Paeoniflorin inhibits pulmonary artery smooth muscle cells proliferation via upregulating A2B adenosine receptor in rat

Traditional Chinese medicine monomers: Targeting pulmonary artery smooth muscle cells proliferation to treat pulmonary hypertension

Pulmonary hypertension (PH) is a complex multifactorial disease characterized by increased pulmonary vascular resistance and pulmonary vascular remodeling (PVR), with high morbidity, disability, and mortality. The abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs) is the main pathological change causing PVR. At present, clinical treatment drugs for PH are limited, which can only improve symptoms and reduce hospitalization but cannot delay disease progression and reduce survival rate. In recent years, numerous studies have shown that traditional Chinese medicine monomers (TCMs) inhibit excessive proliferation of PASMCs resulting in alleviating PVR through multiple channels and multiple targets, which has attracted more and more attention in the treatment of PH. In this paper, the experimental evidence of inhibiting PASMCs proliferation by TCMs was summarized to provide some directions for the future development of these mentioned TCMs as anti-PH drugs in clinical.

Therapeutic potential of paeoniflorin in atherosclerosis: A cellular action and mechanism-based perspective

Epidemiological studies have shown that the incidence, prevalence and mortality of atherosclerotic cardiovascular disease (ASCVD) are increasing globally. Atherosclerosis is characterized as a chronic inflammatory disease which involves inflammation and immune dysfunction. P. lactiflora Pall. is a plant origin traditional medicine that has been widely used for the treatment of various diseases for more than a millennium in China, Japan and Korean. Paeoniflorin is a bioactive monomer extracted from P. lactiflora Pall. with anti-atherosclerosis effects. In this article, we comprehensively reviewed the potential therapeutic effects and molecular mechanism whereby paeoniflorin protects against atherosclerosis from the unique angle of inflammation and immune-related pathway dysfunction in vascular endothelial cells, smooth muscle cells, monocytes, macrophages, platelets and mast cells. Paeoniflorin, with multiple protective effects in atherosclerosis, has the potential to be used as a promising therapeutic agent for the treatment of atherosclerosis and its complications. We conclude with a detailed discussion of the challenges and future perspective of paeoniflorin in translational cardiovascular medicine.

miR-378 associated with proliferation, migration and apoptosis properties in A549 cells and targeted NPNT in COPD

Background

microRNAs contribute to the development and progression of chronic obstructive pulmonary disease (COPD). However, the underlying molecular mechanisms are largely unclear. The goal of this study was to investigate the roles of miR-378 in alveolar epithelial type II cells and identify molecular mechanisms which contribute to the pathogenesis of COPD.

Materials and methods

Human alveolar epithelial (A549) cells were cultured in Dulbecco's Modified Eagle Medium. Cell proliferation was studied by using a cell counting kit-8 (CCK-8) and colony formation assays. Cell apoptosis and cell cycle were analyzed by flow cytometry and wound healing and Transwell were used to analyze the cell migration and. We performed bioinformatics analysis including target gene prediction, gene ontology (GO), Kyoto Encyclopedia of Genes and Genome (KEGG) pathway enrichment and construction of protein-protein interaction (PPI) network. The expression of miR-378 and NPNT from publically available expression microarray of COPD lung tissues was analyzed.

Results

Overexpression of miR-378 significantly increases cell proliferation, migration, and suppress apoptosis. GO analysis demonstrated that the miR-378 involved in transcription, vascular endothelial growth factor receptor signaling pathway, phosphatidylinositol 3-kinase signaling, cell migration, blood coagulation, cell shape, protein stabilization and phosphorylation. Pathway enrichment showed that the 1,629 target genes of miR-378 were associated with mTOR, ErbB, TGF-β, MAPK, and FoxO signaling pathways. Notably, miR-378 directly targets Nephronectin in A549 cells, and miR-378 was upregulated while NPNT was downregulated in COPD lung tissue samples.

Conclusions

These findings suggest that miR-378 can regulate the proliferation, migration, and apoptosis of A549 cells and target NPNT. miR-378 increased in COPD lung tissues while NPNT decreased, and might prove a potential target for novel drug therapy.

