HU-444, a Novel, Potent Anti-Inflammatory, Nonpsychotropic Cannabinoid

An overview on synthetic and biological activities of cannabidiol (CBD) and its derivatives

(-)-Cannabidiol is a class of non-psychoactive plant cannabinoids derived from cannabis plants. Currently, Epidiolex (Cannabidiol) has been approved by the FDA for the treatment of two rare and severe forms of epilepsy related diseases, namely Lennox-Gastaut syndrome (LGS) and Dravet (DS). In addition, Cannabidiol and its structural analogues have received increasing attention due to their potential therapeutic effects such as neuroprotection, anti-epilepsy, anti-inflammation, anti-anxiety, and anti-cancer. Based on literature review, no comprehensive reviews on the synthesis of Cannabidiol and its derivatives have been found in recent years. Therefore, this article summarizes the published synthesis methods of Cannabidiol and the synthesis routes of Cannabidiol derivatives, and introduces the biological activities of some Cannabidiol analogues that have been studied extensively and have significant activities.

Immunomodulatory Actions of Cannabinoids: Clinical Correlates and Therapeutic Opportunities for Allergic Inflammation

Endogenously produced cannabinoids as well as phytocannabinoids broadly exhibit anti-inflammatory actions. Recent emergence of cannabis for multiple medical issues combined with reports on potent immunomodulatory actions of distinct components has underscored the therapeutic potential of cannabis. Although synthetic cannabinoids that are based on structural similarities to the existing class of cannabinoids have been on the rise, their application in therapeutics have been limited owing to toxicity concerns. Herein, we review the current literature that details the immunomodulatory actions of cannabinoids. Further, we highlight the complexities of cannabinoid biology and examine the potential inflammatory risks associated with the use of cannabis including potential for toxic interactions between distinct constituents of cannabis.

Synthetic Strategies for (-)-Cannabidiol and Its Structural Analogs

(-)-Cannabidiol ((-)-CBD), a non-psychoactive phytocannabinoid from Cannabis, and its structural analogs have received growing attention in recent years because of their potential therapeutic benefits, including neuroprotective, anti-epileptic, anti-inflammatory, anxiolytic, and anti-cancer properties. (-)-CBD and its analogs have been obtained mainly based on extraction from the natural source; however, the conventional extraction-based methods have some drawbacks, such as poor quality control along with purification difficulty. Chemical-synthetic strategies for (-)-CBD could tackle these issues, and, additionally, generate novel (-)-CBD analogs that exhibit advanced biological activities. This review concisely summarizes the historic and recent milestones in the synthetic strategies for (-)-CBD and its analogs.

A selective CB2 agonist protects against the inflammatory response and joint destruction in collagen-induced arthritis mice

Rheumatoid arthritis (RA) is a chronic, inflammatory, synovitis-dominated systemic disease with unknown etiology. RA is characterized by the involvement of multiple affected joints, symmetry, and invasive arthritis of the limbs, which can lead to joint deformity, cartilage destruction, and loss of function. Cannabinoid receptor 2 (CB₂) has potent immunomodulatory and anti-inflammatory effects and is predominantly expressed in non-neuronal tissues. In the current study, the role of CB₂ in the process of inflammatory bone erosion in RA was examined. The selective agonist or high-affinity ligand of CB₂ (4-quinolone-3-carboxamides CB2 agonist, 4Q3C CB₂ agonist, 4Q3C) significantly reduced the severity of arthritis, decreased histopathological findings, and markedly reduced bone erosion in collagen-induced arthritis (CIA) mice. In addition, 4Q3C prevented an increase in the nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) ratio and inhibited the formation of osteoclasts in CIA mice. Furthermore, the expression of tumor necrosis factor-alpha, interleukin-1β, cyclooxygenase-2, and inducible nitric oxide synthase was lower in 4Q3C-treated CIA mice than in control CIA mice. Micro-computed tomography corroborated the finding that 4Q3C reduced joint destruction. These data clearly indicate that the CB₂-selective agonist, 4Q3C, may have anti-inflammatory and anti-osteoclastogenesis effects in RA and may be considered to be a novel treatment for RA.

