Effect of combined doses of Δ(9)-tetrahydrocannabinol (THC) and cannabidiolic acid (CBDA) on acute and anticipatory nausea using rat (Sprague- Dawley) models of conditioned gaping

Evaluation of Sex Differences in the Potential of Δ9-Tetrahydrocannabinol, Cannabidiol, Cannabidiolic Acid, and Oleoyl Alanine to Reduce Nausea-Induced Conditioned Gaping Reactions in Sprague-Dawley Rats

Introduction: Cancer patients report nausea as a side effect of their chemotherapy treatment. Using the pre-clinical rodent model of acute nausea-lithium chloride (LiCl)-induced conditioned gaping-our group has demonstrated that exogenous cannabinoids may have antinausea potential. Materials and Methods: With the goal of evaluating the role of sex as a factor in pre-clinical research, we first compared the conditioned gaping reactions produced by varying doses of LiCl in male and female rats using the taste reactivity test (Experiment 1). Results: LiCl produced dose-dependent conditioned gaping similarly in male and female rats with the highest dose (127.2 mg/kg) producing robust conditioned gaping, with this dose used in subsequent experiments. Next, we examined the antinausea potential of THC (Experiment 2), CBD (Experiment 3), cannabidiolic acid (CBDA; Experiment 4) and oleoyl alanine (OlAla; Experiment 5) in both male and female rats. THC, CBD, CBDA, and OlAla dose dependently reduced conditioned gaping in both male and female rats in a similar manner. Conclusions: These results suggest that cannabinoids may be equally effective in treating nausea in both males and females.

Endocannabinoid System and Exogenous Cannabinoids in Depression and Anxiety: A Review

Background: There is a growing liberalization of cannabis-based preparations for medical and recreational use. In multiple instances, anxiety and depression are cited as either a primary or a secondary reason for the use of cannabinoids. Aim: The purpose of this review is to explore the association between depression or anxiety and the dysregulation of the endogenous endocannabinoid system (ECS), as well as the use of phytocannabinoids and synthetic cannabinoids in the remediation of depression/anxiety symptoms. After a brief description of the constituents of cannabis, cannabinoid receptors and the endocannabinoid system, the most important evidence is presented for the involvement of cannabinoids in depression and anxiety both in human and from animal models of depression and anxiety. Finally, evidence is presented for the clinical use of cannabinoids to treat depression and anxiety. Conclusions: Although the common belief that cannabinoids, including cannabis, its main studied components-tetrahydrocannabinol (THC) and cannabidiol (CBD)-or other synthetic derivatives have been suggested to have a therapeutic role for certain mental health conditions, all recent systematic reviews that we report have concluded that the evidence that cannabinoids improve depressive and anxiety disorders is weak, of very-low-quality, and offers no guidance on the use of cannabinoids for mental health conditions within a regulatory framework. There is an urgent need for high-quality studies examining the effects of cannabinoids on mental disorders in general and depression/anxiety in particular, as well as the consequences of long-term use of these preparations due to possible risks such as addiction and even reversal of improvement.

Cannabidiol but not cannabidiolic acid reduces behavioural sensitisation to methamphetamine in rats, at pharmacologically effective doses

RATIONALE

Cannabidiol (CBD) and cannabidiolic acid (CBDA) are non-psychoactive components of the cannabis plant. CBD has been well characterised to have anxiolytic and anticonvulsant activity, whereas the behavioural effects of CBDA are less clear. Preclinical and clinical data suggests that CBD has antipsychotic properties and reduces methamphetamine self-administration in rats. An animal model that is commonly used to mimic the neurochemical changes underlying psychosis and drug dependence is methamphetamine (METH) sensitisation, where repeated administration of the psychostimulant progressively increases the locomotor effects of METH.

OBJECTIVE

The aim of this study was to determine whether CBD or CBDA attenuate METH-induced sensitisation of locomotor hyperactivity in rats.

METHODS

Eighty-six male Sprague Dawley rats underwent METH sensitisation protocol where they were subjected to daily METH (1 mg/kg on days 2 and 8, 5 mg/kg on days 3-7; i.p.) injections for 7 days. After 21 days of withdrawal, rats were given a prior injection of CBD (0, 40 and 80 mg/kg; i.p.) or CBDA (0, 0.1, 10 and 1000 µg/kg; i.p.) and challenged with acute METH (1 mg/kg; i.p.). Locomotor activity was then measured for 60 min.