Paeoniflorin attenuates monocrotaline-induced pulmonary arterial hypertension in rats by suppressing TAK1-MAPK/NF-κB pathways

Pulmonary arterial hypertension (PAH) characterized by pulmonary vascular remodeling is a lethal disease. Paeoniflorin (PF) is a monoterpene glycoside with numerous beneficial functions, such as vasodilation, anti-inflammation and immunomodulation. This study aims to investigate the effects of PF on monocrotaline (MCT)-induced PAH rats. Our data showed that both prophylactic or therapeutic administration of PF alleviated MCT-induced increasing of right ventricular systolic pressure (RVSP), prevented right ventricle hypertrophy and pulmonary arterial remodeling, as well as inhibited inflammatory cell infiltration around pulmonary arteries. Meanwhile, PF blocked MCT-induced endothelial-mesenchymal transition (EndMT) as indicated by the restored expression of endothelial markers in lung. Moreover, PF inhibited MCT-induced down-regulation of bone morphogenetic protein receptor 2 (BMPR2) and suppressed MCT-induced phosphorylation of transforming growth factor-β (TGFβ) activated kinase 1 (TAK1) in vivo. In vitro studies indicated that PF prevented human pulmonary arterial smooth muscle cells (PASMCs) from platelet-derived growth factor-BB (PDGF-BB)-stimulated proliferation and migration. PF also partially reversed TGFβ1, interleukin-1β (IL-1β) and tumor necrosis factor (TNF-α) co-stimulated endothelial-to-mesenchymal transition (EndMT) in cultured human pulmonary artery endothelial cells (HPAECs). Signaling pathway analysis demonstrated that the underlying mechanism might be associated with the inhibition of TAK1-MAPK/NF-κB pathways. Taken together, our results suggested that PF could be a potential drug for the treatment of PAH.

Paeoniflorin inhibits proliferation and promotes autophagy and apoptosis of sweat gland cells

Axillary bromhidrosis is sweat excreted by apocrine glands in the armpits, mouth corners and other parts. The clinical manifestation includes excessive sweating and heavy odor, leading to the growth of bacteria and skin disease. The present study investigated the mechanism underlying the effect of paeoniflorin (PF) in the treatment of bromhidrosis. PF was injected into the feet of rats, and the foot skin was dissected for histological analysis. Primary human sweat gland cells (hSGCs) were isolated from patients with bromhidrosis. After 24 h treatment with PF or 3-methyladenine, the production of reactive oxygen species (ROS), autophagy, apoptosis, proliferation and cell cycle distribution were determined. PF induced nuclear pyknosis in rat SGCs. In vitro PF treatment inhibited cell proliferation with a 25% inhibitory concentration of 9.530 µM. Treatment with 9.530 µM PF for 24 h significantly increased apoptosis, ROS production and autophagy in hSGCs. PF promoted LC3B and Beclin 1 expression, but inhibited p62, phosphorylated (p)-PI3K and p-Akt expression. 3-methyladenine treatment reversed PF-induced changes in hSGCs. PF-induced inhibition of hSGC proliferation was associated with ROS production, apoptosis, and autophagy. These findings provide a basis for treating bromhidrosis.

Anti-inflammatory effects of paeoniflorin caused by regulation of the hif1a/miR-210/caspase1/GSDMD signaling pathway in astrocytes: a novel strategy for hypoxia-induced brain injury in rats

