Cannabidiol modulates the METH-induced conditioned place preference through D2-like dopamine receptors in the hippocampal CA1 region

Hippocampal D1-like dopamine receptor as a novel target for the effect of cannabidiol on extinction and reinstatement of methamphetamine-induced CPP

Methamphetamine (METH) is a major health problem without effective pharmacological treatment. Cannabidiol (CBD), a component of the Cannabis sativa plant, is believed to have the potential to inhibit drug-related behavior. However, the neurobiological mechanisms responsible for the effects of CBD remain unclear. Several studies have proposed that the suppressing effects of CBD on drug-seeking behaviors could be through the modulation of the dopamine system. The hippocampus (HIP) D1-like dopamine receptor (D1R) is essential for forming and retrieving drug-associated memory. Therefore, the present study aimed to investigate the role of D1R in the hippocampal CA1 region on the effects of CBD on the extinction and reinstatement of METH-conditioned place preference (CPP). For this purpose, different groups of rats over a 10-day extinction period were administered different doses of intra-CA1 SCH23390 (0.25, 1, or 4 μg/0.5 μl, Saline) as a D1R antagonist before ICV injection of CBD (10 μg/5 μl, DMSO12%). In addition, a different set of animals received intra-CA1 SCH23390 (0.25, 1, or 4 μg/0.5 μl) before CBD injection (50 μg/5 μl) on the reinstatement day. The results revealed that the highest dose of SCH23390 (4 μg) significantly reduced the accelerating effects of CBD on the extinction of METH-CPP (P < 0.01). Furthermore, SCH23390 (1 and 4 μg) in the reinstatement phase notably reversed the preventive effects of CBD on the reinstatement of drug-seeking behavior (P < 0.05 and P < 0.001, respectively). In conclusion, the current study revealed that CBD made a shorter extinction period and suppressed METH reinstatement in part by interacting with D1-like dopamine receptors in the CA1 area of HIP.

GPR55 activation improves anxiety- and depression-like behaviors of mice during methamphetamine withdrawal

Methamphetamine is a potent and highly addictive neurotoxic psychostimulant that triggers a spectrum of adverse emotional responses during withdrawal. G-protein coupled receptor 55 (GPR55), a novel endocannabinoid receptor, is closely associated with mood regulation. Herein, we developed a murine model of methamphetamine-induced anxiety- and depressive-like behavior during abstinence which showed a decreased GPR55 expression in the hippocampus. Activation of GPR55 mitigated these behavioral symptoms, concomitantly ameliorating impairments in hippocampal neurogenesis and reducing neuroinflammation. These findings underscore the pivotal role of GPR55 in mediating the neuropsychological consequences of methamphetamine withdrawal, potentially via mechanisms involving the modulation of hippocampal neurogenesis and inflammation.

Identification of the circRNA-miRNA-mRNA network for treating methamphetamine-induced relapse and behavioral sensitization with cannabidiol

AIMS

This study aims to investigate the pharmacological effects and the underlying mechanism of cannabidiol (CBD) on methamphetamine (METH)-induced relapse and behavioral sensitization in male mice.

METHODS

The conditioned place preference (CPP) test with a biased paradigm and open-field test were used to assess the effects of CBD on METH-induced relapse and behavioral sensitization in male mice. RNA sequencing and bioinformatics analysis was employed to identify differential expressed (DE) circRNAs, miRNAs, and mRNAs in the nucleus accumbens (NAc) of mice, and the interaction among them was predicted using competing endogenous RNAs (ceRNAs) network analysis.

RESULTS

Chronic administration of CBD (40 mg/kg) during the METH withdrawal phase alleviated METH (2 mg/kg)-induced CPP reinstatement and behavioral sensitization in mice, as well as mood and cognitive impairments following behavioral sensitization. Furthermore, 42 DEcircRNAs, 11 DEmiRNAs, and 40 DEmRNAs were identified in the NAc of mice. The circMeis2-miR-183-5p-Kcnj5 network in the NAc of mice is involved in the effects of CBD on METH-induced CPP reinstatement and behavioral sensitization.

CONCLUSIONS

This study constructed the ceRNAs network for the first time, revealing the potential mechanism of CBD in treating METH-induced CPP reinstatement and behavioral sensitization, thus advancing the application of CBD in METH use disorders.