RESULTS

Rats displayed robust METH sensitisation as evidenced by increased locomotor activity to METH challenge in METH-pretreated versus SAL-pretreated rats. CBD (40 and 80 mg/kg) reduced METH-induced sensitisation. There was no effect of any CBDA doses on METH sensitisation or acute METH-induced hyperactivity.

CONCLUSION

These results demonstrate that CBD, but not CBDA, reduces METH sensitisation of locomotor activity in rats at pharmacologically effective doses, thus reinforcing evidence that CBD has anti-addiction and antipsychotic properties.

Cannabis constituents interact at the drug efflux pump BCRP to markedly increase plasma cannabidiolic acid concentrations

Cannabis is a complex mixture of hundreds of bioactive molecules. This provides the potential for pharmacological interactions between cannabis constituents, a phenomenon referred to as “the entourage effect” by the medicinal cannabis community. We hypothesize that pharmacokinetic interactions between cannabis constituents could substantially alter systemic cannabinoid concentrations. To address this hypothesis we compared pharmacokinetic parameters of cannabinoids administered orally in a cannabis extract to those administered as individual cannabinoids at equivalent doses in mice. Astonishingly, plasma cannabidiolic acid (CBDA) concentrations were 14-times higher following administration in the cannabis extract than when administered as a single molecule. In vitro transwell assays identified CBDA as a substrate of the drug efflux transporter breast cancer resistance protein (BCRP), and that cannabigerol and Δ⁹-tetrahydrocannabinol inhibited the BCRP-mediated transport of CBDA. Such a cannabinoid-cannabinoid interaction at BCRP transporters located in the intestine would inhibit efflux of CBDA, thus resulting in increased plasma concentrations. Our results suggest that cannabis extracts provide a natural vehicle to substantially enhance plasma CBDA concentrations. Moreover, CBDA might have a more significant contribution to the pharmacological effects of orally administered cannabis extracts than previously thought.

Therapeutic Potential of Cannabidiol, Cannabidiolic Acid, and Cannabidiolic Acid Methyl Ester as Treatments for Nausea and Vomiting

Introduction: Nausea and vomiting are the most distressing symptoms reported by oncology patients undergoing anticancer treatment. With the currently available treatments, vomiting and especially nausea remain problematic, highlighting the need for alternative treatments. Discussion: Here we review in vitro and in vivo evidence for the effectiveness of the nonpsychoactive cannabinoid cannabidiol (CBD) in managing nausea and vomiting. In addition, we also review the evidence for CBD's acidic precursor, cannabidiolic acid (CBDA), and a methylated version of CBDA (CBDA-ME) in these phenomena. Finally, we explore the potential role of CBD in the treatment of cannabinoid hyperemesis syndrome. Conclusions: CBD has demonstrated efficacy in reducing nausea and vomiting, with CBDA and CBDA-ME being more potent. The data suggest a need for these compounds to be evaluated in clinical trials for their ability to reduce nausea and/or vomiting.

Constituents of Cannabis Sativa

The Cannabis sativa plant has been used medicinally and recreationally for thousands of years, but recently only relatively some of its constituents have been identified. There are more than 550 chemical compounds in cannabis, with more than 100 phytocannabinoids being identified, including Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD). These phytocannabinoids work by binding to the cannabinoid receptors, as well as other receptor systems. Also within cannabis are the aromatic terpenes, more than 100 of which have been identified. Cannabis and its constituents have been indicated as therapeutic compounds in numerous medical conditions, such as pain, anxiety, epilepsy, nausea and vomiting, and post-traumatic stress disorder. This chapter provides an overview of some of the biological effects of a number of the cannabinoids and terpenes, as well as discussing their known mechanisms of action and evidence of potential therapeutic effects.

Evaluation of repeated or acute treatment with cannabidiol (CBD), cannabidiolic acid (CBDA) or CBDA methyl ester (HU-580) on nausea and/or vomiting in rats and shrews

RATIONALE

When acutely administered intraperitoneally, the non-psychoactive cannabinoid cannabidiol (CBD), its acidic precursor cannabidiolic acid (CBDA) and a stable methyl ester of CBDA (HU-580) reduce lithium chloride (LiCl)-induced conditioned gaping in male rats (a selective preclinical model of acute nausea) via activation of the serotonin 1A (5-HT_1A) receptor.