Context: Hypoxia-induced injury is a classic symptom of obstructive sleep apnea hypopnea syndrome (OSAHS), which is a risk factor of various diseases, such as hypertension, heart failure and stroke. However, there is no effective therapy for hypoxia-induced injury or OSAHS due to the elusive mechanism involved.Objective: This study aimed to assess the effects of paeoniflorin on hypoxia-induced injury and explore the underlying mechanism.Materials and methods: Hypoxic models of SD rats and CTX-TNA2 cells were used to assess the effect of paeoniflorin, and the expressions of hif1a, miR-210, caspase1 and GSDMD were detected using western blots and RT-PCR. Plasmid transfection was performed to explore the role of miR-210 in the effect of paeoniflorin.Results: Firstly, we confirmed that hypoxia induced severe neuronal injury and an enhancement of inflammation in the rat brain, with elevated expression of caspase1, IL1b and IL18. In addition, the results showed an activation of astrocytes and an increased level of pyroptosis under hypoxic conditions, which suggested a critical role of pyroptosis in hypoxiainduced injury of the brain. Furthermore, we found that compared with the controls, paeoniflorin treatment improved hypoxia-induced pyroptosis in astrocytes. Moreover, we detected the activation of hif1a/miR-210 signaling in the effects of paeoniflorin on astrocytes. As expected, the expression of hif1a and miR-210 was significantly upregulated in astrocytes when exposed to hypoxia, while paeoniflorin treatment reversed these enhancements. After transfection of miR-210 mimics, the attenuation of pyroptosis induced by paeoniflorin was suppressed, which was accompanied by an increase of ROS levels, as well as LDH release, indicating a critical role of miR-210 in pyroptosis in astrocytes.Conclusions: Our findings demonstrated that paeoniflorin improved hypoxia-induced pyroptosis in astrocytes via depressing hif1a/miR-210/caspase1/GSDMD signaling, providing robust evidence for the treatment of hypoxic injury and OSAHS.HighlightsHypoxia induces severe injury and inflammatory response in the rat brain;Hypoxia enhanced pyroptotic level and led to an activation of astrocytes.;Paeoniflorin alleviates hypoxia-induced pyroptosis in astrocytes;Transfection of miR-210 mimics suppressed the effects of paeoniflorin on hypoxia-induced pyroptosis in astrocytes.

A novel secreted-cAMP pathway inhibits pulmonary hypertension via a feed-forward mechanism

AIMS

Cyclic adenosine monophosphate (cAMP) is the predominant intracellular second messenger that transduces signals from Gs-coupled receptors. Intriguingly, there is evidence from various cell types that an extracellular cAMP pathway is active in the extracellular space. Herein, we investigated the role of extracellular cAMP in the lung and examined whether it may act on pulmonary vascular cell proliferation and pulmonary vasculature remodelling in the pathogenesis of pulmonary hypertension (PH).

METHODS AND RESULTS

The expression of cyclic AMP-metabolizing enzymes was increased in lungs from patients with PH as well as in rats treated with monocrotaline and mice exposed to Sugen/hypoxia. We report that inhibition of the endogenous extracellular cAMP pathway exacerbated Sugen/hypoxia-induced lung remodelling. We found that application of extracellular cAMP induced an increase in intracellular cAMP levels and inhibited proliferation and migration of pulmonary vascular cells in vitro. Extracellular cAMP infusion in two in vivo PH models prevented and reversed pulmonary and cardiac remodelling associated with PH. Using protein expression analysis along with luciferase assays, we found that extracellular cAMP acts via the A2R/PKA/CREB/p53/Cyclin D1 pathway.

CONCLUSIONS

Taken together, our data reveal the presence of an extracellular cAMP pathway in pulmonary arteries that attempts to protect the lung during PH, and suggest targeting of the extracellular cAMP signalling pathway to limit pulmonary vascular remodelling and PH.

Adenosine Receptors in the Lungs

The ubiquitous adenine nucleoside adenosine (Ado), which plays an important role in cellular energetics, is released from cells under physiologic and pathophysiologic conditions. Another source of extracellular Ado is rapid degradation of extracellular adenosine 5′-triphosphate (ATP) by ectoenzymes. Extracellular Ado acts as an autocrine and paracrine agent by the activation of G protein-coupled cell surface receptors (GPCRs), designated as A₁, A_2A, A_2B, and A₃. Almost four decades ago, published data have indicated that Ado could play a role in immune-mediated histamine release from pulmonary mast cells. Since then, numerous studies have indicated that Ado’s signal transductions are involved in various pulmonary pathologies including asthma and COPD. This chapter is a succinct review of recent studies in this field.

Characterization of molecular signature of the roots of Paeonia lactiflora during growth

