Study On The Efficiency And Safety Of Compound Xiaoyin-Ointment In Animal Models Of Psoriasis

Background:Psoriasis is commonly known as “psora” and is called “arthritic psoriasis” in traditional Chinese medicine. It is a common skin disease featuring epidermis hyperplasia and chronic inflammative reaction of dermis. It appears on body surface with the major clinical manifestation of red spot, scale, discomfort of dryness, itching and others. If not treated promptly or correctly, the disease can be complicated and deteriorate to erythrodermic psoriasis or arthropathicpsoriasis.Thus oral administration combined with externally applied agent can relieve symptoms well.The externally applied agent can play a direct and persistent role with little untoward effect and convenience to use. However, there are some side effects of the existing drug for external use due to high content of hormone.The calcineurin inhibitor are expensive for common patients.Thus we develops a kind of new ointment treating psoriasis—compound xiaoyin-ointment.Objective:1. To conduct safety evaluation to compound Xiaoyin-ointment A and B via test for skin irritation, skin anaphylactic test, acute toxicity test and long term toxicity test.2. To study the effect of compound Xiaoyin-ointment A and B in psoriasis.Methods:1. Test for skin irritation: 32 rats are randomly divided into complete and lesion skin groups per each for compound Xiaoyin-ointment A and B. Apply 0.5g external ointment on the left side and self-control on the right side. Wash clean after 6h and observe whether there are red spots or edema 1h, 24 h, 48 h and 72 h after removingthe ointment.2.Skin anaphylactic test: 32 rats are randomly divided into compound Xiaoyin-ointment A group, compound Xiaoyin-ointment B group, blank control group and positive control group. Apply external ointment and sensitizer 0.2g or m L on the left side and repeat once 1d, 7d and 14 d after. Apply 0.2g corresponding ointment and 0.2ml excimer evenly onto unhairing area on the right side of rats 28 d after and wash clean with warm water 6h later. Observe skin and whole body anaphylaxis right now or 24 h, 48 h and 72 h later.3. Acute toxicity test: 104 rats are randomly divided into control group, complete and lesion skin group per each for compound Xiaoyin-ointment A and B with three dosage each. Apply once every 6h and wash clean 24 h later. Observe 14 d continuously and observe daily and record rats’ body weight, part and general poisoning and death.4. Long term toxicity test: 50 rats are randomly divided into control group,complete and lesion skin groups per each for compound Xiaoyin-ointment A and B.Apply corresponding ointment 2.0g for each group once a day for four consecutive weeks. Continue to feed the rest half of each group after ointment withdrawal and observe for two weeks. Except not applying external ointment during recovery phase,the observational index and administration period don’t change.5. Pharmacodynamics study: 48 rats are randomly divided into blank group,model group, Clobetasol propionate ointment group, Xiaoyin-ointment group,compound Xiaoyin-ointment A and B groups. Except the blank group, apply external imiquimod to irritate psoriasis model and the external ointment to treat. Observe rats’ general status and skin lesion status 8d after and evaluate PASI and conduct pathological examination of skin tissue.Results:1. The result of skin irritation test: no red spots and edema appear on the complete skin groups of compound Xiaoyin-ointment A and B. For skin lesion groups in skin irritation test, except scab on the scratch, no red spots and edemaappear on the rest part.2. The result of skin anaphylactic test: mild-moderate red spots appear on rats in positive control group. No red spots, edema and general anaphylaxis appear on rats in blank control group, compound Xiaoyin-ointment A and B groups.3. The result of acute toxicity test: rats in each group are in good condition and no whole body poisoning or death appears for all. Rats grow weight stably with little difference with control group.4. The result of chronic toxicity test: no death appears for rats in compound Xiaoyin-ointment A and B groups during drug administration and recovery period.The skin and viscera and pathology have no abnormality generally.5. The result of pharmacodynamic test: the comparative differences between each group with model groups are of statistical significance(P<0.05). The comparative differences between every two among Clobetasol propionate ointment group, compound Xiaoyin-ointment A and B groups are of no statistical significance(P>0.05). The comparative differences between Xiaoyin-ointment group and one of the rest groups are of statistical significance(P<0.05).Conclusion:1.The compound Xiaoyin-ointment A and B are all ideal non-toxic and nonirritative and non-sensitizing external ointment.2.The compound Xiaoyin-ointment A and B have definite effect in psoriasis.3.There is no statistical differences between compound Xiaoyin- ointment A and B in the treatment of psoriasis.