OBJECTIVES

To utilise these compounds to manage nausea in the clinic, we must determine if their effectiveness is maintained when injected subcutaneously (s.c) and when repeatedly administered. First, we compared the effectiveness of each of these compounds to reduce conditioned gaping following repeated (7-day) and acute (1-day) pretreatments and whether these anti-nausea effects were mediated by the 5-HT_1A receptor. Next, we assessed whether the effectiveness of these compounds can be maintained when administered prior to each of 4 conditioning trials (once per week). We also evaluated the ability of repeated CBD (7 days) to reduce LiCl-induced vomiting in Suncus murinus. Finally, we examined whether acute CBD was equally effective in male and female rats.

RESULTS

Both acute and repeated (7 day) s.c. administrations of CBD (5 mg/kg), CBDA (1 μg/kg) and HU-580 (1 μg/kg) similarly reduced LiCl-induced conditioned gaping, and these effects were blocked by 5HT_1A receptor antagonism. When administered over 4 weekly conditioning trials, the anti-nausea effectiveness of each of these compounds was also maintained. Repeated CBD (5 mg/kg, s.c.) maintained its anti-emetic efficacy in S. murinus. Acute CBD (5 and 20 mg/kg, s.c.) administration reduced LiCl-induced conditioned gaping similarly in male and female rats.

CONCLUSION

When administered repeatedly (7 days), CBD, CBDA and HU-580 did not lose efficacy in reducing nausea and continued to act via agonism of the 5-HT_1A receptor. When administered across 4 weekly conditioning trials, they maintained their effectiveness in reducing LiCl-induced nausea. Repeated CBD also reduced vomiting in shrews. Finally, CBD's anti-nausea effects were similar in male and female rats. This suggests that these cannabinoids may be useful anti-nausea and anti-emetic treatments for chronic conditions, without the development of tolerance.

Behavioural and molecular effects of cannabidiolic acid in mice

AIMS

Cannabidiolic acid (CBDA) is one of the most abundant phytocannabinoid acids in the Cannabis sativa plant. It has been shown that it is able to exert some therapeutic effects such as antiemetic, anti-inflammatory, anxiolytic or antidepressant, although some of them remain under debate. In the present study we aim to assess the potential behavioural effects of CBDA as well as its modulation of neuroinflammatory markers in the prefrontal cortex (PFC).

MAIN METHODS

The effects of acute and repeated CBDA (0.001-1 mg/kg i.p.) treatments were evaluated on cognitive, emotional, motivational and nociceptive behaviours in male CD1 mice. For this, Y-maze and elevated plus maze paradigms, spontaneous locomotor activity, social interaction, hot-plate, formalin and tail suspension tests were used. We also studied the effects of CBDA on the rewarding responses of cocaine in the conditioned place preference (CPP) paradigm. Finally, PFC was dissected after acute and repeated CBDA treatments to evaluate inflammatory markers.

KEY FINDINGS

Acute CBDA treatment induced antinociceptive responses in the hot-plate test. A 10-day CBDA treatment reduced despair-like behaviour in the tail suspension test. CBDA did not alter the results of the remaining behavioural tests assayed, including cocaine-induced reward in the CPP. Regarding the biochemical analysis, repeated CBDA treatment diminished the level of peroxisome proliferator-activated receptor gamma (PPAR-γ) and increased that of interleukin-6 (IL-6) protein in PFC.

SIGNIFICANCE

These results show that CBDA has limited in vivo effects on the modulation of mice behaviour, supporting the current skepticism regarding its therapeutic potential.

Pharmacological potential of varinic-, minor-, and acidic phytocannabinoids

While natural Δ9-tetrahidrocannabinol (Δ9THC), cannabidiol (CBD), and their therapeutic potential have been extensively researched, some cannabinoids have been less extensively investigated. The present article compiles data from the literature that highlight the health benefits and therapeutic potential of lesser known phytocannabinoids, which we have divided into varinic, acidic, and "minor" (i.e., cannabinoids that are not present in high quantities in common varieties of Cannabis sativa L). A growing interest in these compounds, which are enriched in some cannabis varieties, has already resulted in enough preclinical information to show that they are promising therapeutic agents for a variety of diseases. Every phytocannabinoid has a "preferential" mechanism of action, and often targets the cannabinoid receptors, CB1 and/or CB2. The recent resolution of the structure of cannabinoid receptors demonstrates the atypical nature of cannabinoid binding, and that different binding modes depend on the agonist or partial agonist/inverse agonist, which allows for differential signaling, even acting on the same cannabinoid receptor. In addition, other players and multiple signaling pathways may be targeted/engaged by phytocannabinoids, thereby expanding the mechanistic possibilities for therapeutic use.