The roots of Paeoniae lactiflora Pall. are widely consumed as crude drugs in Asian countries due to their remarkable beneficial health effects. The present research was undertaken to illuminate the dynamic changes in metabolites and enzymes and facilitate selection of the harvesting time when the herb can provide optimum health benefits. P. lactiflora roots were analyzed at 12 stages of growth for monoterpenoid glycosides, phenols, nucleosides, nucleobases, amino acids, and polysaccharides by high-performance liquid chromatography with photodiode array detector, ultra-high pressure liquid chromatography coupled with tandem mass spectrometry, and UV spectrophotometry. The enzyme activities of plant β-glucosidases and esterases were determined by UV methods. The total content of monoterpenoid glycosides and phenols peaked in December. For nucleosides and nucleobases, the highest content appeared in April. The maximum phasic accumulation of the total amino acids took place in March, and the content of total polysaccharides reached a peak value in September. December, April, and March were selected as the appropriate harvesting times for producing natural medicinal or health food products. Plant β-glucosidases and esterases showed the highest activity in December and May, respectively. When the activity of β-glucosidase increased, esterase activity decreased, while the contents of oxypaeoniflora and paeoniflorin increased. When esterase activity increased, the contents of benzoylpaeoniflorin, paeoniflorin, and gallic acid decreased. In conclusion, the results from the present study would be useful in determination of the suitable time for harvesting P. lactiflora roots for medicinal purposes.

Is the adenosine A2B 'biased' receptor a valuable target for the treatment of pulmonary arterial hypertension?

Pulmonary arterial hypertension (PAH) is a maladaptive disorder characterized by increased pulmonary vascular resistance leading to right ventricular failure and death. Adenosine released by injured tissues, such as the lung and heart, influences tissue remodeling through the activation of adenosine receptors. Evidence regarding activation of the low-affinity A_2BAR by adenosine points towards pivotal roles of this receptor in processes associated with both acute and chronic lung diseases. Conflicting results exist concerning the beneficial or detrimental roles of the A_2B 'biased' receptor in right ventricular failure secondary to PAH. In this review, we discuss the pros and cons of manipulating A_2BARs as a putative therapeutic target in PAH.

Adenosine Receptors As Drug Targets for Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a clinical condition characterized by pulmonary arterial remodeling and vasoconstriction, which promote chronic vessel obstruction and elevation of pulmonary vascular resistance. Long-term right ventricular (RV) overload leads to RV dysfunction and failure, which are the main determinants of life expectancy in PAH subjects. Therapeutic options for PAH remain limited, despite the introduction of prostacyclin analogs, endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, and soluble guanylyl cyclase stimulators within the last 15 years. Through addressing the pulmonary endothelial and smooth muscle cell dysfunctions associated with PAH, these interventions delay disease progression but do not offer a cure. Emerging approaches to improve treatment efficacy have focused on beneficial actions to both the pulmonary vasculature and myocardium, and several new targets have been investigated and validated in experimental PAH models. Herein, we review the effects of adenosine and adenosine receptors (A₁, A_2A, A_2B, and A₃) on the cardiovascular system, focusing on the A_2A receptor as a pharmacological target. This receptor induces pulmonary vascular and heart protection in experimental models, specifically models of PAH. Targeting the A_2A receptor could potentially serve as a novel and efficient approach for treating PAH and concomitant RV failure. A_2A receptor activation induces pulmonary endothelial nitric oxide synthesis, smooth muscle cell hyperpolarization, and vasodilation, with important antiproliferative activities through the inhibition of collagen deposition and vessel wall remodeling in the pulmonary arterioles. The pleiotropic potential of A_2A receptor activation is highlighted by its additional expression in the heart tissue, where it participates in the regulation of intracellular calcium handling and maintenance of heart chamber structure and function. In this way, the activation of A_2A receptor could prevent the production of a hypertrophic and dysfunctional phenotype in animal models of cardiovascular diseases.

Identification of bioactive compounds in Shaoyao-Gancao decoction using β2-adrenoceptor affinity chromatography

Shaoyao-Gancao decoction, a Chinese herbal formula, is composed of Paeoniae Radix alba and Glycyrrhiza Radix et rhizoma. It has been widely used to treat muscle spasms and asthma. However, little is known about the bioactive components of Shaoyao-Gancao decoction. In the present study, the bioactive compounds in water-extract of Shaoyao-Gancao decoction were separated by the immobilized β₂ -adrenoceptor affinity column and identified using quadrupole time-of-flight mass spectrometry. The affinity constants of the separated compounds that bind to β₂ -adrenoceptor were determined by frontal analysis. Compound bioactivity was tested in a rat tracheal smooth muscle relaxation assay. We identified the bioactive compounds in the water extract of Shaoyao-Gancao decoction that bound to the β₂ -adrenoceptor as paeoniflorin and liquiritin. Paeoniflorin and liquiritin had only one binding site on the immobilized β₂ -adrenoceptor, and the affinity constants were (2.16 ± 0.10) × 10⁴  M^-1 and (2.95 ± 0.15) × 10⁴  M^-1 , respectively. Both compounds induced a concentration-dependent relaxation of tracheal smooth muscle following K⁺ -stimulated contraction, and the relaxation effects were abrogated by the β₂ -adrenoceptor antagonist, ICI 118551. Therefore, paeoniflorin and liquiritin are bioactive compounds in Shaoyao-Gancao decoction and the β₂ -adrenoceptor affinity chromatography is a useful tool for identifying potential β₂ -adrenoceptor ligands in natural products used in traditional Chinese medicine.

