Raphael Mechoulam

Hebrew University of Jerusalem | HUJI · Faculty of Medicine

Rationale: The endocannabinoid system is known to be involved in learning, memory, emotional processing and regulation of personality patterns. Here we assessed the endocannabinoid profile in the brains of mice with strong characteristics of social dominance and submissiveness. Methods: A lipidomics approach was employed to assess the endocannabino...

The endocannabinoid system (ECS) plays a key modulatory role during synaptic plasticity and homeostatic processes in the brain and has an important role in the neurobiological processes underlying drug addiction. We have previously shown that an elevated ECS response to psychostimulant (cocaine) is involved in regulating the development and express...

Cannabidiol is a phytocannabinoid that lacks the psychotomimetic properties of Δ9-tetrahydrocannabinol (THC), the main psychoactive Cannabis sativa component. Cannabidiol has several potential therapeutic properties, including anxiolytic, antidepressant, and antipsychotic; however, cannabidiol has low oral bioavailability, which can limit its clini...

Cannabinoid receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Cannabinoid Receptors [119]) are activated by endogenous ligands that include N-arachidonoylethanolamine (anandamide), N-homo-γ-linolenoylethanolamine, N-docosatetra-7,10,13,16-enoylethanolamine and 2-arachidonoylglycerol. Potency determinations of endogenous agonists at...

There is growing interest in non-psychoactive phytocannabinoids, namely cannabidiol (CBD), cannabigerol (CBG), and cannabichromene, as potential leads for novel therapeutic agents. In this study, we report on the development of new derivatives in which we methylated either position 4 of olivetol or the phenolic positions of olivetol, or both. We in...

The pathophysiology of major depressive disorder (MDD) is diverse and multi-factorial, yet treatment strategies remain limited. While women are twice as likely to develop the disorder as men, many animal model studies of antidepressant response rely solely on male subjects. The endocannabinoid system has been linked to depression in clinical and pr...

The endocannabinoid system (ECS) plays a key modulatory role during synaptic plasticity and homeostatic processes in the brain, and has an important role in the neurobiological processes underlying drug addiction. We have previously shown that an elevated ECS response to psychostimulant (cocaine) is involved in regulating the development and expres...

Background: In a previous report, we have identified the cannabinoid receptor 2 (CB2) agonist HU308 to possess a beneficial effect in preventing age and trauma-induced osteoarthritis (OA) in mice. The effects of HU308 were largely related to the capacity of this compound to induce cartilage anabolism which was dependent on the CREB/SOX9 axis, and...

Osteoarthritis (OA) is characterized by progressive, irreversible erosion of articular cartilage accompanied with severe pain and immobility. This study aimed to assess the effect and mechanism of action of HU308‐ a selective cannabinoid receptor type 2 (CB2) agonist, in potentially preventing OA‐related joint damage. To test this assumption, Cn2r...

Objective: To assess whether the effects of oral administration of 300 mg of Cannabidiol (CBD) for 28 days on mental health are maintained for a period after the medication discontinuation. Methods: This is a 3-month follow-up observational and clinical trial study. The data were obtained from two studies performed simultaneously by the same team i...

Introduction: Cancer patients report nausea as a side effect of their chemotherapy treatment. Using the pre-clinical rodent model of acute nausea-lithium chloride (LiCl)-induced conditioned gaping-our group has demonstrated that exogenous cannabinoids may have antinausea potential. Materials and Methods: With the goal of evaluating the role of sex...

A comprehensive review of the scientific literature on the possible benefits of CBD, describing findings from both preclinical and human clinical studies. CBD (cannabidiol), a nonintoxicating compound derived from the cannabis plant, can be found in products ranging from lotion and smoothies to chewable gummies and pet treats. It's been promoted—bu...

Antibiotic-resistant Staphylococcus aureus is a major health issue that requires new therapeutic approaches. Accumulating data suggest that it is possible to sensitize these bacteria to antibiotics by combining them with inhibitors targeting efflux pumps, the low-affinity penicillin-binding protein PBP2a, cell wall teichoic acid, or the cell divisi...

Modulation of the endogenous cannabinoid system has been suggested as a potential anticancer strategy. In the search for novel and less toxic therapeutic options, structural modifications of the endocannabinoid anandamide and the synthetic derivative of oleic acid, Minerval (HU-600), were done to obtain 2-hydroxy oleic acid ethanolamide (HU-585), w...

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,...