Intra-Accumbal D1- But not D2-Like Dopamine Receptor Antagonism Reverses the Inhibitory Effects of Cannabidiol on Extinction and Reinstatement of Methamphetamine Seeking Behavior in Rats

Introduction: Methamphetamine (METH) is an addictive psychostimulant that facilitates dopamine transmission to the nucleus accumbens (NAc), resulting in alterations in the mesocorticolimbic brain regions. Cannabidiol (CBD) is considered the second most abundant component of cannabis and is believed to decrease the METH effects. Reversing psychostimulant-induced abnormalities in the mesolimbic dopamine system is the main mechanism for this effect. Various other mechanisms have been proposed: increasing endocannabinoid system activity and modulating gamma-aminobutyric acid (GABA) and glutamate neurons in NAc. However, the exact CBD action mechanisms in reducing drug addiction and relapse vulnerability remain unclear. Methods and Results: The present study aimed to investigate the effects of intracerebroventricular (ICV) administrating 5, 10, and 50 μg/5 μL CBD solutions on the extinction period and reinstatement phase of a METH-induced conditioned place preference. This research also aimed to examine the NAc D1-like dopamine receptor (D1R) and D2-like dopamine receptor (D2R) roles in the effects of CBD on these phases, as mentioned earlier, using SCH23390 and sulpiride microinjections as an antagonist of D1R and D2R. The obtained results showed that microinjection of CBD (10 and 50 μg/5 μL, ICV) suppressed the METH-induced reinstatement and significantly decreased mean extinction latency in treated groups compared to both vehicles and/or untreated control groups. In addition, the results demonstrated that administrating intra-accumbal SCH23390 (1 and 4 μg/0.5 μL saline) reversed the inhibitory effects of CBD on extinction and reinstatement phases while different doses of sulpiride (0.25, 1, and 4 μg/0.5 μL; dimethyl sulfoxide 12%) could not alter the CBD effects. Conclusions: In summary, this study showed that CBD made shorter extinction latencies and suppressed the METH reinstatement, in part, by interacting with D1R but not D2R in the NAc.

Cardamonin mitigates kidney injury by modulating inflammation, oxidative stress, and apoptotic signaling in rats subjected to renal ischemia and reperfusion

Renal ischemia-reperfusion injury (IRI) is a critical health concern that aggravates the pathophysiology of acute kidney injury (AKI), leading to high mortality rates in intensive care units. Cardamonin is a natural compound with anti-inflammatory and antioxidant properties. The current study aimed to evaluate the renoprotective impact of cardamonin against AKI induced by renal IRI. Male rats (n=5 per group) were divided into four groups: the sham group underwent anesthesia and abdominal incision only; the control group experienced bilateral renal artery clamping for 30 minutes followed by 2 hours of reperfusion; the vehicle group received the cardamonin vehicle 30 minutes before ischemia induction; and the cardamonin group was administered 5 mg/kg of cardamonin 30 minutes before ischemia. Blood urea nitrogen (BUN) and creatinine were measured to assess the renal function. Tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), interleukin-6 (IL-6), caspase 3, and F2-isoprostane were assessed in renal tissues. Kidney injury was examined using the hematoxylin and eosin stain method. Compared to the sham group, the control group exhibited significantly higher levels of BUN, creatinine, TNF-α, IL-1β, IL-6, F2-isoprostane, and caspase 3 in renal tissues, along with severe kidney injury as evidenced by histological analysis. Compared to the control group, pretreatment with cardamonin resulted in a significant reduction in these biomarkers and alleviated renal damage. Cardamonin had renoprotective effects against renal ischemia and reperfusion injury via modulating inflammation, oxidative stress, and apoptosis pathways.

N-Oleoyl Glycine and Its Derivatives Attenuate the Acquisition and Expression of Cocaine-Induced Behaviors

Introduction: The endocannabinoid system (ECS) plays a key modulatory role during synaptic plasticity and homeostatic processes in the brain and plays an important role in the neurobiological processes underlying drug addiction. Impaired endocannabinoid (eCB) signaling contributes to dysregulated synaptic plasticity, increased stress responsivity, and craving that propel addiction. Therefore, we hypothesized that boosting the ECS by exogenous administration of selective eCBs will attenuate cocaine-induced behaviors. Materials and Methods: The behavioral paradigms included psychomotor sensitization (PS) and conditioned place preference (CPP). Liquid chromatography-mass spectrometry analysis was used for quantitative profiling of eCBs in mouse brain. Results: We first measured the levels of eCBs in different brain areas of the reward system following chronic cocaine treatment. We found that following daily administration of cocaine, the levels of N-oleoyl glycine (OlGly) were significantly elevated in the nucleus accumbens (NAc) in a region-specific manner. We next tested whether administration of OlGly will attenuate cocaine-induced behaviors. We found that administration of OlGly during withdrawal, but not during acquisition of PS, attenuated the expression of cocaine sensitization. In addition, the administration of OlGly during the acquisition of cocaine CPP, but not during withdrawal, attenuated the expression of cocaine-conditioned reward. To enhance the stability of OlGly and its duration of action, two methylated derivatives of OlGly were synthesized, the monomethylated OlGly (HU-595) and dimethylated OlGly (HU-596). We found that the effect of administration of HU-595 or HU-596 during cocaine conditioning did not differ from the OlGly-induced decrease in the expression of CPP. Conclusion: Our findings suggest that the ECS is involved in the common neurobiological mechanisms underlying the development and expression of cocaine reward and drug-seeking. Boosting the ECS exogenously has beneficial effects against cocaine-induced behaviors.

