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Abstract
Summary
The present study was confirmed to investigate the role of green tea polyphenols as antioxidants in the protection and treatment of ultraviolet B skin photocarcinogenesis and the role of sodium arsenite as cocarcinogen.
Mice were divided into sex groups, each of 36 mice, control group, arsenite group, UVB group, UVB and arsenite group, UVB and green tea group and UVB, arsenite and green tea group. Mice were irradiated with UVB at dose of 200j/m2, 4 hr daily, 3 times per week (each next day). Sodium arsenite was taken at concentration of 10 mg per liter. Green tea was taken at concentration of 6 mg per ml.
UVB radiation induced dysplastic changes in epidermis, preneoplastic hyperplasia of rete pege, hyperplasia of hair follicle, trichofolliculoma, trichofolliculocarcinoma, squamous cell carcinoma, basal cell carcinoma, fibropapilloma, rhabdomyosarcoma and mixed tumors. Green tea treatment prevented induction of preneoplastic hyperplasia of rete pege, hyperplasia of hair follicle, trichofolliculocarcinoma, squamous cell carcinoma, fibropapilloma, rhabdomyosarcoma and mixed tumors. Green tea also reduced dysplastic changes and trichofolliculoma. Arsenite did not express its role as cocarcinogen in this experiment. Green tea treatment has no effect in the UVB and arsenite group.
Giemsa stain revealed increased number of mast cells in benign and malignant tumors. In malignant tumors, they were large in number in relatively differentiated malignant tumors and disappear in undifferentiated malignant tumors.
The number of AgNORs was significantly higher in hyperplasia, benign and malignant tumors as compared with corresponding normal cells. There was significant increase in number of AgNORs in malignant tumors than in benign tumors. AgNORs can be used in grading squmous cell carcinoma.