Evaluation of decarboxylation efficiency of Δ9-tetrahydrocannabinolic acid and cannabidiolic acid by UNODC method

PURPOSE

Decarboxylation of Δ⁹-tetrahydrocannabinolic acid (Δ⁹-THCA) to Δ⁹-tetrahydrocannabinol (Δ⁹-THC) by heating is a common method for determining total Δ⁹-THC. In the manual for cannabis identification and analysis, the United Nations Office on Drugs and Crime (UNODC) proposed decarboxylation conditions. Although the manual's primary analytical target is Δ⁹-THC, some reports also quantified cannabidiol (CBD). The authors assessed the efficiency of decarboxylation of Δ⁹-THCA and cannabidiolic acid (CBDA), a carboxylated form of CBD, under four decarboxylation conditions, including the UNODC condition.

METHODS

Δ⁹-THCA and CBDA were heated in 2-mL glass vials at 150 °C for 12 min after the following treatment: condition A involves the addition of ethanol without capping, condition B involves non addition of solvent without capping, condition C involves non addition of solvent with capping, and condition D (UNODC condition) involves the addition of 0.5 mg/mL tribenzylamine (TBA) in ethanol without capping. The residue after heating was dissolved in methanol and then analyzed by high-performance liquid chromatography.

RESULTS

The production of Δ⁹-THC and CBD was low (≤ 10.1%) under conditions A and B. Under condition C, Δ⁹-THC production was increased (53.4%), but CBD production was hardly improved (11.7%). Under condition D, Δ⁹-THC and CBD production dramatically increased to 83.2 and 71.0%, respectively.

CONCLUSIONS

These findings indicated that TBA improved the production of Δ⁹-THC and CBD from their carboxylated forms; however, even in the presence of TBA, their production did not reach 100%. Forensic toxicologists should understand the effectiveness and limitations of decarboxylation under the UNODC condition.

Lipid nano-carriers loaded with Cannabis sativa extract for epilepsy treatment - in vitro characterization and in vivo efficacy studies

Taking into consideration the latest reported beneficial anticolvusant effects of cannabidiol (CBD) and cannabiodiolic acid (CBDA) for clinical applications and the advantages of lipid nano-systems as carriers for targeted brain delivery, the aim of this study was set in direction of in vitro physico-chemical and biopharmaceutical characterization and in vivo evaluation of nanoliposomes and nanostructured lipid carriers loaded with Cannabis sativa extract intended for safe and efficient transport via blood-brain barrier and treatment of epilepsy. These nanoliposomes and nanostructured lipid formulations were characterized with z-average diameter <200 nm, following unimodal particle size distribution, negative values for Z-potential, high drug encapsulation efficiency and prolonged release during 24h (38.84-60.91 %). Prepared formulations showed statistically significant higher antioxidant capacity compared to the extract. The results from in vivo studies of the anticonvulsant activity demonstrated that all formulations significantly elevated the latencies for myoclonic, clonic and tonic seizures and, therefore, could be used in preventing different types of seizures. A distinction in the potential of the nano-systems was noted, which was probably anticipated by the type and the characteristics of the prepared formulations.

Cannabidiolic acid in Hemp Seed Oil Table Spoon and Beyond

Cannabidiolic acid (CBDA) is the main precannabinoid in industrial hemp. It represents a common constituent of hemp seed oil, but mainly abundant in the aerial parts of the plant (including their processing waste). Thus, the optimization of fast and low-cost purification strategies is mandatory, as well as a deep investigation on its nutraceutical and cosmeceutical properties. To this purpose, CBDA content in hemp seed oil is evaluated, and its recovery from wasted leaves is favorably achieved. The cytotoxicity screening towards HaCaT cells, by means of MTT, SRB and LDH release assays, suggested it was not able to decrease cell viability or perturb cell integrity up to 10 μM concentration. Thus, the ability of CBDA to differentially modulate the release of proinflammatory cytokines and chemokines mediators has been evaluated, finding that CBDA decreased IFN-γ, CXCL8, CXCL10, CCL2, CCL4 and CCL5, mostly in a dose-dependent manner, with 10 μM tested concentration exerting the highest activity. These data, together with those from assessing antimicrobial activity against Gram(+) and Gram(−) bacteria and the antibiofilm formation, suggest that CBDA is able to counteract the inflammatory response, also preventing bacteria colonization.

