Chrysin ameliorates ANTU-induced pulmonary edema and pulmonary arterial hypertension via modulation of VEGF and eNOs

Design, synthesis and Anti-PVY activity of planar chiral thiourea derivatives incorporated with [2.2]Paracyclophane

BACKGROUND

Potato virus Y (PVY) is a prominent representative of plant viruses. It can inflict severe damage upon Solanaceae plants, leading to global dissemination and substantial economic losses. To discover new antiviral agents, a class of planar chiral thiourea molecules through the key step of N-heterocyclic carbene-catalyzed nitrile formation reaction was synthesized with excellent optical purities for antiviral evaluations against plant virus PVY.

RESULTS

The absolute configurations of the planar chiral compounds exhibited obvious distinctions in the anti-PVY activities. Notability, compound (S)-4u exhibited remarkable curative activities against PVY, with a half maximal effective concentration (EC50) of 349.3 μg mL-1, which was lower than that of the ningnanmycin (NNM) (EC50 = 400.8 μg mL-1). Additionally, The EC50 value for the protective effects of (S)-4u was 146.2 μg mL-1, which was superior to that of NNM (276.4 μg mL-1). Furthermore, the mechanism-of-action of enantiomers of planar chiral compound 4u was investigated through molecular docking, defensive enzyme activity tests and chlorophyll content tests.

CONCLUSION

Biological mechanism studies have demonstrated that the configuration of planar chiral target compounds plays a crucial role in the molecular interaction with PVY-CP, enhancing the activity of defense enzymes and affecting chlorophyll content. The current study has provided significant insights into the roles played by planar chiralities in plant protection against viruses. This paves the way for the development of novel green pesticides bearing planar chiralities with excellent optical purities. © 2024 Society of Chemical Industry.

Therapeutic potential of natural flavonoids in pulmonary arterial hypertension: A review

BACKGROUND

Pulmonary arterial hypertension (PAH) is a fatal disease caused by pulmonary vascular remodeling, with a high incidence and mortality. At present, many clinical drugs for treating PAH mainly exert effects by relaxing the pulmonary artery, with limited therapeutic effects, so the search for viable therapeutic agents continues uninterrupted. In recent years, natural flavonoids have shown promising potential in the treatment of cardiovascular diseases. It is necessary to comprehensively elucidate the potential of natural flavonoids to combat PAH.

PURPOSE

To evaluate the potential of natural flavonoids to hinder or slow down the occurrence and development of PAH, and to identify promising drug discovery candidates.

METHODS

Literature was collected from PubMed, Science Direct, Web of science, CNKI databases and Google scholar. The search terms used included "pulmonary arterial hypertension", "pulmonary hypertension", "natural products", "natural flavonoids", "traditional chinese medicine", etc., and several combinations of these keywords.

RESULTS

The resources, structural characteristics, mechanisms, potential and prospect strategies of natural flavonoids for treating PAH were summarized. Natural flavonoids offer different solutions as possible treatments for PAH. These mechanisms may involve various pathways and molecular targets related to the pathogenesis of PAH, such as inflammation, oxidative stress, vascular remodeling, genetic, ion channels, cell proliferation and autophagy. In addition, prospect strategies of natural flavonoids for anti-PAH including structural modification and nanomaterial delivery systems have been explored. This review suggests that the potential of natural flavonoids as alternative therapeutic agents in the prevention and treatment of PAH holds promise for future research and clinical applications.

CONCLUSION

Despite displaying the enormous potential of flavonoids in PAH, some limitations need to be further explored. Firstly, using advanced drug discovery tools, including computer-aided design and high-throughput screening, to further investigate the safety, biological activity, and precise mechanism of action of flavonoids. Secondly, exploring the structural modifications of these compounds is expected to optimize their efficacy. Lastly, it is necessary to conduct well controlled clinical trials and a comprehensive evaluation of potential side effects to determine their effectiveness and safety.

