TNF and ischemia: Figure 3 illustrates that administration of 200 mg/kg/day metformin i.p. for 6 successive days before induction of ischemia and promptly at the onset of reperfusion to rats significantly lowered the hepatic TNF-α (Fig. 3A) and caspase-3 (Fig. 3B) levels as compared to animals subjected to hepatic I/R.