The inhibitory effect of cannabidiol on the rewarding properties of methamphetamine in part mediates by interacting with the hippocampal D1-like dopamine receptors

Cannabidiol (CBD) is a potential treatment to decrease the rewarding properties of psychostimulants. However, the exact mechanism and distinct neuroanatomical areas responsible for the CBD's effects remain unclear. Indicatively, the D1-like dopamine receptors (D1R) in the hippocampus (HIP) are essential for expressing and acquiring drug-associated conditioned place preference (CPP). Therefore, given that involving D1Rs in reward-related behaviors and the encouraging results of CBD in attenuating the psychostimulant's rewarding effects, the present study sought to investigate the role of D1Rs of the hippocampal dentate gyrus (DG) in the inhibitory effects of CBD on the acquisition and expression of METH-induced CPP. To this end, over a 5-day conditioning period by METH (1 mg/kg; sc), different groups of rats were given intra-DG SCH23390 (0.25, 1, or 4 μg/0.5 μl, saline) as a D1Rs antagonist before ICV administration of CBD (10 μg/5 μl, DMSO12%). In addition, a different set of animals, after the conditioning period, received a single dose of SCH23390 (0.25, 1, or 4 μg/0.5 μl) before CBD (50 μg/5 μl) administration on the expression day. The results showed that SCH23390 (1 and 4 μg) significantly reduced the suppressive effects of CBD on the acquisition of METH place preference (P < 0.05 and P < 0.001, respectively). Furthermore, the highest dose of SCH23390 (4 μg) in the expression phase remarkably abolished the preventive effects of CBD on the expression of METH-seeking behavior (P < 0.001). In conclusion, the current study revealed that CBD's inhibitory effect on rewarding properties of METH partially acts through D1Rs in the DG area of the HIP.

PROTECTIVE EFFECT OF EPROSARTAN IN RENAL ISCHEMIA REPERFUSION INJURY BY REGULATING OXIDATIVE STRESS, INFLAMMATION, AND APOPTOTIC CASCADES IN A BILATERAL RAT MODEL

OBJECTIVE

The aim: To evaluate the potential protective effect of Eprosartan (ARB) in bilateral renal IRI in male rats.

PATIENTS AND METHODS

Materials and methods: 20 Sprague-Dawley rats divided into four groups. Sham group had surgery without IRI. Control group was subjected to 30 min ischemia and 2 hours of reperfusion. Vehicle group received 14 ml/kg (IP) injection of solvent mixture containing (10% DMSO, 40% PEG300, 5% Tween-80, and 45% normal saline) 30 minutes before clamping. Eprosartan-treated group with 30 mg/kg Eprosartan intraperitoneally 30 min before occlusion of renal pedicles followed by 30 minutes of ischemia and 2 hours of reperfusion. Serum BUN and Creatinine used to assess renal function. Renal tissue was used to measure the levels of TNF-α, IL-1β, IL-6, F2-isoprostane, and Caspase3 were measured by assessment of renal tissue. Histopathological examinations were conducted to detect parenchymal damage.

RESULTS

Results: Mean serum levels of BUN and Creatinine as well as mean renal tissue levels of TNF-α, IL-1β, IL-6, F2-isoprostane, and Caspase3 were significantly increased in control and vehicle groups together with increase in histological damage score compared to sham group, whereas treatment of rats with Eprosartan resulted in significant reduction in mean serum levels of BUN and Creatinine and mean renal tissue levels of TNF-α, IL-1β, IL-6, F2-isoprostane, and Caspase3 and obvious reduction in tissue injury.

CONCLUSION

Conclusions: This study demonstrates that Eprosartan pretreatment enhances kidney function by decreasing serum BUN and Creatinine, oxidative stress, cytokines, and apoptotic markers.