The Role of Rosmarinic Acid in the Protection Against Inflammatory Factors in Rats Model With Monocrotaline-Induced Pulmonary Hypertension: Investigating the Signaling Pathway of NFκB, OPG, Runx2, and P-Selectin in Heart

ABSTRACT

Shortness of breath and syncope are common symptoms of right ventricular failure caused by pulmonary arterial hypertension (PAH), which is the result of blockage and increased pressure in the pulmonary arteries. There is a significant amount of evidence supporting the idea that inflammation and vascular calcification (VC) are important factors in PAH pathogenesis. Therefore, we aimed to investigate the features of the inflammatory process and gene expression involved in VC in monocrotaline (MCT)-induced PAH rats. MCT (60 mg/kg, i.p.) was used to induce PAH. Animals were given normal saline or rosmarinic acid (RA) (10, 15, and 30 mg/kg, gavage) for 21 days. An increase in right ventricular systolic pressure was evaluated as confirming PAH. To determine the level of inflammation in lung tissue, pulmonary edema and the total and differential white blood cell counts in the bronchoalveolar lavage fluid were measured. Also, the expression of NFκB, OPG, Runx2, and P-selectin genes was investigated to evaluate the level of VC in the heart. Our experiment showed that RA significantly decreased right ventricular hypertrophy, inflammatory factors, NFκB, Runx2, and P-selectin gene expression, pulmonary edema, total and differential white blood cell count, and increased OPG gene expression. Therefore, our research showed that RA protects against MCT-induced PAH by reducing inflammation and VC in rats.

Tsantan Sumtang, a traditional Tibetan medicine, protects pulmonary vascular endothelial function of hypoxia-induced pulmonary hypertension rats through AKT/eNOS signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Tsantan Sumtang (TS), originated from the Four Tantras, is an empirical Tibetan medicine prescription, which has been widely used for treating cardiovascular diseases in the clinic in Qinghai Province of China. Our previous studies found that TS alleviated hypoxia-induced pulmonary hypertension (HPH) in rats. However, the effect and bioactive fractions of TS on hypoxia-injured pulmonary vascular endothelium are unknown.

AIM OF THE STUDY

To investigate the effect, bioactive fractions and pharmacological mechanism of TS on hypoxia-injured pulmonary vascular endothelium in vivo and in vitro.

MATERIALS AND METHODS

In vivo studies, HPH animal model was established, and TS was administrated for four weeks. Then, hemodynamic indexes, ex vivo pulmonary artery perfusion experiment, morphological characteristics, nitric oxide (NO) production, and the protein expression of protein kinase B (AKT)/endothelial nitric oxide synthase (eNOS) and AMP-activated protein kinase (AMPK)/eNOS signaling were determined. In vitro studies, 1% O2-induced pulmonary artery endothelial cells (PAECs) injury model was applied for screening bioactive fractions of TS by cell proliferation assay and NO production measurement. The associated proteins of AKT/eNOS signaling were further measured to elucidate underlying mechanism of bioactive fraction of TS via using phosphatidylinositol-3 kinase (PI3K) inhibitor LY294002. Ultra-high performance liquid chromatography with hybrid quadrupole-orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS) was used to reveal the chemical profile of bioactive fraction of TS.

RESULTS

TS showed protective effect on the integrity of distal pulmonary arterial endothelium in HPH rats. Tsantan Sumtang dilated pulmonary arterial rings in HPH rats. TS enhanced NO bioavailability in lung tissue via regulating AKT/eNOS signaling. Furthermore, in the cellular level, cell viability as well as NO content of hypoxia-injured PAECs were elevated by fraction 17 of water extract of TS (WTS), through activating the AKT/eNOS signaling. Ellagic acid could be one of compositions in fraction 17 of WTS to produce NO in hypoxia-injured PAECs.

CONCLUSION

TS restored pulmonary arterial endothelial function in HPH rats. The bioactive fraction 17 was screened, which protected hypoxia-injured PAECs via upregulating AKT/eNOS signaling.

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.

The protective effect of chrysin against oxidative stress and organ toxicity in rats exposed to propetamphos

The aim of this study was to investigate the protective efficacy of chrysin against propetamphos exposure. For this purpose, 2 to 3-month-old 40 male Wistar Albino rats were used. These animals were randomly assigned to four groups. The animals in the control group received the vehicle substance (corn oil) alone. Groups 2, 3 and 4 were administered with 50 mg/kg.bw/day of chrysin (in corn oil), 10 mg/kg.bw/day of propetamphos (in corn oil), and 10 mg/kg.bw/day of propetamphos plus 50 mg/kg.bw/day of chrysin, respectively, for 28 days. Some oxidative stress/lipid peroxidation parameters (MDA, SOD, CAT, GSH-Px, NO, glutathione) and serum biochemical parameters (triglyceride, cholesterol, creatinine, BUN, creatine phosphokinase, ALT, ALP and pseudocholinesterase) were analyzed in tissue/blood samples. Also, histopathological findings were observed. According to the data obtained, no significant alteration had occurred in these parameters and the histological findings in the group given chrysin alone, when compared to the control group. Significant unfavorable alterations were detected in the oxidative stress/lipid peroxidation/antioxidant status parameters, all biochemical parameters and histopathological findings of the group that received propetamphos alone. In the group that was given both chrysin and propetamphos, remedial/recovery alterations were observed in the oxidative stress/lipid peroxidation/antioxidant status values, serum biochemical parameters and histopathological findings, such that the values and histopathological findings showed partly similarity to those of the control group. In result, it is suggested that chrysin may provide protection against propetamphos exposure and propetamphos-induced organ damage in rats at a certain level.

