Vasorelaxant and blood pressure lowering effects of alchemilla vulgaris: A comparative study of methanol and aqueous extracts

Background: In the last decade, a growing interest particularly in determining the cardiovascular effects of herbal extracts took place among researchers. Objective: Herein, we aimed to investigate the microvascular and blood pressure lowering effects of two differently processed extracts of the same herb, Alchemilla vulgaris (Rosaceaea), which was revealed to contain high levels of vasoactive compounds. Materials and Methods: For the purpose, endothelium intact rat mesenteric arteries were mounted in a myograph system and contracted with prostaglandin F 2α (PGF 2α: 3 × 10−5 M) or potassium chloride (K + : 40 mM). Then, aqueous and methanol extracts were added at 0.01-10 mg/ml concentrations in a cumulative manner. Results: Both extracts produced relaxations in PGF 2α (3 × 10−5 M) precontracted arteries which were insensitive to the inhibitors of endothelium derived vasoactive substances namely, L G -nitro-L-arginine (10−4 M), ODQ (10−5 M) and indomethacin (10−5 M) or removal of endothelium. Opposite vascular effects were observed when extracts were applied in K + precontracted arteries. In addition, oral administration of the methanol extract of Alchemilla vulgaris, but not the aqueous extract, reduced blood pressure significantly in L-NAME hypertensive rats. Conclusion: Our results demonstrated that the methanol extract of Alchemilla vulgaris has more prominent and favourable vascular effects in normal and experimental hypertensive conditions reinforcing its traditional use in cardiovascular disorders, in particular hypertension. These results most likely give rise to further studies to reveal its mechanism of action and clinical value of this herb

Asymmetric dimethylarginine (ADMA) levels are increased in patients with fibromyalgia: Correlation with tumor necrosis factor-alpha (TNF-alpha) and 8-iso-prostaglandin F-2 alpha (8-iso-PGF(2 alpha))

Objective: The aim of the study was to investigate serum levels of asymmetric dimethylarginine (ADMA), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and plasma levels of 8-iso-prostaglandin F-2 alpha (8-iso-PGF(2 alpha),) in patients with fibromyalgia

Endothelium-dependent vasorelaxant effect of Alchemilla vulgaris methanol extract: a comparison with the aqueous extract in rat aorta

We aimed to investigate the vascular effects of methanol extract (ME) and aqueous extract (AE) of Alchemilla vulgaris (Rosaceaea). Increasing concentrations of the ME (0.01-10 mg/mL) produced relaxations in noradrenaline (NA: 10(-6) M) and K+ (40mM) precontracted aortas while contractions were obtained with the AE (0.01-10 mg/mL). Responses to the ME were inhibited in the presence of putative inhibitors of endothelial vasodilators or after removal of the endothelium. Pretreatment of aortic rings with the ME (10 mg/mL, 20 min) reduced the maximal contractions to NA and K+, whereas an enhanced contractility was observed with the AE (10 mg/mL, 20 min). Total flavonoid content was higher in the ME than in the AE. Quercetin was determined particularly high in the ME while gallic acid was high in the AE. Our results indicated that the ME of A. vulgaris displays favourable vascular effects via endothelium-dependent mechanisms

Acute simvastatin inhibits K-ATP channels of porcine coronary artery myocytes

Background: Statins (3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors) consumption provides beneficial effects on cardiovascular systems. However, effects of statins on vascular KATP channel gatings are unknown.\ud \ud Methods: Pig left anterior descending coronary artery and human left internal mammary artery were isolated and endothelium-denuded for tension measurements and Western immunoblots. Enzymatically-dissociated/cultured arterial myocytes were used for patch-clamp electrophysiological studies and for [Ca²⁺]ᵢ, [ATP]ᵢ and [glucose](o) uptake measurements.\ud \ud Results: The cromakalim (10 nM to 10 μM)- and pinacidil (10 nM to 10 μM)-induced concentration-dependent relaxation of porcine coronary artery was inhibited by simvastatin (3 and 10 μM). Simvastatin (1, 3 and 10 μM) suppressed (in okadaic acid (10 nM)-sensitive manner) cromakalim (10 mM)-and pinacidil (10 μM)-mediated opening of whole-cell K-ATP channels of arterial myocytes. Simvastatin (10 mu M) and AICAR (1 mM) elicited a time-dependent, compound C (1 μM)-sensitive [H-3]-2-deoxy- glucose uptake and an increase in [ATP]ᵢ levels. A time (2-30 min)- and concentration (0.1-10 μM)-dependent increase by simvastatin of p-AMPKα-Thr¹⁷² and p-PP2A-Tyr³⁰⁷ expression was observed. The enhanced p-AMPK alpha-Thr¹⁷² expression was inhibited by compound C, ryanodine (100 μM) and KN93 (10 μM). Simvastatin-induced p-PP2A-Tyr³⁰⁷ expression was suppressed by okadaic acid, compound C, ryanodine, KN93, phloridzin (1 mM), ouabain (10 μM), and in [glucose](o)-free or [Na+](o)-free conditions.\ud \ud Conclusions: Simvastatin causes ryanodine-sensitive Ca²⁺ release which is important for AMPKα-Thr¹⁷² phosphorylation via Ca²⁺/CaMK II.AMPKα-Thr¹⁷² phosphorylation causes [glucose](o) uptake (and an [ATP]ᵢ increase), closure of K-ATP channels, and phosphorylation of AMPK alpha-Thr¹⁷² and PP2A-Tyr³⁰⁷ resulted. Phosphorylation of PP2A-Tyr³⁰⁷ occurs at a site downstream of AMPKα-Thr¹⁷² phosphorylation