Cannabinoids stimulate and inhibit testosterone production in vitro and in vivo

The major psychoactive Δ⁹-tetrahydrocannabinol (THC) and the non-psychoactive cannabinol (CBN) of cannabidiol (CBD) can both stimulate and inhibit testicular testosterone (T) production $\text{in vitro}$ and $\text{in vivo}$. At nanomolar concentrations, these cannabinoids stimulate T production by decapsulated mouse testes while, in micromolar amounts, the effects are markedly inhibitory.     

Cannabinoid bis-homologues: Miniaturised synthesis and GLC study

Rapid miniaturised syntheses (1–20 mg.) of the cannabidiol, Δ¹- and Δ^1,6-tetrahydrocannabinol, cannabinol, cannabigerol, cannabichromen, cannabicyclol and cannabicitran structures with Me, Prⁿ, Amⁿ and Heptⁿ side-chains have been carried out. This makes possible a GLC, and TLC, study of these 32 natural, or potentially natural, cannabinoids.     

Anticonvulsant properties of delta 9-tetrahydrocannabinol and other cannabinoids

Anticonvulsant doses of Δ⁹-tetrahydrocannabinol (Δ⁹-THC) markedly lower body temperature in mice at an ambient temperature of 22°C, but there is little such effect at 30°C. The anticonvulsant properties of Δ⁹-THC are as follows: The drug abolishes hind-limb extension in a maximal electroshock (MES) test, elevates both the MES (extensor) and 6-Hz-electroshock thresholds, exerts no effect on the 60-Hz-electroshock threshold, and enhances minimal seizures caused by pentylenetetrazol. All anticonvulsant properties studied, with the exception of the 60-Hz-electroshock threshold, were unaffected by the hypothermia resulting at 22°C. Additional experiments with Δ⁹-THC indicated that chronic treatment results in the development of tolerance, as determined by the MES test with rats. The four principal naturally occurring cannabinoids, Δ⁹-THC, Δ⁸-THC, cannabinol and cannabidiol, display anticonvulsant activity, as does the major, primary metabolite of Δ⁹-THC, 11-hydroxy-Δ⁹-THC. Of all agents investigated in mice, the synthetic cannabinoids, dimethylheptylpyran and its isomers, are the most potent anticonvulsants. The results of a study of the relative motor toxicity and anticonvulsant activity of the cannabinoids demonstrate that these properties are at least partially separable among the various agents.     

Influence of anticonvulsant cannabinoids on posttetanic potentiation at isolated bullfrog ganglia

The effects of anticonvulsant cannabinoids on posttetanic potentiation (PTP) at bullfrog paravertebral ganglia $\text{in vitro}$ were investigated electrophysiologically. Two Δ⁹-tetrahydrocannabinol metabolites, 11-hydroxy-Δ⁹-tetrahydrocannabinol and 8α, 11-dihydroxy-Δ⁹-tetrahydrocannabinol, as well as cannabidiol, markedly depressed PTP. In contrast, Δ⁹-tetrahydrocannabinol had no such effect. Thus, the findings of the present study clearly demonstrate that pharmacological properties of these hydroxylated metabolites of Δ⁹-tetrahydrocannabinol are not identical to those of their parent compound.     

Photochemical decomposition of cannabidiol in its resin base

Cannabidiol in fiber-type Cannabis sativa resin from floral tissues showed a gradual and consistent decline over time when irradiated with 1320 kJ/m²/day of UV and visible radiation. The concentration of Δ⁹-tetrahydrocannabinol in the resin was not affected by the treatment. Therefore, the trace amounts of Δ⁹-tetrahydrocannabinol detected in some fiber-type C. sativa are probably not of photochemical origin.     

