Effect of nattokinase supplementation on plasma fibrinogen levels, whole blood viscosity and mortality in experimental sepsis in rats

Introduction

Nattokinase is a serin protease derived from fermentation of boiled soy bean that has a potent fibrinolytic effect [1]. The aim of this experimental study was to investigate the effects of nattokinase on plasma fibrinogen levels, whole blood viscosity and mortality in rats with sepsis.

Methods

Fifty adult female Wistar rats were used in the study. Nattokinase (6 mg/day) was given via the intragastric route for 7 days. Sepsis was induced by cecal ligation–puncture. Analysis of plasma fibrinogen levels, whole blood viscosity and survival was performed.

Results

Mean plasma fibrinogen levels of rats that received nattokinase prior to cecal ligation–puncture were lower than the others that did not receive nattokinase prior to cecal ligation–puncture and the sham-operated group, but the differences were not statistically significant. Mean blood viscosity of rats analyzed with the Rheolog™ scanning capillary viscometer was lower in the nattokinase-supplemented animals with cecal ligation–puncture group at a 1/second shear rate (P < 0.05) (Figure 1). Nattokinase supplementation did not significantly influence survival rates and survival times of the rats after cecal ligation–puncture.

Figure 1

Comparison of mean blood viscosity data of the groups Lap (sham-operated group), CLP (cecal ligation–puncture group) and Nat + CLP (nattokinase-supplemented cecal ligation–puncture group).

Conclusion

The results of our in vivo study were not sufficient to prove the fibrinogenolytic effect of nattokinase but confirmed the results of a previous in vitro study investigating the effect of nattokinase on blood viscosity. More in vivo and in vitro studies with large study populations are required to investigate the use of nattokinase to prevent and treat sepsis-related disseminated intravascular coagulation.