Arthritis and cannabinoids: HU-210 and Win-55,212-2 prevent IL-1alpha-induced matrix degradation in bovine articular chondrocytes in-vitro.

Cannabinoids have analgesic, immunomodulatory and anti-inflammatory properties and attenuate joint damage in animal models of arthritis. In this study the mechanisms of action of the synthetic cannabinoid agonists, HU-210 and Win-55,212-2, were studied to determine if they affected interleukin-1 alpha (IL-1alpha)-induced proteoglycan and collagen degradation in bovine nasal cartilage explant cultures and prostaglandin E2 (PGE2) production in primary cultures of bovine articular chondrocytes. The effects of the inactive enantiomer, Win-55,212-3, were compared with those of the active enantiomer, Win-55,212-2, to determine if the effects were cannabinoid (CB)-receptor mediated. The chondrocytes and explants were stimulated by IL-1alpha (100 U mL(-1) identical with 0.06 nM and 500 U mL(-1) identical with 0.3 nM, respectively). Proteoglycan breakdown was determined as sulfated glycosaminoglycan (sGAG) release using the dimethylmethylene blue assay. Collagen degradation was determined as hydroxyproline in the conditioned culture media and cartilage digests. PGE2 was determined by ELISA. Expression of cannabinoid receptors, CB1 and CB2; cyclooxygenase-1 and -2 (COX-1 and COX-2); inducible nitric oxide synthase (iNOS); as well as activation of nuclear factor-kappa B (NF-kappaB) in chondrocytes were studied using immunoblotting techniques and immunofluorescence. The results showed that HU-210 and Win-55,212-2 (5-15 microM) significantly inhibited IL-1-alpha stimulated proteoglycan (P < 0.001) and collagen degradation (P < 0.001). Win-55,212-2 (5-10 microM) also significantly inhibited PGE2 production (P < 0.01). At 5 microM, Win-55,212-2 inhibited the expression of iNOS and COX-2 and activation of NF-kappaB. Chondrocytes appeared to constitutively express cannabinoid receptors CB1 and CB2. It is concluded that biologically stable synthetic cannabinoids protect cartilage matrix from degradation induced by cytokines and this effect is possibly CB-receptor mediated and involves effects on prostaglandin and nitric oxide metabolism. Cannabinoids could also be producing these effects via inhibition of NF-kappaB activation.

Effects of cannabinoids on nitric oxide production by chondrocytes and proteoglycan degradation in cartilage.

Cannabinoids have been reported to have anti-inflammatory effects and reduce joint damage in animal models of arthritis. This suggests a potential therapeutic role in arthritis of this group of compounds. Cannabinoids were studied to determine whether they have direct effects on chondrocyte metabolism resulting in cartilage protection. Synthetic cannabinoids, R-(+)-Win-55,212 (Win-2) and S-(-)-Win-55,212 (Win-3) and the endocannabinoid, anandamide, were investigated on unstimulated or IL-1-stimulated nitric oxide (NO) production in bovine articular chondrocytes as well as on cartilage proteoglycan breakdown in bovine nasal cartilage explants. Win-2 significantly inhibited (P < 0.05) NO production in chondrocytes at 1-10 microM concentrations. The combined CB(1) and CB(2) cannabinoid receptor antagonists, AM281 and AM630, respectively, at 100 microM did not block this effect, but instead they potentiated it. Anandamide and Win-2 (5-50 microM) also inhibited the release of sulphated glycosaminoglycans in bovine cartilage explants. The results suggest that some cannabinoids may prevent cartilage resorption, in part, by inhibiting cytokine-induced NO production by chondrocytes and also by inhibiting proteoglycan degradation.

Cannabinoids in pain and inflammation.

Cannabinoids exhibit medicinal properties including analgesic, anti-inflammatory and immunosuppressive properties. This paper reviews some of the recent findings in the study of cannabinoids in pain and inflammation. Some of the effects of cannabinoids are receptor mediated and others are receptor independent. Endocannabinoids naturally reduce pain and are cerebroprotective. Natural and synthetic cannabinoids have the potential to reduce nociception, reverse the development of allodynia and hyperalgesia, reduce inflammation and inflammatory pain and protect from secondary tissue damage in traumatic head injury.

A first step incorporating smoking education into a Brazilian medical school curriculum: results of a survey to assess the cigarette smoking knowledge, attitudes, behaviour, and clinical practices of medical students.

Smoking-related illnesses are the leading causes of morbidity and mortality in Brazil. Despite a smoking prevalence of approximately 40%, there is limited national effort to reduce tobacco use in Brazil by means of public education and training of health care professionals to promote smoking education. In particular, the need for information about tobacco warrants increased emphasis in undergraduate medical education. An educational program on nicotine addiction during medical school could facilitate the incorporation of smoking cessation interventions into routine medical practice. As a preliminary step toward implementing a tobacco education and intervention program, this study was designed to assess knowledge and attitudes about smoking among Brazilian medical students. Five hundred thirteen (N = 513) medical students from the Federal University of Rio Grande do Sul, the southernmost state of Brazil, completed a self-reported questionnaire during the 1995-1996 academic school year. Most students recognize the adverse health effects of smoking and the importance of their professional role in promoting smoking cessation. In contradiction, however, few medical students currently provide their patients who smoke with even minimal intervention. This discrepancy supports the idea that training in nicotine addiction and smoking cessation techniques will help medical students to develop the skills and confidence needed to successfully intervene with their current and future patients.