Hypothermic action of delta 9-tetrahydrocannabinol, 11-hydroxy-delta 9-tetrahydrocannabinol and 11-hydroxy-delta 8-tetrahydrocannabinol in mice

The hypothermic activity of Δ⁹-tetrahydrocannabinol (Δ⁹-THC), a metabolite, 11-hydroxy-Δ⁹-tetrahydrocannabinol (11-OH-Δ⁹-THC) and 11-hydroxy-Δ⁸-tetrahydrocannabinol (11-OH-Δ⁸-THC) has been determined in male mice maintained at an ambient temperature of 20 ± 1°C. The mean body temperature of mice that received 2, 4, 16 or 32 mg/kg, i. v., of a tetrahydrocannabinol was significantly lower than that of vehicle treated mice (p <0.05) within 2 minutes after drug administration. Dose-response relationships show the intrinsic activity of Δ⁹-THC to be significantly greater than that of 11-OH-Δ⁹-THC or 11-OH-Δ⁸-THC in this system (p <0.05). The data indicate that the hypothermic activity of Δ⁹-THC cannot be explained entirely by metabolism to 11-OH-Δ⁹-THC.     

Acquisition of tolerance to Δ-9-THC as measured by the response of a cellular function

The development of tolerance to delta-9-tetrahydrocannabinol (Δ-9-THC) was investigated by measuring respiration in brain tissue after acute or chronic administration. Mice were given either single or seven daily repeated intraperitoneal injections of 50 mg/Kg of delta-9-tetrahydrocannabinol (Δ-9-THC) or control vehicle. The final injection for all drug treated animals included radiolabeled ³H-Δ-9-THC. The mice were sacrificed at 1 hour, 2 hours, 4 hours, 24 hours, and 7 days after the final injection. Δ-9-THC depressed respiration, but after repeated injections was significantly less effective in this regard, indicating acquisition of tolerance to Δ-9-THC. Because the concentration of radiolabeled cannabinoids in brain tissue from each group is not appreciably different, a cellular as opposed to distributional mode of tolerance is suggested.     

Inhibition of sea urchin fertilization by fatty acid ethanolamides and cannabinoids

The influence of saturated and unsaturated fatty acid ethanolamides as well as Δ⁹-tetrahydrocannabinol (Δ⁹-THC), WIN 55,212-2 and cannabinoid CB₁ receptor antagonist SR 141716 on sea urchin fertilization was studied. The ethanolamides of arachidonic, oleic and linoleic acids but not saturated fatty acid (C₁₄–C₂₀) derivatives inhibited fertilization when pre-incubated with sperm cells. Δ⁹-THC and WIN 55,212-2 also inhibited fertilization, Δ⁹-THC being ten times as potent as WIN 55,212-2. Selective cannabinoid CB₁ receptor antagonist SR 141716 also blocked fertilization and did not antagonize the action of Δ⁹-THC. The obtained results indicate that different unsaturated fatty acid ethanolamides may control sea urchin fertilization, and that sea urchin sperm cell cannabinoid receptor may differ from the known cannabinoid receptor subtypes.     

Systemic Injections of Cannabidiol Enhance Acetylcholine Levels from Basal Forebrain in Rats

Cannabis sativa is a plant that contains more than 500 components, of which the most studied are Δ⁹-tetrahydrocannabinol (Δ⁹-THC) and cannabidiol (CBD). Several studies have indicated that CBD displays neurobiological effects, including wake promotion. Moreover, experimental evidence has shown that injections of CBD enhance wake-related compounds, such as monoamines (dopamine, serotonin, epinephrine, and norepinephrine). However, no clear evidence is available regarding the effects of CBD on additional wake-related neurochemicals such as acetylcholine (ACh). Here, we demonstrate that systemic injections of CBD (0, 5, 10 or 30 mg/kg, i.p.) at the beginning of the lights-on period, increase the extracellular levels of ACh collected from the basal forebrain and measured by microdialysis and HPLC means. Moreover, the time course effects on the contents of ACh were present 5 h post-injection of CBD. Altogether, these data demonstrate that CBD increases ACh levels in a brain region related to wake control. This study is the first to show the effects of ACh levels in CBD-treated rats and suggests that the basal forebrain might be a site of action of CBD for wakefulness modulation.     