The Adenosinergic System as a Therapeutic Target in the Vasculature: New Ligands and Challenges

Adenosine is an adenine base purine with actions as a modulator of neurotransmission, smooth muscle contraction, and immune response in several systems of the human body, including the cardiovascular system. In the vasculature, four P1-receptors or adenosine receptors—A₁, A_2A, A_2B and A₃—have been identified. Adenosine receptors are membrane G-protein receptors that trigger their actions through several signaling pathways and present differential affinity requirements. Adenosine is an endogenous ligand whose extracellular levels can reach concentrations high enough to activate the adenosine receptors. This nucleoside is a product of enzymatic breakdown of extra and intracellular adenine nucleotides and also of S-adenosylhomocysteine. Adenosine availability is also dependent on the activity of nucleoside transporters (NTs). The interplay between NTs and adenosine receptors’ activities are debated and a particular attention is given to the paramount importance of the disruption of this interplay in vascular pathophysiology, namely in hypertension., The integration of important functional aspects of individual adenosine receptor pharmacology (such as in vasoconstriction/vasodilation) and morphological features (within the three vascular layers) in vessels will be discussed, hopefully clarifying the importance of adenosine receptors/NTs for modulating peripheral mesenteric vascular resistance. In recent years, an increase interest in purine physiology/pharmacology has led to the development of new ligands for adenosine receptors. Some of them have been patented as having promising therapeutic activities and some have been chosen to undergo on clinical trials. Increased levels of endogenous adenosine near a specific subtype can lead to its activation, constituting an indirect receptor targeting approach either by inhibition of NT or, alternatively, by increasing the activity of enzymes responsible for ATP breakdown. These findings highlight the putative role of adenosinergic players as attractive therapeutic targets for cardiovascular pathologies, namely hypertension, heart failure or stroke. Nevertheless, several aspects are still to be explored, creating new challenges to be addressed in future studies, particularly the development of strategies able to circumvent the predicted side effects of these therapies.

Hypoxia-Induced Mitogenic Factor Acts as a Nonclassical Ligand of Calcium-Sensing Receptor, Therapeutically Exploitable for Intermittent Hypoxia-Induced Pulmonary Hypertension

Hypoxia-induced mitogenic factor (HIMF) is an inflammatory cytokine playing important role(s) in the development of hypoxic pulmonary hypertension. The molecular target mediating HIMF-stimulated downstream events remains unclear. The coimmunoprecipitation screen identified extracellular calcium-sensing receptor (CaSR) as the binding partner for HIMF in pulmonary artery smooth muscle cells. The yeast 2-hybrid assay then revealed the binding of HIMF to the intracellular, not the extracellular, domain of extracellular CaSR. The binding of HIMF enhanced the activity of extracellular CaSR and mediated hypoxia-evoked proliferation of pulmonary artery smooth cells and the development of pulmonary vascular remodeling and pulmonary hypertension, all of which was specifically attenuated by a synthesized membrane-permeable peptide flanking the core amino acids of the intracellular binding domain of extracellular CaSR. Thus, HIMF induces pulmonary hypertension as a nonclassical ligand of extracellular CaSR, and the binding motif of extracellular CaSR can be therapeutically exploitable.

