Effects of Rare Phytocannabinoids on the Endocannabinoid System of Human Keratinocytes

A systematic review of analytical methodologies capable of analysing phytocannabinoids in cosmetics

As cannabidiol (CBD) is not considered to be a drug and because of its potential health claims, it is an interesting compound that is often found in cosmetics. However, the safety of CBD, as well as the presence of trace amounts of other phytocannabinoids, including the psychoactive substance ∆9 -tetrahydrocannabinol (THC), is still being debated. A robust analytical technique capable of analysing cosmetic products and determining their phytocannabinoid content will be crucial in assessing the safety of these products. This systematic review aims to highlight the current analytical tools that could be used to analyse phytocannabinoids in cosmetics. The ideal method would be able to analyse high levels of CBD in combination with trace levels of THC and their acids. The method should provide good recoveries and accuracies in a variety of matrices while providing information on up-coming phytocannabinoids such as cannabichromene (CBC), cannabigerol (CBG) and cannabinol (CBN). The systematic review approach was based on the Preferred Reporting Items for Systematic review and Meta-Analyses method. The research focused on studies published from January 2010 to December 2022 in PubMed and Scopus. A total of 15 datasets met the inclusion and exclusion criteria and were tabulated to allow easy comparison. Although some of the reviewed methods can handle multiple matrices and provide satisfactory recoveries, this review process did not identify an ideal method. The most suitable methods either could not quantify phytocannabinoid acids or were not sensitive enough to quantify trace levels of psychoactive phytocannabinoids.

Mannich-type modifications of (-)-cannabidiol and (-)-cannabigerol leading to new, bioactive derivatives

(-)-Cannabidiol (CBD) and (-)-cannabigerol (CBG) are two major non-psychotropic phytocannabinoids that have many beneficial biological properties. However, due to their low water solubility and prominent first-pass metabolism, their oral bioavailability is moderate, which is unfavorable for medicinal use. Therefore, there is a great need for appropriate chemical modifications to improve their physicochemical and biological properties. In this study, Mannich-type reaction was used for the synthetic modification of CBD and CBG for the first time, and thus fifteen new cannabinoid derivatives containing one or two tertiary amino groups were prepared. Thereafter the antiviral, antiproliferative and antibacterial properties of the derivatives and their effects on certain skin cells were investigated. Some modified CBD derivatives showed remarkable antiviral activity against SARS-CoV-2 without cytotoxic effect, while synthetic modifications on CBG resulted in a significant increase in antiproliferative activity in some cases compared to the parent compound.

The Anti-Inflammatory Action of Cannabigerol Accompanied by the Antioxidant Effect of 3-O-ethyl Ascorbic Acid in UVA-Irradiated Human Keratinocytes

Excessive daily exposure of human skin to natural UVA radiation leads to impaired redox homeostasis in epidermal keratinocytes, resulting in changes in their proteome. Commonly used antioxidants usually exhibit protection in a narrowed range, which makes it necessary to combine their effects. Therefore, the aim of this study was to analyze the protective effect of cannabigerol (CBG) and 3-O-ethyl ascorbic acid (EAA), used separately and together, on the proteomic profile of UVA irradiated keratinocytes. Proteomic analysis with the use of the Q Exactive HF mass spectrometer, combined with biostatistic tests, performed on UVA-irradiated keratinocytes indicated enhanced and lowered expression of 186 and 160 proteins, respectively. CBG treatment after UVA irradiation reduced these numbers to 110 upregulated and 49 downregulated proteins, while EAA eliminated all these changes. CBG completely eliminated the UV-induced effect on the expression of pro-inflammatory proteins and significantly increased the level of proteins responsible for cellular locomotion. On the other hand, CBG reduced the level of UVA-induced 4-hydroxynonenal protein adducts fivefold, whereas EAA had no effect on this modification. At the same time, CBG and EAA did not modify the expression/structure of proteins in relation to the nonirradiated control keratinocytes in the case of an unaccompanied use or slightly modified the protein profile when used in a mixture. The combined protective effects of CBG on protein structure and EAA on protein expression profile allowed us to obtain a wider protection of cells against UVA radiation, compared with when the compounds were used alone. SIGNIFICANCE STATEMENT: Proteomic analysis of human skin cells allows to conclude that 3-O-ethyl ascorbic acid eliminates UVA-induced changes in the expression of keratinocyte proteins, while cannabigerol significantly reduces 4-hydroxynonenal protein adducts. The combined protective effects of cannabigerol on protein structure and of 3-O-ethyl ascorbic acid on protein expression profile allowed to obtain a wider protection of cells against UVA radiation.

