Identification of CB1 Ligands among Drugs, Phytochemicals and Natural-Like Compounds: Virtual Screening and In Vitro Verification

Go to ACS Chemical Neuroscience

“Cannabinoid receptor type 1 (CB1) is an important modulator of many key physiological functions and thus a compelling molecular target. However, safe CB1 targeting is a non-trivial task. In recent years, there has been a surge of data indicating that drugs successfully used in the clinic for years (e.g. paracetamol) show CB1 activity. Moreover, there is a lot of promise in finding CB1 ligands in plants other than Cannabis sativa. In this study, we searched for possible CB1 activity among already existing drugs, their metabolites, phytochemicals, and natural-like molecules. We conducted two iterations of virtual screening, verifying the results with in vitro binding and functional assays. The in silico procedure consisted of a wide range of structure- and ligand-based methods, including docking, molecular dynamics, and quantitative structure-activity relationship (QSAR). As a result, we identified travoprost and ginkgetin as CB1 ligands, which provides a starting point for future research on the impact of their metabolites or preparations on the endocannabinoid system. Moreover, we found five natural-like compounds with submicromolar or low micromolar affinity to CB1, including one mixed partial agonist/antagonist viable for hit-to-lead phase. Finally, the computational procedure established in this work will be of use for future screening campaigns for novel CB1 ligands.”

https://pubmed.ncbi.nlm.nih.gov/36197801/

https://pubs.acs.org/doi/10.1021/acschemneuro.2c00502

A Cannabinoid Hairy-Tale: Hair Loss or Hair Gain?

Journal of Cosmetic Dermatology

“Background: Few studies have reported on the use of cannabinoid products to treat hair loss.

Aim: This article aims to reconcile cannabinoids’ impact on hair growth.

Method: A comprehensive and structured search was conducted in PubMed and Google Scholar on 23 June 2022.

Result: While cannabidiol (CBD), a phytocannabinoid, may cause hair growth, several other phytocannabinoids may lead to hair loss. Additionally, the effect of CBD on hair growth may be concentration-dependent. CBD may cause hair loss at high concentrations (≥10 μM). Therefore, the concentration of CBD needs to be adjusted so that it is optimal for hair growth. One trial found that once-daily application of CBD-rich topical cannabis extract for six months increased nonvellus hair count by approximately 93.5% in 35 Caucasian AGA patients: 28 males aged 28-72 years [average 43 years] and 7 females aged 46-76 years [average 61 years]. Each application contained 3-4 mg of CBD. The CBD-rich topical cannabis extract was prepared by ultra-pulverizing Cannabis sativa [hemp] flower into a green chalk-like powder [10.78% CBD and 0.21% tetrahydrocannabinol] and then infusing the powder into a lanolin paste and Emu oil carrier.

Conclusion: Topical CBD preparations require further studies to establish their safety and efficacy profile. An ideal topical cannabinoid preparation should contain CBD at the right concentration and lack phytocannabinoid adulterants.”

https://pubmed.ncbi.nlm.nih.gov/36181341/

https://onlinelibrary.wiley.com/doi/10.1111/jocd.15427


Cannabinoid receptors in the inflammatory cells of canine atopic dermatitis

Frontiers in Veterinary Science accepted into PubMed Central - Science &  research news | Frontiers

“Background: Atopic dermatitis (AD) is one of the most common cutaneous inflammatory and pruritic diseases in dogs. Considering its multifactorial nature, AD can be a challenging disease to manage, and the therapeutic strategy must often be multimodal. In recent years, research has been moving toward the use of natural products which have beneficial effects on inflammation and itching, and no side effects. Cannabinoid receptors have been demonstrated to be expressed in healthy and diseased skin; therefore, one of the potential alternative therapeutic targets for investigating AD is the endocannabinoid system (ECS).

Objective: To immunohistochemically investigate the expression of the cannabinoid receptor type 2 (CB2R), and the cannabinoid-related receptors G protein-coupled receptor 55 (GPR55), transient receptor potential vanilloid 1 (TRPV1) and ankyrin 1 (TRPA1) in mast cells (MCs), macrophages, dendritic cells (DCs), T cells, and neutrophils of the skin of dogs with AD.

