy as a cognitive enhancer premature. However, mechanistic results are encouraging; in particular, the ginsenosides Rg3 , Rh1 , Rh2 , Rb1 , Rd, Rg2 , and Rb3 , along with the aglycones protopanaxadiol and protopanaxatriol, warrant further attention. Compound K has a promising pharmacokinetic profile and can affect neurotransmission and neuroprotection. Properly conducted trials using standardized tests in healthy individuals reflecting the target population for ginseng supplementation are required to address inconsistencies in results from acute studies. The evidence summarized here suggests ginseng has potential, but unproven, benefits on cognition.
[Show abstract][Hide abstract] ABSTRACT: Increased food consumption following ∆(9)-tetrahydrocannabinol-induced cannabinoid type 1 receptor agonism is well documented. However, possible non-∆(9)-tetrahydrocannabinol phytocannabinoid-induced feeding effects have yet to be fully investigated. Therefore, we have assessed the effects of the individual phytocannabinoids, cannabigerol, cannabidiol and cannabinol, upon feeding behaviors.
Adult male rats were treated (p.o.) with cannabigerol, cannabidiol, cannabinol or cannabinol plus the CB(1)R antagonist, SR141716A. Prior to treatment, rats were satiated and food intake recorded following drug administration. Data were analyzed for hourly intake and meal microstructure.
Cannabinol induced a CB(1)R-mediated increase in appetitive behaviors via significant reductions in the latency to feed and increases in consummatory behaviors via increases in meal 1 size and duration. Cannabinol also significantly increased the intake during hour 1 and total chow consumed during the test. Conversely, cannabidiol significantly reduced total chow consumption over the test period. Cannabigerol administration induced no changes to feeding behavior.
This is the first time cannabinol has been shown to increase feeding. Therefore, cannabinol could, in the future, provide an alternative to the currently used and psychotropic ∆(9)-tetrahydrocannabinol-based medicines since cannabinol is currently considered to be non-psychotropic. Furthermore, cannabidiol reduced food intake in line with some existing reports, supporting the need for further mechanistic and behavioral work examining possible anti-obesity effects of cannabidiol.
[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: 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: 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 hyperphagic effect of Delta9-tetrahydrocannabinol (Delta9THC) in humans and rodents is well known. However, no studies have investigated the importance of Delta9THC composition and any influence other non-Delta9THC cannabinoids present in Cannabis sativa may have. We therefore compared the effects of purified Delta9THC, synthetic Delta9THC (dronabinol), and Delta9THC botanical drug substance (Delta9THC-BDS), a Delta9THC-rich standardized extract comparable in composition to recreationally used cannabis.
Adult male rats were orally dosed with purified Delta9THC, synthetic Delta9THC, or Delta9THC-BDS, matched for Delta9THC content (0.34-2.68 mg/kg). Prior to dosing, subjects were satiated, and food intake was recorded following Delta9THC administration. Data were then analyzed in terms of hourly intake and meal patterns.
All three Delta9THC substances tested induced significant hyperphagic effects at doses >or=0.67 mg/kg. These effects included increased intake during hour one, a shorter latency to onset of feeding and a greater duration and consumption in the first meal. However, while some differences in vehicle control intakes were observed, there were significant, albeit subtle, differences in pattern of effects between the purified Delta9THC and Delta9THC-BDS.
All Delta9THC compounds displayed classical Delta9THC effects on feeding, significantly increasing shortterm intake whilst decreasing latency to the first meal. We propose that the subtle adjustment to the meal patterns seen between the purified Delta9THC and Delta9THC-BDS are due to non-Delta9THC cannabinoids present in Delta9THC-BDS. These compounds and other non-cannabinoids have an emerging and diverse pharmacology and can modulate Delta9THC-induced hyperphagia, making them worth further investigation for their therapeutic potential.
[Show abstract][Hide abstract] ABSTRACT: We have designed and implemented a low-cost digital system using closed-circuit television cameras coupled to a digital acquisition system for the recording of in vivo behavioral data in rodents and for allowing observation and recording of more than 10 animals simultaneously at a reduced cost, as compared with commercially available solutions. This system has been validated using two experimental rodent models: one involving chemically induced seizures and one assessing appetite and feeding. We present observational results showing comparable or improved levels of accuracy and observer consistency between this new system and traditional methods in these experimental models, discuss advantages of the presented system over conventional analog systems and commercially available digital systems, and propose possible extensions to the system and applications to nonrodent studies.
Behavior Research Methods 06/2009; 41(2):446-51. DOI:10.3758/BRM.41.2.446 · 2.12 Impact Factor