Faculty Bibliography

Ajulemic acid (AJA) is a synthetic analog of the tetrahydrocannabinol (THC) metabolite THC-11-oic acid; THC is a major active ingredient of the drug marijuana derived from the plant cannabis. AJA has potent analgesic and anti-inflammatory activity without the psychotropic action of THC. Unlike the nonsteroidal anti-inflammatory drugs, AJA is not ulcerogenic at therapeutic doses, making it a promising anti-inflammatory drug. However, the mechanism of AJA action remains unknown. Here we report that AJA binds directly and specifically to the peroxisome proliferator-activated receptor gamma (PPARgamma), a pharmacologically important member of the nuclear receptor superfamily. Functional assay indicates that AJA activates the transcriptional activity of both human and mouse PPARgamma at pharmacological concentrations. Activation of PPARgamma by AJA requires the AF-2 helix of the receptor, suggesting that AJA activates PPARgamma through the ligand-dependent AF-2 function. AJA binding consistently enables PPARgamma to recruit nuclear receptor coactivators. In addition, we show that AJA inhibits interleukin-8 promoter activity in a PPARgamma-dependent manner, suggesting a link between the anti-inflammatory action of AJA and the activation of PPARgamma. Finally, we find that AJA treatment induces differentiation of 3T3 L1 fibroblasts into adipocytes, a process mediated by PPARgamma. Together, these data indicate that PPARgamma may be a molecular target for AJA, providing a potential mechanism for the anti-inflammatory action of AJA, and possibly other cannabinoids. These studies also implicate other potential therapeutic actions of AJA through PPARgamma activation in multiple signaling pathways

Oral administration of ajulemic acid (AjA), a cannabinoid acid devoid of psychoactivity, reduces joint tissue damage in rats with adjuvant arthritis. Because interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNFalpha) are central to the progression of inflammation and joint tissue injury in patients with rheumatoid arthritis, we investigated human monocyte IL-1beta and TNFalpha responses after the addition of AjA to cells in vitro. Peripheral blood and synovial fluid monocytes (PBM and SFM) were isolated from healthy subjects and patients with inflammatory arthritis, respectively, treated with AjA (0-30 microM) in vitro, and then stimulated with lipopolysaccharide. Cells were harvested for mRNA, and supernatants were collected for cytokine assay. Addition of AjA to PBM and SFM in vitro reduced both steady-state levels of IL-1beta mRNA and secretion of IL-1beta in a concentration-dependent manner. Suppression was maximal (50.4%) at 10 microM AjA (P<0.05 vs untreated controls, N=7). AjA did not influence TNFalpha gene expression in or secretion from PBM. Reduction of IL-1beta by AjA may help explain the therapeutic effects of AjA in the animal model of arthritis. Development of nonpsychoactive therapeutically useful synthetic analogs of Cannabis constituents, such as AjA, may help resolve the ongoing debate about the use of marijuana as medicine

The marijuana plant (Cannabis sativa) and preparations derived from it have been used for medicinal purposes for thousands of years. It is likely that the therapeutic benefits of smoked marijuana are due to some combination of its more than 60 cannabinoids and 200-250 non-cannabinoid constituents. Several marijuana constituents, the carboxylic acid metabolites of tetrahydrocannabinol, and synthetic analogs are free of cannabimimetic central nervous system activity, do not produce behavioral changes in humans, and are effective antiinflammatory and analgesic agents. One cannabinoid acid in particular, ajulemic acid, has been studied extensively in in vitro systems and animal models of inflammation and immune responses. This commentary reviews a portion of the work done by investigators interested in separating the medicinal properties of marijuana from its psychoactive effects. Understanding the mechanisms of the therapeutic effects of nonpsychoactive cannabinoids should lead to development of safe effective treatment for several diseases, and may render moot the debate about 'medical marijuana'

Abnormalities of LFTs and liver function occur not infrequently in patients with rheumatic conditions, and many diagnostic possibilities exist. Systemic inflammation that is related to uncontrolled rheumatic disease and periods of disease remission have been described as a cause for fluctuations in levels of serum aminotransferases. Although these benign extra-articular manifestations of rheumatic disease are the most common manifestations, more serious hepatic involvement, including vasculitis, nodular regenerative hyperplasia, and primary biliary cirrhosis, have been observed in specific rheumatic diseases. The cause of rheumatic disease is unclear. Occult HCV infection and associated cryoglobulinemia can mimic rheumatic disease. HCV infection should be suspected routinely in patients with mixed cryoglobulinemia, especially because antiviral therapy may be beneficial. The medical management of rheumatic disease involves medications that are often hepatotoxic. Routine laboratory monitoring, imaging studies, and, if necessary, biopsy examination in situations in which serum aminotransferases remain abnormal, are recommended

N-arachidonylglycine (NAGly), the carboxylic analog of the endocannabinoid anandamide, occurs in rat and bovine brain as well as in peripheral sites and shows activity against tonic, formalin-induced pain. It was also observed, using cell membrane preparations, that it inhibits the hydrolytic activity of fatty acid amide hydrolase (FAAH) on anandamide (N-arachidonylethanolamide). These data suggested that it may serve as an endogenous regulator of tissue anandamide concentrations. In this report, we show findings derived from mass spectrometric analyses, indicating that blood levels of anandamide in rats given 10 mg/kg p.o. of NAGly were increased significantly by more than 9-fold when compared with vehicle-treated controls. In vitro evidence in RAW 264.7 cells using a deuterium-labeled NAGly demonstrated that it was not a precursor or source of arachidonic acid for the observed 50% rise in anandamide levels, suggesting that the increase was due to some effect other than increased biosynthesis of anandamide. Moreover, the findings presented here suggest that NAGly can serve as a model for the design of agents to provide pharmacological control of tissue anandamide concentrations