Effect of combined doses of Δ9-tetrahydrocannabinol and cannabidiol or tetrahydrocannabinolic acid and cannabidiolic acid on acute nausea in male Sprague-Dawley rats

RATIONALE

This study evaluated the potential of combined cannabis constituents to reduce nausea.

OBJECTIVES

Using the lithium chloride (LiCl)-induced conditioned gaping model of nausea in male rats, we aimed to: 1) Determine effective anti-nausea doses of cannabidiol (CBD) 2) Determine effectiveness and the mechanism of action of combined subthreshold doses of CBD and Δ⁹-tetrahydrocannabinol (THC) 3) Determine effective doses of synthetic cannabidiolic acid (CBDA) 4) Determine effective doses of synthetic tetrahydrocannabinolic acid (THCA) 5) Determine the mechanism of action for THCA 6) Determine effectiveness and the mechanism of action of combined subthreshold doses of CBDA and THCA RESULTS: CBD (0.5-5 mg/kg, intraperitoneal [i.p.]) reduces LiCl-induced conditioned gaping (but 0.1, 20, 40 mg/kg are ineffective). Combined subthreshold doses of CBD (0.1 mg/kg, i.p.) and THC (0.1 mg/kg, i.p.) produce suppression of conditioned gaping, and this effect is blocked by administration of either WAY100635 (a serotonin 1A [5-HT_1A]) receptor antagonist or SR141716 (SR; a CB₁ receptor antagonist). THCA (0.01 mg/kg, i.p.) reduces conditioned gaping and administration of MK886 (a peroxisome proliferator-activated receptor alpha [PPARα] antagonist) blocked THCA's anti-nausea effect. Combined subthreshold doses of CBDA (0.00001 mg/kg, i.p.) and THCA (0.001 mg/kg, i.p.) produce suppression of conditioned gaping, and this effect is blocked by administration of WAY100635 or MK886.

CONCLUSION

Combinations of very low doses of CBD + THC or CBDA + THCA robustly reduce LiCl-induced conditioned gaping. Clinical trials are necessary to determine the efficacy of using single or combined cannabinoids as adjunct treatments with existing anti-emetic regimens to manage chemotherapy-induced nausea.

The ventral pallidum as a critical region for fatty acid amide hydrolase inhibition of nausea-induced conditioned gaping in male Sprague-Dawley rats

Here we investigate the involvement of the ventral pallidum (VP) in the anti-nausea effect of fatty acid amide hydrolase (FAAH) inhibition with PF-3845, and examine the pharmacological mechanism of such an effect. We explored the potential of intra-VP PF-3845 to reduce the establishment of lithium chloride (LiCl)-induced conditioned gaping (a model of acute nausea) in male Sprague-Dawley rats. As well, the role of the cannabinoid 1 (CB₁) receptors and the peroxisome proliferator-activated receptors-α (PPARα) in the anti-nausea effect of PF-3845 was examined. Finally, the potential of intra-VP GW7647, a PPARα agonist, to reduce acute nausea was also evaluated. Intra-VP PF-3845 dose-dependently reduced acute nausea by a PPARα mechanism (and not a CB₁ receptor mechanism). Intra-VP administration of GW7647, similarly attenuated acute nausea. These findings suggest that the anti-nausea action of FAAH inhibition may occur in the VP, and may involve activation of PPARα to suppress acute nausea.

Effect of cannabidiolic acid and ∆9-tetrahydrocannabinol on carrageenan-induced hyperalgesia and edema in a rodent model of inflammatory pain

RATIONALE

Cannabidiol (CBD), a non-intoxicating component of cannabis, or the psychoactive Δ⁹-tetrahydrocannabiol (THC), shows anti-hyperalgesia and anti-inflammatory properties.