Purification of Δ9-Tetrahydrocannabinol,an Active Constituent of Marihuana,by Accelerated Microparticulate Gel Chromatography

A technique is described by which Δ⁹ -tetrahydrocannabinol, the principal psychotomimetic constituent of marihuana and hashish, can be isolated in a chromatographically pure state from synthetic or natural products by pressure-accelerated chromatography through columns of ultrafine silica gel packed by centrifugal force.     

Δ9-tetrahydrocannabinol and dimethylheptylpyran induced tachycardia in the conscious rat

Since cannabinoids lead to dose-related tachycardia in man but dose dependent bradycardia has been reported thus far in laboratory animals, there would seem to be a need for an experimental model in which the effect seen in man (tachycardia) could be reproduced and explored. In the conscious rat, the compounds Δ⁹-tetrahydrocannabinol (Δ⁹-THC) and dimethylheptylpyran (DMHP) injected i.p. led to dose-related increases in heart rate at 10–20 minutes after administration. In vehicle (ethanol) control rats there were small increases in heart rate. Propranolol given before Δ⁹-THC resulted in a parallel shift to the right of the dose-effect curve. Adrenalectomy led to a significant (p<0.01) decrease in tachycardia following Δ⁹-THC and DMHP while ganglionic block markedly decreased the heart rate increases after Δ⁹-THC (p<0.001). Systolic blood pressure at nearly all doses of Δ⁹-THC was minimally affected, although it tended to decrease with increasing dose. Tachycardia in the rat may be the result of a centrally mediated release of epinephrine from the adrenal gland.     

Allylbenzene analogs of Δ9-tetrahydrocannabinol as tumor growth inhibitors

A series of substituted allylbenzene derivatives was tested $\text{in vitro}$ for ability to inhibit cell growth in the KB cell line. None of the compounds was as active as Δ⁹-tetrahydrocannabinol. It is suggested that inhibition of cell growth by cannabinoids requires a polycyclic system which may act by an intercalaction mechanism.     

Hydroxylation and glycosylation of Δ9-tetrahydrocannabinol by Catharanthus roseus cell suspension culture

Δ⁹-tetrahydrocannabinol is the active constituent in Cannabis sativa, with reported analgesic, anti-emetic, anti-oxidative, neuroprotective, and anti-inflammatory activities. Δ⁹-THC has been used to treat a number of disease states including pain, anxiety, asthma, glaucoma, and hypertension. Poor water solubility of Δ⁹-THC greatly reduces its clinical effectiveness. Consequently, there is a need to modify the compound to increase its polarity and pharmaceutical efficacy. The aim of this study was to test the capability of Catharanthus roseus suspension cultured cells to convert Δ⁹-THC into more polar derivatives. The transformed metabolites were analyzed and isolated by HPLC. Structures of some new derivatives were proposed on the basis of molecular ion peaks and fragmentation patterns obtained from LC-MS and UV spectra obtained by HPLC, respectively. Δ⁹-THC was rapidly absorbed by Catharanthus roseus cultured cells and upon biotransformation new glycosylated and hydroxylated derivatives were isolated by preparative HPLC. In addition, cannabinol was detected as degradation product, including its glycosylated derivative. Based on these results, it is concluded that Catharanthus cultured cells have great potential to transform Δ⁹-THC into more polar derivatives and can be used for the large scale production of new cannabinoids, which can be a source of new compounds with interesting pharmacological profiles.     

Delta9-tetrahydrocannabinol: subcortical spike bursts and motor manifestations in a Fischer rat treated orally for 109 days

A total of 12 Fischer rats was prepared surgically for chronic EEG recording from cortical and subcortical sites. Most rats, within 2 to 9 weeks after electrode implantation, developed polyspike activity in cortical and subcortical recordings that were without motor manifestations. Six of these rats, chronically treated po with Δ⁹-tetrahydrocannabinol (Δ⁹-THC) 10 mg/kg exhibited acute EEG changes with more frequent occurrence of EEG desynchronization and polyspike activity. On day 109 one of 6 rats displayed consulsive activity, with jerky movements of the head and paws, characteristics of Δ⁹-THC neurotoxicity. EEG alterations concomitant with motor signs included bursts of spikes of approximately 0.2 sec that occurred in subcortical, but not in cortical, recordings. It is concluded that in the Fischer rat acute and chronic treatment with Δ⁹-THC facilitated the occurrence of surgically-induced “polyspike” activity while chronic treatment caused occasional transient subcortical spike bursts with concomitant motor manifestations.     

