Optimization of spectrophotometric method for determination nattokinase activity in dietary supplements

Abstract

Nattokinase is an enzyme with a strong fibrinolytic activity that can be used for preventing thrombolytic diseases. The fibrinolytic activity of the Nattokinase in dietary supplements is determined by spectrophotometric method. In this study, the conditions of the assay were examined and finally optimized as pH: 8.5, reaction temperature: 40oC, and reaction time: 60 minutes. The proposed method was validated and successfully applied to determine the Nattokinase activity in 10 dietary supplements. The results showed that the proportion of measured activity compared to label product activity were within in the range 79.1 - 98.0%. The effect of herbal compounds and excipients on Nattokinase activity were also surveyed. From the evaluated results and application to commercial samples, this method will be a valuable contribution to quality control of dietary supplement products containing Nattokinase.