Administration of gammalinolenic acid (GLA), an unsaturated fatty acid, reduces joint inflammation in patients with rheumatoid arthritis. Addition of GLA in vitro suppresses release of interleukin-1beta (IL-1beta) from human monocytes stimulated with lipopolysaccharide (LPS). LPS-induced IL-1beta release is followed by IL-1-induced IL-1beta release, an amplification process termed 'autoinduction.' We show here, using IL-1alpha stimulation to simulate autoinduction, that administration of GLA to healthy volunteers and to patients with inflammatory arthritis reduces LPS-induced IL-1beta secretion mainly by reducing autoinduction of IL-1beta. GLA reduces LPS-induced pro-IL-1beta mRNA modestly and IL-la-induced pro-IL-1beta gene expression markedly. In addition to reducing amplification of IL-1beta, GLA increases the amount of IL-1 receptor antagonist (IL-1Ra) secreted from stimulated cells, thereby facilitating an increase in the secreted IL-1Ra/IL-1beta ratio. IL-1beta is important to host defense, but the amplification mechanism may be excessive in genetically predisposed individuals. Thus, reduction of IL-1beta autoinduction may be protective in some patients with endotoxic shock and with diseases characterized by chronic inflammation

Administration of gammalinolenic acid (GLA), an unsaturated fatty acid, reduces joint inflammation in patients with rheumatoid arthritis. Addition of GLA in vitro suppresses release of IL-1beta from human monocytes stimulated with LPS. LPS-induced IL-1beta release is followed by IL-1-induced IL-1beta release, an amplification process termed autoinduction. We show here with peripheral blood monocytes from normal volunteers and from patients with rheumatoid arthritis by using IL-1R antagonist to block autoinduction and IL-1alpha stimulation to simulate autoinduction that approximately 40% of IL-1beta released from LPS-stimulated cells is attributable to autoinduction and that GLA reduces autoinduction of IL-1beta while leaving the initial IL-1beta response to LPS intact. Experiments with cells in which transcription and protein synthesis were blocked suggest that GLA induces a protein that reduces pro-IL-1beta mRNA stability. IL-1beta is important to host defense, but the amplification mechanism may be excessive in genetically predisposed patients. Thus, reduction of IL-1beta autoinduction may be protective in some patients with endotoxic shock and with diseases characterized by chronic inflammation

Rheumatoid arthritis is characterized by infiltration of T lymphocytes, macrophages and plasma cells into the synovium, and the initiation of a chronic inflammatory state that involves overproduction of proinflammatory cytokines and a dysregulated T-helper-1-type response. Eicosanoids synthesized from arachidonic acid and cytokines cause progressive destruction of cartilage and bone. The n-6 polyunsaturated fatty acid gamma-linolenic acid is the precursor of di-homo-gamma-linolenic acid. The latter and the n-3 polyunsaturated fatty acid eicosapentaenoic acid, which is found in fish oil, are able to decrease the production of arachidonic acid-derived eicosanoids and to decrease the production of proinflammatory cytokines and reactive oxygen species, and the reactivity of lymphocytes. A number of double-blind, placebo-controlled trials of gamma-linolenic acid and fish oil in rheumatoid arthritis have shown significant improvements in a variety of clinical outcomes. These fatty acids should be included as part of the normal therapeutic approach to rheumatoid arthritis. However, it is unclear what the optimal dosage of the fatty acids is, or whether there would be extra benefit from using them in combination

In addition to the well studied hydrolytic metabolism of anandamide, a number of oxidative processes are also possible. Several routes somewhat analogous to the metabolism of free arachidonic acid have been reported. These involve mediation by various lipoxygenases and COX-2 and lead to ethanolamide analogs of the prostaglandins and HETES. The physiological significance of these products is not well understood at this time. There are also preliminary data suggesting a pathway involving oxidation of the hydroxy group of anandamide to a putative metabolite, N-arachidonyl glycine (AA-gly). This molecule displays activities in experimental models that suggest that it may play a role in some of the activities attributed to its precursor, anandamide

BACKGROUND: Oils enriched in gammalinolenic acid, an unsaturated fatty acid, reduce joint pain and swelling in patients with rheumatoid arthritis. The cytokines interleukin-1 beta and tumor necrosis factor-alpha appear to contribute directly to joint tissue damage in patients with rheumatoid arthritis. Agents designed to interfere with the actions of interleukin-1 beta and tumor necrosis factor-alpha are being used to treat rheumatoid arthritis. METHODS: We examined the influence of gammalinolenic acid added to cells in vitro and administered orally in vivo on interleukin-1 beta and tumor necrosis factor-alpha secretion from activated human peripheral blood monocytes. Secretion of both cytokines was reduced by gammalinolenic acid. Administration of safflower oil as a polyunsaturated fatty acid control devoid of gammalinolenic acid did not change secretion of either cytokine. CONCLUSION: Suppression of IL-beta and TNF-alpha secretion by activated cells may be one mechanism whereby gammalinolenic acid suppresses synovitis in patients with rheumatoid arthritis