Two pairs of phloroglucinol enantiomers from Hypericum wightianum and their stereochemical structures / 中国中药杂志

The chemical constituents in the ethanol extract of Hypericum wightianum(Hypericaceae) were purified by column chromatography and identified via magnetic resonance imaging(NMR), high-resolution mass spectrum, and circular dichroism. A total of 22 compounds were identified, including eight polyprenylated phloroglucinols(1-8), three chromones(9-11), and three terpenoids(14-16) and so on. Among them, compounds 16 and 17 were first reported in the genus Hypericum, and compounds 1-11, 14, 15, and 19 were first isolated from H. wightianum. Compounds 1-4 were previously reported as two pairs of enantiomers. This study reported the chiral resolutions and absolute configurations of compounds 1-4 for the first time.

Chemical constituents of Hypericum stellatum and their antioxidant bioactivities / 中国中药杂志

Hypericum stellatum is an important ethnomedicinal plant endemic to southwest China. Ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) was applied to analyze the chemical constituents of H. stellatum. Seventeen compounds from H. stellatum were tentatively identified using UPLC-Q-TOF-MS data. Antioxidant activity and total phenolic content were investigated by DPPH assay and Folin-Ciocalted methods. The EtOAc extract with high total phenolic content showed prominent antioxidant activity. The EtOAc extract of H. stellatum was separated and purified by column chromatography, including silica gel, Sephedex LH-20, and RP-HPLC. The isolates were defined by 1D, 2D NMR data. As a result, ten compounds were isolated and assigned as quercetin (Ⅰ), quercetin 3---D-glucopyranoside (Ⅱ), 1,3,6,7-tetrahydroxylxanthone (Ⅲ), 1,3,5,6-tetrahydroxyxanthone (Ⅳ), 1,3,7-trihydroxyxanthone (Ⅴ), 3, 6, 7-trihydroxy-1-methoxyxanthone (Ⅵ), calycinoxanthon D (Ⅶ), caffeic acid ethyl ester (Ⅷ), chlorogenic acid (Ⅸ) and chlorogenic acid ethyl ester (Ⅹ). This is the first report on chemical constituents and bioactivity of H. stellatum. The antioxidant activity of chemical constituents was tentatively found, which provided a foundation for further researches on the genus Hypericum and the traditional uses of H. stellatum.

Effects and mechanisms of the functional parts of Dahuang Zhechong pill containing serum on platelet-derived growth factor-stimulated proliferation of vascular smooth muscle cells / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate and compare the effects and mechanisms of three functional parts of Dahuang Zhechong Pill (DHZCP), including drugs with the function of removing blood stasis and promoting blood circulation (FP-I), drugs with the function of expelling heat and moistening dryness (FP-II), and drugs with the function of nourishing yin and replenishing blood (FP-III) of DHZCP, on platelet-derived growth factor (PDGF)-stimulated vascular smooth muscle cells (VSMCs) proliferation with the method of serum pharmacology.</p><p><b>METHODS</b>VSMCs proliferation of rat was assayed by measuring the cell viability with the 3-(4, 5-dimethylthiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) method. DNA synthesis in VSMCs was examined by detecting 5'-bromo-2'-deoxyuridine incorporation with the immunocytochemical method. Cycle of VSMCs was evaluated with flow cytometry. Expression of cyclin D1, p27, PKCα, and phosphorylated extracellular signal regulated kinase 1/2 (ERK1/2) was quantified by the Western blotting method.</p><p><b>RESULTS</b>The FP-I and FP-III containing serum was capable of inhibiting PDGF-stimulated proliferation and DNA synthesis of VSMCs, arrested VSMCs in G phase, downregulated cyclin D1, and upregulated p27 expression (P <0.01 or P <0.05). The FP-I and FP-III containing serum also inhibited the PDGF-induced phosphorylation of tyrosine of ERK1/2 and PKCα expression (P <0.01 or P <0.05).</p><p><b>CONCLUSIONS</b>FP-I and FP-III of DHZCP are able to inhibit VSMCs proliferation via interrupting PKCα-ERK1/2 signaling, modulating the expression of cell cycle proteins to result in arresting the cells in G phase. The inhibitory effect is mainly related to the function of removing blood stasis and promoting blood circulation, slightly to the function of nourishing yin and replenishing blood, but not to the function of expelling heat and moistening dryness.</p>

