ABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: We investigated the antiproliferative effects of baicalein, isolated from Scutellaria baicalensis (Huang-qin), on ET-1-mediated pulmonary artery smooth muscle cells (PASMCs) proliferation and the mechanisms underlying these effects. MATERIALS AND METHODS: Intrapulmonary artery smooth muscle cells were isolated and cultured from female Sprague-Dawley rats and used during passages 3-6. The proliferation of PASMCs was quantified by cell counting and XTT assay. The protein expression of TRPC1 and PKCα were determined by western blotting. The cell cycle pattern was assayed by flow cytometry. The intracellular calcium concentrations ([Ca(2+)](i)) were measured using the fluorescent indicator fura-2-AM and flow cytometry. RESULTS: Baicalein (0.3-3 µM) inhibited PASMCs proliferation, promoted cell cycle progression, enhanced [Ca(2+)](i) levels, increased capacitative Ca(2+) entry (CCE), upregulated the canonical transient receptor potential 1 (TRPC1) channel and membrane protein kinase Cα (PKCα) expression induced by ET-1 (0.1 µM). The PKC activator PMA (1 µM) reversed the inhibitory effects of baicalein on ET-1-induced upregulation of TRPC1 expression and S phase accumulation, while the PKC inhibitor chelerythrine (1 µM) potentiated baicalein-mediated G(2)/M phase arrest and TRPC1 channel inhibition. CONCLUSION: Our findings suggest that baicalein protects against ET-1-induced PASMCs proliferation via modulation of the PKC-mediated TRPC channel.
Subject(s)
Cell Proliferation/drug effects , Endothelin-1/physiology , Flavanones/pharmacology , Muscle, Smooth, Vascular/drug effects , Pulmonary Artery/drug effects , Scutellaria baicalensis/chemistry , TRPC Cation Channels/antagonists & inhibitors , Animals , Calcium/metabolism , Cells, Cultured , Female , Flavanones/isolation & purification , Flow Cytometry , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/metabolism , Protein Kinase C-alpha/antagonists & inhibitors , Pulmonary Artery/cytology , Pulmonary Artery/metabolism , Rats , Rats, Sprague-Dawley , TRPC Cation Channels/metabolismABSTRACT
San-Huang-Xie-Xin-Tang (SHXT) is a traditional Chinese medicinal formula containing Coptidis rhizoma, Scutellariae radix and Rhei rhizoma. The present study aimed to determine the preventive effects of standardized SHXT on lipopolysaccharides (LPS)-induced arterial hypotension, protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), cytokines formation and prostaglandin E2 (PGE2) production. LPS-induced activation of iNOS has been recognized to increase cytokines and nitric oxide, some of them play predominant roles in sepsis. Intravenous injection of LPS (10 mg/kg) caused a marked decrease of the mean arterial pressure in normotensive rats. However, the LPS-induced arterial hypotension was inhibited by SHXT (0.01 and 0.03 g/kg), when it was given 30 min before LPS. Moreover, plasma level of cytokines and PGE2 were lowered by SHXT. In RAW 264.7 cells, SHXT (20-200 microg/ml) dose-dependently inhibited LPS (1 microg/ml)-induced iNOS and COX-2 expression, and it also significantly decreased LPS-induced cytokines in a dose-dependent manner. In conclusion, our data suggest that SHXT prevented LPS-induced arterial hypotension, which might be mediated through its inhibition activities on the expression of iNOS and COX-2, cytokines formation and PGE2 production. Therefore, its protection activity against LPS-induced arterial hypotension and inflammatory mediators release might be beneficial in the treatment of endotoxin shock and/or associated inflammation.
Subject(s)
Drugs, Chinese Herbal/therapeutic use , Hypotension/prevention & control , Inflammation Mediators/antagonists & inhibitors , Phytotherapy , Animals , Blood Pressure/drug effects , Blotting, Western , Cell Line , Cell Survival , Cyclooxygenase 2 , Cytokines/blood , Cytokines/metabolism , Dinoprostone/blood , Dose-Response Relationship, Drug , Drugs, Chinese Herbal/pharmacology , Heart Rate/drug effects , Hypotension/chemically induced , Injections, Intravenous , Lipopolysaccharides , Nitric Oxide Synthase/metabolism , Nitric Oxide Synthase Type II , Prostaglandin-Endoperoxide Synthases/metabolism , Rats , Rats, Wistar , Time FactorsABSTRACT
Urgosedin is a newly synthesized compound especially with serotonergic and alpha-adrenergic blocking actions. In rat isolated thoracic aorta, urgosedin competitively antagonized norepinephrine-, clonidine-, and serotonin-induced vasocontractions in a concentration-dependent manner. In radioligand binding experiments, urgosedin had significant binding affinities on alpha1/alpha2, 5-HT1A, 5-HT1B and 5-HT2A receptors. Intravenous injection of lipopolysaccharide (LPS) produced a biphasic hypotension in normotensive rats. Although intravenous injection of urgosedin caused minor depressor actions in the normotensive Wistar rat, urgosedin significantly attenuated the secondary prolonged hypotension produced by LPS. The plasma levels of cytokines (IL-1beta, IL-6, TNF-alpha, and IFN-gamma) and hypoglycemia induced by LPS were also reduced by urgosedin. Moreover, the acute survival rates (350 minutes) of endotoxic shock increased from 0% (LPS group) to 100% in the groups pretreated with urgosedin. In RAW264.7 cells, urgosedin inhibited LPS-induced inducible nitric oxide synthase (iNOS) expression. In conclusion, our data suggest that urgosedin was a newly potent serotonergic and mild alpha-adrenergic blocking agent. Its prevention of LPS-induced hypotension and hypoglycemia might partially mediate through its inhibition activities on the iNOS expression and cytokines formation. Urgosedin might be an effective pharmacological agent against LPS-induced hypotension, hypoglycemia, and the formation of pro-inflammatory mediators.