OBJECTIVES

The present study evaluates the anti-inflammatory and anti-hyperalgesia effects of CBD's potent acidic precursor, cannabidiolic acid (CBDA), in a rodent model of carrageenan-induced acute inflammation in the rat hind paw, when administered systemically (intraperitoneal, i.p.) or orally before and/or after carrageenan. In addition, we assess the effects of oral administration of THC or CBDA, their mechanism of action, and the efficacy of combined ineffective doses of THC and CBDA in this model. Finally, we compare the efficacy of CBD and CBDA.

RESULTS

CBDA given i.p. 60 min prior to carrageenan (but not 60 min after carrageenan) produced dose-dependent anti-hyperalgesia and anti-inflammatory effects. In addition, THC or CBDA given by oral gavage 60 min prior to carrageenan produced anti-hyperalgesia effects, and THC reduced inflammation. The anti-hyperalgesia effects of THC were blocked by SR141716 (a cannabinoid 1 receptor antagonist), while CBDA's effects were blocked by AMG9810 (a transient receptor potential cation channel subfamily V member 1 antagonist). In comparison to CBDA, an equivalent low dose of CBD did not reduce hyperalgesia, suggesting that CBDA is more potent than CBD for this indication. Interestingly, when ineffective doses of CBDA or THC alone were combined, this combination produced an anti-hyperalgesia effect and reduced inflammation.

CONCLUSION

CBDA or THC alone, as well as very low doses of combined CBDA and THC, has anti-inflammatory and anti-hyperalgesia effects in this animal model of acute inflammation.

Emergency Department Burden of Nausea and Vomiting Associated With Cannabis Use Disorder: US Trends From 2006 to 2013

BACKGROUND AND AIMS

Chronic cannabis use is associated with nausea and vomiting that may lead to emergency department (ED) visits, multiple diagnostic tests, and procedures. The aim of this study was to analyze recent trends in ED visits for vomiting associated with cannabis use disorder between 2006 and 2013.

METHODS

Data were obtained from the National Emergency Department Sample records in which vomiting (ICD-9-CM codes 787.01, 787.03, and 536.2) was a primary diagnosis in combination with cannabis abuse or dependence (304.3, 304.30, 304.31, 304.32, 304.33, 305.2, 305.20, 305.21, 305.22, and 305.23) and were seen in the ED between 2006 and 2013. The National Emergency Department Sample collects data from more than 25 million visits in over 950 EDs and is weighted to provide national estimates.

RESULTS

The rate of ED visits for vomiting with cannabis use disorder from 2006 compared with 2013 increased from 2.3 to 13.3 per 100,000 ED visits, while the mean inflation-adjusted costs increased 68.5% from $2758.43 to $4647.62, respectively. Men between the ages of 20 and 29 were the most common group to present to the ED for vomiting with cannabis use disorder. The Midwest and West had the higher rates of ED visits for vomiting with cannabis use disorder compared with the Northeast and South.

CONCLUSIONS

ED visits for vomiting associated with cannabis use disorder is common and is associated with significant medical costs. Further research on the role of cannabis use in nausea and vomiting is warranted.

Effects of Cannabinoid Agonists and Antagonists on Sleep and Breathing in Sprague-Dawley Rats

Study Objectives

There are no pharmacological treatments for obstructive sleep apnea syndrome, but dronabinol showed promise in a small pilot study. In anesthetized rats, dronabinol attenuates reflex apnea via activation of cannabinoid (CB) receptors located on vagal afferents; an effect blocked by cannabinoid type 1 (CB1) and/or type 2 (CB2) receptor antagonists. Here, using a natural model of central sleep apnea, we examine the effects of dronabinol, alone and in combination with selective antagonists in conscious rats chronically instrumented to stage sleep and measure cessation of breathing.

Methods

Adult male Sprague-Dawley rats were anesthetized and implanted with bilateral stainless steel screws into the skull for electroencephalogram recording and bilateral wire electrodes into the nuchal muscles for electromyogram recording. Each animal was recorded by polysomnography on multiple occasions separated by at least 3 days. The study was a fully nested, repeated measures crossover design, such that each rat was recorded following each of 8 intraperitoneal injections: vehicle; vehicle and CB1 antagonist (AM 251); vehicle and CB2 antagonist (AM 630); vehicle and CB1/CB2 antagonist; dronabinol; dronabinol and CB1 antagonist; dronabinol and CB2 antagonist; and dronabinol and CB1/CB2 antagonist.

