Effect of tea leaf extract on 8-OHdG expression in gill epithelium. A shows negative 8-OHdG expression in the gill epithelium. B shows severe 8-OHdG expression in the gill epithelium (arrowhead) of CMN exposure. C shows moderate 8-OHdG expression in the gill epithelium (arrowhead) of 50 mg of TLE on CMN exposure. D shows mild 8-OHdG expression in the gill epithelium (arrowhead) of 100 mg of TLE on CMN exposure, H and E, Bar: 50 µm.