cannabidiol and Edema

Although preclinical studies generally report robust antinociceptive effects of cannabinoids in rodent persistent pain models, randomized controlled trials in chronic pain patients report limited pain relief from cannabis/cannabinoids. Differences between animal and human studies that may contribute to these discrepant findings include route of cannabis/cannabinoid administration, type of cannabis/cannabinoid, and how pain is measured. To address these factors, rats with complete Freund adjuvant (CFA)-induced hind paw inflammation were exposed acutely or repeatedly to vaporized cannabis extract that was either tetrahydrocannabinol (THC) or cannabidiol (CBD)dominant. One measure of evoked pain (mechanical threshold), 2 functional measures of pain (hind paw weight-bearing, and locomotor activity), and hind paw edema were assessed for up to 2 hours after vapor exposure. Acute exposure to vaporized THC-dominant extract (200 or 400 mg/mL) decreased mechanical allodynia and hind paw edema and increased hind paw weight-bearing and locomotor activity, with no sex differences. After repeated exposure to vaporized THC-dominant extract (twice daily for 3 days), only the antiallodynic effect was significant. Acute exposure to vaporized CBD-dominant cannabis extract (200 mg/mL) did not produce any effects in either sex; repeated exposure to this extract (100, 200, or 400 mg/mL) decreased mechanical allodynia in male rats only. Sex differences (or lack thereof) in the effects of vaporized cannabis extracts were not explained by sex differences in plasma levels of THC, CBD, or their major metabolites. These results suggest that although vaporized THC-dominant extract is likely to be modestly effective against inflammatory pain in both male and female rats, tolerance may develop, and the CBD-dominant extract may be effective only in male rats.

Topics: Animals; Cannabidiol; Cannabinoid Receptor Agonists; Cannabinoids; Cannabis; Chronic Pain; Dronabinol; Edema; Female; Humans; Hyperalgesia; Male; Rats

Symptom-alleviating therapies for osteoarthritis (OA) management are inadequate. Long-term application of first-line treatments, such as nonsteroidal anti-inflammatory drugs, is limited due to associated side effects. We believe that a combination of traditionally used botanical extracts, which have diverse active components that target multiple inflammatory pathways, may provide a safe and efficacious alternative to address the multifactorial nature of OA. Recently, cannabidiol (CBD), the major nonpsychoactive component of the hemp plant, has gained renewed global attention for its pharmacological actions. It has shown promise in reducing pain and inflammation in preclinical models of arthritis. In this study, widely employed inflammatory and noninflammatory animal pain models, such as the hot plate test, visceral pain model (writhing test), and carrageenan-induced rat paw edema model, were utilized to evaluate the antinociceptive and anti-inflammatory activity of CBD alone and in combination with standardized bioflavonoid compositions. CBD was tested at 5, 10, 20, and 40 mg/kg orally and at 5% topically. Administered alone, CBD produced dose-correlated, statistically significant pain inhibition in all the models. Enhanced performance in pain and inflammation reduction was observed when CBD was orally administered in complex with the bioflavonoid compositions. Data from this study show that for clinically meaningful efficacy against OA, CBD may have to be delivered in higher dosage or formulated with other medicinal plants with similar activities.

Topics: Analgesics; Animals; Anti-Inflammatory Agents; Cannabidiol; Carrageenan; Disease Models, Animal; Edema; Flavonoids; Inflammation; Plant Extracts; Rats

Cannabidiol, the major non-psychoactive component of marijuana, has various pharmacological actions of clinical interest. It is reportedly effective as an anti-inflammatory and anti-arthritic in murine collagen-induced arthritis. The present study examined the anti-inflammatory and anti-hyperalgesic effects of cannabidiol, administered orally (5-40 mg/kg) once a day for 3 days after the onset of acute inflammation induced by intraplantar injection of 0.1 ml carrageenan (1% w/v in saline) in the rat. At the end of the treatment prostaglandin E2 (PGE2) was assayed in the plasma, and cyclooxygenase (COX) activity, production of nitric oxide (NO; nitrite/nitrate content), and of other oxygen-derived free radicals (malondialdehyde) in inflamed paw tissues. All these markers were significantly increased following carrageenan. Thermal hyperalgesia, induced by carrageenan and assessed by the plantar test, lasted 7 h. Cannabidiol had a time- and dose-dependent anti-hyperalgesic effect after a single injection. Edema following carrageenan peaked at 3 h and lasted 72 h; a single dose of cannabidiol reduced edema in a dose-dependent fashion and subsequent daily doses caused further time- and dose-related reductions. There were decreases in PGE2 plasma levels, tissue COX activity, production of oxygen-derived free radicals, and NO after three doses of cannabidiol. The effect on NO seemed to depend on a lower expression of the endothelial isoform of NO synthase. In conclusion, oral cannabidiol has a beneficial action on two symptoms of established inflammation: edema and hyperalgesia.

Topics: Administration, Oral; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cannabidiol; Cannabis; Carrageenan; Dose-Response Relationship, Drug; Edema; Hyperalgesia; Male; Nitric Oxide; Rats; Rats, Wistar

Delta9-Tetrahydrocannabinol (Delta9-THC) and (-)-cannabidiol are major constituents of the Cannabis sativa plant with different pharmacological profiles: (-)-Delta9-tetrahydrocannabinol, but not (-)-cannabidiol, activates cannabinoid CB1 and CB2 receptors and induces psychoactive and peripheral effects. We have tested a series of (+)-cannabidiol derivatives, namely, (+)-cannabidiol-DMH (DMH-1,1-dimethylheptyl-), (+)-7-OH-cannabidiol-DMH, (+)-7-OH- cannabidiol, (+)-7-COOH- cannabidiol and (+)-7-COOH-cannabidiol-DMH, for central and peripheral (intestinal, antiinflammatory and peripheral pain) effects in mice. Although all (+)-cannabidiols bind to cannabinoid CB1 and CB2 receptors, only (+)-7-OH-cannabidiol-DMH was centrally active, while all (+)-cannabidiol analogues completely arrested defecation. The effects of (+)-cannabidiol-DMH and (+)-7-OH-cannabidiol-DMH were partially antagonized by the cannabinoid CB1 receptor antagonist N-(piperidiny-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (SR141716), but not by the cannabinoid CB2 receptor antagonist N-[-(1S)-endo-1,3,3-trimethil bicyclo [2.2.1] heptan-2-yl-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528), and had no effect on CB1(-/-) receptor knockout mice. (+)-Cannabidiol-DMH inhibited the peripheral pain response and arachidonic-acid-induced inflammation of the ear. We conclude that centrally inactive (+)-cannabidiol analogues should be further developed as antidiarrheal, antiinflammatory and analgesic drugs for gastrointestinal and other peripheral conditions.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Cannabidiol; Defecation; Ear, External; Edema; Female; Formaldehyde; Gastrointestinal Motility; Mice; Peripheral Nervous System; Receptor, Cannabinoid, CB1; Receptors, Cannabinoid