Results

Dronabinol decreased the percent time spent in rapid eye movement (REM) sleep. CB receptor antagonists did not reverse this effect. Dronabinol also decreased apneas during sleep, and this apnea suppression was reversed by CB1 or CB1/CB2 receptor antagonism.

Conclusions

Dronabinol's effects on apneas were dependent on CB1 receptor activation, while dronabinol's effects on REM sleep were CB receptor-independent.

Cannabidiolic acid methyl ester, a stable synthetic analogue of cannabidiolic acid, can produce 5-HT1A receptor-mediated suppression of nausea and anxiety in rats

BACKGROUND AND PURPOSE

The aim of this study was to compare the abilities of cannabidiolic acid methyl ester (HU-580) and cannabidiolic acid (CBDA) to enhance 5-HT_1A receptor activation in vitro and produce 5-HT_1A -mediated reductions in nausea and anxiety in vivo.

EXPERIMENTAL APPROACH

We investigated the effects of HU-580 and CBDA on (i) activation by 8-hydroxy-2-(di-n-propylamino)tetralin of human 5-HT_1A receptors in CHO cell membranes, using [³⁵ S]-GTPγS binding assays, (ii) gaping by rats in acute and anticipatory nausea models, and (iii) stress-induced anxiety-like behaviour, as indicated by exit time from the light compartment of a light-dark box of rats subjected 24 h earlier to six tone-paired foot shocks.

KEY RESULTS

HU-580 and CBDA increased the E_max of 8-hydroxy-2-(di-n-propylamino) tetralin in vitro at 0.01-10 and 0.1-10 nM, respectively, and reduced signs of (i) acute nausea at 0.1 and 1 μg·kg^-1 i.p. and at 1 μg·kg^-1 i.p., respectively, and (ii) anticipatory nausea at 0.01 and 0.1 μg·kg^-1 , and at 0.1 μg·kg^-1 i.p. respectively. At 0.01 μg·kg^-1 , HU-580, but not CBDA, increased the time foot-shocked rats spent in the light compartment of a light-dark box. The anti-nausea and anti-anxiety effects of 0.01 or 0.1 μg·kg^-1 HU-580 were opposed by the 5-HT_1A antagonist, WAY100635 (0.1 mg·kg^-1 i.p.).

CONCLUSIONS AND IMPLICATIONS

HU-580 is more potent than CBDA at enhancing 5-HT_1A receptor activation, and inhibiting signs of acute and anticipatory nausea, and anxiety. Consequently, HU-580 is a potential medicine for treating some nausea and anxiety disorders and possibly other disorders ameliorated by enhancement of 5-HT_1A receptor activation.

Evaluation of cannabinoids concentration and stability in standardized preparations of cannabis tea and cannabis oil by ultra-high performance liquid chromatography tandem mass spectrometry

BACKGROUND

Cannabis has been used since ancient times to relieve neuropathic pain, to lower intraocular pressure, to increase appetite and finally to decrease nausea and vomiting. The combination of the psychoactive cannabis alkaloid Δ9-tetrahydrocannabinol (THC) with the non-psychotropic alkaloids cannabidiol (CBD) and cannabinol (CBN) demonstrated a higher activity than THC alone. The Italian National Institute of Health sought to establish conditions and indications on how to correctly use nationally produced cannabis to guarantee therapeutic continuity in individuals treated with medical cannabis.

METHODS

The evaluation of cannabinoids concentration and stability in standardized preparations of cannabis tea and cannabis oil was conducted using an easy and fast ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) assay.

RESULTS

Extraction efficiency of oil was significantly higher than that of water with respect to the different cannabinoids. This was especially observed in the case of the pharmacologically active THC, CBD and their acidic precursors. Fifteen minutes boiling was sufficient to achieve the highest concentrations of cannabinoids in the cannabis tea solutions. At ambient temperature, a significant THC and CBD decrease to 50% or less of the initial concentration was observed over 3 and 7 days, respectively. When refrigerated at 4 °C, similar decreasing profiles were observed for the two compounds. The cannabinoids profile in cannabis oil obtained after pre-heating the flowering tops at 145 °C for 30 min in a static oven resulted in a complete decarboxylation of cannabinoid acids CBDA and THCA-A. Nevertheless, it was apparent that heat not only decarboxylated acidic compounds, but also significantly increased the final concentrations of cannabinoids in oil. The stability of cannabinoids in oil samples was higher than that in tea samples since the maximum decrease (72% of initial concentration) was observed in THC coming from unheated flowering tops at ambient temperature. In the case of the other cannabinoids, at ambient and refrigerated temperatures, 80%-85% of the initial concentrations were measured up to 14 days after oil preparation.