Despite attenuating the positive symptoms, drugs currently used to treat schizophrenia frequently do not improve the negative symptoms and cognitive impairments. In addition, they show low tolerability, which has been associated with high rates of treatment discontinuation. Recent evidence suggests that the endocannabinoid system may be a target fo...

A series of novel cannabinoid-type derivatives were synthesized by the coupling of (1S,4R)-(+) and (1R,4S)-(−)-fenchones with various resorcinols/phenols. The fenchone-resorcinol derivatives were fluorinated using Selectfluor and demethylated using sodium ethanethiolate in dimethylformamide (DMF). The absolute configurations of four compounds were...

Background Despite the absence of rigorous prospective studies, there has been an increase in the use of cannabis-based medicinal products. During the study period, the use of medical cannabis in Israel was tightly regulated by national policy. Through a prospective study of approximately 10,000 patients, we aimed to characterize the medical cannab...

Rationale The fatty acid amide oleoyl glycine (OlGly) and its more stable methylated form oleoyl alanine (OlAla) reduce naloxone-precipitated morphine withdrawal (MWD)-induced conditioned gaping (nausea) responses in rats. In addition, OlGly has been shown to reduce lithium chloride (LiCl)–induced conditioned gaping in rats and vomiting in Suncus m...

Chemotherapy-induced peripheral neuropathy (CIPN) is the main dose-limiting adverse effect of chemotherapy drugs such as paclitaxel (PTX). PTX causes marked molecular and cellular damage, mainly in the peripheral nervous system, including sensory neurons in the dorsal root ganglia (DRG). Several studies have shown the therapeutic potential of canna...

Background Cannabidiol (CBD), the non-psychotropic compound from Cannabis sativa, shows positive results on controlling several health disturbances; however, comparable data regarding additional chemical from C. sativa, such as cannabidiolic acid (CBDA), is scarce due to its instability. To address this limitation, a stable CBDA analogue, CBDA meth...

Importance: Owing to its anti-inflammatory properties and antiviral "in vitro" effect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), cannabidiol (CBD) has been proposed as a potential treatment for coronavirus disease 2019 (COVID-19). Objective: To investigate the safety and efficacy of CBD for treating patients with mild to...

Rationale: The endocannabinoidome mediators, N -Oleoylglycine (OlGly) and N -Oleoylalanine (OlAla), have been shown to reduce acute naloxone-precipitated morphine withdrawal affective and somatic responses. Objectives: To determine the role and mechanism of action of OlGly and OlAla in withdrawal responses from chronic exposure to opiates in male S...

Interest in CBG (cannabigerol) has been growing in the past few years, due to its anti-inflammatory properties and other therapeutic benefits. Here we report the synthesis of three new CBG derivatives (HUM-223, HUM-233 and HUM-234) and show them to possess anti-inflammatory and analgesic properties. In addition, unlike CBG, HUM-234 also prevents ob...

A cannabinoid anticancer para-quinone, HU-331, which was synthesized by our group five decades ago, was shown to have very high efficacy against human cancer cell lines in-vitro and against in-vivo grafts of human tumors in nude mice. The main mechanism was topoisomerase IIα catalytic inhibition. Later, several groups synthesized related compounds....

Candida albicans is a common fungal pathogen in humans. Biofilm formation is an important virulence factor of C. albicans infections. We investigated the ability of the plant-derived cannabidiol (CBD) to inhibit the formation and removal of fungal biofilms. Further, we evaluated its mode of action. Our findings demonstrate that CBD exerts pronounce...

Perinatal exposure to Δ9-tetrahydrocannabinol (THC) affects brain development and might increase the incidence of psychopathology later in life, which seems to be related to a dysregulation of endocannabinoid and/or dopaminergic systems. We here evaluated the transcriptional regulation of the genes encoding for the cannabinoid CB1 receptor (Cnr1) a...

RationaleWhen acutely administered intraperitoneally, the non-psychoactive cannabinoid cannabidiol (CBD), its acidic precursor cannabidiolic acid (CBDA) and a stable methyl ester of CBDA (HU-580) reduce lithium chloride (LiCl)–induced conditioned gaping in male rats (a selective preclinical model of acute nausea) via activation of the serotonin 1A...

Rationale Oleoyl glycine, a little studied fatty acid amide similar in structure to anandamide, interferes with nicotine addiction in mice and acute naloxone-precipitated morphine withdrawal (MWD) in rats. Because endogenous oleoyl glycine is subject to rapid enzymatic deactivation, we evaluated the potential of more stable analogs to interfere wit...

