Abstract
PR-B is a protein composition of Persicae semen (mol. wt.=about 10000) ; and its antiinflammatory activity is comparable to that of indomethacin in the carrageenin-induced hind paw edema test. In order to explore the mode of anti-inflammatory action of PR-B, inhibitory activities of PR-B on kinin-release by kallikrein and superoxide anion production were investigated in vitro. PR-B produced a dose-related inhibition of kinin-release by kallikrein at concentrations of 10-5-10-3M, and its potency (IC50=1.4×10-4M) was comparable to that of soybean trypsin inhibitor (SBTI) ; superoxide dismutase (SOD) and N-α-p-tosyl-L-lysine-chrolomethylketone, a synthetic trypsin inhibitor were inactive. The potency of PR-B as a trypsin inhibitor (IC50=3.2×10-4 M or more than 104- M) was much weaker than that of SBTI (IC50=7.2 or 7.4×10-8M) ; SOD was inactive. In contrast to those activities, PR-B had comparatively strong SOD-like activity ; i.e., PR-B inhibited dose-relatedly the superoxide anion production by peritoneal macrophages of guinea pigs at concentrations of 10-6-5×10-5M, and its potency (IC50=5.7×10-6M) was approximately equivalent to that of SBTI while much weaker than that of SOD (IC50=5.7×10-9M). Lysozyme and egg albumin as reference proteins lacked the SOD-like activity. The anti-edema activity of PR-B given intravenously was stronger than that of SBTI and SOD in the carrageenininduced hind paw edema test in rats. These results were discussed in connection with the mode of anti-inflammatory action of PR-B.
