Plant Natural Products Calycosin and Gallic Acid Synergistically Attenuate Neutrophil Infiltration and Subsequent Injury in Isoproterenol-Induced Myocardial Infarction: A Possible Role for Leukotriene B4 12-Hydroxydehydrogenase?

Figure 1

Bioactivity-guided isolation of the active compounds from Radix Astragali for LTB4DH induction. (a) Schematic illustration of the bioactivity-guided fractionation procedure. The active compounds were isolated from Radix Astragali extract through ethanol precipitation, extraction with organic solvents, and HPLC separation on a C18 column. The active fractions were highlighted with star and in bold. (b) RT-PCR detection of LTB4DH induction. The fractions in combination with gallic acid (GA) were assayed by semiquantitative RT-PCR for LTB4DH induction in HepG2 cells. (c) HPLC separation and RT-PCR detection of LTB4DH induction. Nine HPLC fractions in combination with gallic acid (GA) were assayed by semiquantitative RT-PCR for LTB4DH induction in HepG2 cells. The concentration of each fraction was normalized against the concentration of raw Radix Astragali (5.18 mg/mL). Representative HPLC profile and RT-PCR analysis were shown. (d) Chemical identification by HPLC-ESI-MS technique. The MS profiles of fraction 6 and 8 were shown. The structures of calycosin and formononetin were generated by ChemSketch software (http://www.acdlabs.com).