Candidiasis is a fungal infection caused by Candida species that have formed a biofilm on epithelial linings of the body. The most frequently affected areas include the vagina, oral cavity and the intestine. In severe cases, the fungi penetrate the epithelium and cause systemic infections. One approach to combat candidiasis is to prevent the adhesi...

Infections caused by antibiotic-resistant strains of Staphylococcus aureus have reached epidemic proportions globally. Our previous study showed antimicrobial effects of anandamide (AEA) and arachidonoyl serine (AraS) against methicillin (MET)-resistant S. aureus (MRSA) strains, proposing the therapeutic potential of these endocannabinoid/endocanna...

Gestational methylazoxymethanol acetate (MAM) treatment produces offspring with adult phenotype relevant to schizophrenia, including positive- and negative-like symptoms, cognitive deficits, dopaminergic dysfunction, structural and functional abnormalities. Here we show that adult rats prenatally treated with MAM at gestational day 17 display signi...

Traumatic brain injury (TBI) is one of the main cause of death in young people and currently no drugs to treat brain injury exist. Recently, we have reported that mice with mild-TBI with a specific injury in the insula, showed elevated levels of a little investigated N -acyl amino acid, the N -oleoyl-glycine (OlGly). N -acyl-amino acids have recent...

Rationale Acute naloxone-precipitated morphine withdrawal (MWD) produces a conditioned place aversion (CPA) in rats even after one or two exposures to high-dose (20 mg/kg, sc) morphine followed 24-h later by naloxone (1 mg/kg, sc). However, the somatic withdrawal reactions produced by acute naloxone-precipitated MWD in rats have not been investigat...

Endocannabinoid/endocannabinoid-like (EC/EC-like) are natural endogenous compounds which have been found to affect MRSA pathogenicity. Our previous studies showed that EC/EC-like was able to impair staphylococcal biofilm formation and maintenance as well as to alter biofilm-associated virulence factors. In the present study, we investigated the com...

Background and purpose: Chronic neuropathic pain (NEP) is associated with growing therapeutic cannabis use. To promote quality of life without psychotropic effects, cannabinoids other than Δ9-tetrahydrocannabidiol, including cannabidiol and its precursor cannabidiolic acid (CBDA), are being evaluated. Due to its instability, CBDA has been understu...

Research in the cannabinoid field, namely on phytocannabinoids, the endogenous cannabinoids anandamide and 2-arachidonoyl glycerol and their metabolizing and synthetic enzymes, the cannabinoid receptors, and anandamide-like cannabinoid compounds, has expanded tremendously over the last few years. Numerous endocannabinoid-like compounds have been di...

Background Excessive daytime sleepiness and cataplexy are among the symptoms of narcolepsy, a sleep disorder caused by the loss of hypocretin/orexin (HCRT/OX) neurons placed into the Hypothalamus (LH). Several treatments for managing narcolepsy include diverse drugs to induce alertness, such as antidepressants, amphetamine, or modafinil, etc. Recen...

Oleoyl serine (OS), an endogenous fatty acyl amide (FAA) found in bone, has been shown to have an anti-osteoporotic effect. OS, being an amide, can be hydrolyzed in the body by amidases. Hindering its amide bond by introducing adjacent substituents has been demonstrated as a successful method for prolonging its skeletal activity. Here, we tested th...

Rationale Oleoyl glycine (OlGly), a recently discovered fatty acid amide that is structurally similar to N- acylethanolamines, which include the endocannabinoid, anandamide (AEA), as well as endogenous peroxisome proliferator-activated receptor alpha (PPARα) agonists oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), has been shown to interf...

Introduction: The endocannabinoid anandamide (AEA) is a neurotransmitter produced and released "on demand." Numerous studies have been conducted on AEA and on the endocannabinoid system (ECS), but none of them have investigated their effect on prokaryotes. Quorum sensing (QS) is a process of bacteria-bacteria communication. In this cross-Talk, the...

There has been a dramatic increase in the number of children diagnosed with autism spectrum disorders (ASD) worldwide. Recently anecdotal evidence of possible therapeutic effects of cannabis products has emerged. The aim of this study is to characterize the epidemiology of ASD patients receiving medical cannabis treatment and to describe its safety...

Abstract Infections caused by antibiotic-resistant strains of Staphylococcus aureus have reached epidemic proportions globally. Staphylococcal biofilms are associated with increased antimicrobial resistance and are generally less affected by host immune factors. Therefore, there is an urgent need for novel agents that not only aim at multidrug-resi...