DMH-CBD, a cannabidiol analog with reduced cytotoxicity, inhibits TNF production by targeting NF-kB activity dependent on A2A receptor

Cannabidiol (CBD) is a natural compound with psychoactive therapeutic properties well described. Conversely, the immunological effects of CBD are still poorly explored. In this study, the potential anti-inflammatory effects and underlying mechanisms of CBD and its analog Dimethyl-Heptyl-Cannabidiol (DMH-CBD) were investigated using RAW 264.7 macrophages. CBD and DMH-CBD suppressed LPS-induced TNF production and NF-kB activity in a concentration-dependent manner. Both compounds reduced the NF-kB activity in a μM concentration range: CBD (IC₅₀ = 15 μM) and DMH-CBD (IC₅₀ = 38 μM). However, the concentrations of CBD that mediated NF-kB inhibition were similar to those that cause cytotoxicity (LC₅₀ = 58 μM). Differently, DMH-CBD inhibited the NF-kB activation without cytotoxic effects at the same concentrations, although it provokes cytotoxicity at long-term exposure. The inhibitory action of the DMH-CBD on NF-kB activity was not related to the reduction in IkBα degradation or either p65 (NF-kB) translocation to the nucleus, although it decreased p38 MAP kinase phosphorylation. Additionally, 8-(3-Chlorostyryl) caffeine (CSC), an A_2A antagonist, reversed the effect of DMH-CBD on NF-kB activity in a concentration-dependent manner. Collectively, our results demonstrated that CBD reduces NF-kB activity at concentrations intimately associated with those that cause cell death, whereas DMH-CBD decreases NF-kB activity at non-toxic concentrations in an A_2A receptor dependent-manner.

The protective effects of Δ9 -tetrahydrocannabinol against inflammation and oxidative stress in rat liver with fructose-induced hyperinsulinemia

OBJECTIVES

A large amount of fructose is metabolized in the liver and causes hepatic functional damage. Δ⁹ -tetrahydrocannabinol (THC) is known as a therapeutic agent for clinical and experimental applications. The study aims to investigate the effects of THC treatment on inflammation, lipid profiles and oxidative stress in rat liver with hyperinsulinemia.

METHODS

Sprague-Dawley rats were divided into groups: control, fructose (10% fructose in drinking water for 12 weeks), THC (1.5 mg/kg/day for the last 4 weeks, intraperitoneally) and fructose+THC groups. Biochemical parameters were measured spectrophotometrically. ELISA method was used for insulin measurement. Apoptosis and inflammation markers were detected by the streptavidin-biotin peroxidase method.

KEY FINDINGS

The consumptions of food and fluid are inversely proportional to fructose and non-fructose groups. Insulin levels were the highest in fructose group. The reduced glutathione-S-transferase level significantly increased in fructose + THC group compared with fructose group. Total cholesterol level in the fructose + THC group was higher than the fructose group. Caspase-3 and NF-κβ immunopositive cell numbers increased in fructose + THC rats compared with fructose group. The number of IL-6 immunopositive cell decreased in fructose + THC group compared with fructose group.

CONCLUSIONS

According to the result, long-term and low-dose THC administration may reduce hyperinsulinemia and inflammation in rats to some extent.

Cannabinoid-Based Therapies and Brain Development: Potential Harmful Effect of Early Modulation of the Endocannabinoid System

The endocannabinoid retrograde signaling pathway is widely expressed in the central nervous system, where it plays major roles in regulating synaptic plasticity (excitatory and inhibitory) through long-term potentiation and long-term depression. The endocannabinoid system (ECS) components-cannabinoid receptors, endocannabinoids and synthesis/degradation enzymes-are expressed and are functional from early developmental stages and throughout adolescent cortical development, regulating progenitor cell fate, neural differentiation, migration and survival. This may potentially confer increased vulnerability to adverse outcomes from early cannabinoid exposure. Cannabidiol (CBD) is one of the most studied exogenous cannabinoids, and CBD-enriched Cannabis extracts have been widely (and successfully) used as adjuvants to treat children with refractory epilepsy, and there is even a Food and Drug Administration (FDA)-approved drug with purified CBD derived from Cannabis. However, there is insufficient information on possible long-term changes in the central nervous system caused by cannabinoid treatments during early childhood. Like the majority of cannabinoids, CBD is able to exert its effects directly and indirectly through the ECS, which can perturb the regulatory processes mediated by this system. In addition, CBD has a large number of non-endocannabinoid targets, which can explain CBD's effects. Here, we review the current knowledge about CBD-based therapies-pure and CBD-enriched Cannabis extracts-in studies with pediatric patients, their side effects, and their mechanisms of action regarding the central nervous system and neurodevelopment aspects. Since Cannabis extracts contain Δ⁹-tetrahydrocannabinol (Δ⁹-THC), we consider that pure CBD is possibly safer for young patients. Nevertheless, CBD, as well as other natural and/or synthetic cannabinoids, should be studied in more detail as a therapeutic alternative to CBD-enriched Cannabis extracts for young patients.