Beneficial Effects of Paeoniflorin Enriched Extract on Blood Pressure Variability and Target Organ Damage in Spontaneously Hypertensive Rats

Blood pressure variability (BPV) is associated with the development and progression of severe target organ damage (TOD). This study aims to evaluate the protective effect of paeoniflorin enriched extract from Radix Paeoniae Alba (PG) on BPV and TOD in spontaneously hypertensive rats (SHR). All SHR were orally treated with distilled water, metoprolol (MP, 20 mg/kg), and PG (PG-H, 90 mg/kg or PG-L, 30 mg/kg) for a single time or daily for 7 weeks. The 24-hour dynamic blood pressure was monitored and then calculated BPV including long- and short-term systolic blood pressure variability (SBPV), diastolic blood pressure variability (DBPV), mean blood pressure variability (MBPV), and heart rate variability (HRV) as well as the 24-hour-SBP, 24-hour-DBP, and 24-hour-MBP. The protective effects of PG on TOD were observed by histopathologic and biochemical detection. The results indicated that long- and short-term SBPV, DBPV, MBPV, and HRV as well as 24-hour-SBP, 24-hour-DBP, and 24-hour-MBP showed no significant changes after single-dose administration of PG and significantly decreased after administration with PG for 7 weeks. PG could also markedly improve the damage of aorta, heart, kidney, and brain. This study suggested that PG could notably reduce BPV, stabilize blood pressure, and mitigate TOD in SHR.

Paeoniflorin protects diabetic mice against myocardial ischemic injury via the transient receptor potential vanilloid 1/calcitonin gene-related peptide pathway

Background

Diabetes mellitus has multiple complications including neuropathy and increases cardiovascular events. Paeoniflorin (PF), a monoterpene glycoside, plays an essential role in neuroprotection and ischemic heart disease. In this study, we aimed to investigate the hypothesis that PF protects mice with diabetes mellitus against myocardial ischemic injury, and determine its associated mechanisms.

Results

Myocardial infarction (MI) was generated in the streptozotocin-mediated diabetic mice, which were pretreated with either vehicle or PF, respectively. Myocardial infarct size, myocardial enzyme, cardiac function, circulating calcitonin gene-related peptide (CGRP) concentration, histological analysis and the expression of associated molecules were determined and compared among different experimental groups. Compared to diabetic hearts pretreated with vehicle, hearts pretreated with PF exhibited less tissue damage and better CGRP concentration in serum when subjected to myocardial ischemia. Transient receptor potential vanilloid 1(TRPV1) gene knockout attenuated PF-mediated cardioprotection. Moreover, a specific Ca²⁺/calmodulin-dependent protein kinase (CaMK) inhibitor, KN-93, increased tissue damage and decreased CGRP activity in serum. Meanwhile, pretreated with PF increased the phosphorylation of cAMP response element binding protein (CREB).

Conclusions

Taken together, these findings demonstrate that PF protects diabetic mice against MI at least partially via the TRPV1/CaMK/CREB/CGRP signaling pathway.

Simultaneous determination of paeoniflorin from total glucosides of paeony in Sprague-Dawley rats and spontaneously hypertensive rats by high-performance liquid chromatography-tandem mass spectrometry: in vivo and in vitro studies

Paeoniflorin is a well-known monoterpene glucoside in the herbal drug that exhibits a number of biological activities. The pharmacokinetic characteristics of paeoniflorin from total glucosides of paeony in spontaneously hypertensive rats (SHR) are still unclear. It is essential to investigate the in vivo and in vitro pharmacokinetic differences of paeoniflorin from total glucosides of paeony in Sprague-Dawley (SD) and SHR. The in vivo pharmacokinetic data were analyzed using DAS 2.0 software and the in vitro metabolic characteristics were measured using rat hepatic microsomes. The concentration of paeoniflorin in biological samples was determined using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry method, which showed good precision and stability. The plasma concentration-time profiles of paeoniflorin following oral administration of total glucosides of paeony showed a single peak and there were significant differences in the mean values of AUC_(0-t) , AUC_(0-∞) , CL_z /F and T_max between SD and SHR (p < 0.05). The metabolic rate of paeoniflorin from total glucosides of paeony was slower in SHR than in SD rats (p < 0.05). The results might be useful in further applications of paeoniflorin and total glucosides of paeony. Copyright © 2016 John Wiley & Sons, Ltd.

Paeoniflorin, a novel heat-shock protein inducing compound, and human myometrial contractility in vitro

AIM

Heat shock proteins (HSPs) are synthesized in virtually all organisms in response to increases in temperature. They are associated with a relaxant effect on the human myometrium and are present in decreased concentration in the myometrium at the time of labor. Paeoniflorin is derived from Paeonia lactiflora and has been shown to induce the synthesis of HSPs in cultured mammalian cells. The purpose of the study was to evaluate the effect of paeoniflorin on human uterine contractility.

