Oregon grape's therapeutic uses
Oregon grape, scientifically known as Mahonia aquifolium, has a range of therapeutic uses, particularly in treating skin conditions. Traditionally, both the roots and bark of this shrub have been utilized for various ailments, including psoriasis, fungal infections, eczema, and acne, although evidence supporting its effectiveness is often inconclusive or preliminary. The herb is primarily applied topically, with studies indicating that creams containing 10 percent Oregon grape extract may help reduce symptoms of psoriasis, albeit not as effectively as standard medications.
Research suggests that Oregon grape possesses anti-inflammatory and antimicrobial properties, which may contribute to its therapeutic benefits. However, the use of Oregon grape should be approached with caution; while generally deemed safe for topical use, oral consumption, especially by pregnant women, is discouraged due to potential side effects associated with its berberine content. Furthermore, individuals with severe liver or kidney issues should avoid it, as safety in these populations has not been established. Overall, while Oregon grape is valued for its potential health benefits, more rigorous research is needed to fully understand its efficacy and safety.
Oregon grape's therapeutic uses
Definition: Natural plant product used to treat specific health conditions.
Principal proposed use: Psoriasis
Other proposed uses: Acne, athlete’s foot and other fungal infections, eczema
Overview
The roots and bark of the shrub Mahonia aquifolium (commonly known as Oregon grape) have traditionally been used both orally and topically to treat skin problems. They were also used for other conditions, such as gastritis, fever, hemorrhage, jaundice, gallbladder disease, and cancer. In addition, mahonia was used as a bitter tonic to improve appetite.
According to some experts, M. aquifolium is identical to the plant named Berberis aquifolium, but others point to small distinctions. B. vulgaris, commonly called barberry, is a close relative of these herbs but is not identical.
Therapeutic Dosages
Topical ointments or creams containing 10 percent Oregon grape extract are generally applied three times daily to the affected areas.
Therapeutic Uses
Oregon grape is primarily used as a topical treatment for psoriasis. Growing evidence suggests that it may help reduce symptoms, although it does not seem to be as effective for this purpose as standard medications.
Oregon grape has been proposed as a treatment for other skin diseases, such as fungal infections (such as athlete’s foot), eczema, and acne. However, the evidence is either extremely preliminary or inconclusive. For example, a double-blind, placebo-controlled study of eighty-eight people with eczema tested a cream containing extracts of M. aquifolium, Viola tricolor, and Centella asiatica. The results failed to show benefit overall.
Many studies have been performed on purified berberine, a major chemical constituent of Oregon grape and other herbs such as goldenseal, but it is not clear whether their results apply to the whole herb. In addition, impossibly high dosages of the herb would be required to duplicate the amount of berberine used in many of these studies.
Oregon grape has also been studied for its anti-inflammatory and antimicrobial properties and the health benefits these supply.
Scientific Evidence
Evidence from two double-blind, placebo-controlled studies and one comparative trial suggest that cream made from the herb Oregon grape may help reduce symptoms of psoriasis, although it does not seem to be as effective as standard medications.
In a double-blind study published in 2006, two hundred people were given either a cream containing 10 percent Oregon grape extract or a placebo twice a day for three months. The results indicate that the people using Oregon grape experienced greater benefits than those in the placebo group, and the difference was statistically significant. The treatment was well tolerated, though in a few people, it caused a rash or a burning sensation.
Benefits were also seen in a double-blind, placebo-controlled study of eighty-two people with psoriasis. However, the study design had a significant flaw: the treatment salve was darker in color than the placebo, possibly allowing participants to guess which was which.
Another study found that dithranol, a conventional drug used to treat psoriasis symptoms, was more effective than Oregon grape. Regrettably, the authors failed to state whether this study was double-blind. Forty-nine participants applied one treatment to their left side and the other to their right side for four weeks. Skin biopsies were then analyzed and compared with samples taken at the beginning of the study. The physicians evaluating changes in skin tissue were unaware of which treatments had been used on the samples. Greater improvements were seen in the dithranol group.
A large open study in which 443 participants with psoriasis used Oregon grape topically for twelve weeks found the herb to be helpful for 73.7 percent of the group. Without a placebo group, it is not possible to know whether Oregon grape was truly responsible for the improvement seen, but the trial does help to establish the herb’s safety and tolerability. Laboratory research suggests Oregon grape has some effects at the cellular level that might be helpful in psoriasis, such as slowing the rate of abnormal cell growth and reducing inflammation.
Research suggests Oregon grape may provide additional health benefits. Test tube studies have shown Orgeon grape has antimicrobial properties capable of killing fungi bacteria, and protozoa. One human study published in 2015, as well as several animal studies, showed Oregon grade’s anti-inflammatory properties were effective in treating Irritable Bowel Syndrome and heartburn.
Safety Issues
Oregon grape appears to be safe when used as directed. In the large open study described above, only 5 of the 443 participants reported side effects of burning, redness, and itching. However, because Oregon grape contains berberine, which has been reported to cause uterine contractions and to increase levels of bilirubin, oral consumption of Oregon grape should be avoided by pregnant women. Safety in young children, nursing women, or people with severe liver or kidney disease has not been established. There is an additional concern regarding the berberine content of Oregon grape. One study found that berberine impairs the metabolism of the drug cyclosporine, thereby raising its levels. This could potentially cause toxicity.
Bibliography
Bernstein, S., et al. “Treatment of Mild to Moderate Psoriasis with Relieva, a Mahonia aquifolium Extract.” American Journal of Therapeutics 13 (2006): 121-126.
Bjarnadottir, Adda. “What Is Oregon Grape? Uses and Side Effects.” Healthline, 24 Oct. 2019, www.healthline.com/nutrition/oregon-grape#bottom-line. Accessed 26 Aug. 2023.
Klovekorn, W., A. Tepe, and U. Danesch. “A Randomized, Double-Blind, Vehicle-Controlled, Half-side Comparison with a Herbal Ointment Containing Mahonia aquifolium, Viola tricolor, and Centella asiatica for the Treatment of Mild-to-moderate Atopic Dermatitis.” International Journal of Clinical Pharmacology and Therapeutics 45 (2007): 583-591.
Sheldon, Dawn. “Oregon Grape: Benefits, Side Effects, Dosage, and More.” Verywell Health, 28 Sept. 2022, www.verywellhealth.com/oregon-grape-benefits-4590368. Accessed 26 Aug. 2023.
Wu, X., et al. “Effects of Berberine on the Blood Concentration of Cyclosporin A in Renal Transplanted Recipients: Clinical and Pharmacokinetic Study.” European Journal of Clinical Pharmacology 61, no. 8 (2005): 567-572.