Green tea extract can improve sperm quality and protect against damage caused by cadmium chloride in rats. The researchers studied male rats and divided them into different groups to test the effects of cadmium chloride and green tea extract on reproductive organs and sperm. They found that green tea extract increased the size and number of cells in the testes, while reducing the negative effects of cadmium chloride on sperm motility, count, and testosterone levels. The extract also decreased lipid peroxidation in cell membranes, preventing tissue damage in the long term.