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.

Development of a novel cannabinoid-loaded microemulsion towards an improved stability and transdermal delivery

The aim of this study was to develop a stable microemulsion (ME) for transdermal delivery of tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA). The lipid-based vehicles were selected by screening cannabinoid solubility and the emulsifying ability of surfactants. Pseudo-ternary phase diagrams were constructed by formulation of cannabinoids with Capryol® 90 as oil phase, Tween® 80, Solutol® HS15, Procetyl® AWS, and Cremophor® RH40 as surfactants, ethanol as cosurfactant, and distilled water as the aqueous phase. A significant improvement in transmembrane flux (J_ss), permeability coefficient (K_p), and enhancement ratio (E_R) was found in one system compared to other formulations. This ME consisted of 1.0% (w/w) of cannabinoids, 5% (w/w) of Capryol® 90, 44% (w/w) S_mix (2:1, Procetyl® AWS and Ethanol) and 50.0% (w/w) of distilled water. Additionally, the effects of pH on the permeation of the cannabinoids were investigated. Based on the pH value THCA and CBDA-loaded ME exhibited the highest permeation at pH 5.17 and pH 5.25. After storing the pH-adjusted P2 ME and the optimized P2 ME for 180 days at 4℃ and 25℃, the content of cannabinoids was over 95%. Consequently, the cannabinoid-loaded ME system is a promising option for solubilizing and stabilizing lipophilic drugs like cannabinoids and utilize them for transdermal delivery.

Effective determination of the principal non-psychoactive cannabinoids in fiber-type Cannabis sativa L. by UPLC-PDA following a comprehensive design and optimization of extraction methodology

Cannabidiol (CBD) and cannabidiolic acid (CBDA) represent the most abundant non-psychoactive cannabinoids in fiber-type Cannabis sativa L. (hemp) and both have demonstrated high therapeutic potential. Hence, efficient extraction coupled with reliable determination of these compounds is crucial for informed utilization of hemp and is increasingly needed in the present state of harmonization efforts. In this context, a systematic approach for extraction optimization was followed, which initially involved comparison of three widely available extraction techniques, i.e. ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), and dynamic maceration (DM). These were applied on samples of different hemp varieties (n = 3) using ethanol as a safe and efficient solvent. UAE showed the most promising results and was further optimized by means of response surface methodology (RSM), based on a circumscribed central composite design. The conditions maximizing CBD, CBDA, and total CBD content as well as extraction yield were determined with high desirability (0.97) and were experimentally confirmed. The optimized UAE method was also compared with a previously reported extraction procedure, demonstrating superior performance. For the quantitation of CBD and CBDA in hemp extracts, a reversed-phase UPLC-PDA method was developed and validated. Chromatographic separation was achieved in less than 10 min, while satisfactory results for linearity (R² > 0.996), precision (RSD < 2.0%), and accuracy (recovery rates of 93.1-101.0%) were obtained for both analytes. Limits of detection were determined as 0.07 and 0.04 μg mL^-1 for CBD and CBDA, respectively, indicating sufficient sensitivity. The good performance of the method was verified by the evaluation of additional parameters (e.g. matrix effect, extraction recovery), which was largely enabled by the use of isolated standards. The whole analytical workflow, involving both optimized UAE extraction and UPLC-PDA determination, entails simplified manipulation and may offer a reliable and cost-effective approach for routine quality control of hemp regarding the principal cannabinoids.

Cannabidiolic acid exhibits entourage-like improvements of anticonvulsant activity in an acute rat model of seizures

OBJECTIVES

Cannabidiolic acid (CBDa) is pharmacologically unique from cannabidiol (CBD), but its chemical instability poses challenges for potential clinical utility. Here, we used magnesium ions to stabilize two cannabidiolic acid-enriched hemp extracts (Mg-CBDa and Chylobinoid, the latter of which also contains minor cannabinoid constituents) and compared their anticonvulsant activities with CBD in the maximal electroshock seizure test (MES) in rats.

