Clinical Assessment of Patients With Recalcitrant Psoriasis in a Randomized, Observer-Blind, Vehicle-Controlled Trial Using Indigo Naturalis

Abstract

Intervention:The patients applied either indigo naturalis ointment or vehicle ointment topically to each of 2 bilaterally symmetrical psoriatic plaque lesions for 12 weeks (depending on the date of enrollment in the study). Main Outcome Measures:The outcomes were assessed using the following criteria: the sum of ery-thema, scaling, and induration scores and the clearing percentage of the target plaque lesion assessed by 2 blinded observers.Results: Significant reductions in the sum of scaling, erythema, and induration scores (PϽ.001) (mean score, 6.3 after indigo naturalis treatment vs 12.8 in control subjects) and plaque area percentage (P Ͻ .001) (mean percentage, 38.5% after indigo naturalis treatment vs 90% in controls) were achieved with topical application of indigo naturalis ointment. Approximately 31 of 42 patients (74%) experienced clearance or near clearance of their psoriasis in the indigo ointment-treated lesion. Conclusion:Topical indigo naturalis ointment was a novel, safe, and effective therapy for plaque-type psoriasis.

Anti-psoriatic effects of indigo naturalis on the proliferation and differentiation of keratinocytes with indirubin as the active component

“…We have been developing an alternative approach by topically applying the drug to skin lesions and thousands of psoriasis patients have been treated by this method since 2003 [5]. Results from randomized, observer-blind, vehicle controlled trials of an intra-patient comparison study demonstrated the safe and effective use of topical indigo naturalis ointment for the treatment of chronic plaque psoriasis [23]. The present study, for the first time, demonstrates that indigo naturalis can decrease PCNA expression in both psoriatic lesions and in vitro cultured keratinocytes.…”

The Malassezia Genus in Skin and Systemic Diseases

“…Malassezia yeasts have been shown to induce the TLR2 pathway (26). However, only to demonstrate the complexity of the participation of Malassezia yeasts in psoriasis pathogenesis, indirubin, a Malassezia-synthesized indole, was successfully employed for the treatment of this disease (200).…”

Indirubin, an acting component of indigo naturalis, inhibits EGFR activation and EGF-induced CDC25B gene expression in epidermal keratinocytes

“…Our previous clinical studies found that topical indigo naturalis ointment was a safe and effective therapy for plaque-type psoriasis [6,7]. We also demonstrated that indigo naturalis and one of its major components, indirubin, could inhibit the cell proliferation of cultured epidermal keratinocytes [8].…”