Jiying Yang

The attenuation effect of 3,4-dihydroxy-phenyl lactic acid and salvianolic acid B on venular thrombosis induced in rat mesentery by photochemical reaction

3,4-dihydroxy-phenyl lactic acid (DLA) and salvianolic acid B (SAB) are two major water-soluble components of Salvia miltiorrhiza (SM). Previous works have revealed the ability of DLA and SAB to scavenge oxygen free radicals, inhibiting the expression of adhesion molecules CD11b/CD18 in neutrophil. Cardiotonic pills (CP), which is a traditional Chinese medicine compound preparation containing DLA and SAB, was found to inhibit venular thrombosis induced by photochemical reaction (PR) in rat mesentery. The present study addressed the effect of DLA and SAB on PR-induced thrombosis in rat mesentery by utilizing a microcirculation dynamic viewing system. The result demonstrated that both DLA and SAB delayed thrombus-initiation time, while DLA also prolonged thrombus half-size time. The experiments explored the mechanism underlying that the dihydrorhodamine 123 (DHR) fluorescence in the mesenteric venular walls after PR challenge was diminished by pretreatment with either DLA or SAB, the expression of CD18 in neutrophils elicited by PR was depressed by administration of DLA, while mast cell degranulation in rat mesentery induced by PR was damped by SAB. The antioxidant potential of the two substances is likely to be responsible for their most beneficial effects on thrombosis, through either directly scavenging the peroxides produced and/or indirectly depressing the expression of adhesion molecules in neutrophil.

Improving effect of post-treatment with Panax notoginseng saponins on lipopolysaccharide-induced microcirculatory disturbance in rat mesentery

Panax notoginseng saponin (PNS) is the collective of the major effective components of Panax notoginseng. The present study intended to explore the effect of post-treatment of PNS on rat mesentery microcirculatory disturbance induced by lipopolysaccharide (LPS) continuous challenge. By virtue of a microcirculation observation system, the vascular hemodynamics were determined continuously until 60 min of LPS (2 mg/kg/h) infusion through the left femoral vein. After observation, blood was taken for assessment of the expression of CD11b/CD18 in neutrophils and the concentration of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interferon-gamma (INF-gamma) in plasma with flow-cytometry. The number of leukocytes adherent to venular wall, the intensity of hydrogen peroxide dependent dihydrorhodamine 123 (DHR) fluorescence in the venular walls and albumin leakage from venules were increased impressively after 20 min of LPS infusion, the RBCs velocity diminished after 30 min, and degranulated mast cells increased remarkably after 60 min. Post-treatment with PNS (5 mg/kg/h) through the left jugular vein from 20 min of LPS exposure resulted in significant reduction in the number of adherent leukocytes, degranulation of mast cell, expression of CD11b and the concentration of IL-6, INF-gamma, while had no influence on the intensity of DHR fluorescence and albumin leakage. The results suggested that post-treatment with PNS significantly attenuated microcirculatory disturbance induced by LPS.

Effects of dihydroxylphenyl lactic acid on inflammatory responses in spinal cord injury

The initial mechanical tissue disruption of spinal cord injury (SCI) is followed by a period of secondary injury that increases the size of the lesion. Secondary injuries are associated with edema, inflammation, excessive cytokine release, excitotoxicity and cell apoptosis. 3,4-dihydroxyphenyl lactic acid (DLA) is one of the major water-soluble components of chemical constituents from Salvia miltiorrhiza (SM). To investigate the inhibition effects of DLA on secondary injury of SCI, focusing especially on suppression of inflammatory responses and the mechanism of this effect, the following studies were performed: Basso, Beattie, and Bresnahan (BBB) scores to assess motor functions till 10 days after SCI; Nissl and Fast Blue histological staining and immunohistochemistry of inhibitory-kappa B-alpha (IκB-α) and nuclear factor-kappa B (NF-κB) p65 subunit protein; levels of myeloperoxidase (MPO) activity analysis as an indicator of polymorphonuclear infiltration; IL-6 production in plasma 10 days after SCI; Western blot analysis to determine cytoplasm levels of IκB-α and NF-κB p65 subunit proteins in the nuclear fractions 10 days after SCI. DLA significantly attenuated the motor function and tissue damage following SCI in rats, significant reduced polymorphonuclear cell infiltration and IL-6 production, as well as reduced cytoplasm IκB-α degradation and the nuclear translocation of NF-κB p65 subunit protein after SCI. In conclusion, the results clearly demonstrate that DLA inhibit the inflammation responses induced by SCI via inhibiting effect of production of IL-6 and nuclear translocation of NF-κB.