Animals: Samples of skin tissues were collected from eight dogs with AD (AD-dogs).

Materials and methods: The immunofluorescent stained cryosections of the skins of 8 dogs with AD having antibodies against CB2R, GPR55, TRPV1, TRPA1 were semiquantitatively evaluated. The inflammatory cells were identified using antibodies against tryptase (mast cells), ionized calcium binding adaptor molecule 1 (IBA1) (macrophages/DCs), CD3 (T cells), and calprotectin (neutrophils). The proportions of MCs, macrophages/DCs, T cells, and neutrophils expressing CB2R, GPR55, TRPV1 and TRPA1 were evaluated.

Results: The cells of the inflammatory infiltrate showed immunoreactivity (IR) for all or for some of the cannabinoid and cannabinoid-related receptors studied. In particular, MCs and macrophages/DCs showed CB2R-, GPR55-, TRPA1-, and TRPV1-IR; T cells showed CB2R-, GPR55- and TRPA1-IR, and neutrophils expressed GPR55-IR. Co-localization studies indicated that CB2R-IR was co-expressed with TRPV1-, TRPA1-, and GPR55-IR in different cellular elements of the dermis of the AD-dogs.

Conclusions and clinical importance: Cannabinoid receptor 2, and cannabinoid-related receptors GPR55, TRPV1 and TRPA1 were widely expressed in the inflammatory infiltrate of the AD-dogs. Based on the present findings, the ECS could be considered to be a potential therapeutic target for dogs with AD, and may mitigate itch and inflammation.”

https://pubmed.ncbi.nlm.nih.gov/36187821/

“The evidence regarding the effect of cannabinoid and cannabinoid-related receptors on MCs, macrophages and DCs (CB2R, GPR55, TRPV1, TRPA1), T-cells (CB2R, GPR55, TRPA1), and on neutrophils (GPR55) suggests the possibility that the manipulation of the inflammatory cell functions with endocannabinoids and cannabinoids could result in a novel approach to the treatment of AD. Phytocannabinoids could potentially modulate inflammatory responses by regulating more than one underlying mechanism (inflammatory cells, keratinocytes, sensory nerves, fibroblasts, etc.).”

https://www.frontiersin.org/articles/10.3389/fvets.2022.987132/full

Changes in the expression of endocannabinoid system components in an experimental model of chemotherapy-induced peripheral neuropathic pain: Evaluation of sex-related differences

Experimental Neurology

“Chemotherapy-induced neuropathic pain is a serious clinical problem and one of the major side effects in cancer treatment. The endocannabinoid system (ECS) plays a crucial role in regulating pain neurotransmission, and changes in the expression of different components of the ECS have been reported in experimental models of persistent pain. In addition, sex differences have been observed in ECS regulation and function. The aim of our study was to evaluate whether administration of oxaliplatin, a neurotoxic antineoplastic agent, induced changes in the expression of ECS components in peripheral and central stations of the pain pathway, and if those changes exhibited sexual dimorphism. Adult male and female rats were injected with oxaliplatin or saline, and mechanical and cold hypersensitivity and allodynia were evaluated using Von Frey and Choi Tests. The mRNA levels corresponding to cannabinoid receptors (CB1, CB2), cannabinoid-related receptors (GPR55, 5HT1A, TRPV1) and to the main enzymes involved in the synthesis (DAGL, DAGL, NAPE-PLD) and degradation (MGL, FAAH) of endocannabinoids were assessed in lumbar dorsal root ganglia (DRGs) and spinal cord by using real time RT-PCR. In addition, the levels of the main endocannabinoids, 2-arachidonoylglycerol (2-AG) and anandamide (AEA), were evaluated using commercial ELISA kits. Oxaliplatin administration induced the development of mechanical and cold hypersensitivity and allodynia in male and female animals. Oxaliplatin also induced early and robust changes in the expression of several components of the ECS in DRGs. A marked upregulation of CB1, CB2, 5HT1A and TRPV1 was detected in both sexes. Interestingly, while DAGL mRNA levels remained unchanged, DAGL was downregulated in male and upregulated in female rats. Finally, MGL and NAPE-PLD showed increased levels only in male animals, while FAAH resulted upregulated in both sexes. In parallel, reduced 2-AG and AEA levels were detected in DRGs from male or female rats, respectively. In the lumbar spinal cord, only TRPV1 mRNA levels were found to be upregulated in both sexes. Our results reveal previously unreported changes in the expression of cannabinoid receptors, ligands and enzymes occurring mainly in the peripheral nervous system and displaying certain sexual dimorphism. These changes may contribute to the physiopathology of oxaliplatin-induced neuropathic pain in male and female rats. A better understanding of these dynamic changes will facilitate the development of mechanism- and sex-specific approaches to optimize the use of cannabinoid-based medicines for the treatment of chemotherapy-induced pain.”