Goods and Bads of the Endocannabinoid System as a Therapeutic Target: Lessons Learned after 30 Years

The cannabis derivative marijuana is the most widely used recreational drug in the Western world and is consumed by an estimated 83 million individuals (∼3% of the world population). In recent years, there has been a marked transformation in society regarding the risk perception of cannabis, driven by its legalization and medical use in many states in the United States and worldwide. Compelling research evidence and the Food and Drug Administration cannabis-derived cannabidiol approval for severe childhood epilepsy have confirmed the large therapeutic potential of cannabidiol itself, Δ9-tetrahydrocannabinol and other plant-derived cannabinoids (phytocannabinoids). Of note, our body has a complex endocannabinoid system (ECS)-made of receptors, metabolic enzymes, and transporters-that is also regulated by phytocannabinoids. The first endocannabinoid to be discovered 30 years ago was anandamide (N-arachidonoyl-ethanolamine); since then, distinct elements of the ECS have been the target of drug design programs aimed at curing (or at least slowing down) a number of human diseases, both in the central nervous system and at the periphery. Here a critical review of our knowledge of the goods and bads of the ECS as a therapeutic target is presented to define the benefits of ECS-active phytocannabinoids and ECS-oriented synthetic drugs for human health. SIGNIFICANCE STATEMENT: The endocannabinoid system plays important roles virtually everywhere in our body and is either involved in mediating key processes of central and peripheral diseases or represents a therapeutic target for treatment. Therefore, understanding the structure, function, and pharmacology of the components of this complex system, and in particular of key receptors (like cannabinoid receptors 1 and 2) and metabolic enzymes (like fatty acid amide hydrolase and monoacylglycerol lipase), will advance our understanding of endocannabinoid signaling and activity at molecular, cellular, and system levels, providing new opportunities to treat patients.

Therapeutic Potential of Minor Cannabinoids in Dermatological Diseases-A Synthetic Review

Dermatological diseases pose a significant burden on the quality of life of individuals and can be challenging to treat effectively. In this aspect, cannabinoids are gaining increasing importance due to their therapeutic potential in various disease entities including skin diseases. In this synthetic review, we comprehensively analyzed the existing literature in the field of potential dermatological applications of a lesser-known subgroup of cannabinoids, the so-called minor cannabinoids, such as cannabidivarin (CBDV), cannabidiforol (CBDP), cannabichromene (CBC), tetrahydrocannabivarin (THCV), cannabigerolic acid (CBGA), cannabigerol (CBG), cannabielsoin (CBE), cannabimovone (CBM) or cannabinol (CBN), while drawing attention to their unique pharmacological properties. We systematically searched the available databases for relevant studies and analyzed the data to provide an overview of current thematic knowledge. We looked through the full-text, bibliographic and factographic databases, especially Scopus, Web of Science, PubMed, Polish Scientific Journals Database, and selected the most relevant papers. Our review highlights that minor cannabinoids exhibit diverse pharmacological activities, including anti-inflammatory, analgesic, antimicrobial, and anti-itch properties. Several studies have reported their efficacy in mitigating symptoms associated with dermatological diseases such as psoriasis, eczema, acne, and pruritus. Furthermore, minor cannabinoids have shown potential in regulating sebum production, a crucial factor in acne pathogenesis. The findings of this review suggest that minor cannabinoids hold therapeutic promise in the management of dermatological diseases. Further preclinical and clinical investigations are warranted to elucidate their mechanisms of action, determine optimal dosage regimens, and assess long-term safety profiles. Incorporating minor cannabinoids into dermatological therapies could potentially offer novel treatment options of patients and improve their overall well-being.

Aβ Chronic Exposure Promotes an Activation State of Microglia through Endocannabinoid Signalling Imbalance

Dysfunctional phenotype of microglia, the primary brain immune cells, may aggravate Alzheimer’s disease (AD) pathogenesis by releasing proinflammatory factors, such as nitric oxide (NO). The endocannabinoids N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) are bioactive lipids increasingly recognised for their essential roles in regulating microglial activity both under normal and AD-driven pathological conditions. To investigate the possible impact of chronic exposure to β-amyloid peptides (Aβ) on the microglial endocannabinoid signalling, we characterised the functional expression of the endocannabinoid system on neonatal microglia isolated from wild-type and Tg2576 mice, an AD-like model, which overexpresses Aβ peptides in the developing brain. We found that Aβ-exposed microglia produced 2-fold more 2-AG than normal microglia. Accordingly, the expression levels of diacylglycerol lipase-α (DAGLα) and monoacylglycerol lipase (MAGL), the main enzymes responsible for synthesising and hydrolysing 2-AG, respectively, were consistently modified in Tg2576 microglia. Furthermore, compared to wild-type cells, transgenic microglia basally showed increased expression of the cannabinoid 2 receptor, typically upregulated in an activated proinflammatory phenotype. Indeed, following inflammatory stimulus, Aβ-exposed microglia displayed an enhanced production of NO, which was abolished by pharmacological inhibition of DAGLα. These findings suggested that exposure to Aβ polarises microglial cells towards a pro-AD phenotype, possibly by enhancing 2-AG signalling.