The current study explores the therapeutic potential of Cannabidiol (CBD), a compound in the Cannabis plant, using both sexes of 2 “depressive-like” genetic models, Wistar Kyoto (WKY) and Flinders Sensitive Line (FSL) rats. Rats ingested CBD (30 mg/kg) orally. In the saccharin preference test, following a previous report of a pro-hedonic effect of...

Cannabis is one of the most widely used plant drugs in the world today. In spite of the large number of scientific reports on medical marijuana, there still exists much controversy surrounding its use and the potential for abuse due to the undesirable psychotropic effects. However, recent developments in medicinal chemistry of novel non-psychoactiv...

In agreement with the neurodevelopmental hypothesis of schizophrenia, prenatal exposure of rats to the antimitotic agent methylazoxymethanol acetate (MAM) at gestational day 17 produced long-lasting behavioral alterations such as social withdrawal and cognitive impairment in the social interaction test and in the novel object recognition test, resp...

Objective: Cannabidiol (CBD), one of the non-psychotomimetic compounds of Cannabis sativa, causes anxiolytic-like effects in animals, with typical bell-shaped dose-response curves. No study, however, has investigated whether increasing doses of this drug would also cause similar curves in humans. The objective of this study was to compare the acut...

Among a multitude of hormonal and metabolic complications, individuals with Prader‐Willi syndrome (PWS) exhibit significant bone abnormalities, including decreased BMD, osteoporosis, and subsequent increased fracture risk. Here we show in mice that loss of Magel2, a maternally imprinted gene in the PWS critical region, results in reduced bone mass,...

Autacoid local injury antagonist amides (ALIAmides) are a family of endogenous bioactive acyl ethanolamides that include the renowned palmitoyl ethanolamide (PEA), oleoyl ethanolamide (OEA), and stearoyl ethanolamide (SEA), and that are involved in several biologic processes such as nociception, lipid metabolism and inflammation. The role of ALIAmi...

Background and purpose: Cannabidiolic acid methyl ester (HU-580) was recently shown to reduce stress-induced anxiety-like behavior in rats. The aim of this study was to examine the antidepressant effect of HU-580 in two different rat models of depression. Experimental approach: Using the forced swim test (FST), we evaluated the effect of HU-580...

Cigarette smokers with brain damage involving the insular cortex display cessation of tobacco smoking, suggesting that this region may contribute to nicotine addiction. In the present study, we speculated that molecules in the insular cortex that are sensitive to experimental traumatic brain injury (TBI) in mice might provide leads to ameliorate ni...

Introduction: There is a substantial growth in the use of medical cannabis in recent years and with the aging of the population, medical cannabis is increasingly used by the elderly. We aimed to assess the characteristics of elderly people using medical cannabis and to evaluate the safety and efficacy of the treatment. Methods: A prospective stu...

Background and purpose: To compare the abilities of cannabidiolic acid methyl ester (HU-580) and cannabidiolic acid (CBDA) to enhance 5-HT1A receptor activation in vitro and to produce 5-HT1A -mediated reductions of nausea and anxiety in vivo. Experimental approach: We investigated the effects of HU-580 and CBDA on (i) activation by 8-hydroxy-2-...

Cannabidiol (CBD) is a non-psychoactive component of marijuana, which has anti-inflammatory effects. It has also been approved by FDA for various orphan diseases for exploratory trials. Herein, we investigated the effects of CBD on liver injury induced by chronic plus binge alcohol feeding in mice. CBD or vehicle was administered daily throughout t...

Rationale: Cannabis is commonly used by humans to relieve stress. Objectives and methods: Here, we evaluate the potential of intraperitoneally (i.p.) administered Δ(9)-tetrahydrocannabiol (THC) and cannabidiolic acid (CBDA, the precursor of cannabidiol [CBD]) to produce dose-dependent effects on anxiety-like responding in the light-dark (LD) eme...

Cannabidiol (CBD) is a phytocannabinoid with multiple pharmacological effects and several potential therapeutic properties. Its low oral bioavailability, however, can limit its clinical use. Preliminary results indicate that fluorination of the CBD molecule increases its pharmacological potency. Here, we investigated whether HUF-101 (3, 10, and 30...

Although histone acetylation is one of the most widely studied epigenetic modifications, there is still a lack of information regarding how the acetylome is regulated during brain development and pathophysiological processes. We demonstrate that the embryonic brain (E15) is characterized by an increase in H3K9 acetylation as well as decreases in th...