Cannabidiol prevents methamphetamine-induced neurotoxicity by modulating dopamine receptor D1-mediated calcium-dependent phosphorylation of methyl-CpG-binding protein 2

In the past decade, methamphetamine (METH) abuse has sharply increased in the United States, East Asia, and Southeast Asia. METH abuse not only leads to serious drug dependence, but also produces irreversible neurotoxicity. Currently, there are no approved pharmacotherapies for the treatment of METH use disorders. Cannabidiol (CBD), a major non-psychoactive (and non-addictive) cannabinoid from the cannabis plant, shows neuroprotective, antioxidative, and anti-inflammatory properties under METH exposure. At present, however, the mechanisms underlying these properties remain unclear, which continues to hinder research on its therapeutic potential. In the current study, computational simulations showed that CBD and METH may directly bind to the dopamine receptor D1 (DRD1) via two overlapping binding sites. Moreover, CBD may compete with METH for the PHE-313 binding site. We also found that METH robustly induced apoptosis with activation of the caspase-8/caspase-3 cascade in-vitro and in-vivo, while CBD pretreatment prevented these changes. Furthermore, METH increased the expression of DRD1, phosphorylation of Methyl-CpG-binding protein 2 (MeCP2) at serine 421 (Ser421), and level of intracellular Ca2+in-vitro and in-vivo, but these effects were blocked by CBD pretreatment. The DRD1 antagonist SCH23390 significantly prevented METH-induced apoptosis, MeCP2 phosphorylation, and Ca2+ overload in-vitro. In contrast, the DRD1 agonist SKF81297 markedly increased apoptosis, MeCP2 phosphorylation, and Ca2+ overload, which were blocked by CBD pretreatment in-vitro. These results indicate that CBD prevents METH-induced neurotoxicity by modulating DRD1-mediated phosphorylation of MeCP2 and Ca2+ signaling. This study suggests that CBD pretreatment may resist the effects of METH on DRD1 by competitive binding.

Cannabidiol inhibits methamphetamine-induced dopamine release via modulation of the DRD1-MeCP2-BDNF-TrkB signaling pathway

RATIONALE

Adaptive alteration of dopamine (DA) system in mesocorticolimbic circuits is an extremely intricate and dynamic process, which contributes to maintaining methamphetamine (METH)-related disorders. There are no approved pharmacotherapies for METH-related disorders. Cannabidiol (CBD), a major non-psychoactive constituent of cannabis, has received attention for its therapeutic potential in treating METH-related disorders. However, the major research obstacles of CBD are the yet to be clarified mechanisms behind its therapeutic potential. Recent evidence showed that DA system may be active target of CBD. CBD could be a promising dopaminergic medication for METH-related disorders.

OBJECTIVES

We investigated the role of the DA receptor D1 (DRD1)-methyl-CpG-binding protein 2 (MeCP2)-brain-derived neurotrophic factor (BDNF)-tyrosine receptor kinase B (TrkB) signaling pathway in DA release induced by METH. Investigating the intervention effects of CBD on the DRD1-MeCP2-BDNF-TrkB signaling pathway could help clarify the underlying mechanisms and therapeutic potential of CBD in METH-related disorders.

RESULTS

METH (400 μM) significantly increased DA release from primary neurons in vitro, which was blocked by CBD (1 μM) pretreatment. METH (400 μM) significantly increased the expression levels of DRD1, BDNF, and TrkB, but decreased the expression of MeCP2 in the neurons, whereas CBD (1 μM) pretreatment notably inhibited the protein changes induced by METH. In addition, DRD1 antagonist SCH23390 (10 μM) inhibited the DA release and protein change induced by METH in vitro. However, DRD1 agonist SKF81297 (10 μM) induced DA release and protein change in vitro, which was also blocked by CBD (1 μM) pretreatment. METH (2 mg/kg) significantly increased the DA level in the nucleus accumbens (NAc) of rats with activation of the DRD1-MeCP2-BDNF-TrkB signaling pathway, but these changes were blocked by CBD (40 or 80 mg/kg) pretreatment.

CONCLUSIONS

This study indicates that METH induces DA release via the DRD1-MeCP2-BDNF-TrkB signaling pathway. Furthermore, CBD significantly inhibits DA release induced by METH through modulation of this pathway.

