Antioxidative potentiality of a Kampo formulation measured by an ex vivo study

Antioxidants in herbs or crude herbal formulations are well known. The antioxidative effect of a Kampo formulation, Bofu-tsusho-san (BTS), was studied in healthy human subjects by means of an ex vivo study of the lag time of low-density lipoprotein (LDL) oxidation.

Eighteen (18) healthy young males (22 +/- 3 years old), who were screened out from 38 males by strict screening tests of serum lipids, were randomly assigned into 3 groups (active BTS 7.5 g/day, placebo of BTS 7.5 g/day, and vitamin E 500 mg and vitamin C 1000 mg/day). The BTS groups were assigned in a double-blind manner. These 3 groups took each test drug, and the antioxidant effects of their plasma were estimated by assessing the susceptibility of LDL to oxidation induced by 2-2'-azobis (4-methoxy-2,4-dimethyl-valeronitrile) via an ex vivo study. The antioxidative activity was evaluated by measuring the lag time of the production of conjugated dienes. Along with lag time, plasma ephedrine, plasma baicalin, serum lipid peroxide, serum free fatty acids (nonesterified fatty acids), urinary 8(OH)dG/creatinine, blood pressure, and heart rate were monitored for 24 hours.

Although lag time of the placebo group revealed no significant changes, the active BTS group showed some tendency of prolonged plasma lag time (p = 0.08). However, urinary 8(OH)dG/creatinine and serum lipid peroxide did not show no significant changes. The physiologic changes were compatible with the pharmacokinetic results of ephedrine and its sympathomimetic effect in the active BTS group.

Although the systemic antioxidative effects of BTS have not been ascertained, the antioxidative potentiality on LDL oxidation was suggested by the ex vivo study.