An Atmospheric Pressure Chemical Ionization MS/MS Assay Using Online Extraction for the Analysis of 11 Cannabinoids and Metabolites in Human Plasma and Urine

BACKGROUND

Although, especially in the United States, there has been a recent surge of legalized cannabis for either recreational or medicinal purposes, surprisingly little is known about clinical dose-response relationships, pharmacodynamic and toxicodynamic effects of cannabinoids such as Δ9-tetrahydrocannabinol (THC). Even less is known about other active cannabinoids.

METHODS

To address this knowledge gap, an online extraction, high-performance liquid chromatography coupled with tandem mass spectrometry method for simultaneous quantification of 11 cannabinoids and metabolites including THC, 11-hydroxy-Δ9-tetrahydrocannabinol, 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid, 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid glucuronide (THC-C-gluc), cannabinol, cannabidiol, cannabigerol, cannabidivarin, Δ9-tetrahydrocannabivarin (THCV), and 11-nor-9-carboxy-Δ9-tetrahydrocannabivarin (THCV-COOH) was developed and validated in human urine and plasma.

RESULTS

In contrast to atmospheric pressure chemical ionization, electrospray ionization was associated with extensive ion suppression in plasma and urine samples. Thus, the atmospheric pressure chemical ionization assay was validated showing a lower limit of quantification ranging from 0.39 to 3.91 ng/mL depending on study compound and matrix. The upper limit of quantification was 400 ng/mL except for THC-C-gluc with an upper limit of quantification of 2000 ng/mL. The linearity was r > 0.99 for all analyzed calibration curves. Acceptance criteria for intrabatch and interbatch accuracy (85%-115%) and imprecision (<15%) were met for all compounds. In plasma, the only exceptions were THCV (75.3%-121.2% interbatch accuracy) and cannabidivarin (interbatch imprecision, 15.7%-17.2%). In urine, THCV did not meet predefined acceptance criteria for intrabatch accuracy.

CONCLUSIONS

This assay allows for monitoring not only THC and its major metabolites but also major cannabinoids that are of interest for marijuana research and clinical practice.

The Endogenous Cannabinoid System: A Budding Source of Targets for Treating Inflammatory and Neuropathic Pain

A great need exists for the development of new medications to treat pain resulting from various disease states and types of injury. Given that the endogenous cannabinoid (that is, endocannabinoid) system modulates neuronal and immune cell function, both of which play key roles in pain, therapeutics targeting this system hold promise as novel analgesics. Potential therapeutic targets include the cannabinoid receptors, type 1 and 2, as well as biosynthetic and catabolic enzymes of the endocannabinoids N-arachidonoylethanolamine and 2-arachidonoylglycerol. Notably, cannabinoid receptor agonists as well as inhibitors of endocannabinoid-regulating enzymes fatty acid amide hydrolase and monoacylglycerol lipase produce reliable antinociceptive effects, and offer opioid-sparing antinociceptive effects in myriad preclinical inflammatory and neuropathic pain models. Emerging clinical studies show that 'medicinal' cannabis or cannabinoid-based medications relieve pain in human diseases such as cancer, multiple sclerosis, and fibromyalgia. However, clinical data have yet to demonstrate the analgesic efficacy of inhibitors of endocannabinoid-regulating enzymes. Likewise, the question of whether pharmacotherapies aimed at the endocannabinoid system promote opioid-sparing effects in the treatment of pain reflects an important area of research. Here we examine the preclinical and clinical evidence of various endocannabinoid system targets as potential therapeutic strategies for inflammatory and neuropathic pain conditions.

