isolation-intrapulmonary-artery-smooth-muscle-cells-to-investigate

Isolation of Intrapulmonary Artery and Smooth Muscle Cells to Investigate Vascular Responses

The intrapulmonary artery (IPA) and vascular smooth muscle cells (VSMCs) isolated from rat lungs can be used to study the underlying mechanisms of ...

Naresuan University

 Ethnopharmacological studies demonstrated the potential for  species to treat inflammation, cancer, and cardio-metabolic diseases. The aim of the study was to investigate the vasorelaxant effect of ethanolic  (EM) extract and its main phenanthrene on rat isolated mesenteric artery and to investigate the hypotensive effect of EM.  The vasorelaxant effects of EM extract or phenanthrene and the underlying mechanisms were evaluated on second-order mesenteric arteries from Sprague Dawley rats. In addition, the acute hypotensive effect was evaluated in anesthetized rats infused with cumulative concentrations of the EM extract.  Both EM extract (10-1 mg/ml) and phenanthrene (10-10 M) relaxed endothelium-intact arteries, an effect that was partly reduced by endothelium removal ( < 0.001). A significant decrease in the relaxant effect of the extract and the phenanthrene was observed with L-NAME and apamin/charybdotoxin in endothelium-intact vessels, and with iberiotoxin in denuded vessels. SNP (sodium nitroprusside)-induced relaxation was significantly enhanced by EM extract and phenanthrene. By contrast, ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxaline-1-one), 4-aminopyridine and glibenclamide (endothelium-denuded vessels) and indomethacin (endothelium-intact vessels) had no effect. In calcium-free solution, both the EM extract and phenanthrene inhibited extracellular Ca-induced contraction in high KCl and phenylephrine (PE) pre-contracted rings. They also inhibited the intracellular Ca release sensitive to PE. The acute infusion of EM extract (20 and 70 mg/kg) induced an immediate and transient dose-dependent hypotensive effect.  The ethanolic extract of EM tubers and its main active compound, 1-(4'-hydroxybenzyl)-4,8-dimethoxyphenanthrene-2,7-diol (phenanthrene) induced vasorelaxant effects on rat resistance vessels, through pleiotropic effects including endothelium-dependent effects (NOS activation, enhanced EDH production) and endothelium-independent effects (opening of K channels, inhibition of Ca channels, inhibition of intracellular Ca release and PDE inhibition).

Vasorelaxant and Hypotensive Effects of an Ethanolic Extract of  and Its Main Compound 1-(4'-Hydroxybenzyl)-4,8-Dimethoxyphenanthrene-2,7-Diol.

Extract of the wild orchid, Eulophia macrobulbon (EM) inhibits phosphodiesterase5 (PDE5) suggesting it could preferentially dilate the pulmonary vasculature.

Eulophia macrobulbon extract relaxes rat isolated pulmonary artery and protects against monocrotaline-induced pulmonary arterial hypertension.

The leaves of  spp. promote "physiological balance", and are "cardiotonic and provide blood nourishment". In Asia, these leaves are increasingly consumed as tea and claimed to provide benefits to cardiovascular function, albeit without any scientific proof. Therefore, this study sought to evaluate the action of  leaf aqueous extract (AE) on vascular function and vascular smooth muscle cytotoxicity. AE and a main constituent, mangiferin were investigated for their vasorelaxation of rat mesenteric arteries and aortae . Acute cytotoxicity of AE (0.1-1000 μg/ml) and mangiferin (0.1-100 μM) on rat enzymatically isolated vascular smooth muscle cells was assayed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. AE dilated rat mesenteric arteries (EC∼107 μg/ml, E∼95%) more than aorta (EC∼265 μg/ml, E∼76%,  < 0.05). AE-induced vasodilation in mesenteric artery was reduced by endothelial removal (EC∼202 μg/ml,  < 0.05), incubation with endothelial nitric oxide synthase (eNOS) (100 μM, L-NAME) (EC∼309 μg/ml,  < 0.05), and partly reduced by L-type Ca channel blockade at higher concentrations. Likewise, mangiferin (1-100 μM) dilated the mesenteric artery more potently than the aorta. However, its maximum relaxation was less than with AE (41% in the mesenteric artery and <10% in the aorta). Isolated vascular smooth muscle cells incubated in AE or mangiferin for 1 h showed no cytotoxicity. Thus, AE is a vasorelaxant while being free of acute cytotoxicity towards vascular smooth muscle, thus potentially ameliorating human vascular dysfunction.

Extract of  leaves and mangiferin are vasodilators while showing no cytotoxicity.

A double-blind randomized controlled trial was used to assess the comedogenic potential of the dermatological products containing d-Alpha tocopheryl acetate. A total of 15 healthy males (20-45 years old) with prominent follicular orifices and the ability to form comedones on the upper aspect of the back were enrolled. Each participant was given pads containing 4 test products. The positive control arm received a pad containing octyl palmitate which is a reported comedogenic material. The negative control arm received a pad without any test material. Participants were randomized to apply either the positive, negative or the active test cream to the application area for 4 weeks. Comedones were identified using epidermal biopsy under a stereomicroscope. The average number of microcomedone before exposure (baseline) with octyl palmitate was 6.1 ± 0.6 (mean ± SEM), and changed to 27.3 ± 4.7 which was more than 50% increase in comedone formation in every subject with the average change from base line was 365.4 ± 87.6%. In the negative control arm the average number of microcomedone at baseline was 6.4 ± 1.1 and at 4 week-application was 3.4 ± 0.6 (-43.0 ± 9.5% increased). All tested products produced less than a 50% increase in the number of microcomedones. Analyzed data from 12 subjects indicated non-comedogenic potential of the tested products containing-alpha tocopheryl acetate and other ingredients including lanolin, kernel oil and avocado oil and sunflower oil, etc. The octyl palmitate produced more than 50% increase in comedone formation in every analyzed subject.

Safety assessment on comedogenicity of dermatological products containing d-alpha tocopheryl acetate in Asian subjects: A double-blind randomized controlled trial.

Article	Year
Vasorelaxant and Hypotensive Effects of an Ethanolic Extract of and Its Main Compound 1-(4'-Hydroxybenzyl)-4,8-Dimethoxyphenanthrene-2,7-Diol. Frontiers in pharmacology\| PubMed ID: 29872393	2018
Eulophia macrobulbon extract relaxes rat isolated pulmonary artery and protects against monocrotaline-induced pulmonary arterial hypertension. Phytomedicine : international journal of phytotherapy and phytopharmacology\| PubMed ID: 30466974	2018
Extract of leaves and mangiferin are vasodilators while showing no cytotoxicity. Journal of traditional and complementary medicine\| PubMed ID: 31453117	2019
Safety assessment on comedogenicity of dermatological products containing d-alpha tocopheryl acetate in Asian subjects: A double-blind randomized controlled trial. Contemporary clinical trials communications\| PubMed ID: 34471722	2021

Sutthinee Wisutthathum

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