Cytokine profiling in pulmonary arterial hypertension: the role of redox homeostasis and sex

Pulmonary arterial hypertension (PAH) is a fatal disease with a well-established sexual dimorphism. Activated inflammatory response and altered redox homeostasis, both known to manifest in a sex-specific manner, are implicated in the pathogenic mechanisms involved in PAH development. This study aimed to evaluate the impact of sex and plasma redox status on circulating cytokine profiles. Plasma oxidation-reduction potential (ORP), as a substitute measure of redox status, was analyzed in male and female Group 1 PAH and healthy subjects. The profiles of 27 circulating cytokines were compared in 2 PAH groups exhibiting the highest and lowest quartile for plasma ORP, correlated with clinical parameters, and used to predict patient survival. The analysis of the PAH groups with the highest and lowest ORP revealed a correlation between elevated cytokine levels and increased oxidative stress in females. In contrast, in males, cytokine expressions were increased in the lower oxidative environment (except for IL-1b). Correlations of the increased cytokine expressions with PAH severity were highly sex-dependent and corresponded to the increase in PAH severity in males and less severe PAH in females. Machine learning algorithms trained on the combined cytokine and redox profiles allowed the prediction of PAH mortality with 80% accuracy. We conclude that the profile of circulating cytokines in PAH patients is redox- and sex-dependent, suggesting the vital need to stratify the patient cohort subjected to anti-inflammatory therapies. Combined cytokine and/or redox profiling showed promising value for predicting the patients' survival.

Chrysin promotes angiogenesis in rat hindlimb ischemia: Impact on PI3K/Akt/mTOR signaling pathway and autophagy

Limb ischemia occurs due to obstruction of blood perfusion to lower limbs, a manifestation that is associated with peripheral artery disease (PAD). Angiogenesis is important for adequate oxygen delivery. The present study investigated a potential role for chrysin, a naturally occurring flavonoid, in promoting angiogenesis in hindlimb ischemia (HLI) rat model. Rats were allocated into four groups: (1) sham-operated control, (2) HLI: subjected to unilateral femoral artery ligation, (3) HLI + chrysin: received 100 mg/kg, i.p. chrysin immediately after HLI, and (4) HLI + chrysin + rapamycin: received 6 mg/kg/day rapamycin i.p. for 5 days then subjected to HLI and dosed with 100 mg/kg chrysin, i.p. Rats were killed 18 h later and gastrocnemius muscles were collected and divided into parts for (1) immunohistochemistry detection of CD31 and CD105, (2) qRT-PCR analysis of eNOS and VEGFR2, (3) colorimetric analysis of NO, (4) ELISA estimation of TGF-β, VEGF, ATG5 and Beclin-1, and (5) Western blot analysis of p-PI3K, PI3K, p-Akt, Akt, p-mTOR, mTOR, and HIF-1α. Chrysin significantly enhanced microvessels growth in HLI muscles as indicated by increased CD31 and CD105 levels and decreased TGF-β. Chrysin's proangiogenic effect is potentially mediated by increased VEGF, VEGFR2 and activation of PI3K/AKT/mTOR pathway, which promoted eNOS and NO levels as it was reversed by the mTOR inhibitor, rapamycin. Chrysin also inhibited autophagy as it decreased ATG5 and Beclin-1. The current study shows that chrysin possesses a proangiogenic effect in HLI rats and might be useful in patients with PAD.

The Effect of Blood Flow-Restricted Low Resistance Training on Microvascular Circulation of Myocardium in Spontaneously Hypertensive Rats

Objective: The purpose of this study was to explore the effect of blood flow-restricted low resistance training on microvascular rarefaction in the myocardium of spontaneously hypertensive rats (SHRs).