MATERIAL AND METHODS

Samples of human myometrium were taken at lower segment cesarean section. Dissected muscle strips were suspended under isometric conditions and exposed to cumulative additions of paeoniflorin in concentrations ranging from 1 nmol/L to 10 mol/L. Control experiments were simultaneously performed.

RESULTS

Paeoniflorin was found to exert an inhibitory effect on spontaneous and agonist-induced contractions compared to control strips. The mean maximal inhibition values were: 42.21% ± 9.26 for spontaneous contractions (n = 6; P < 0.0001) and 47.84% ± 9.05 for oxytocin-induced contractions (n = 6; P < 0.0001).

CONCLUSION

The HSP inducing compound, paeoniflorin, had a relaxant effect on human uterine contractility in vitro. These results reinforce the fact that HSPs may play a physiological role in the onset of labor and may also provide future targets for novel tocolytic treatments.

Roles of different mitochondrial electron transport chain complexes in hypoxia-induced pulmonary vasoconstriction

This study was designed to investigate the roles of different mitochondrial electron transport chain (ETC) complexes (I, II, III, and IV) on hypoxia-induced hypoxic pulmonary vasoconstriction (HPV). The third and fourth pulmonary arteries were collected from the normal tissues adjacent to tumors in 16 patients with lung cancer who had undergone lung cancer resections to isolate pulmonary artery smooth muscle cells (PASMCs). PASMCs were divided into seven groups and exposed to one of the following treatments: (1) normoxia (21% O(2), 5% CO(2), and 74% N(2)); (2) hypoxia (1% O(2), 5% CO(2), 94% N(2)); (3) hypoxia plus ETC complex I inhibitor MPP; (4) hypoxia plus ETC complex II inhibitor TTFA; (5) hypoxia plus ETC complex III Q(o) (pre) site inhibitor myxothiazol; (6) hypoxia plus ETC complex III Qi (post) site inhibitor antimycin A; (7) hypoxia plus ETC complex IV inhibitor NaN(3). Intracellular [Ca(2+) ]i and [ROS]i, mitochondrial [ROS]i, and PA rings tension were measured. Intracellular [Ca(2+) ]i and [ROS]i, mitochondrial [ROS]i, and PA ring tension were increased after hypoxia for 10 min. Mitochondrial ETC complex inhibitor MPP, TTFA, and myxothiazol significantly reduced [Ca(2+) ]i [ROS]i and PA tension (P < 0.01), whereas antimycin A and NaN(3) did not effectively reduce them. These results demonstrated it were mitochondrial ETC complex I, II, and III Q(o) site but not III Q(i) site and complex IV contribute to hypoxic pulmonary vasoconstriction and pulmonary hypertension.

Common Mechanism of Pathogenesis in Gastrointestinal Diseases Implied by Consistent Efficacy of Single Chinese Medicine Formula: A PRISMA-Compliant Systematic Review and Meta-Analysis

Gastrointestinal (GI) disorders often manifest similar symptoms with overlapping clinical diagnosis and unmet medical needs. Traditional Chinese medicine (TCM) has history-proven benefits for GI diseases; albeit language barrier prevents Western readers from accessing the original reports in Chinese. The TCM formula Si-Ni-San (SNS) consists of 4 herbs targeting on homeostatic disturbances characterized by "reflux" and "irritable" problems. Here we used SNS as a therapeutic tool to explore the common mechanisms of pathogenesis in non-neoplastic GI diseases.Data sources from PUBMED, Chinese National Knowledge Infrastructure, and Wanfang databases were searched for clinical trials. Comparisons were SNS as intervention and Western conventional medicine as control, which treat patients with upper GI disorders (gastroesophageal reflux disease, peptic ulcer, chronic gastritis, duodenogastric reflux), lower GI diseases (irritable bowel syndrome, ulcerative colitis), and functional dyspepsia. Participants and studies in accordance with the Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement were eligible. We used the Jadad scale to assess methodological qualities, the fixed or random-effect model to evaluate therapeutic efficacy, and the funnel plots to explore publication bias. Outcome was clinical efficacy defined by symptom relief with normal GI endoscopy, radiology, and pathology.We included 83 studies involving 7762 participants: 1708 versus 1397 of the upper GI disorders in 34 studies, 901 versus 768 of the lower GI diseases in 19 studies, 1641 versus 1348 of functional dyspepsia in 30 studies, and 328 versus 287 of relapse rate in 8 studies. Six studies had a Jadad score >2 points and the rest were <2 points. Pooled data showed significant efficacy of SNS for the upper GI disorders (odds ratio [OR] = 3.9, 95% confidence interval [CI] = 3.09-4.92), lower GI diseases (OR = 4.91, 95% CI = 3.71-6.51), and functional dyspepsia (N = 2989; OR = 3.94, 95% CI = 3.17-4.90). The relapse rate was 12.9% for SNS, significantly <46.5% for conventional therapies (OR = 0.16, 95% CI = 0.11-0.25).The consistent efficacy of the single TCM formula implicates common mechanisms of pathogenesis in GI disorders.