Dahuang zhechong pill containing serum inhibited platelet-derived growth factor-stimulated vascular smooth muscle cells proliferation by inducing G1 arrest partly via suppressing protein kinase C α-extracellular regulated kinase 1/2 signaling pathway / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate effects of dahuang zhechong pill ( DHZCP) on the cell cycle and the related signal pathways in vascular smooth muscle cells (VSMCs) stimulated by platelet-derived growth factor (PDGF) with the method of serum pharmacology.</p><p><b>METHODS</b>DNA synthesis in VSMCs was examined by detecting 5'-bromo-2'-deoxyuridine incorporation with the immunocytochemical method. The cycle of VSMCs was evaluated with flow cytometry. Expressions of cyclin D1, p27, protein kinase Cα (PKCα), and phosphorylated extracellular signal regulated kinase 1/2 (ERK1/2) were quantified by Western blot method.</p><p><b>RESULTS</b>DHZCP containing serum significantly inhibited DNA synthesis of PDGF-stimulated VSMCs, arrested the cells in G G(1) phase, modulated the protein expressions of cyclin D D(1) and p27, and suppressed the activation of PKCα and ERK1/2.</p><p><b>CONCLUSION</b>DHZCP containing serum inhibits VSMCs proliferation via modulating the expressions of cell cycle proteins to arrest the cell in G G(1) phase, which is attributed to, at least in part, suppressing PKCα-ERK1/2 signaling in VSMCs.</p>

Inhibitory effects of rosiglitazone on angiotensin II-induced toll-like receptor 4 expression and myeloperoxidase activity in RAW264.7 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of rosiglitazone on angiotensin II (Ang II)-induced mRNA and protein expressions of toll-like receptor 4 (TLR4) and myeloperoxidase (MPO) activity in RAW264.7 cells to explore its anti- inflammatory and anti-atherosclerotic mechanisms.</p><p><b>METHODS</b>Murine RAW264.7 cells were pretreated with rosiglitazone at 2.5, 5, and 10 micromol/L prior to exposure to AngII (0.1 micromol/L). TLR4 mRNA level was analyzed by RT-PCR, and TLR4 protein expression by Western blotting. MPO activity in the cell supernatant was assayed by colorimetry. In another experiment, the cells were pretreated with a neutralizing anti-TLR4 antibody (1 mg/L) for 1 h prior to rosiglitazone (10 micromol/L) treatment for 1 h, and subsequently stimulated with AngII or LPS (100 micromol/L) for 24 h to observe the change of MPO activity.</p><p><b>RESULTS</b>Rosiglitazone downregulated AngII-induced mRNA and protein expressions of TLR4, and inhibited MPO activity in RAW264.7 cells in a concentration-dependent manner. The TLR4 blocker partially antagonized the effect of AngII on MPO activity, and the inhibitory effect was markedly enhanced by rosiglitazone. Rosiglitazone significantly inhibited LPS (a specific TLR4 ligand)-induced MPO activity in RAW264.7 cells.</p><p><b>CONCLUSION</b>Rosiglitazone downregulates Ang II-induced TLR4 expression in RAW264.7 cells and inhibits MPO secretion possibly by interfering with TLR4 to relieve the inflammatory reaction, which may be one of its anti-atherosclerotic mechanisms.</p>

Inhibitory effect of fenofibrate on angiotensin II-induced toll-like receptor 4 expression, myeloperoxidase activity and expression in RAW264.7 cells / 药学学报

This study is to investigate the effect of fenofibrate on angiotensin II (Ang II)-induced toll-like receptor 4 (TLR4) expression, myeloperoxidase (MPO) activity and expression in murine macrophage line RAW264.7 cells and explore its anti-inflammatory mechanism. TLR4 and MPO mRNA levels were analyzed by RT-PCR, and TLR4 and MPO protein expressions were measured by Western blotting. MPO activity in the cell supernatant was assayed with colorimetry. The results showed that fenofibrate reduced Ang II-induced mRNA and protein expression of TLR4 and inhibited activity, mRNA and protein expression of MPO in RAW264.7 cells in concentration-dependent manner. In addition, TLR4 blocker partially antagonized the effect of Ang II on MPO activity in RAW264.7 cells, and fenofibrate potentiated the inhibitory effect. Meanwhile, fenofibrate significantly suppressed LPS (TLR4 special ligand)-induced MPO activity in RAW264.7 cells. In conclusion, fenofibrate downregulated Ang II-induced TLR4 expression and blocked MPO secretion in RAW264.7 cells via interfering with the TLR4-dependent signaling pathway to alleviate inflammation, which might be one of its novel anti-inflammatory mechanisms.