CONCLUSIONS

As the first and most important aim of the different cannabis preparations is to guarantee therapeutic continuity in treated individuals, a strictly standardized preparation protocol is necessary to assure the availability of a homogeneous product of defined stability.

Effect of prior foot shock stress and Δ9-tetrahydrocannabinol, cannabidiolic acid, and cannabidiol on anxiety-like responding in the light-dark emergence test in rats

RATIONALE

Cannabis is commonly used by humans to relieve stress.

OBJECTIVES AND METHODS

Here, we evaluate the potential of intraperitoneally (i.p.) administered Δ⁹-tetrahydrocannabiol (THC) and cannabidiolic acid (CBDA, the precursor of cannabidiol [CBD]) to produce dose-dependent effects on anxiety-like responding in the light-dark (LD) emergence test of anxiety-like responding in rats, when administered acutely or chronically (21 days). As well, we evaluate the potential of THC, CBDA, and CBD to reduce anxiogenic responding produced by foot shock (FS) stress 24 h prior to the LD test.

RESULTS

In the absence of the explicit FS stressor, THC (1 and 10 mg/kg) produced anxiogenic-like responding when administered acutely or chronically, but CBDA produced neither anxiogenic- nor anxiolytic-like responding. Administration of FS stress 24 h prior to the LD test enhanced anxiogenic-like responding (reduced time spent and increased latency to enter the light compartment) in rats pretreated with either vehicle (VEH) or THC (1 mg/kg); however, administration of CBDA (0.1-100 μg/kg) or CBD (5 mg/kg) prevented the FS-induced anxiogenic-like responding (an anxiolytic-like effect). The 5-hydroxytryptamine 1A (5-HT_1A) receptor antagonist, WAY100635, reversed CBDA's anxiolytic effect (1 μg/kg). Combining an anxiolytic dose of CBDA (1 μg/kg) or CBD (5 mg/kg) with an anxiogenic dose of THC (1 mg/kg) did not modify THC's anxiogenic effect.

CONCLUSION

These results suggest the anxiolytic effects of CBDA and CBD may require the presence of a specific stressor.

From Phytocannabinoids to Cannabinoid Receptors and Endocannabinoids: Pleiotropic Physiological and Pathological Roles Through Complex Pharmacology

Apart from having been used and misused for at least four millennia for, among others, recreational and medicinal purposes, the cannabis plant and its most peculiar chemical components, the plant cannabinoids (phytocannabinoids), have the merit to have led humanity to discover one of the most intriguing and pleiotropic endogenous signaling systems, the endocannabinoid system (ECS). This review article aims to describe and critically discuss, in the most comprehensive possible manner, the multifaceted aspects of 1) the pharmacology and potential impact on mammalian physiology of all major phytocannabinoids, and not only of the most famous one Δ9-tetrahydrocannabinol, and 2) the adaptive pro-homeostatic physiological, or maladaptive pathological, roles of the ECS in mammalian cells, tissues, and organs. In doing so, we have respected the chronological order of the milestones of the millennial route from medicinal/recreational cannabis to the ECS and beyond, as it is now clear that some of the early steps in this long path, which were originally neglected, are becoming important again. The emerging picture is rather complex, but still supports the belief that more important discoveries on human physiology, and new therapies, might come in the future from new knowledge in this field.

Effect of combined oral doses of Δ(9)-tetrahydrocannabinol (THC) and cannabidiolic acid (CBDA) on acute and anticipatory nausea in rat models

RATIONALE

The purpose of this study was to evaluate the potential of oral combined cannabis constituents to reduce nausea.

OBJECTIVE

The objective of this study was to determine the effect of combining subthreshold oral doses of Δ(9)-tetrahydrocannabinol (THC) and cannabidiolic acid (CBDA) on acute and anticipatory nausea in rat models of conditioned gaping.

MATERIAL AND METHODS

The potential of intragastric (i.g.) administration of THC, CBDA, or combined doses, to interfere with acute nausea-induced conditioned gaping (acute nausea) or the expression of contextually elicited conditioned gaping (anticipatory nausea), was evaluated.