An Overview on Medicinal Chemistry of Synthetic and Natural Derivatives of Cannabidiol

Cannabidiol (CBD) has been traditionally used in Cannabis-based preparation, however historically, it has received far less interest as a single drug than the other components of Cannabis. Currently, CBD generates considerable interest due to its beneficial neuroprotective, antiepileptic, anxiolytic, antipsychotic, and anti-inflammatory properties. Therefore, the CBD scaffold becomes of increasing interest for medicinal chemists. This review provides an overview of the chemical structure of natural and synthetic CBD derivatives including the molecular targets associated with these compounds. A clear identification of their biological targets has been shown to be still very challenging.

Plastic and Neuroprotective Mechanisms Involved in the Therapeutic Effects of Cannabidiol in Psychiatric Disorders

Beneficial effects of cannabidiol (CBD) have been described for a wide range of psychiatric disorders, including anxiety, psychosis, and depression. The mechanisms responsible for these effects, however, are still poorly understood. Similar to clinical antidepressant or atypical antipsychotic drugs, recent findings clearly indicate that CBD, either acutely or repeatedly administered, induces plastic changes. For example, CBD attenuates the decrease in hippocampal neurogenesis and dendrite spines density induced by chronic stress and prevents microglia activation and the decrease in the number of parvalbumin-positive GABA neurons in a pharmacological model of schizophrenia. More recently, it was found that CBD modulates cell fate regulatory pathways such as autophagy and others critical pathways for neuronal survival in neurodegenerative experimental models, suggesting the potential benefit of CBD treatment for psychiatric/cognitive symptoms associated with neurodegeneration. These changes and their possible association with CBD beneficial effects in psychiatric disorders are reviewed here.

Excess cerebral TNF causing glutamate excitotoxicity rationalizes treatment of neurodegenerative diseases and neurogenic pain by anti-TNF agents

The basic mechanism of the major neurodegenerative diseases, including neurogenic pain, needs to be agreed upon before rational treatments can be determined, but this knowledge is still in a state of flux. Most have agreed for decades that these disease states, both infectious and non-infectious, share arguments incriminating excitotoxicity induced by excessive extracellular cerebral glutamate. Excess cerebral levels of tumor necrosis factor (TNF) are also documented in the same group of disease states. However, no agreement exists on overarching mechanism for the harmful effects of excess TNF, nor, indeed how extracellular cerebral glutamate reaches toxic levels in these conditions. Here, we link the two, collecting and arguing the evidence that, across the range of neurodegenerative diseases, excessive TNF harms the central nervous system largely through causing extracellular glutamate to accumulate to levels high enough to inhibit synaptic activity or kill neurons and therefore their associated synapses as well. TNF can be predicted from the broader literature to cause this glutamate accumulation not only by increasing glutamate production by enhancing glutaminase, but in addition simultaneously reducing glutamate clearance by inhibiting re-uptake proteins. We also discuss the effects of a TNF receptor biological fusion protein (etanercept) and the indirect anti-TNF agents dithio-thalidomides, nilotinab, and cannabinoids on these neurological conditions. The therapeutic effects of 6-diazo-5-oxo-norleucine, ceptriaxone, and riluzole, agents unrelated to TNF but which either inhibit glutaminase or enhance re-uptake proteins, but do not do both, as would anti-TNF agents, are also discussed in this context. By pointing to excess extracellular glutamate as the target, these arguments greatly strengthen the case, put now for many years, to test appropriately delivered ant-TNF agents to treat neurodegenerative diseases in randomly controlled trials.

Human Metabolites of Cannabidiol: A Review on Their Formation, Biological Activity, and Relevance in Therapy

Cannabidiol (CBD), the main nonpsychoactive constituent of Cannabis sativa, has shown a wide range of therapeutically promising pharmacological effects either as a sole drug or in combination with other drugs in adjunctive therapy. However, the targets involved in the therapeutic effects of CBD appear to be elusive. Furthermore, scarce information is available on the biological activity of its human metabolites which, when formed in pharmacologically relevant concentration, might contribute to or even account for the observed therapeutic effects. The present overview summarizes our current knowledge on the pharmacokinetics and metabolic fate of CBD in humans, reviews studies on the biological activity of CBD metabolites either in vitro or in vivo, and discusses relevant drug–drug interactions. To facilitate further research in the area, the reported syntheses of CBD metabolites are also catalogued.