Methods: Four-week-old male SHRs were randomly divided into the following groups: Wistar-Kyoto (WKY), SHR control (SHR-SED), high-intensity resistance training (HIRT), low-intensity resistance training (LIRT), and blood flow-restricted low resistance training (BFRT). The exercise groups began to receive exercise intervention for 8 weeks at the age of 7 weeks. Blood pressure (BP), heart rate (HR), cardiac function, capillary density, and Vascular endothelial growth factor -Phosphatidylinositol 3-kinase-Protein kinase B-Endothelial nitric oxide synthetase (VEGF-Pi3k-Akt-eNOS) were assessed.

Results: 1) BP and HR of BFRT decreased significantly, Ejection fraction (EF) and Fraction shortening (FS) increased, and the effect of BFRT on lowering BP and HR was better than that of other groups (p < 0.05); 2) The expression of VEGF, VEGFR2, p-VEGFR2, Pi3k, Akt, p-Akt, eNOS and p-eNOS in the myocardium of the BFRT was significantly upregulated, and eNOS expression was significantly higher than other groups (p < 0 05); 3) the expression of VEGF in the blood of the BFRT was significantly upregulated, higher than SHR-SED, lower than HIRT (p < 0.05), and there was no significant difference between BFRT and LIRT(p > 0.05); 4) the capillary density in the myocardium of BFRT was significantly higher than other exercise groups (p < 0 05).

Conclusion: Blood flow-restricted low resistance training can activate the VEGF-Pi3k-Akt-eNOS pathway, upregulate the expression of VEGF in blood, improve microvascular rarefaction, and promote myocardial microvascular circulation, thereby improving cardiac function and lowering blood pressure, achieving the preventive effect of early hypertension.

Natural ingredients from Chinese materia medica for pulmonary hypertension

Pulmonary hypertension (PH) is a severe pathophysiological condition characterized by pulmonary artery remodeling and continuous increases in pulmonary artery pressure, which may eventually develop to right heart failure and death. Although newly discovered and incredible treatment strategies in recent years have improved the prognosis of PH, limited types of effective and economical drugs for PH still makes it as a life-threatening disease. Some drugs from Chinese materia medica (CMM) have been traditionally applied in the treatment of lung diseases. Accumulating evidence suggests active pharmaceutical ingredients (APIs) derived from those medicines brings promising future for the prevention and treatment of PH. In this review, we summarized the pharmacological effects of APIs derived from CMM which are potent in treating PH, so as to provide new thoughts for initial drug discovery and identification of potential therapeutic strategies in alternative medicine for PH.

miR-1226-3p Promotes eNOS Expression of Pulmonary Arterial Endothelial Cells to Mitigate Hypertension in Rats via Targeting Profilin-1

In pulmonary arterial hypertension (PAH), microRNAs (miRNAs) are related with dysfunction of pulmonary arterial endothelial cells. miR-1226-3p was found to be downregulated in the serum of PAH patients, while few studies have illustrated the regulation mechanism of miR-1226-3p on PAH. In this study, we aimed to systematically investigate the role of miR-1226-3p in PAH. Sprague-Dawley (SD) rats were treated with monocrotaline (MCT) to establish the PAH models. The right ventricular systolic pressure (RVSP), ratio of the right ventricle to the left ventricle with septum (RV/(LV+S) ratio), and nitric oxide (NO) content were used to reflect the symptom of the rats. The rat models were used to observe the regulation mechanism of miR-1226-3p on PAH, and dual-luciferase reporter assay was used to verify the binding effect of miR-1226-3p to Pfn1. Besides, the qRT-PCR and western blot were used to measure the expression levels of miR-1226-3p and some keys proteins such as eNOS and Pfn1, respectively. The results showed that the PAH models were established successfully. The RVSP levels and the RV/(LV+S) ratio of the PAH rats were higher than those indexes in normal rats, while the NO content showed the opposite trends. Besides, the decreased miR-1226-3p and eNOS were, respectively, found in the PAH rats and rPAECs, and overexpressed miR-1226-3p could reverse the disadvantages of the PAH rats including increased RVSP, high RV/(LV+S) ratio, and decreased NO content. Furthermore, miR-1226-3p could directly target the 3'-UTR of Profilin-1 (Pfn1). Overexpressed Pfn1 led to decreased eNOS, while miR-1226-3p could partly inhibit the expression of Pfn1 and increase the expression level of eNOS in rPAECs. In summary, this study suggests miR-1226-3p as a protector to increase eNOS, improve NO content in rPAECs of the PAH rats via targeting Pfn, and finally protect the rats from the injury induced by PAH.