https://pubmed.ncbi.nlm.nih.gov/36179876/

https://www.sciencedirect.com/science/article/abs/pii/S0014488622002576?via%3Dihub

Expression of cannabinoid receptors CB1 and CB2 in canine cutaneous mast cell tumours

Research in Veterinary Science

“Cannabinoid receptors (CB1 and CB2) belong to endocannabinoid system (ECS), which is also composed from endocannabinoids and the enzymatic systems involved in their biosynthesis and degradation. The expression of CB1 and CB2 have been previously identified in normal canine mast cell and in atopic dermatitis. Canine cutaneous mast cell tumours (cMCTs) are among the most common cutaneous neoplasms in dogs and have a highly variable clinical behaviour. Expression of CB1-CB2 was assessed by means of immunohistochemistry in thirty-seven dogs (from 2019 to 2021) with proven histological diagnosis of cMCT. Dogs were divided in two groups according to the Kiupel’s grading system: high-grade (HG) cMCT and low-grade (LG) cMCT. A semiquantitative (score 0-3) and quantitative assessment of immunoreactivity (IR) was performed for each case. Our results show that there CB1 and CB2 are highly expressed in LG- cMCT, in contrast to HG- cMCT.”

https://pubmed.ncbi.nlm.nih.gov/36179546/

https://www.sciencedirect.com/science/article/abs/pii/S0034528822002946?via%3Dihub

Effects of β-caryophyllene, A dDietary Cannabinoid, in Animal Models of Drug Addiction

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“Background: β-caryophyllene (BCP) is a natural bicyclic sesquiterpene found in Cannabis and other plants. BCP is currently used as a food additive, although pharmacological studies suggest its potential therapeutic application for the treatment of certain brain disorders. The mechanisms of action of BCP remain uncertain, possibly including full agonism at the cannabinoid CB 2 receptor (CB 2 R).

Objective: The study aims to investigate the BCP’s potential as a new drug for the treatment of substance use disorders, by reviewing preclinical studies with animal models.

Results: BCP has been investigated in behavioral paradigms, including drug self-administration, conditioned place preference, and intracranial self-stimulation; the drugs tested were cocaine, nicotine, alcohol, and methamphetamine. Remarkably, BCP prevented or reversed behavioral changes resulting from drug exposure. As expected, the mechanism of action entails CB 2 R activation, although this is unlikely to constitute the only molecular target to explain such effects. Another potential target is the peroxisome proliferator-activated receptor.

Conclusion: Preclinical studies report promising results with BCP in animal models of substance use disorders. Further research, including studies in humans, are warranted to establish its therapeutic potential and its mechanisms of action.”

https://pubmed.ncbi.nlm.nih.gov/36173065/

https://www.eurekaselect.com/article/126579

The role of cannabinoids in neurodevelopmental disorders of children and adolescents

PubMed | MIT Libraries News

“Introduction: Neurodevelopmental disorders have a multifactorial etiology that results from the interaction between biological and environmental factors. The biological basis of many of these disorders is only partially understood, which makes therapeutic interventions, especially pharmacological ones, particularly difficult. The impact of medical cannabis on neurological and psychiatric disorders has been studied for a long time. This study aimed to review the currently available clinical and pre-clinical studies regarding the use of cannabinoids in pediatric neurodevelopmental disorders and to draw attention to the potential therapeutic role of cannabidiol in this field.

Development: Cannabidiol is an endocannabinoid system modulator and exerts its effects on both developing and mature brains through numerous mechanisms. Cannabidiol holds a relatively high toxicity limit and current literature suggests that it may have anxiolytic, antipsychotic, and neuroprotective properties. Clinical evidence suggests that early treatment with cannabidiol might be a promising therapy for neurodevelopmental disorders, including intellectual disability, autism spectrum disorders, tics, and attention/deficit hyperactivity disorder.

