Motor, visual and emotional deficits in mice after closed-head mild traumatic brain injury are alleviated by the novel CB2 inverse agonist SMM-189.

We have developed a focal blast model of closed-head mild traumatic brain injury (TBI) in mice. As true for individuals that have experienced mild TBI, mice subjected to 50-60 psi blast show motor, visual and emotional deficits, diffuse axonal injury and microglial activation, but no overt neuron loss. Because microglial activation can worsen brain damage after a concussive event and because microglia can be modulated by their cannabinoid type 2 receptors (CB2), we evaluated the effectiveness of the novel CB2 receptor inverse agonist SMM-189 in altering microglial activation and mitigating deficits after mild TBI. In vitro analysis indicated that SMM-189 converted human microglia from the pro-inflammatory M1 phenotype to the pro-healing M2 phenotype. Studies in mice showed that daily administration of SMM-189 for two weeks beginning shortly after blast greatly reduced the motor, visual, and emotional deficits otherwise evident after 50-60 psi blasts, and prevented brain injury that may contribute to these deficits. Our results suggest that treatment with the CB2 inverse agonist SMM-189 after a mild TBI event can reduce its adverse consequences by beneficially modulating microglial activation. These findings recommend further evaluation of CB2 inverse agonists as a novel therapeutic approach for treating mild TBI.

Mechanism of anti-glioma activity and in vivo efficacy of the cannabinoid ligand KM-233.

Glioblastoma multiforme (GBM) is the most common and devastating form of primary central nervous system malignancy. The prognosis for patients diagnosed with GBM is poor, having a median survival rate of 12-15 months. Despite modern advances in the development of antineoplastic agents, the efficacy of newer anti-cancer agents in the treatment of GBM is yet to be determined. Thus, there remains a significant unmet need for new therapeutic strategies against GBM. A promising chemotherapeutic intervention has emerged from studies of cannabinoid receptor agonists wherein tetrahydrocannabinol has been the most extensively studied. The novel cannabinoid ligand KM-233 was developed as a lead platform for future optimization of biopharmaceutical properties of classical based cannabinoid ligands. Treatment of U87MG human GBM cells with KM-233 caused a time dependent change in the phosphorylation profiles of MEK, ERK1/2, Akt, BAD, STAT3, and p70S6K. Almost complete mitochondrial depolarization was observed 6 h post-treatment followed by a rapid increase in cleaved caspase 3 and significant cytoskeletal contractions. Treatment with KM-233 also resulted in a redistribution of the Golgi-endoplasmic reticulum structures. Dose escalation studies in the orthotopic model using U87MG cells revealed an 80 % reduction in tumor size after 12 mg/kg daily dosing for 20 days. The evaluation of KM-233 against primary tumor tissue in the side flank model revealed a significant decrease in the rate of tumor growth. These findings indicate that structural refinement of KM-233 to improve its biopharmaceutical properties may lead to a novel and efficacious treatment for GBM.

Evaluation of novel vanilloid-based hemostatic agents in rats.

BACKGROUND: : Hemostatic dressings containing clotting factors, biodegradable matrices, and recombinant proteins have been developed to control bleeding for battlefield trauma and trauma in clinical settings. Our present study evaluates the use of a vanilloid compound in biodegradable hemostatic dressings in a rat model of trauma. METHODS: : Male Sprague-Dawley rats (n = 180) were randomly divided into treatment groups and control groups and subjected to a lethal groin injury at 30 degrees C and 37 degrees C. Treatment groups included hemostatic matrices consisting of Protosan and graded doses of 2.5%, 5%, 10%, 15%, and 20% of the vanilloid agonist CAP-305. Powder or bilayer patch formulations were applied to the injury site. The seal integrity was assessed by reperfusion of the animal to a minimum mean-arterial pressure (MAP) of 80 mm Hg and monitoring for 60 minutes postinjury. RESULTS: : Powder and patch formulations loaded with varying concentrations of CAP-305 were evaluated. Powders containing 2.5% to 20% drug by weight showed 40% to 80% seal rates at 37 degrees C (p < 0.0001), whereas no significant results were obtained at 30 degrees C compared with the control animals. Conversely, bilayer patches loaded with 5% to 20% drug exhibited a consistent 70% seal rate (p < 0.0001) at 37 degrees C and 70% to 90% seal rates (p < 0.0001) in hypothermic animals when compared with controls. CONCLUSIONS: : Our study demonstrates the efficacy of CAP-305 loaded hemostatic dressings in the rat model of lethal groin injury. This study provides relevant proof of concept for the development of vanilloid agonists as hemostatic agents.

Design and synthesis of novel tri-aryl CB2 selective cannabinoid ligands.

A novel series of cannabinoid ligands with a structurally unique tri-aryl core has been designed, synthesized and assayed. Receptor binding assays show that these compounds possess CB2 receptor sub-type selectivity with binding affinities ranging from 1.07 (+/-0.05) for 7 to 4.77 (+/-0.57) nM for 6. The selectivity of the compounds was enhanced 9-600-fold for the CB2 receptor over the CB1 receptor. The results of our present study identify a novel, highly selective cannabinoid scaffold with a non-classical core.