RESULTS

For acute nausea, i.g. administration of subthreshold doses of THC (0.5 and 1 mg/kg) or CBDA (0.5 and 1 μg/kg) significantly suppressed acute nausea-induced gaping, whereas higher individual doses of both THC and CBDA were maximally effective. Combined i.g. administration of higher doses of THC and CBDA (2.5 mg/kg THC-2.5 μg/kg CBDA; 10 mg/kg THC-10 μg/kg CBDA; 20 mg/kg THC-20 μg/kg CBDA) also enhanced positive hedonic reactions elicited by saccharin solution during conditioning. For anticipatory nausea, combined subthreshold i.g. doses of THC (0.1 mg/kg) and CBDA (0.1 μg/kg) suppressed contextually elicited conditioned gaping. When administered i.g., THC was effective on its own at doses ranging from 1 to 10 mg/kg, but CBDA was only effective at 10 μg/kg. THC alone was equally effective by intraperitoneal (i.p.) and i.g. administration, whereas CBDA alone was more effective by i.p. administration (Rock et al. in Psychopharmacol (Berl) 232:4445-4454, 2015) than by i.g. administration.

CONCLUSIONS

Oral administration of subthreshold doses of THC and CBDA may be an effective new treatment for acute nausea and anticipatory nausea and appetite enhancement in chemotherapy patients.

Cannabinoids As Potential Treatment for Chemotherapy-Induced Nausea and Vomiting

Despite the advent of classic anti-emetics, chemotherapy-induced nausea is still problematic, with vomiting being somewhat better managed in the clinic. If post-treatment nausea and vomiting are not properly controlled, anticipatory nausea—a conditioned response to the contextual cues associated with illness-inducing chemotherapy—can develop. Once it develops, anticipatory nausea is refractive to current anti-emetics, highlighting the need for alternative treatment options. One of the first documented medicinal uses of Δ⁹-tetrahydrocannabinol (Δ⁹-THC) was for the treatment of chemotherapy-induced nausea and vomiting (CINV), and recent evidence is accumulating to suggest a role for the endocannabinoid system in modulating CINV. Here, we review studies assessing the therapeutic potential of cannabinoids and manipulations of the endocannabinoid system in human patients and pre-clinical animal models of nausea and vomiting.

What is nausea? A historical analysis of changing views

The connotation of "nausea" has changed across several millennia. The medical term 'nausea' is derived from the classical Greek terms ναυτια and ναυσια, which designated the signs and symptoms of seasickness. In classical texts, nausea referred to a wide range of perceptions and actions, including lethargy and disengagement, headache (migraine), and anorexia, with an awareness that vomiting was imminent only when the condition was severe. However, some recent articles have limited the definition to the sensations that immediately precede emesis. Defining nausea is complicated by the fact that it has many triggers, and can build-up slowly or rapidly, such that the prodromal signs and symptoms can vary. In particular, disengagement responses referred to as the "sopite syndrome" are typically present only when emetic stimuli are moderately provocative, and do not quickly culminate in vomiting or withdrawing from the triggering event. This review considers how the definition of "nausea" has evolved over time, and summarizes the physiological changes that occur prior to vomiting that may be indicative of nausea. Also described are differences in the perception of nausea, as well as the accompanying physiological responses, that occur with varying stimuli. This information is synthesized to provide an operational definition of nausea.

Cannabinoid Regulation of Acute and Anticipatory Nausea

Chemotherapy-induced nausea is one of the most distressing symptoms reported by patients undergoing treatment, and even with the introduction of newer antiemetics such as ondansetron and aprepitant, nausea remains problematic in the clinic. Indeed, when acute nausea is not properly managed, the cues of the clinic can become associated with this distressing symptom resulting in anticipatory nausea for which no effective treatments are available. Clinical trials exploring the potential of exogenous or endogenous cannabinoids to reduce chemotherapy-induced nausea are sparse; therefore, we must rely on the data from pre-clinical rat models of nausea. In this review, we explore the human and pre-clinical animal literature examining the potential for exogenous and endogenous cannabinoid treatments to regulate chemotherapy-induced nausea. The pre-clinical evidence points to a compelling need to evaluate the antinausea potential of cannabidiol, cannabidiolic acid, and treatments that boost the functioning of the endocannabinoid system in human clinical trials.