Oregon Grape (Mahonia aquifolium) and Psoriasis: evidence and sources

Background: Due to the emerging trend of alternative medicine, patients inquire about natural remedies to alleviate their symptoms. Dermatologists should be aware of the efficacy and safety of topical botanical treatments available on the market. Mahonia aquifolium, native to the United States, has been recently shown to have anti-inflammatory properties useful in cutaneous disorders. Objective: Our aim was to review clinical trials that assess the efficacy and safety of Mahonia aquifolium in cutaneous disorders. Design: We searched PubMed, MEDLINE, and the Web of Science databases and performed a manual search of clinical trials in the references. We excluded in vivo and in vitro animal trials. Risk of bias was assessed using the Cochrane Risk of Bias Tool. Results: Of the 502 articles identified, eight met the inclusion criteria. Specifically, seven trials studied the effects of Mahonia aquifolium in psoriasis and one studied that in atopic dermatitis. Clinical trials have not been identified in any other cutaneous disorder using this plant extract. Risk of bias of included trials were either unclear or low risk. Five of seven studies showed a statistically significant improvement with Mahonia aquifolium in psoriasis, while one study showed efficacy in the treatment of atopic dermatitis. Conclusion: Several studies have shown that Mahonia aquifolium leads to a statistically significant improvement of symptoms in psoriasis and atopic dermatitis with minimal side effects.

Psoriasis is usually treated with local and systemic medications that have varying degrees of efficacy and safety profiles. We investigated the efficacy and safety of an alternative treatment from natural sources, Mahonia aquifolium, for the management of mild to moderate psoriasis. Two hundred subjects participated in a randomized, double-blind, placebo-controlled study using either the topical cream Reliéva (a homeopathic product containing a proprietary M. aquifolium extract) or control (placebo) twice a day for 12 weeks. Efficacy and safety were assessed using the Psoriasis Area Severity Index (PASI) and the Quality of Life Index (QLI) questionnaires at different times throughout the 12-week study. The PASI was evaluated by the physician at the beginning (week 0) and end (week 12) of the study. The QLI was assessed by patients at weeks 0, 4, 8, and 12. The results indicate statistically significant (P < 0.05) improvements in PASI and QLI in the Mahonia-treated group, compared with the control group. The side effects reported were infrequent, < 1% and minor; the most frequent side effects were rash, a burning sensation when applying the cream, and clothing stain. These data indicate that Reliéva, a proprietary form of M. aquifolium, is effective and well tolerated in patients with mild to moderate psoriasis.

This monograph summarizes 3 recent clinical trials and the worldwide clinical experience with Mahonia aquifolium in patients with psoriasis. Study 1 was an open-label study to evaluate the safety of Mahonia aquifolium in 39 patients treated for 12 weeks. Assessments made were modified PASI, global assessment, psoriasis history questionnaire, Dermatology Life Quality Index, and Psoriasis Disability Index. The results indicate statistically significant improvement in PASI score and Dermatology Life Quality Index after 4 weeks of treatment. This response continued 1 month after the end of treatment. Study 2 was a clinical trial of 32 patients with mild to moderate bilateral psoriasis treated up to 6 months. One side of the body received Mahonia and the other standard psoriatic treatment (eg, Dovonex cream). The primary outcomes were patient ratings of the Mahonia-treated side alone and the comparison between treatments received on each side of their body. Eighty-four percent of patients rated the Mahonia-treated psoriasis as good to excellent response. When compared with standard treatment, 63% of patients rated Mahonia aquifolium equal to or better than the standard psoriatic treatment. Study 3 was an observational study of 33 patients with mild to moderate bilateral psoriasis treated for 1 month. The results indicate improvement in psoriasis after 1 week of treatment. The side treated with Mahonia did as well or better than the side treated with the vehicle cream. Results from these 3 open-label clinical trials are in agreement with published data that include placebo-controlled studies. Taken together, these clinical studies conducted by several investigators in several countries indicate that Mahonia aquifolium is a safe and effective treatment of patients with mild to moderate psoriasis.

The effects of the extract of the bark of Mahonia aquifolium and its main constituents (berberine, berbamine, oxyacanthine) on 5-lipoxygenase, lipid peroxidation in phospholipid liposomes induced by 2,2'-azo-(bis-2-amidinopropane), deoxyribose degradation, and their reactivities against the free radical 2,2-diphenyl-1-picrylhydrazyl have been studied. The extract of M. aquifolium inhibits 5-LO with an IC50 value of 50 microM, whereas no appreciable effects were observed by its constituent alkaloids. Reactivity against DPPH increased in the following order: berberine < M. aquifolium < oxyacanthine, berbamine. Pro-oxidant effects by M. aquifolium or its constituents can be excluded, since deoxyribose degradation was not influenced as determined by the release of malondialdehyde. The most prominent feature of M. aquifolium is its efficacy in inhibition of lipid peroxidation (IC50 = 5 microM) which was not mediated by the alkaloids berberine, berbamine, and oxyacanthine.