chrysin and Hypertension--Pulmonary

In pulmonary arterial hypertension (PAH), right ventricular failure is accompanied by metabolic alterations in cardiomyocytes, which may be due to mitochondrial dysfunction and decreased energy production. Chrysin (CH) is a phytochemical with pharmacological activity that is involved in the regulation of mitochondrial biogenesis. The present study investigated the role of CH in the right ventricle (RV) by analyzing the cardiac transcriptome and metabolome of a SU5416(a vascular endothelial growth factor receptor blocker, /hypoxia (Su/Hx) rat model of PAH. RNA‑sequencing of the RV transcriptome between Su/Hx, Su/Hx with CH (Su/Hx + CH) and control groups, extracellular matrix (ECM) organization and ECM‑receptor interaction‑associated genes were upregulated in the RV of Su/Hx but not Su/Hx + CH rats. Furthermore, expression of mitochondrial function‑, energy production‑, oxidative phosphorylation‑ and tricarboxylic acid (TCA) cycle‑associated genes was decreased in the RV of Su/Hx rats; this was reverse by CH. Metabolomic profiling analysis of Su/Hx and Su/Hx + CH rats showed no significant changes in glycolysis, TCA cycle, glutathione, NADH or NADPH. By contrast, in the RV of Su/Hx rats, decreased adenylate energy charge was partially reversed by CH administration, suggesting that CH was involved in the improvement of mitochondrial biogenesis. Reverse transcription‑quantitative PCR analysis revealed that expression of peroxisome proliferator‑activated receptor γ, a master regulator of fatty acid metabolism and mitochondrial biogenesis, was increased in the RV of Su/Hx + CH rats. CH ameliorated cardiac abnormality, including cardiac fibrosis, RV hypertrophy and PH. The present study suggested that CH altered patterns of gene expression and levels of mitochondrial metabolites in cardiomyocytes, thus improving RV dysfunction in a Su/Hx PAH rat model.

Topics: Animals; Disease Models, Animal; Flavonoids; Heart Ventricles; Hypertension, Pulmonary; Organelle Biogenesis; Pulmonary Arterial Hypertension; Rats; Rats, Sprague-Dawley; Vascular Endothelial Growth Factor A

Chrysin (CH) is the main ingredient of many medicinal plants. Our previous study showed that CH could suppress hypoxia-induced pulmonary arterial smooth muscle cells proliferation and alleviate chronic hypoxia-induced pulmonary hypertension by targeting store-operated Ca entry (SOCE)-[Ca]i pathway. In this study, we investigated the effect of CH on monocrotaline-induced pulmonary hypertension (MCTPH) and the mechanism behind it. Results show that, in MCTPH model rats, (1) CH significantly reduced the enhancement of right ventricular pressure, right ventricular hypertrophy, and pulmonary vascular remodeling; (2) CH markedly suppressed the promotion of SOCE and [Ca]i in pulmonary arterial smooth muscle cells; and (3) CH obviously inhibited the MCT-upregulated proliferating cell nuclear antigen, TRPC1, TRPC4, and TRPC6 expression in distal pulmonary arteries. These results demonstrate that CH likely alleviates MCTPH by targeting TRPC1,4,6-SOCE-[Ca]i pathway.

Topics: Animals; Antihypertensive Agents; Arterial Pressure; Calcium Signaling; Disease Models, Animal; Flavonoids; Hypertension, Pulmonary; Hypertrophy, Right Ventricular; Monocrotaline; Muscle, Smooth, Vascular; Pulmonary Artery; Rats, Sprague-Dawley; TRPC Cation Channels; Vascular Remodeling; Ventricular Function, Right; Ventricular Pressure; Ventricular Remodeling

Chrysin (CH), the main ingredient of many medicinal plants, has been reported to be a very potent flavonoid possessing a large number of pharmacological activities. Recent studies have shown that CH significantly improves hemodynamic parameters such as right ventricular pressure, right ventricular hypertrophy, and pulmonary vascular remodeling in a rat model of chronic hypoxia-induced pulmonary hypertension (CHPH). These improvements are through the inhibition of NOX4 expression, reactive oxygen species and malondialdehyde production, pulmonary arterial smooth muscle cell (PASMC) proliferation, and collagen accumulation. In this study, we investigated another mechanism by which CH alleviates CHPH by regulating intracellular calcium concentrations ([Ca]i) in PASMCs, as well as the underlying signaling pathway. The results show that (1) in CHPH model rats, CH substantially attenuated elevated right ventricular pressure, right ventricular hypertrophy, and pulmonary vascular remodeling; (2) in cultured rat distal PASMCs, CH inhibited the hypoxia-triggered promotion of cell proliferation, store-operated Ca entry and [Ca]i; and (3) CH significantly suppressed the hypoxia-upregulated HIF-1α, BMP4, TRPC1, and TRPC6 expression in distal pulmonary arteries (PAs) and cultured rat distal PASMCs. These results indicate that CH likely exerts its CHPH protective activity by regulating [Ca]i, which may result from the downregulation of HIF-1α, BMP4, TRPC1, and TRPC in PASMCs.