Effects of baicalin on collagen Ι and collagen ΙΙΙ expression in pulmonary arteries of rats with hypoxic pulmonary hypertension

The synthesis and accumulation of collagen play an important role in the formation and progression of hypoxic pulmonary hypertension. Baicalin has been reported to prevent bleomycin-induced pulmonary fibrosis. However, the role of baicalin in the treatment of pulmonary hypertension remains unknown. A disintegrin and metalloprotease with thrombospondin type-1 motif (ADAMTS-1) is a secreted enzyme that acts on a wide variety of extracellular matrix (ECM) substrates associated with vascular diseases. In this study, we aimed to investigate the effects of baicalin on the synthesis of collagen I in rats with pulmonary hypertension induced by hypoxia and the changes in ADAMTS-1 expression. A total of 24 Sprague Dawley rats were randomly assigned to 3 groups as follows: the control group (C), the hypoxia group (H) and the hypoxia + baicalin group (B). The rats in groups H and B were kept in a normobaric hypoxic chamber for 4 weeks, and the rats in group C were exposed to room air. We measured the hemodynamic indexes, including mean pulmonary artery pressure (mPAP), mean systemic (carotid) artery pressure (mSAP), and then calculated the mass ratio of right ventricle to left ventricle plus septum [RV/(LV + S)] to reflect the extent of right ventricular hypertrophy. We measured the mRNA and protein expression levels of type I collagen, type III collagen and ADAMTS-1 by hybridization in situ, and immunohistochemistry and western blot analysis, respectively. The results revealed that treatment with baicalin significantly reduced pulmonary artery pressure and attenuated the remodeling of the pulmonary artery under hypoxic conditions by increasing the expression of ADAMTS-1, so that the synthesis of type I collagen and its mRNA expression were inhibited. In conclusion, baicalin effectively inhibits the synthesis of collagen I in pulmonary arteries and this is associated with an increase in the expression of ADAMTS-1. Thus, treatment with baicalin may be an effective method for lowering pulmonary artery pressure and preventing pulmonary artery remodeling.

Antihypertensive effect of radix paeoniae alba in spontaneously hypertensive rats and excessive alcohol intake and high fat diet induced hypertensive rats

Radix Paeoniae Alba (Baishao, RPA) has long been used in traditional Chinese medicine formulation to treat hypertension by repression the hyperfunction of liver. However, whether the RPA itself has the antihypertensive effect or not is seldom studied. This study was to evaluate the protective effect of RPA on hypertensive rats. Alcohol in conjunction with a high fat diet- (ACHFD-) induced hypertensive rats and spontaneously hypertensive rats (SHR) was constantly received either RPA extract (25 or 75 mg/kg) or captopril (15 mg/kg) all along the experiments. As a result, RPA extract (75 mg/kg) could significantly reduce systolic blood pressure of both ACHFD-induced hypertensive rats and SHR after 9-week or 4-week treatment. In ACHFD-induced hypertensive rats, the blood pressure was significantly increased and the lipid profiles in serum including triglyceride, total cholesterol, LDL-cholesterol, and HDL-cholesterol were significantly deteriorated. Also, hepatic damage was manifested by a significant increase in alanine transaminase (ALT) and aspartate transaminase (AST) in serum. The RPA extract significantly reversed these parameters, which revealed that it could alleviate the liver damage of rats. In SHR, our result suggested that the antihypertensive active of RPA extract may be related to its effect on regulating serum nitric oxide (NO) and endothelin (ET) levels.