Cannabinoids, inflammation, and fibrosis.

Cannabinoids apparently act on inflammation through mechanisms different from those of agents such as nonsteroidal anti-inflammatory drugs (NSAIDs). As a class, the cannabinoids are generally free from the adverse effects associated with NSAIDs. Their clinical development thus provides a new approach to treatment of diseases characterized by acute and chronic inflammation and fibrosis. A concise survey of the anti-inflammatory actions of the phytocannabinoids Δ9-tetrahydrocannabinol (THC), cannabidiol, cannabichromene, and cannabinol is presented. Mention is also made of the noncannabinoid plant components and pyrolysis products, followed by a discussion of 3 synthetic preparations-Cesamet (nabilone; Meda Pharmaceuticals, Somerset, NJ, USA), Marinol (dronabinol; THC; AbbVie, Inc., North Chicago, IL, USA), and Sativex (Cannabis extract; GW Pharmaceuticals, Cambridge United Kingdom)-that have anti-inflammatory effects. A fourth synthetic cannabinoid, ajulemic acid (AJA; CT-3; Resunab; Corbus Pharmaceuticals, Norwood, MA, USA), is discussed in greater detail because it represents the most recent advance in this area and is currently undergoing 3 phase 2 clinical trials by Corbus Pharmaceuticals. The endogenous cannabinoids, including the closely related lipoamino acids, are then discussed. The review concludes with a presentation of a possible mechanism for the anti-inflammatory and antifibrotic actions of these substances. Thus, several cannabinoids may be considered candidates for development as anti-inflammatory and antifibrotic agents. Of special interest is their possible use for treatment of chronic inflammation, a major unmet medical need.-Zurier, R. B., Burstein, S. H. Cannabinoids, inflammation, and fibrosis.

Treatment of rheumatoid arthritis with marine and botanical oils: an 18-month, randomized, and double-blind trial.

Objective. To determine whether a combination of borage seed oil rich in gamma linolenic acid (GLA) and fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is superior to either oil alone for treatment of rheumatoid arthritis (RA). Methods. Patients were randomized into a double-blind, 18-month trial. Mixed effects models compared trends over time in disease activity measures. Results. No significant differences were observed in changes in disease activity among the three randomized groups. Each group exhibited significant reductions in disease activity (DAS28) at 9 months (fish: -1.56[-2.16, -0.96], borage: -1.33[-1.83, -0.84], combined: -1.18[-1.83, -0.54]) and in CDAI (fish: -16.95[-19.91, -13.98], borage: -11.20[-14.21, -8.19], and combined: -10.31[-13.61, -7.01]). There were no significant differences in change of RA medications among the three groups. Reduced disease activity in study patients was similar to matched patients from an RA registry, and reduction in DMARD use was greater (P < 0.03) in study patients. Conclusion. All 3 treatment groups exhibited similar meaningful clinical responses after 9 months, improvements which persisted for 18 months, and a response similar to matched patients from an RA registry. Study patients were able to reduce DMARD therapy given in combination with TNF antagonists to a greater extent than registry patients. This paper is dedicated to the memory of Dr. John T. Sharp, M.D., a pioneer and innovator in the field of musculoskeletal radiology.

Treatment of rheumatoid arthritis with marine and botanical oils: influence on serum lipids.

The gap in mortality between patients with rheumatoid arthritis (RA) and the general population (1.5-3.0 fold risk) is increasing. This disparity is attributable mainly to cardiovascular disease (CVD), as the CVD risk is comparable to patients with diabetes mellitus. The purpose of this study is to determine whether borage seed oil rich in gamma-linolenic acid, fish oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), or the combination of both oils are useful treatments for dyslipidemia in patients with RA. We randomized patients into a double blind, 18 month trial. Mixed effects models were used to compare trends over time in serum lipids. No significant differences were observed between the three groups: All three treatment groups exhibited similar meaningful improvement in the lipid profile at 9 and 18 months. When all groups were combined, these treatments significantly reduced total and LDL-cholesterol and triglycerides, increased HDL-cholesterol, and improved the atherogenic index. All improvements observed at 9 months persisted at 18 months (P < 0.001 verses baseline). Conclusion. Marine and botanical oils may be useful treatment for rheumatoid arthritis patients who are at increased risk for cardiovascular disease compared to the general population.