METHODS

Sprague-Dawley rats received intraperitoneal (i.p.) injections of Chylobinoid, Mg-CBDa, or CBD at varying doses at discrete time points. Rats were challenged with a 0.2 s, 60 Hz, 150 mA corneal stimulation and evaluated for resultant hindlimb tonic extension. Dose-response relationships were calculated using Probit analysis and statistical significance was assessed with a two-sample z-test.

RESULTS

Median effective doses (ED₅₀) and 95 % confidence intervals were calculated for each compound and adjusted according to percentage of CBDa (w/w): Chylobinoid: 76.7 (51.7-109.2) mg/kg. Mg-CBDa: 115.4 (98.8-140.9) mg/kg. CBD: 68.8 (56.6-80.0) mg/kg.

SIGNIFICANCE

CBDa-enriched hemp extracts exhibited dose-dependent protection in the MES model at doses comparable, but not more effective than, CBD. Chylobinoid was more effective than Mg-CBDa despite lower CBDa content. Test compounds should be compared by sub-chronic dosing in the MES test in order to assess safety and pharmacokinetic profiles. CBDa should be evaluated in pharmacoresistant and chronic animal models of epilepsy.

Cannabidiolic acid dampens the expression of cyclooxygenase-2 in MDA-MB-231 breast cancer cells: Possible implication of the peroxisome proliferator-activated receptor β/δ abrogation

A growing body of experimental evidence strongly suggests that cannabidiolic acid (CBDA), a major component of the fiber-type cannabis plant, exerts a variety of biological activities. We have reported that CBDA can abrogate cyclooxygenase-2 (COX-2) expression and its enzymatic activity. It is established that aberrant expression of COX-2 correlates with the degree of malignancy in breast cancer. Although the reduction of COX-2 expression by CBDA offers an attractive medicinal application, the molecular mechanisms underlying these effects have not fully been established. It has been reported that COX-2 expression is positively controlled by peroxisome proliferator-activated receptor β/δ (PPARβ/δ) in some cancerous cells, although there is "no" modulatory element for PPARβ/δ on the COX-2 promoter. No previous studies have examined whether an interaction between PPARβ/δ-mediated signaling and COX-2 expression exists in MDA-MB-231 cells. We confirmed, for the first time, that COX-2 expression is positively modulated by PPARβ/δ-mediated signaling in MDA-MB-231 cells. CBDA inhibits PPARβ/δ-mediated transcriptional activation stimulated by the PPARβ/δ-specific agonist, GW501516. Furthermore, the disappearance of cellular actin stress fibers, a hallmark of PPARβ/δ and COX-2 pathway activation, as evoked by the GW501516, was effectively reversed by CBDA. Activator protein-1 (AP-1)-driven transcriptional activity directly involved in the regulation of COX-2 was abrogated by the PPARβ/δ-specific inverse agonists (GSK0660/ST-247). Thus, it is implicated that there is positive interaction between PPARβ/δ and AP-1 in regulation of COX-2. These data support the concept that CBDA is a functional down-regulator of COX-2 through the abrogation of PPARβ/δ-related signaling, at least in part, in MDA-MB-231 cells.

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.

Effect of combined doses of Δ(9)-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.

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.

Elucidation of structure-function relationship of THCA and CBDA synthase from Cannabis sativaL

