Study On The Efficiency And Safety Of Co-glycyrrhetinic Acid Cream

The pharmacodynamics and acute toxicity of Co-glycyrrhetinic acid cream are studied in this paper. Part I:The the efficiency and safety of Co-glycyrrhetinic acid creamObjective: The effect of Co-glycyrrhetinic acid cream on ear-swollen mice induced by xylene, itch-causing experiment induced by 4-aminopyride and on capillary permeability of rat skin.Methods:1 The effect of Co-glycyrrhetinic acid cream on ear-swollen mice induced by xylene. 70 Kunming mice, weigh 18-20 g, were randomly divided into 7 groups, such as positive control group(Compound Dex), model group(no cream base), negative control group1(cream base), negative control group 2(cream base containing Menthol), treatment group 1(low-dose group, 0.25%, g/g, deterred by Glycyrrhetic acid), treatment group 2(middle-dose group, 0.5%, g/g, deterred by Glycyrrhetic acid),treatment group 3(high-dose group, 1%, g/g, Glycyrrhetic acid). The medication method: 0.2g different creams for each group(administrate drug to right ear and matrix to left ear) were smeared on both sides of the mice auricles. An hour later, 0.03 ml xylene was dropped onto the both sides of right auricle of mice to induce inflammation. Two hours later, killed the mice with cervical dislocation method and took out round ear flake with puncher from symmetrical part of two ears. Then weigh the flake and calculate the swelling degree.2 The effect of Co-glycyrrhetinic acid cream on capillary permeability of rat skin. 50 rat, back hair was removed, were randomly divided into 5 groups: positive control group 1(Compound Dex), model group(Matrix only), treatment group 1(low-dose group, 0.25%, g/g, Glycyrrhetic Acid), treatment group 2(middle-dose group, 0.5%, g/g, deterred by Glycyrrhetic acid), treatment group 3(high-dose group, 1%, g/g, deterred by Glycyrrhetic acid). 24 hours later,smeared the drug at the dose of 5g/kg.In 1 hour after administration, injected 1% Evans Blue(5ml/kg) into caudal vein, at the same time, injected 0.1% Histamine Phosphate(0.1ml for each rat) subcutaneously into the part where the drug was smeared before. In 20 minutes after injection, killed the rats and took away the blue-dyed skin of hypogastric region. Cut the skin into pieces, put into 5.0ml acetone-Stroke-physiological saline solution and immersed it for 48 hours. Took out from the solution and centrifuged it. Match the shade(use Absorbance A value directly) of supernatant on the chromometer(wave length is 590nm)3 The effect of Co-glycyrrhetinic acid cream on itch-causing experiment induced by 4-aminopyride. 80 Kunming mice were randomly divided into 8 groups:positive control group 1(Compound Dex), positive control group 2(Compound Dex), model group(Matrix only), negative control group1(Marix), negative control group 2(Blank Matrix containing Menthol), treatment group 1(low-dose group, 0.25%, g/g, deterred by Glycyrrhetic acid), treatment group 2(middle-dose group, 0.5%, g/g, deterred by Glycyrrhetic acid), treatment group 3(high-dose group, 1%, g/g, deterred by Glycyrrhetic acid). Removed an area of 2cm x 3cm hair from the neck and back of mice(make sure that skin is not damaged) and administrate the mice 24 hours later. Smeared 1g emulsifiable paste externally onto hair-removed area and injected lmg/kg 4-aminopyridine(prepare 0.5% solution with NS and diluted the solution to 0.01% with NS) subcutaneously in the neck and back of each mouse after 30 minutes. Observed the duration and frequency of mice licking response within 10 minutes, at the same time, calculated the response inhibition rate.Results:1 The effect of Co-glycyrrhetinic acid cream on ear-swollen mice induced by xylene. The study showed that both of negative control group 1 and negative control group 2 have a tendency of inhibiting ear swelling, however, there was no significant difference between them. All of Low-dose group(0.25%, g/g, deterred by Glycyrrhetic acid), Middle-dose group(0.5%, g/g, deterred by Glycyrrhetic acid)and High-dose group(1%, g/g, deterred by Glycyrrhetic acid)significantly inhibit the ear swelling induced by xylene and there were certain dose-effect relationship, Low-dose group and High-dose group have much more significant inhibitory effect compared to model group and the differences are statistically significant, High-dose group and positive control group have similar inhibitory effect. Both of two different matrixes have certain tendency of anti-inflammatory effect, but no statistical significance.2 The effect of Co-glycyrrhetinic acid cream on on capillary permeability of rat skin. Each group significantly inhibited the enhanced capillary permeability of rat skin induce by histamine and there were dose-effect relationship, 0.5%(g/g) Pseudolaric acid B and positive control group have similar effect.3 The effect of Co-glycyrrhetinic acid cream on itch-causing experiment induced by 4-aminopyride. Each group inhibited the skin itch induced by 4-aminopyride and there were dose-dependent relationship, especially the drug efficacy of middle and high dose group was significantly better than the drugs of positive control group, such as Compound Dex and compound menthol ointment.Conclusion: Pseudolaric acid B, which has desirable anti-inflammation and anti-itch effect, can significantly inhibit the ear swelling induced by xylene, enhanced capillary permeability of rat skin induce by histamine and the skin itch induced by 4-aminopyride. PartⅡ The study on toxicity of Co-glycyrrhetinic acid creamObjective: Study the acute toxic effect of Co-glycyrrhetinic acid cream on animals and the effect of Co-glycyrrhetinic acid cream on normal volunteers.Method:1 The acute toxic effect of Co-glycyrrhetinic acid cream on animals. Using a limited method to detect percutaneous acute toxicity. Took 30 rats with half males and half females and removed the back hair. After 24 h, the rats were divided into damaged skin group, complete skin group and the matrix control group. Administration skin area(area of 30cm2/rat) accounts for about 10% of the animal body surface area, smeared the skin area with 5000 mg/kg of body weight dose(concentration of 4.9% g/g), which were covered by a layer of thin film and fixed with no stimulation tape. Closed contact time is 24 h. Then observe the survival condition of rats for 14 d.2 The effect of Co-glycyrrhetinic acid cream on normal volunteers. 10 normal volunteers were selected. Test plan were signed by Ethics committee and the informed consent was sign bynormal volunteers. The self-contrasted method was used to measure the ECG of normal volunteers and other detection. The administration site was Forearm and thigh respectively, and administration area was 10X30 cm2 with the dose of 3g for 7days. The Cream was coated 1hour laster in the 7th day detect in gelectrocardiogram(ecg) and observe the the influence on respiration, heart rate and skin for 7days and after the treatment, followed up to 14 days.Results:1 At the dose of 5000mg/kg Co-glycyrrhetinic acid cream, there were no death in both of normal skin group and damaged skin group and no influence on respiration, heart rate and skin.2 The administration of Co-glycyrrhetinic acid cream with area: 10X30 cm2 and dose: 3g/day/person, 1 times a day for 7days, and Co-glycyrrhetinic acid cream has no influence on normal ECG,respiration, heart rate and skin.Conclusion: As a new external applied agent to treat eczema, dermatitis and skin itch, Pseudolaric acid B has desirable efficacy and safety.