Effect of Vitamin C Administration on Neutrophil Apoptosis in Septic Patients After Abdominal Surgery

Objective

To investigate the effect of parenteral administration of vitamin C on neutrophil apoptosis by determining Fas receptor expression and caspase-3, poly (ADP-ribose) polymerase (PARP), and Bcl-2 levels in neutrophils from septic abdominal surgery patients.

Study design

Twenty septic abdominal surgery patients were studied in a prospective, randomized, double-blinded clinical trial. A group of healthy volunteers (n = 10) constituted a reference group for baseline parameter values. The patients were randomly assigned to a vitamin C-treated (n = 10) or placebo-treated (n = 10) group. For a 6-d period from 12 h post-surgery, the vitamin C group received 450 mg/d of the vitamin in 3 doses and the placebo group an identical administration of 5% dextrose. Early-morning peripheral blood samples were obtained daily from 24 h after vitamin C administration until d 6 post-surgery (T1d-T6d).

Results

Vitamin C group showed a nonsignificant reduction in Fas (CD95) expression on CD15-positive peripheral blood neutrophils, significantly decreased caspase-3, and PARP levels (caspase-3: T4d: P < 0.05, T5d: P < 0.05, T6d P < 0.01; and PARP: T3d: P < 0.05, T4d: P < 0.05, T6d: P < 0.05), and significantly increased Bcl-2 levels (T3d: P = 0.001) versus placebo group.

Conclusions

Postoperative vitamin C treatment of septic abdominal surgery patients exerts an antiapoptotic effect on peripheral blood neutrophils, reducing caspase-3 and PARP levels, and increasing Bcl-2 levels. However, these antiapoptotic effects are not maintained at all time points.

Key Words: abdominal surgery patients, apoptosis, Bcl-2, caspase-3, Fas, neutrophils, PARP, sepsis, vitamin C