Cannabidiol impairs the rewarding effects of methamphetamine: Involvement of dopaminergic receptors in the nucleus accumbens

Cannabidiol, as component of cannabis, can potentially hinder the rewarding impact of drug abuse; however, its mechanism is ambiguous. Moreover, the nucleus accumbens (NAc), as a key area in the reward circuit, extensively receives dopaminergic projections from the ventral tegmentum area. To elucidate the role of accumbal D1 and D2 dopamine receptor families in Cannabidiol's inhibitory impact on the acquisition and expression phases of methamphetamine (MET), the conditioned place preference (CPP) procedure as a common method to assay reward characteristics of drugs was carried out. Six groups of rats were treated by various doses of SCH23390 or Sulpiride (0.25, 1, and 4 μg/0.5 μL) in the NAc as D1 or D2 dopamine receptor family antagonists, respectively, prior to infusion of Cannabidiol (10 μg/5 μL) in the lateral ventricle (LV) over conditioning phase in the acquisition experiments. In the second step of the study, animals received SCH23390 or Sulpiride in the NAc before Cannabidiol (50 μg/5 μL) infusion into the LV in the expression phase of MET to illuminate the influence of SCH23390 or Sulpiride on the inhibitory impact of Cannabidiol on the expression of MET-induced CPP. Intra-NAc administration of either SCH23390 or Sulpiride impaired Cannabidiol's suppressive impact on the expression phase, while just Sulpiride could suppress the Cannabidiol's impact on the acquisition phase of the MET-induced CPP. Also, the inhibitory impact of Sulpiride was stranger in both phases of MET reward. It seems that Cannabidiol prevents the expression and acquisition phases of MET-induced CPP partly through the dopaminergic system in the NAc.

CBD-mediated regulation of heroin withdrawal-induced behavioural and molecular changes in mice

Cannabidiol (CBD) may represent a promising therapeutic tool for treating opioid use disorder (OUD). This study was aimed to evaluate the effects of CBD on the behavioural and gene expression alterations induced by spontaneous heroin withdrawal. Thirty hours after cessation of 8-day heroin treatment (5, 10, 20 and 40 mg·kg^-1 /12 h; s.c.), spontaneous heroin withdrawal was evaluated in CD1 male mice. The effects of CBD (5, 10 and 20 mg·kg^-1 ; i.p.) on withdrawal-related behaviour were evaluated by measuring anxiety-like behaviour, motor activity and somatic signs. Furthermore, gene expression changes of mu-opioid receptor (Oprm1), proopiomelanocortin (Pomc), cannabinoid CB1 (Cnr1) and CB2 (Cnr2) receptors in the nucleus accumbens (NAcc) and tyrosine hydroxylase (TH) and Pomc in the ventral tegmental area (VTA) were also evaluated by real-time PCR. Anxiety-like behaviour, motor activity and withdrawal-related somatic signs were significantly increased in heroin-treated mice compared to the control group. Interestingly, CBD treatment significantly reduced these behavioural impairments and normalized gene expression of Cnr1 and Pomc in the NAcc and TH in the VTA of mice exposed to spontaneous heroin withdrawal. Also, CBD induced an up-regulation of Cnr2, whereas it did not change the increased gene expression of Oprm1 in the NAcc of abstinent animals. The results suggest that CBD alleviates spontaneous heroin withdrawal and normalizes the associated gene expression changes. Future studies are needed to determine the relevance of CBD as a potential therapeutic tool for the treatment of heroin withdrawal.

Cannabidiol and substance use disorder: Dream or reality

BACKGROUND

Cannabidiol (CBD) is one of the major constituents of Cannabis sativa L. that lacks psychotomimetic and rewarding properties and inhibits the rewarding and reinforcing effects of addictive drugs such as cocaine, methamphetamine (METH), and morphine. Additionally, CBD's safety profile and therapeutic potential are currently evaluated in several medical conditions, including pain, depression, movement disorders, epilepsy, multiple sclerosis, Alzheimer's disease, ischemia, and substance use disorder. There is no effective treatment for substance use disorders such as addiction, and this review aims to describe preclinical and clinical investigations into the effects of CBD in various models of opioid, psychostimulant, cannabis, alcohol, and nicotine abuse. Furthermore, the possible mechanisms underlying the therapeutic potential of CBD on drug abuse disorders are reviewed.

METHODS

The current review considers and summarizes the preclinical and clinical investigations into CBD's effects in various models of drug abuse include opioids, psychostimulants, cannabis, alcohol, and nicotine.

RESULTS

Several preclinical and clinical studies have proposed that CBD may be a reliable agent to inhibit the reinforcing and rewarding impact of drugs.

CONCLUSIONS

While the currently available evidence converges to suggest that CBD could effectively reduce the rewarding and reinforcing effects of addictive drugs, more preclinical and clinical studies are needed before CBD can be added to the therapeutic arsenal for treating addiction.