D-Allose has a strong suppressive effect against ischemia/reperfusion injury: a comparative study with allopurinol and superoxide dismutase.

Background/purpose: D-Allose, a rare sugar, is one of the potent inhibitors of ischemia/reperfusion injury of the rat liver. To investigate the potency of this powerful agent we examined its effect against ischemia/reperfusion injury and compared it to that of allopurinol and superoxide dismutase.

Methods: Male Lewis rats were given water ad libitum preoperatively for 12 h and anesthetized by isoflurane inhalation anesthesia. Drugs were administered through a polyethylene catheter inserted into the portal vein for 2 h (D-allose), 10 min (allopurinol), or 5 min (superoxide dismutase) before ischemia, and the livers were then subjected to 70% ischemia, induced by crossclamping the vessels to the lateral and median lobes of the liver for 90 min. Rats were divided into four groups: group 1, pretreated with vehicle (normal saline); group 2, treated with D-allose; group 3, treated with allopurinol; and group 4, treated with superoxide dismutase. The effects of the drugs were evaluated by liver hemodynamics, neutrophil count, myeloperoxidase, liver enzymes, and histological studies.

Results: D-Allose improved liver hemodynamics (P < 0.001) and postischemic animal survival (P < 0.05) significantly compared with the control group and nonsignificantly compared with the allopurinol and superoxide dismutase groups. Myeloperoxidase activity in the postischemic liver tissue was decreased significantly (P < 0.05) by D-allose compared with all other treatment and control groups. Neutrophil count was also significantly (P < 0.05) decreased in the D-allose group compared with than that in the control group, as well as the superoxide dismutase group. Only D-allose produced a statistically significant decrease in the level of liver enzymes, compared with levels in the control group.

Conclusions: The moderately protective effect of D-allose, which caused no clinical side effects, is encouraging. D-Allose had the best protective effect against neutrophil-related postischemic injury of the liver tissue, followed by allopurinol and superoxide dismutase. However, a more extensive study is needed to ensure the effects as well as the mechanisms of the effect of this rare sugar.