Conclusions: This review hopefully draws attention to an emerging body of evidence concerning cannabidiol’s significant potential to safely improve many of the common symptoms affecting children and adolescents with neurodevelopmental disorders, especially autism spectrum disorder.”

https://pubmed.ncbi.nlm.nih.gov/36169325/

Targeting the endocannabinoid system for the treatment of abdominal pain in irritable bowel syndrome

Nature Reviews Gastroenterology & Hepatology

“The management of visceral pain in patients with disorders of gut-brain interaction, notably irritable bowel syndrome, presents a considerable clinical challenge, with few available treatment options.

Patients are increasingly using cannabis and cannabinoids to control abdominal pain. Cannabis acts on receptors of the endocannabinoid system, an endogenous system of lipid mediators that regulates gastrointestinal function and pain processing pathways in health and disease.

The endocannabinoid system represents a logical molecular therapeutic target for the treatment of pain in irritable bowel syndrome.

Here, we review the physiological and pathophysiological functions of the endocannabinoid system with a focus on the peripheral and central regulation of gastrointestinal function and visceral nociception. We address the use of cannabinoids in pain management, comparing them to other treatment modalities, including opioids and neuromodulators. Finally, we discuss emerging therapeutic candidates targeting the endocannabinoid system for the treatment of pain in irritable bowel syndrome.”

https://pubmed.ncbi.nlm.nih.gov/36168049/

https://www.nature.com/articles/s41575-022-00682-y

Endocannabinoid-Binding Receptors as Drug Targets

Book cover

“Cannabis plant has been used from ancient times with therapeutic purposes for treating human pathologies, but the identification of the cellular and molecular mechanisms underlying the therapeutic properties of the phytocannabinoids, the active compounds in this plant, occurred in the last years of the past century.

In the late 1980s and early 1990s, seminal studies demonstrated the existence of cannabinoid receptors and other elements of the so-called endocannabinoid system. These G protein-coupled receptors (GPCRs) are a key element in the functions assigned to endocannabinoids and appear to serve as promising pharmacological targets. They include CB1, CB2, and GPR55, but also non-GPCRs can be activated by endocannabinoids, like ionotropic receptor TRPV1 and even nuclear receptors of the PPAR family.

Their activation, inhibition, or simply modulation have been associated with numerous physiological effects at both central and peripheral levels, which may have therapeutic value in different human pathologies, then providing a solid experimental explanation for both the ancient medicinal uses of Cannabis plant and the recent advances in the development of cannabinoid-based specific therapies.

This chapter will review the scientific knowledge generated in the last years around the research on the different endocannabinoid-binding receptors and their signaling mechanisms. Our intention is that this knowledge may help readers to understand the relevance of these receptors in health and disease conditions, as well as it may serve as the theoretical basis for the different experimental protocols to investigate these receptors and their signaling mechanisms that will be described in the following chapters.”

https://pubmed.ncbi.nlm.nih.gov/36152178/

https://link.springer.com/protocol/10.1007/978-1-0716-2728-0_6

Endocannabinoid Metabolism and Transport as Drug Targets

Book cover

“The wide distribution of the endocannabinoid system (ECS) throughout the body and its pivotal pathophysiological role offer promising opportunities for the development of novel therapeutic drugs for treating several diseases. However, the need for strategies to circumvent the unwanted psychotropic and immunosuppressive effects associated with cannabinoid receptor agonism/antagonism has led to considerable research in the field of molecular alternatives, other than type-1 and type-2 (CB1/2) receptors, as therapeutic targets to indirectly manipulate this pro-homeostatic system. In this context, the use of selective inhibitors of proteins involved in endocannabinoid (eCB) transport and metabolism allows for an increase or decrease of the levels of N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) in the sites where these major eCBs are indeed needed. This chapter will briefly review some preclinical and clinical evidence for the therapeutic potential of ECS pharmacological manipulation.”

https://pubmed.ncbi.nlm.nih.gov/36152188/

https://link.springer.com/protocol/10.1007/978-1-0716-2728-0_16