In order to prove intestinal absorption of serrapeptase, concentration of serrapeptase in plasma, lymph and extract of inflammatory tissue of rats that received an oral dose of serrapeptase was determined by sandwich enzyme immunoassay（EIA）. The detection limit of the EIA was 0.05ng/mL. Serrapeptase was detected from plasma and lymph when 30mg/kg or more and 1mg/kg or more of serrapeptase, respectively, was administered. Serrapeptase in plasma and lymph peaked 0.25 to 0.5h post dose and almost disappeared by 6h. The serrapeptase concentrations in plasma and lymph were dose dependent. Cmax in plasma and lymph at a dose of 100mg/kg were 0.87±0.41 and 43±42ng/mL, respectively. Serrapeptase was detected in the abscess caused by carrageenin and the carrageenin−induced inflammatory tissue at concentrations higher than that in plasma. Serrapeptase in plasma, lymph and inflammatory site retained the protease activity.
　　It is suggested that serrapeptase is absorbed from intestine, distributed to the inflammatory site via blood or lymph and exhibits its anti−inflammatory activity in rats.