Inhibitory Effects of Paeonidlorin on ACE Activity in Vitro

This is a study attempting to develop an efficient Reversed Phase-High Performance Liquid Chromatographic (RP-HPLC) method for determining the inhibitory activity of angiotensin converting enzyme (ACE). The content of enzymolysis product hippuric acid was determined using RP-HPLC method. RP-HPLC was performed on a Brava BDS C18 column (250 mm×4.6 mm, 5 μm) using a mobile phase consisting of 0.01% formic acid solution-acetonitrile (25:75) at 30°C with a flow rate of 1.0 mL·min−1 and a detection wavelength at 228 nm. Test results showed that the calibration curve was linear in the range of 1.17-149 μg·mL−1 (r=0.9999) for hippuric acid. The average recovery (n=6) of hippuric acid was 100.4% (relative standard deviation, RSD=0.88%). The intra-day and inter-day RSDs were at 1.32% and 1.96% respectively. The IC50 of Paeoniflorin was 37.47 μmol·L−1. This method is desirable for determining the inhibitory activity of ACE due to its sensitive, accurate, and reliable performance with good repeatability.