Study On Human Skin Model To Evaluate Corrosion/Irritation Of Fungicide

A big number of experimental animals were used to carry out the safety evaluation of all kinds of chemicals every year. Although the whole animal experiments have the advantages of high accuracy and being well-developed, it is limited by high cost, time-consuming, and restriction by ethics. Therefore, reducing the use of animals is one of the important developing directions of chemical safety evaluation, where in vitro toxicity test method is a good alternative for animal experiment and receives extensive attention of both scientists and regulation recently.Skin corrosion and irritation of touching material, such as cosmetics and pesticide, are required for test based on relevant laws and regulations of chemical management. In recent years, human skin model implements a rapid development, attributable to its better correlation with humans, and is widely used in cosmetic. Up to now, the human skin model has not been applied in pesticides, where the accuracy and feasibility is required to be validated. As a country with large pesticide production and use, it is critical to develop alternative methods of animal skin evaluation for the corrosion/irritation test of pesticide in China.To explore the feasibility and the influencing factors of human skin model in evaluating the safety of pesticide, as an alternative approach to the animal experiment, human skin model was developed and the skin corrosion and irritation of fungicides were measured. Human fibroblasts mixing with rat rail collagen is to simulate the dermal tissue, and human keratinocytes form the stratum corneum through air liquid interface upon the dermal tissue, co-constructing the human skin model. Human skin model’s cell activity is higher than0.6, and biopsy analysis results show that the morphological structure has a good similarity with human skin tissue. ET50of1%TritonX-100and IC50of SLS verified the barrier function of the skin model, where2.2h and1.71mg/mL meet the requirements. The human skin model was validated by evaluating chemicals with known corrosion and irritation. The test of skin corrosion is completely accurate, and the accuracy of irritation is80%.The corrosion and irritation were evaluated according to cellular activity and IL-la releasing level in human skin model, compared with the results of animal experiment. The corrosion results from human skin model for ten fungicides totally agreed with the results of the animal test. In irritation test, IL-la analysis contributed to improve the sensitivity and accuracy of the human skin model, and the consistency of the animal results and skin model results reached80%. No information is available for classifying the corrosive strength in human skin model test. Therefore, referential value for corrosion classification was suggested, based on the relative cell activity of corrosive chemicals with different corrosion The present study preliminarily suggested that human skin model exhibited good performance in the identification of fungicides corrosion and irritation and showed a good application prospect as an alternative approach in the safety evaluation of pesticide.