Cannabinoids, endocannabinoids, and related analogs in inflammation.

This review covers reports published in the last 5 years on the anti-inflammatory activities of all classes of cannabinoids, including phytocannabinoids such as tetrahydrocannabinol and cannabidiol, synthetic analogs such as ajulemic acid and nabilone, the endogenous cannabinoids anandamide and related compounds, namely, the elmiric acids, and finally, noncannabinoid components of Cannabis that show anti-inflammatory action. It is intended to be an update on the topic of the involvement of cannabinoids in the process of inflammation. A possible mechanism for these actions is suggested involving increased production of eicosanoids that promote the resolution of inflammation. This differentiates these cannabinoids from cyclooxygenase-2 inhibitors that suppress the synthesis of eicosanoids that promote the induction of the inflammatory process.

Potential anti-inflammatory actions of the elmiric (lipoamino) acids.

A library of amino acid-fatty acid conjugates (elmiric acids) was synthesized and evaluated for activity as potential anti-inflammatory agents. The compounds were tested in vitro for their effects on cell proliferation and prostaglandin production, and compared with their effects on in vivo models of inflammation. LPS stimulated RAW 267.4 mouse macrophage cells were the in vitro model and phorbol ester-induced mouse ear edema served as the principal in vivo model. The prostaglandin responses were found to be strongly dependent on the nature of the fatty acid part of the molecule. Polyunsaturated acid conjugates produced a marked increase in media levels of i15-deoxy-PGJ(2) with minimal effects on PGE production. It is reported in the literature that prostaglandin ratios in which the J series predominates over the E series promote the resolution of inflammatory conditions. Several of the elmiric acids tested here produced such favorable ratios suggesting that their potential anti-inflammatory activity occurs via a novel mechanism of action. The ear edema assay results were generally in agreement with the prostaglandin assay findings indicating a connection between them.

Fibroblast-like synovial cells derived from synovial fluid.

OBJECTIVE: To obtain fibroblast-like synovial cells (FLS) from synovial fluid (SF). METHODS: SF aspirated from joints of patients with rheumatoid arthritis (RA), other types of inflammatory arthritis, and osteoarthritis (OA) was centrifuged and the resulting cell pellet resuspended in growth medium. After 2 days, nonadherent cells were removed. FLS were also cultured from surgical specimens of synovial tissue (td-FLS). Phenotype characterization of fluid derived FLS (fd-FLS) was accomplished by flow cytometry and immunohistochemistry staining. Tumor necrosis factor-alpha (TNF-alpha) induced interleukin 6 (IL-6), IL-8, and cyclooxygenase 2 (COX-2) mRNA levels were assessed. RESULTS: Second and later passage fd-FLS exhibited uniform fibroblast-like morphology. Fd-FLS and td-FLS expressed a similar profile of cell surface antigens including the fibroblast marker Thy-1. Less than 2% of either cell type expressed surface markers characteristic of dendritic cells, phagocytic cells, T cells, or leukocytes. Immunohistochemistry staining revealed the presence of fibroblast products prolyl-4 hydroxylase, procollagen I, and procollagen III in both culture types. TNF-a induced increases in IL-6, IL-8, and COX-2 mRNA were suppressed by dexamethasone in both fd-FLS and td-FLS. CONCLUSION: FLS can be cultured from SF. The fibroblast phenotype was confirmed by analysis of surface antigens and intracellular proteins. Inflammatory mediators produced after stimulation of both fd-FLS and td-FLS were suppressed by dexamethasone. In addition to providing a more accessible source of FLS, fd-FLS may also facilitate study of synovial cells in early RA when tissue specimens are not readily available.

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

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.

Prospects for cannabinoids as anti-inflammatory agents.

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".