Cannabinoids are secondary natural products from the plant Cannabis sativaL. Therapeutic indications of cannabinoids currently comprise a significant area of medicinal research. We have expressed the Δ⁹-tetrahydrocannabinolic acid synthase (THCAS) and cannabidiolic acid synthase (CBDAS) recombinantly in Komagataella phaffii and could detect eight different products with a cannabinoid scaffold after conversion of the precursor cannabigerolic acid (CBGA). Besides five products remaining to be identified, both enzymes were forming three major cannabinoids of C. sativa - Δ⁹-tetrahydrocannabinolic acid (THCA), cannabidiolic acid (CBDA) and cannabichromenic acid (CBCA). In pursuit of improved enzyme properties for a biotechnological cannabinoid production, we performed site-directed mutagenesis to investigate the glycosylation pattern, the C-terminal berberine-bridge-enzyme (BBE) domain, the active site and the product specificity of both enzymes. The THCAS variant T_N89Q+N499Q (lacking two glycosylation sites) exerted about two-fold increased activity compared to wild-type enzyme. Variant T_H494C+R532C (additional disulfide bridge) exerted about 1.7-fold increased activity compared to wild-type enzyme and a shifted temperature optimum from 52 °C to 57 °C. We generated two CBDAS variants, C_S116A and C_A414V, with 2.8 and 3.3-fold increased catalytic activities for CBDA production. C_A414V additionally showed a broadened pH spectrum and a 19-fold increased catalytic activity for THCA production. These studies lay the groundwork for further research as well as biotechnological cannabinoid production.

Effect of prior foot shock stress and Δ(9)-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.

Neuromotor tolerability and behavioural characterisation of cannabidiolic acid, a phytocannabinoid with therapeutic potential for anticipatory nausea

RATIONALE

Anticipatory nausea (AN) is a poorly controlled side effect experienced by chemotherapy patients. Currently, pharmacotherapy is restricted to benzodiazepine anxiolytics, which have limited efficacy, have significant sedative effects and induce dependency. The non-psychoactive phytocannabinoid, cannabidiolic acid (CBDA), has shown considerable efficacy in pre-clinical AN models, however determination of its neuromotor tolerability profile is crucial to justify clinical investigation. Provisional evidence for appetite-stimulating properties also requires detailed investigation.

OBJECTIVES

This study aims to assess the tolerability of CBDA in locomotor activity, motor coordination and muscular strength tests, and additionally for ability to modulate feeding behaviours.

METHODS

Male Lister Hooded rats administered CBDA (0.05-5 mg/kg; p.o.) were assessed in habituated open field (for locomotor activity), static beam and grip strength tests. A further study investigated whether these CBDA doses modulated normal feeding behaviour. Finally, evidence of anxiolytic-like effects in the habituated open field prompted testing of 5 mg/kg CBDA for anxiolytic-like activity in unhabituated open field, light/dark box and novelty-suppressed feeding (NSF) tests.

RESULTS

CBDA had no adverse effects upon performance in any neuromotor tolerability test, however anxiolytic-like behaviour was observed in the habituated open field. Normal feeding behaviours were unaffected by any dose. CBDA (5 mg/kg) abolished the increased feeding latency in the NSF test induced by the 5-HT1AR antagonist, WAY-100,635, indicative of anxiolytic-like effects, but had no effect on anxiety-like behaviour in the novel open field or light/dark box.

CONCLUSIONS

CBDA is very well tolerated and devoid of the sedative side effect profile of benzodiazepines, justifying its clinical investigation as a novel AN treatment.

Suppression of lithium chloride-induced conditioned gaping (a model of nausea-induced behaviour) in rats (using the taste reactivity test) with metoclopramide is enhanced by cannabidiolic acid

We aimed to determine the potential of various doses of metoclopramide (MCP, a dopamine antagonist) to reduce lithium chloride (LiCl)-induced conditioned gaping (a nausea-induced behaviour) in rats, using the taste reactivity test. We then evaluated whether an ineffective low dose of cannabidiolic acid (CBDA, 0.1 μg/kg, Rock and Parker, 2013), the potent acidic precursor of cannabidiol (CBD, a non-psychoactive component of cannabis) could enhance the anti-nausea effects of an ineffective low dose of MCP. MCP (3.0 mg/kg) reduced conditioned gaping responses. Coadministration of ineffective doses of MCP (0.3 mg/kg) and CBDA (0.1 μg/kg) enhanced the suppression of conditioned gaping, over that of either drug alone, without interfering with conditioned taste avoidance. MCP dose-dependently reduced nausea-induced conditioned gaping in rats. As well, the suppression of conditioned gaping was enhanced when ineffective doses of MCP and CBDA were coadministered. These data suggest that CBDA could be a powerful adjunct treatment to anti-emetic regimens for chemotherapy-induced nausea.