• The Korean Journal of Physiology and Pharmacology
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• v.4 no.6
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• pp.515-523
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• 2000

Polymorphonuclear leukocytes (PMNs) play an important role in myocardial ischemia/reperfusion (MI/R) injury. Moreover, platelets are also important blood cells that can aggravate myocardial ischemic injury. This study was designed to test the effects of PMNs and platelets separately and together in provoking cardiac dysfunction in isolated perfused rat hearts following ischemia and reperfusion. Additional control rat hearts were perfused with $75{\times}10^6$ PMNs, with $75{\times}10^6$ platelets, or with $75{\times}10^6\;PMNs+75{\times}10^6$ platelets over a five minute perfusion followed by a 75 min observation period. No significant reduction in coronary flow (CF), left ventricular developed pressure (LVDP), or the first derivative of LVDP (dP/dt max) was observed at the end of the observation period in any non-ischemic group. Similarly, global ischemia (I) for 20 min followed by 45 minutes of reperfusion (R) produced no sustained effects on the final recovery of any of these parameters in any group of hearts perfused in the absence of blood cells. However, I/R hearts perfused with either PMNs or platelets alone exhibited decreases in these variables of $5{\sim}10%$ (p＜0.05 from control). Furthermore, I/R hearts perfused with both PMNs and platelets exhibited decreases of 50 to 60% in all measurements of cardiac function (p＜0.01). These dual cell perfused I/R hearts also exhibited marked increases in cardiac myeloperoxidase (MPO) activity indicating a significant PMN infiltration, and enhanced P-selectin expression on the coronary microvascular endothelium. All cardiaodynamic effects as well as PMN accumulation and P-selectin expression were markedly attenuated by a recombinant soluble PSGL-1 which inhibits selectin mediated cell adhesion. These results provide evidence that platelets and PMNs act synergistically in provoking post-reperfusion cardiac dysfunction, and that this may be largely due to cell to cell interactions mediated by P-selectin. These results also demonstrate that a recombinant soluble PSGL-1 reduces myocardial reperfusion injury by platelet and PMNs interaction.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.3
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• pp.402-408
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• 2007

This study was conducted in order to evaluate the antioxidant activity of extruded ginseng in different extracted fractions. Each of the fractions obtained from extruded ginseng and ginseng (control) were extracted with 80% ethanol, and then the lipophilic components were removed with ether while the hydrophilic components were separated with water-saturated butanol. Each of the 80% ethanol/butanol/water layers were collected and evaporated to acquire samples for tests of saponin content and antioxidant activity. The antioxidant activity of extruded ginseng fractions and ginseng fractions were determined via the oxygen radical absorbance capacity (ORAC) assay. Overall, the extruded ginseng samples harbored saponin contents of 2.2 (Rg1), 2.3 (Re), 1.2 (Rc), 1.3 (Rb2), and 2.2 (Rd) times that measured in the ginseng prior to extrusion. Antioxidant capacity was also higher, not only in the 80% ethanol/butanol which harbor a significant quantity of saponin, but also in the water fractions, which harbor relatively low quantities of saponin as compared to the control samples. All three of the fractions extracted from extruded ginseng evidence significantly higher antioxidant capacity than the controls (0.05