Rare Phytocannabinoids Exert Anti-Inflammatory Effects on Human Keratinocytes via the Endocannabinoid System and MAPK Signaling Pathway

Increasing evidence supports the therapeutic potential of rare cannabis-derived phytocannabinoids (pCBs) in skin disorders such as atopic dermatitis, psoriasis, pruritus, and acne. However, the molecular mechanisms of the biological action of these pCBs remain poorly investigated. In this study, an experimental model of inflamed human keratinocytes (HaCaT cells) was set up by using lipopolysaccharide (LPS) in order to investigate the anti-inflammatory effects of the rare pCBs cannabigerol (CBG), cannabichromene (CBC), Δ⁹-tetrahydrocannabivarin (THCV) and cannabigerolic acid (CBGA). To this aim, pro-inflammatory interleukins (IL)-1β, IL-8, IL-12, IL-31, tumor necrosis factor (TNF-β) and anti-inflammatory IL-10 levels were measured through ELISA quantification. In addition, IL-12 and IL-31 levels were measured after treatment of HaCaT cells with THCV and CBGA in the presence of selected modulators of endocannabinoid (eCB) signaling. In the latter cells, the activation of 17 distinct proteins along the mitogen-activated protein kinase (MAPK) pathway was also investigated via Human Phosphorylation Array. Our results demonstrate that rare pCBs significantly blocked inflammation by reducing the release of all pro-inflammatory ILs tested, except for TNF-β. Moreover, the reduction of IL-31 expression by THCV and CBGA was significantly reverted by blocking the eCB-binding TRPV1 receptor and by inhibiting the eCB-hydrolase MAGL. Remarkably, THCV and CBGA modulated the expression of the phosphorylated forms (and hence of the activity) of the MAPK-related proteins GSK3β, MEK1, MKK6 and CREB also by engaging eCB hydrolases MAGL and FAAH. Taken together, the ability of rare pCBs to exert an anti-inflammatory effect in human keratinocytes through modifications of eCB and MAPK signaling opens new perspectives for the treatment of inflammation-related skin pathologies.

Cannabinoid Compounds as a Pharmacotherapeutic Option for the Treatment of Non-Cancer Skin Diseases

The endocannabinoid system has been shown to be involved in various skin functions, such as melanogenesis and the maintenance of redox balance in skin cells exposed to UV radiation, as well as barrier functions, sebaceous gland activity, wound healing and the skin's immune response. In addition to the potential use of cannabinoids in the treatment and prevention of skin cancer, cannabinoid compounds and derivatives are of interest as potential systemic and topical applications for the treatment of various inflammatory, fibrotic and pruritic skin conditions. In this context, cannabinoid compounds have been successfully tested as a therapeutic option for the treatment of androgenetic alopecia, atopic and seborrhoeic dermatitis, dermatomyositis, asteatotic and atopic eczema, uraemic pruritis, scalp psoriasis, systemic sclerosis and venous leg ulcers. This review provides an insight into the current literature on cannabinoid compounds as potential medicines for the treatment of skin diseases.

Minor Phytocannabinoids: A Misleading Name but a Promising Opportunity for Biomedical Research

Despite the very large number of phytocannabinoids isolated from Cannabis (Cannabis sativa L.), bioactivity studies have long remained focused on the so called “Big Four” [Δ⁹-THC (1), CBD (2), CBG (3) and CBC (4)] because of their earlier characterization and relatively easy availability via isolation and/or synthesis. Bioactivity information on the chemical space associated with the remaining part of the cannabinome, a set of ca 150 compounds traditionally referred to as “minor phytocannabinoids”, is scarce and patchy, yet promising in terms of pharmacological potential. According to their advancement stage, we sorted the bioactivity data available on these compounds, better referred to as the “dark cannabinome”, into categories: discovery (in vitro phenotypical and biochemical assays), preclinical (animal models), and clinical. Strategies to overcome the availability issues associated with minor phytocannabinoids are discussed, as well as the still unmet challenges facing their development as mainstream drugs.

The Origin and Biomedical Relevance of Cannabigerol

The constant search for new pharmacologically active compounds, especially those that do not exhibit toxic effects, intensifies the interest in plant-based ingredients and their potential use in pharmacotherapy. One of the plants that has great therapeutic potential is Cannabis sativa L., a source of the psychoactive Δ⁹-tetrahydrocannabinol (Δ⁹-THC), namely cannabidiol (CBD), which exhibits antioxidant and anti-inflammatory properties, and cannabigerol (CBG)-a biologically active compound that is present in much smaller quantities. CBG is generated during the non-enzymatic decarboxylation of cannabigerolic acid, a key compound in the process of biosynthesis of phytocannabinoids and consequently the precursor to various phytocannabinoids. By interacting with G-protein-coupled receptors, CBG exhibits a wide range of biological activities, inter alia, anti-inflammatory, antibacterial and antifungal activities, regulation of the redox balance, and neuromodulatory effects. Due to the wide spectrum of biological activities, CBG seems to be a very promising compound to be used in the treatment of diseases that require multidirectional pharmacotherapy. Moreover, it is suggested that due to the relatively rapid metabolism of cannabigerol, determination of the concentration of the phytocannabinoid in blood or oral fluid can be used to determine cannabis use. Therefore, it seems obvious that new therapeutic approaches using CBG can be expected.