Oxidative Stress, GTPCH1, and Endothelial Nitric Oxide Synthase Uncoupling in Hypertension

Significance: Hypertension has major health consequences, which is associated with endothelial dysfunction. Endothelial nitric oxide synthase (eNOS)-produced nitric oxide (NO) signaling in the vasculature plays an important role in maintaining vascular homeostasis. Considering the importance of NO system, this review aims to provide a brief overview of the biochemistry of members of NO signaling, including GTPCH1 [guanosine 5'-triphosphate (GTP) cyclohydrolase 1], tetrahydrobiopterin (BH4), and eNOS. Recent Advances: Being NO signaling activators and regulators of eNOS signaling, BH4 treatment is getting widespread attention either as potential therapeutic agents or as preventive agents. Recent clinical trials also support that BH4 treatment could be considered a promising therapeutic in hypertension. Critical Issues: Under conditions of BH4 depletion, eNOS-generated superoxides trigger pathological events. Abnormalities in NO availability and BH4 deficiency lead to disturbed redox regulation causing pathological events. This disturbed signaling influences the development of systemic hypertension as well as pulmonary hypertension. Future Directions: Considering the importance of BH4 and NO to improve the translational significance, it is essential to continue research on this field to manipulate BH4 to increase the efficacy for treating hypertension. Thus, this review also examines the current state of knowledge on the effects of eNOS activators on preclinical models and humans to utilize this information for potential therapy.

Possible Potential Effects of Honey and Its Main Components Against Covid-19 Infection

Coronavirus disease 2019 (COVID-19) is a viral pneumonia that is spreading rapidly worldwide. The main feature of this disease is a severe acute respiratory syndrome and caused by coronavirus 2 (SARS-CoV-2). There are several unknowns about the pathogenesis and therapeutically treatment of COVID-19 infection. In addition, available treatment protocols have not been effective in managing COVID-19 infection. It is proposed that natural anti-oxidants such as lemon, green tea, saffron, curcuma longa, etc. with high flavonoids like safranal, crocin, crocetin, catechins, resveratrol, calebin A, curcumin have therapeutic potential against viral infections. In this context, honey and its main components are being investigated as an option for patients with COVID-19. The present study may indicate that honey and its main components inhibit the entry of the virus into the host cell and its replication as well as modulate the inflammatory cascade. This review provides basic information for the possible potential effects of honey and its main components for fighting with SARS-CoV-2.

Chrysin mitigates bleomycin-induced pulmonary fibrosis in rats through regulating inflammation, oxidative stress, and hypoxia

Pulmonary fibrosis is a chronic condition characterized by fibroblast proliferation, and the infiltration of inflammatory cells that can initiate local tissue hypoxia. In this study the effect of chrysin (50 mg/kg/orally) in a model of bleomycin (BLM)-induced pulmonary fibrosis was studied. Chrysin managed to decrease mortality rate associated with BLM instillation and it managed to improve lung architecture and lung fibrosis by decreasing hydroxyproline content and transforming growth factor-β1 (TGF-β1) protein expression. Chrysin showed anti-inflammatory effect displayed by the decrease in inflammatory cells infiltrates, the decline in permeability of the alveolar/capillary barrier and the reduction in lactate dehydrogenase (LDH) activity. Chrysin demonstrated potent antioxidant effect by decreasing lipid peroxidation, increasing antioxidant defense mechanisms by increasing superoxide dismutase (SOD) activity and reduced glutathione (GSH) content. Additionally, the effect of chrysin on nitric oxide (NOx) content was assessed, where chrysin decreased NOx, increased the protein expression of endothelial nitric oxide synthase (eNOS), and decreased inducible nitric oxide synthase (iNOS) protein expression. Chrysin also succeeded in decreasing thioredoxin-interacting protein (TXNIP), the negative regulator of thioredoxin system, showing potent antioxidant effect. Finally, both tissue and bronchoalveolar lavage fluid contents of hypoxia inducible factor one alpha (HIF1α) were decreased by chrysin indicating that chrysin decreased local tissue hypoxia. In conclusion, this study exposed a possible proof that chrysin could mitigate pulmonary fibrosis induced by BLM through its anti-inflammatory, antioxidant, antifibrotic effects and its effect in alleviating hypoxia.