Cannabidiol Found to Ease Oxidative Stress, Inflammation in Rat Model
Treatment with cannabidiol (CBD) reduced inflammation and lessened damaging oxidative stress in a rat model of pulmonary hypertension (PH), a new study reports.
“The promising results of our research may form the basis for a more detailed study of the effects of CBD or its derivatives on PH, especially in humans,” the researchers wrote.
The team said their findings — of CBD’s “relaxing effect on pulmonary vessels” — suggest it “could be a successful adjunctive [add-on] therapy in the treatment of PH.”
CBD is one of the main biologically active molecules found in the cannabis plant. The other, called tetrahydrocannabinol (THC), is mainly responsible for the “high” induced by recreational cannabis use.
While cannabidiol has a variety of other effects on the body, it in particular is known to exert anti-inflammatory effects. It also acts as an antioxidant, meaning it helps to reduce oxidative stress — a form of cellular damage caused by highly reactive oxygen-containing molecules.
Now, scientists in Poland sought to investigate the anti-inflammatory and antioxidant effects of CBD in a rat model of PH. A daily dose of 10 mg/kg was used for 21 days (three weeks) in these rats, in which pulmonary hypertension was induced by administering a chemical called monocrotaline.
The researchers noted that this model was chosen because it induces a potent inflammatory response in the lungs’ blood vessels.
“The aim of the study was to evaluate whether chronic administration of CBD had a beneficial effect on the parameters of oxidative stress and inflammation in rats with [monocrotaline]-induced PH,” the team wrote.
Compared with the lungs of healthy rats, lung tissue in the untreated animals with pulmonary hypertension exhibited a significant decrease — by about 35% — in total antioxidant capacity (TAC). As the term suggests, TAC refers to a tissue’s ability to reduce oxidative stress. Levels of a naturally occurring antioxidant called glutathione also were reduced in the pulmonary hypertension rats, by about 48%.
In contrast, animals treated with cannabidiol exhibited a significant increase in TAC, by about 36%, while glutathione levels increased by approximately 51%.
Untreated rats with pulmonary hypertension also exhibited marked increases in a number of inflammatory signaling molecules, including NF-kB — which rose 100% — and TNF-alpha, which increased by 67%. The inflammatory signaling molecule MCP-1 also increased, by 10 times.
Mice treated with CBD, meanwhile, had reduced levels of all three molecules: NF-kB by 40%, TNF-alpha by 40%, and MCP-1 by 77%. Other inflammatory markers followed similar trends.
“Altogether, we have shown for the first time that CBD improved antioxidant capacity and reduced inflammation in the rat model of [monocrotaline]-induced PH,” the scientists concluded.
Tissue analyses also suggested that rats with pulmonary hypertension exhibited a marked increase in cannabinoid receptors in the lungs. These are protein receptors that can respond to CBD and other compounds found in cannabis.
The researchers found treatment with CBD led to a reduction in levels of a certain class of cannabinoid receptors called CB1-Rs, which are generally pro-inflammatory. Levels of other receptors (CB2-Rs) were not affected by CBD treatment.