Table 1.

Clinical experiment of treating psoriasis with indigo naturalis

Drugs	Clinic types of experiments	Types of psoriasis	Number of examinees	Usage time	Results	Refs.
Indigo naturalis oil extract	A non-controlled pilot study	Nail psoriasis	n = 28	24 weeks	The Nail Psoriasis Severity Index (NAPSI) decreased from 36.1 ± 14.7 to 14.9 ± 11.1, and the average Nasi score decreased from 11.7 ± 3.9 to 3.6 ± 3.2	[82]
Indigo naturalis ointment	A randomized, double-blind, placebo-controlled study	Moderate psoriasis	n = 24 (drug:16, placebo: 8)	8 weeks	In 56.3% of patients, the psoriasis area and severity index scores were improved by 75%, and IL-17 in skin genes of these patients was significantly down regulated compared with placebo	[83]
Indigo naturalis ointment or vehicle ointment	A randomized, observer-blind, vehicle-controlled study	Recalcitrant psoriasis	n = 42	12 weeks	Compared with placebo, the scores of erythema, scale and lump and plaque area of indigo naturalis in treatment site were significantly reduced. The symptoms of psoriasis disappeared or nearly disappeared in 74% of patients with indigo naturalis	[81]
Indigo naturalis composite ointment	–	Pediatric psoriasis	8-year-old boy	8 weeks	After treating with indigo naturalis composite ointment, the lesions of systemic psoriasis disappeared completely, and the affected body surface decreased from nearly 80–0%. Remission has lasted for over 2 years without any adverse reaction	[84]
Indigo naturalis oil extract drops	–	Pediatric nail psoriasis with periodic pustular eruption	A 13-year-old girl	6 months	After treat in one month, the pustulation of the nails and the crusted, keratotic erythematous lesions disappeared. A completely normal nail unit without Beau’s lines was achieved after 6 months without any adverse reaction Remission has lasted for over 1 year	[85]