Endocrine effects of chronic intraventricular administration of delta9-tetrahydrocannabinol to prepuberal and adult male rats.

The daily intraventricular administration of Δ⁹-tetrahydrocannabinol (Δ⁹-THC) in microgram amounts for a week to prepuberal and adult rats had definite endocrine effects. Prostate weights were reduced and plasma and pituitary levels of growth hormone (GH) were increased in prepuberal rats. Pituitary levels of prolactin (PRL) were increased both in prepuberal and in adult animals while pituitary and adrenal weights and plasma corticosterone (B) levels were increased in adult rats. On the other hand, brain weights were significantly reduced by Δ⁹-THC in prepuberal and significantly increased in adult animals. No changes in brain levels of noradrenaline (NA), dopamine (DA) or serotonin (5-HT) were found in treated animals. These results indicate that Δ⁹-THC may modify some endocrine functions when injected directly into the brain in microgram amounts. They show on the other hand that young and adult animals may respond differently to the chronic administration of the psychoactive drug, although the difference may be due to a biphasic effect of different doses.     

Protective effect of cannabidiol against cadmium hepatotoxicity in rats

The protective effect of cannabidiol, the non-psychoactive component of Cannabis sativa, against liver toxicity induced by a single dose of cadmium chloride (6.5 mg kg^?1 i.p.) was investigated in rats. Cannabidiol treatment (5 mg kg^?1/day, i.p.) was applied for five days starting three days before cadmium administration. Cannabidiol significantly reduced serum alanine aminotransferase, and suppressed hepatic lipid peroxidation, prevented the depletion of reduced glutathione and nitric oxide, and catalase activity, and attenuated the elevation of cadmium level in the liver tissue resulted from cadmium administration. Histopathological examination showed that cadmium-induced liver tissue injury was ameliorated by cannabidiol treatment. Immunohistochemical analysis revealed that cannabidiol significantly decreased the cadmium-induced expression of tumor necrosis factor-α, cyclooxygenase-2, nuclear factor-κB, caspase-3, and caspase-9, and increased the expression of endothelial nitric oxide synthase in liver tissue. It was concluded that cannabidiol may represent a potential option to protect the liver tissue from the detrimental effects of cadmium toxicity.     

Seasonal fluctuations in cannabinoid content of Kansas Marijuana

Marijuana (Cannabis sativa L.) was sampled at nine progressive growth stages in Riley County, Kansas, and analyzed for four major cannabinoids: cannabidiol (CBD), della-8-tetrahydrocannabinol (delta-8-THC), delta-9-tetrahydrocannabinol (delta-9-THC), and cannabinol (CBN). Seasonal fluctuation in cannabinoids were related to stage of plant development. Cannabinoids were lowest in seedlings, highest prior to flowering and at an intermediate level thereafter until physiological maturity. Cannabinoids were highest in flowers and progressively lower in leaves, petioles, stems, seeds, and roots. Cannabinoid content of male and female flowers was not significantly different. Cannabidiol occurred in the highest concentrations (0.01 to 0.94% of dry matter) in all plant parts; delta-9-THC, the next highest (0.0001 to 0.06%) in the study over time. Cannabidiol content of leaf tissue of plants sampled from ten locations at flowering, ranged from 0.12 to 1.7%; delta-9-THC, from 0.01 to 0.49%. Some variation was attributed to environmental factors. Results indicate transformation of CBD to delta-9-THC to CBN. Environmental stress apparently increased delta-9-THC concentration, and bivalent ions: Mg, Mn, and Fe of leaf tissue could have regulated enzyme systems responsible for cannabinoid synthesis.     

