Bax/Bcl-2 expression ratio in liver of Balb/c mice exposed to AFB1 (250 μg/Kg b.w.) for 15 days then 30 days and prevention by cactus cladode extract (50 mg/Kg b.w) before or after AFB1 administration. Results were expressed as means ± S.D. from independent experiments. (*) indicated significant difference (p < 0.05) from control.