Ajulemic Acid, a Synthetic Nonpsychoactive Cannabinoid Acid, Bound to the Ligand Binding Domain of the Human Peroxisome Proliferator-activated Receptor γ*

  “Ajulemic acid (AJA) is a synthetic analog of THC-11-oic acid, a metabolite of tetrahydrocannabinol (THC), the major active ingredient of the recreational drug marijuana derived from the plant Cannabis sativa. AJA has potent analgesic and anti-inflammatory activity in vivo, but without the psychotropic action of THC. However, its precise mechanism of action remains unknown. Biochemical studies indicate that AJA binds directly and selectively to the isotype γ of the peroxisome proliferator-activated receptor (PPARγ) suggesting that this may be a pharmacologically relevant receptor for this compound and a potential target for drug development in the treatment of pain and inflammation. Here, we report the crystal structure of the ligand binding domain of the γ isotype of human PPAR in complex with ajulemic acid, determined at 2.8-Å resolution. Our results show a binding mode that is compatible with other known partial agonists of PPAR, explaining their moderate activation of the receptor, as well as the structural basis for isotype selectivity, as observed previously in vitro. The structure also provides clues to the understanding of partial agonism itself, suggesting a rational approach to the design of molecules capable of activating the receptor at levels that avoid undesirable side effects.”

“AJA (also known as CT-3, IP-751, or 1′,1′-dimethylheptyl-Δ8-tetrahydrocannabinol-11-oic acid) was originally designed based on observations of the metabolic transformations of THC using the metabolite THC-11-oic acid as a template. AJA suppresses neuropathic pain in humans and prevents joint tissue injury in rat models of inflammatory arthritis. In all cases, these effects are observed without producing the motor side effects associated with THC.”

“In summary, our results show that AJA, as well as other THC analogs, in presenting specific binding together with minimal toxicity and good bioavailability may provide useful novel templates for rational drug design aimed at PPARγ regulation.”

 http://www.jbc.org/content/282/25/18625.long

Ajulemic acid: A novel cannabinoid produces analgesia without a “high”.

Abstract

   “A long-standing goal in cannabinoid research has been the discovery of potent synthetic analogs of the natural substances that might be developed as clinically useful drugs. This requires, among other things, that they be free of the psychotropic effects that characterize the recreational use of Cannabis. An important driving force for this goal is the long history of the use of Cannabis as a medicinal agent especially in the treatment of pain and inflammation. While few compounds appear to have these properties, ajulemic acid (AJA), also known as CT-3 and IP-751, is a potential candidate that could achieve this goal. Its chemical structure was derived from that of the major metabolite of Delta9-THC, the principal psychotropic constituent of Cannabis. In preclinical studies it displayed many of the properties of non-steroidal anti-inflammatory drugs (NSAIDs); however, it seems to be free of undesirable side effects. The initial short-term trials in healthy human subjects, as well as in patients with chronic neuropathic pain, demonstrated a complete absence of psychotropic actions. Moreover, it proved to be more effective than placebo in reducing this type of pain as measured by the visual analog scale. Unlike the narcotic analgesics, signs of dependency were not observed after withdrawal of the drug at the end of the one-week treatment period. Data on its mechanism of action are not yet complete; however, the activation of PPAR-gamma, and regulation of eicosanoid and cytokine production, appear to be important for its potential therapeutic effects.”

http://www.ncbi.nlm.nih.gov/pubmed/15240185

Antihyperalgesic properties of the cannabinoid CT-3 in chronic neuropathic and inflammatory pain states in the rat.

Abstract

   “CT-3 (ajulemic acid) is a synthetic analogue of a metabolite of Delta9-tetrahydrocannabinol that has reported analgesic efficacy in neuropathic pain states in man. Here we show that CT-3 binds to human cannabinoid receptors in vitro, with high affinity at hCB1 (Ki 6 nM) and hCB2 (Ki 56 nM) receptors. In a functional GTP-gamma-S assay CT-3 was an agonist at both hCB1 and hCB2 receptors (EC50 11 and 13.4 nM, respectively). In behavioural models of chronic neuropathic and inflammatory pain in the rat, oral administration of CT-3 (0.1-1 mg/kg) produced up to 60% reversal of mechanical hyperalgesia. In both models the antihyperalgesic activity was prevented by the CB1-antagonist SR141716A but not the CB2-antagonist SR144528. In the tetrad of tests for CNS activity, CT-3 (1-10 mg/kg, po) produced dose-related catalepsy, deficits in locomotor performance, hypothermia, and acute analgesia. Comparison of 50% maximal effects in the tetrad and chronic pain assays produced an approximate therapeutic index of 5-10. Pharmacokinetic analysis showed that CT-3 exhibits significant but limited brain penetration, with a brain/plasma ratio of 0.4 measured following oral administration, compared to ratios of 1.0-1.9 measured following subcutaneous administration of WIN55,212-2 or Delta9-THC. These data show that CT-3 is a cannabinoid receptor agonist and is efficacious in animal models of chronic pain by activation of the CB1 receptor. Whilst it shows significant cannabinoid-like CNS activity, it exhibits a superior therapeutic index compared to other cannabinoid compounds, which may reflect a relatively reduced CNS penetration.”

http://www.ncbi.nlm.nih.gov/pubmed/15936883

Effect of the cannabinoid ajulemic acid on rat models of neuropathic and inflammatory pain.

Abstract

   “There is increasing evidence that cannabinoid agonists alleviate the abnormal pain sensations associated with animal models of neuropathic and inflammatory pain. However, cannabinoids produce a number of motor and psychotropic side effects. In the present study we found that systemic administration of the cannabinoid acid derivative 1′,1′-dimethylheptyl-delta-8-tetrahydrocannabinol-11-oic acid (ajulemic acid, IP-751) and the non-selective cannabinoid receptor agonist HU-210 reduced mechanical allodynia in a nerve-injury induced model of neuropathic pain and in the CFA-induced model of inflammatory pain. In contrast, HU-210, but not ajulemic acid reduced motor performance in the rotarod test. These findings suggest that ajulemic acid reduces abnormal pain sensations associated with chronic pain without producing the motor side effects associated with THC and other non-selective cannabinoid receptor agonists.”

http://www.ncbi.nlm.nih.gov/pubmed/15925096

Ajulemic acid (IP-751): Synthesis, proof of principle, toxicity studies, and clinical trials

Abstract

  “Ajulemic acid (CT-3, IP-751, 1′,1′-dimethylheptyl-Delta8-tetrahydrocannabinol-11-oic acid) (AJA) has a cannabinoid-derived structure; however, there is no evidence that it produces psychotropic actions when given at therapeutic doses. In a variety of animal assays, AJA shows efficacy in models for pain and inflammation. Furthermore, in the rat adjuvant arthritis model, it displayed a remarkable action in preventing the destruction of inflamed joints. A phase-2 human trial with chronic, neuropathic pain patients suggested that AJA could become a useful drug for treating this condition. Its low toxicity, particularly its lack of ulcerogenicity, further suggests that it will have a highly favorable therapeutic index and may replace some of the current anti-inflammatory/analgesic medications. Studies to date indicate a unique mechanism of action for AJA that may explain its lack of adverse side effects.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2751505/