According to a study published in the November issue of Archives of Dermatology, an effective treatment for plaque-type psoriasis can be found in traditional Chinese medicine. Yin-Ku Lin, M.D. (Chang Gung Memorial Hospital and Chang Gung University, Taoyuan, Taiwan) and colleagues found that an ointment based on the dark-blue, plant-based powder indigo naturalis can be used treat the skin condition.
No cure exists for the chronic skin disease known as psoriasis, but there are therapies that lead to remission of the condition. Lin and colleagues write that, “Traditional Chinese medicine is one of the most frequently chosen alternative therapies in China and Taiwan, and psoriasis has been treated for centuries with topical and oral herbal preparations.” They add that, “Indigo naturalis is one of the Chinese herbal remedies that has been reported to exhibit potential antipsoriatic efficacy. However, long-term systemic use has been occasionally associated with irritation of the gastrointestinal tract and adverse hepatic [liver] effects.”
Further studying the safety and efficacy of indigo naturalis, the researchers conducted a randomized trial with 42 patients suffering from treatment-resistant psoriasis. Between May 2004 and April 2005, participants enrolled in the study that required two ointment applications on their bodies: one was an indigo naturalis ointment applied to a psoriatic plaque on an arm, elbow, leg, or knee of one side of the body, and a second was a non-medicated ointment applied to a parallel plaque on the other side of their body. At the beginning of the study and after two, four, six, eight, ten, and twelve weeks, researchers assess the patients and photographed the skin plaques.
Lin and colleagues report that 12 weeks of treatment resulted in significant improvements in scaling, redness (erythema), and hardening (induration) for the plaques treated with the indigo naturalis ointment compared to the plaques treated with non-medicated ointment. “Weighting the sum of scaling, erythema and induration scores by the lesion area and comparing between the start and end of the study, the indigo naturalis ointment – treated lesions showed an 81 percent improvement, whereas the vehicle [non-medicated] ointment – treated lesions showed a 26 percent improvement,” explain the researchers.
Thirty-four patients completed the study, and none experienced worsening psoriasis conditions in the areas that received the indigo naturalis ointment. In fact, 75% of these patients had complete or near complete clearings of the psoriasis in the treated areas. Although no patients experienced serious adverse effects, four patients reported some itching in the area of the indigo naturalis ointment that last for a few days at the beginning of treatment.
The authors conclude: “We present a randomized controlled trial showing the use of topical indigo naturalis ointment for the treatment of chronic plaque psoriasis to be both safe and effective. Future research for a more potent extraction from this crude herb that can provide better absorption and convenience would help improve patient compliance with the treatment regimen. However, much more research will be necessary to clarify the pharmacology of indigo naturalis.”
Clinical Assessment of Patients With Recalcitrant Psoriasis in a Randomized, Observer-Blind, Vehicle-Controlled Trial Using Indigo Naturalis
Yin-Ku Lin; Chee-Jen Chang; Ya-Ching Chang; Wen-Rou Wong; Shu-Chen Chang; Jong-Hwei Su Pang
Archives of Dermatology (2008). 144: pp. 1457 – 1464.
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Written by: Peter M Crosta