Topics: Animals; Antihypertensive Agents; Bone Morphogenetic Protein 4; Calcium; Calcium Signaling; Cell Proliferation; Cells, Cultured; Flavonoids; Hypertension, Pulmonary; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Pulmonary Artery; Rats, Sprague-Dawley; TRPC Cation Channels; Vascular Remodeling; Ventricular Function, Right; Ventricular Pressure; Ventricular Remodeling

Alpha-naphthylthiourea (ANTU), a rodenticide induces lung toxicity. Chrysin a flavonoid possesses antioxidant, anti-inflammatory, and antihypertensive potential. The aim of this study was to evaluate the efficacy of chrysin against ANTU-induced pulmonary edema (PE) and pulmonary arterial hypertension (PAH) in laboratory rats. Sprague-Dawley rats were used to induce PE (ANTU, 10 mg/kg, ip) and PAH (ANTU, 5 mg/kg, ip, 4 weeks). Animals were treated with chrysin (10, 20, and 40 mg/kg) and various biochemical, molecular, and histological parameters were evaluated. Acute administration of ANTU induces PE revealed by significant (P < 0.05) increase in relative lung weight, pleural effusion volume, lung edema, bronchoalveolar lavage fluid cell counts, total protein, 5-hydroxytryptamine (5-HT), lactate dehydrogenase (LDH), and γ-glutamyl transferase (GGT), whereas pretreatment with chrysin (20 and 40 mg/kg, ip) significantly (P < 0.05) attenuated these ANTU-induced biochemical and histological alterations. Repeated administration of ANTU caused induction of PAH evaluated by significant (P < 0.05) alterations in electrocardiographic, hemodynamic changes, and left ventricular function, whereas chrysin (20 and 40 mg/kg, p.o.) treatment significantly (P < 0.05) attenuated these alterations. ANTU-induced hematological and serum biochemical (aspartate transaminase, alanine transaminase, LDH, and creatinine kinase MB) alterations were significantly (P < 0.05) inhibited by chrysin. It also significantly (P < 0.05) decreased elevated levels of oxido-nitrosative stress in the right ventricle (RV) and lung. Chrysin significantly (P < 0.05) attenuated downregulated endothelial nitric oxide synthase and upregulated vascular endothelial growth factor messenger RNA and protein expressions both in the RV and pulmonary artery. Chrysin inhibited ANTU-induced PE and PAH via modulation of inflammatory responses (5-HT, LDH, and GGT), oxido-nitrosative stress, and VEGF and eNOs levels.

Topics: Animals; Flavonoids; Hypertension, Pulmonary; Lung; Male; Nitric Oxide Synthase Type III; Pulmonary Artery; Pulmonary Edema; Rats; Rats, Sprague-Dawley; Thiourea; Vascular Endothelial Growth Factor A

The aim of the present study is to investigate the protective effect of chrysin (5,7-dihydroxyflavone) on right ventricular remodeling in a rat model of monocrotaline-induced pulmonary arterial hypertension (PAH). PAH rats were induced by a single injection of monocrotaline (60 mg x kg(-1), sc) and were administered with chrysin (50 or 100 mg x kg(-1) x d(-1)) for 4 weeks. At the end of experiment, the right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) were monitored via the right jugular vein catheterization into the right ventricle. Right ventricle (RV) to left ventricle (LV) + septum (S) and RV to tibial length were calculated. Right ventricular morphological change was observed by HE staining. Masson's trichrome stain was used to demonstrate collagen deposition. The total antioxidative capacity (T-AOC) and malondialdehyde (MDA) levels in right ventricle were determined according to the manufacturer's instructions. The expressions of collagen I, collagen III, NADPH oxidase 4 (NOX4) and nuclear factor-kappa B (NF-κB) were analyzed by immunohistochemisty, qPCR and (or) Western blot. The results showed that chrysin treatment for 4 weeks attenuated RVSP, mPAP and right ventricular remodeling index (RV/LV+S and RV/Tibial length) of PAH rats induced by monocrotaline. Furthermore, monocrotaline-induced right ventricular collagen accumulation and collagen I and collagen III expression were both significantly suppressed by chrysin. The expressions of NOX4, NF-κB and MDA contents were obviously decreased, while the T-AOC was significantly increased in right ventricule from PAH rats with chrysin treatment. These results suggest that chrysin ameliorates right ventricular remodeling of PAH induced by monocrotaline in rats through its down-regulating of NOX4 expression and antioxidant activity, and inhibiting NF-κB expression and collagen accumulation.

Topics: Animals; Blotting, Western; Collagen; Disease Models, Animal; Flavonoids; Heart Ventricles; Hypertension, Pulmonary; Monocrotaline; NADPH Oxidase 4; NADPH Oxidases; NF-kappa B; Rats; Ventricular Remodeling