However, five scientific studies have overshadowed herbal lore by demonstrating the oil offers a benefit to alleviating inflammation. One study, published in the journal Experimental and Toxicologic Pathology, discovered that oregano oil significantly improved rat colitis, or inflammation of the colon. When compared to the control group, the oregano-treated rats showed much greater success in terms of visual disease signs such as ulceration and swelling,
In a different study, this one reported in the journal Mediators of Inflammation, thyme and oregano oils were used in conjunction and found to benefit colitis in mice. The oils reduced the levels of cytokines, biochemical traditionally associated with inflammation. The results found oil treatment led to lower mortality, greater body-weight gain, and reduced tissue damage in the animals.
In regards to benefits to the liver, an investigation reported in the journal Phytomedicine examined the effects of carvacrol on liver regeneration. Carvacrol is one of the key active ingredients in oregano oil. Rats with their livers surgically removed were assigned to two different groups. One group was treated with carvacrol and the other served as the control group. The carvacrol group experienced noticeably increased liver-weight gain.
A fourth study in Phytomedicine discovered that carvacrol protected the livers of rats that also had blood supply restricted to those organs. The investigators found that carvacrol was nontoxic to rat livers used in the study.
The final study, published in the Proceedings of the National Academy of Sciences, has found that an active ingredient in oregano can cure additional instances of inflammation. This ingredient, known as beta-carophyllin (E-BCP), was administered to mice with inflamed paws. In seven out of ten experiments, there was a subsequent improvement in inflammation symptoms. Researchers believe E-BCP might be of possible use in treating osteoporosis and arteriosclerosis.
Beta-carophyllin works by docking on specific receptor structures in the cell-membrane – the so-called cannabinoid-CB2 receptors. The result is a change in cell behavior, inhibiting the cell’s production of phlogogenic signal substances. According to investigator Dr. Jürg Gertsch, E-BCP has been used to treat mice with swollen paws due to inflammations. In 70 percent of cases where the treatment had been administered, the swelling subsequently subsided.