Synthesis and structure–activity relationship of substitutions at the C-1 position of Δ9-tetrahydrocannabinol

A novel series of Δ9-tetrahydrocannabinol (Δ9-THC) analogues were synthesized to determine their potential as cannabinoid receptor modulators. Chemistry focused on conversion of the phenol of Δ9-THC to other functionality through palladium catalyzed reactions with an intermediate triflate 2. Two analogues with sub 100 nM affinity for the CB₁ and CB₂ receptors were identified.     

Potent inhibition of human cytochrome P450 3A isoforms by cannabidiol: role of phenolic hydroxyl groups in the resorcinol moiety

AimsIn this study, we examined the inhibitory effects of Δ⁹-tetrahydrocannabinol (Δ⁹-THC), cannabidiol (CBD), and cannabinol (CBN), the three major cannabinoids, on the activity of human cytochrome P450 (CYP) 3A enzymes. Furthermore, we investigated the kinetics and structural requirement for the inhibitory effect of CBD on the CYP3A activity.Main methodsDiltiazem N-demethylase activity of recombinant CYP3A4, CYP3A5, CYP3A7, and human liver microsomes (HLMs) in the presence of cannabinoids was determined.Key findingsAmong the three major cannabinoids, CBD most potently inhibited CYP3A4 and CYP3A5 (IC₅₀ = 11.7 and 1.65 μM, respectively). The IC₅₀ values of Δ⁹-THC and CBN for CYP3A4 and CYP3A5 were higher than 35 μM. For CYP3A7, Δ⁹-THC, CBD, and CBN inhibited the activity to a similar extent (IC₅₀ = 23–31 μM). CBD competitively inhibited the activity of CYP3A4, CYP3A5, and HLMs (K_i = 1.00, 0.195, and 6.14 μM, respectively). On the other hand, CBD inhibited the CYP3A7 activity in a mixed manner (K_i = 12.3 μM). Olivetol partially inhibited all the CYP3A isoforms tested, whereas d-limonene showed lack of inhibition. The lesser inhibitory effects of monomethyl and dimethyl ethers of CBD indicated that the ability of CYP3A inhibition by the cannabinoid attenuated with the number of methylation on the phenolic hydroxyl groups in the resorcinol moiety.SignificanceThis study indicated that CBD most potently inhibited catalytic activity of human CYP3A enzymes, especially CYP3A4 and CYP3A5. These results suggest that two phenolic hydroxyl groups in the resorcinol moiety of CBD may play an important role in the CYP3A inhibition.     

The effect of cannabichromene on adult neural stem/progenitor cells

Apart from the psychotropic compound Δ⁹-tetrahydrocannabinol (THC), evidence suggests that other non-psychotropic phytocannabinoids are also of potential clinical use. This study aimed at elucidating the effect of major non-THC phytocannabinoids on the fate of adult neural stem progenitor cells (NSPCs), which are an essential component of brain function in health as well as in pathology. We tested three compounds: cannabidiol, cannabigerol, and cannabichromene (CBC), and found that CBC has a positive effect on the viability of mouse NSPCs during differentiation in vitro. The expression of NSPC and astrocyte markers nestin and Glial fibrillary acidic protein (GFAP), respectively, was up- and down-regulated, respectively. CBC stimulated ERK1/2 phosphorylation; however, this effect had a slower onset in comparison to typical MAPK stimulation. A MEK inhibitor, U0126, antagonized the up-regulation of nestin but not the down-regulation of GFAP. Based on a previous report, we studied the potential involvement of the adenosine A1 receptor in the effect of CBC on these cells and found that the selective adenosine A1 receptor antagonist, DPCPX, counteracted both ERK1/2 phosphorylation and up-regulation of nestin by CBC, indicating that also adenosine is involved in these effects of CBC, but possibly not in CBC inhibitory effect on GFAP expression. Next, we measured ATP levels as an equilibrium marker of adenosine and found higher ATP levels during differentiation of NSPCs in the presence of CBC. Taken together, our results suggest that CBC raises the viability of NSPCs while inhibiting their differentiation into astroglia, possibly through up-regulation of ATP and adenosine signalling.