Study on anti-atherosclerotic mechanisms of divided functional recipes of dahuang zhechong pill in rabbits / 中国中药杂志

<p><b>OBJECTIVE</b>To study anti-atherosclerotic mechanisms of divided functional recipes of Dahuang Zhechong pill (DHZCP) in rabbits.</p><p><b>METHOD</b>The atherosclerotic rabbit model was established by high fat feeding combined with immune endothelial injury. Male New Zealand rabbits were divided into 9 groups: normal control group, model control group, Danshen positive control group, and 6 DHZCP-divided groups including divided functional recipes No. 1, 2, 3 with low and high doses for each divided recipe. After intragastric administration for 60 days, blood lipids and serum MDA and NO levels and SOD activity and plasma ET concentration, and contents of hydroxyproline and proteins in the vascular wall were determined.</p><p><b>RESULT</b>Compared with the model group, the level of blood lipids did not significantly change, serum MDA and ET levels, and the contents of hydroxyproline and proteins in the vascular wall significantly decreased (P < 0.05), and SOD activity and NO level increased in the divided functional recipes (all P < 0.05).</p><p><b>CONCLUSION</b>The divided functional recipes of DHZCP can inhibit development of atherosclerosis via a non-lowering lipid mechanisms, including anti-peroxidation of lipids, protection of endothelial function, and decrease of formation of extracellular matrix by reducing synthesis of collage and protein on the vascular wall. Among them, the divided functional recipe No. 1 exhibits the most obvious effect.</p>

Effect of the disassembled recipes of dahuang zhechong pill on proliferation and apoptosis of vascular smooth muscle cells in atherosclerotic rabbits / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the effects of the disassembled recipes of Dahuang Zhechong Pill (DRDZP) on proliferation and apoptosis of vascular smooth muscle cell (VSMC) of thoracic aorta in atherosclerotic rabbits.</p><p><b>METHODS</b>The atherosclerotic rabbit model was induced by high-cholesterol diet and immune injury of endothelium. Expression of proliferating cell nuclear antigen (PCNA) in VSMC was detected by SP immunohistochemical technique, and VSMC apoptosis was observed with TUNEL technique.</p><p><b>RESULTS</b>Compared with the model control, PCNA expression in VSMC decreased, while apoptotic cells increased significantly in all the groups treated by DR-DZP (P < 0.01).</p><p><b>CONCLUSION</b>All the DR-DZP could inhibit VSMC proliferation and promote its apoptosis to modulate the balance between cell proliferation and apoptosis, so as to exert antiatherosclerotic action, among which the disassembled-recipe I is the main composition to contribute to antiatherosclerotic action of Dahuang Zhechong Pill.</p>

Anti-atherosclerotic effects of divided functional recipes of Dahang Zhechong pill in rabbits / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effects of the divided functional recipes of Dahuang Zhechong pill( DHZCP) on atherosclerosis in rabbits.</p><p><b>METHOD</b>The atherosclerotic model was established by the combination of hypercholesterol feeding and immune-injured endothelium in rabbits. Male New Zealand rabbits were randomly divided into nine groups: normal group, model group, Danshen group (0. 5 g x kg(-1) ), the low-dose(0. 5 g x kg(-1) ) and high-dose( 1.0 g - kg(-1) ) groups of the first divided recipe, the low-dose(0. 75 g x kg-' ) and high-dose(1. 5 g x kg(-1)) groups of the second divided recipe, the low-dose(0. 8 g x kg(-1) ) and high-dose( 1.6 g x kg(-1) ) groups of the third divided recipe. The effects of the divided functional recipes of DHZCP were observed in macropathology, histopathology and ultrastructure. Image analyzing system was used to determine atherosclerotic plaque area, intima thickness(IT) and intima-media thickness(IMT) in rabbit aorta.</p><p><b>RESULT</b>The divided functional recipes of DHZCP could significantly decreased the deposit of lipid and the atherosclerotic plaque area in aorta intima, relieve the histopathological changes of atherosclerosis, and inhibited the proliferation of vascular smooth muscle cells and collagen to reduce pachynsis of vascular intima. The divided functional recipes of DHZCP also reduced IT, IMT and IT/MT and reversed the contractive vascular remodeling.</p><p><b>CONCLUSION</b>The divided functional recipes of DHZCP produce the different anti-atherosclerotic action, among which the first divided functional recipe exhibits more effective action.</p>