Cardiovascular Effects of Micromeria graeca (L.) Benth. ex Rchb in Normotensive and Hypertensive Rats

2020 ◽  
Vol 20 (8) ◽  
pp. 1253-1261
Author(s):  
Mourad Akdad ◽  
Mohamed Eddouks

Aims: The present study was performed in order to analyze the antihypertensive activity of Micromeria graeca (L.) Benth. ex Rchb. Background: Micromeria graeca (L.) Benth. ex Rchb is an aromatic and medicinal plant belonging to the Lamiaceae family. This herb is used to treat various pathologies such as cardiovascular disorders. Meanwhile, its pharmacological effects on the cardiovascular system have not been studied. Objective: The present study aimed to evaluate the effect of aqueous extract of aerial parts of Micromeria graeca (AEMG) on the cardiovascular system in normotensive and hypertensive rats. Methods: In this study, the cardiovascular effect of AEMG was evaluated using in vivo and in vitro investigations. In order to assess the acute effect of AEMG on the cardiovascular system, anesthetized L-NAME-hypertensive and normotensive rats received AEMG (100 mg/kg) orally and arterial blood pressure parameters were monitored during six hours. In the sub-chronic study, rats were orally treated for one week, followed by blood pressure assessment during one week of treatment. Blood pressure was measured using a tail-cuff and a computer-assisted monitoring device. In the second experiment, isolated rat aortic ring pre-contracted with Epinephrine (EP) or KCl was used to assess the vasorelaxant effect of AEMG. Results: Oral administration of AEMG (100 mg/kg) provoked a decrease of arterial blood pressure parameters in hypertensive rats. In addition, AEMG induced a vasorelaxant effect in thoracic aortic rings pre-contracted with EP (10 μM) or KCl (80 mM). This effect was attenuated in the presence of propranolol and methylene blue. While in the presence of glibenclamide, L-NAME, nifedipine or Indomethacin, the vasorelaxant effect was not affected. Conclusion: This study showed that Micromeria graeca possesses a potent antihypertensive effect and relaxes the vascular smooth muscle through β-adrenergic and cGMP pathways.

Author(s):  
El-Ouady Fadwa ◽  
Mohamed Eddouks

Aims: The aim of the study was to investigate experimentally the antihypertensive effect of Ruta Montana. Background: Ruta montana L. is traditionally used in Moroccan herbal medicine to treat hypertension. This study aimed to evaluate experimentally the hypotensive and vasoactive properties of this plant. Objective: The objective of the study was to evaluate the effect of the aqueous extract of Ruta Montana on blood pressure parameters in LNAME-induced hypertensive rats and to determine the vasorelaxant activity of this aqueous extract. Methods: The antihypertensive effect of the aqueous extract obtained from Ruta montana aerial parts (RMAPAE) (200 mg/kg) was evaluated in normal and anesthetized hypertensive rats. Blood pressure parameters (systolic blood pressure (SBP), mean blood pressure (MBP) and diastolic blood pressure (DBP)) and heart rate were measured using a tail-cuff and a computer-assisted monitoring device. The acute and chronic effect of RMAPAE was recorded during 6 hours for the acute experiment and during 7 days for the sub-chronic test. In the other set, the vasorelaxant effect of RMAPAE on the contractile response was undertaken in isolated thoracic aorta. Results: The results indicated that RMAPAE extract significantly decreased SBP, MBP, DBP and heart rate in L-NAMEinduced hypertensive rats. Furthermore, RMAPAE was demonstrated to induce a dose dependent relaxation in the aorta precontracted with Epinephrine or KCl. More interestingly, this vasorelaxant activity of RMAPAE seems to be probably mediated through the prostaglandins pathway. Conclusion: The present study illustrates the beneficial action of Ruta montana on hypertension and supports then its use as an antihypertensive agent.


Author(s):  
Mohammed Ajebli ◽  
Mohamed Eddouks

Aims and objective: The aim of the study was to investigate the effect of aqueous aerial part extract of Mentha pulegium L. (Pennyrile) (MPAE) on arterial pressure parameters in rats. Background: Mentha pulegium is a medicinal plant used to treat hypertension in Morocco. Material and methods: In the current study, MPAE was prepared and its antihypertensive activity was pharmacologically investigated. L-NAME-hypertensive and normotensive rats have received orally MPAE (180 and 300 mg/kg) during six hours for the acute experiment and during seven days for the sub-chronic treatment. Thereafter, systolic, diastolic, mean arterial blood pressure and heart rate were evaluated. While, in the in vitro experiment, isolated denuded and intact thoracic aortic rings were suspended in a tissue bath system and the tension changes were recorded. Results: A fall in blood pressure was observed in L-NAME-induced hypertensive treated with MPAE. The extract also produced a dose-dependent relaxation of aorta pre-contracted with NE and KCl. The study showed that the vasorelaxant ability of MPAE seems to be exerted through the blockage of extracellular Ca2+ entry. Conclusion: The results demonstrate that the extract of pennyrile exhibits antihypertensive activity. In addition, the effect may be, at least in part, due to dilation of blood vessels via blockage of Ca2+ channels.


1999 ◽  
Vol 276 (3) ◽  
pp. H944-H952 ◽  
Author(s):  
Stephanie W. Watts ◽  
Gregory D. Fink

We previously demonstrated a change in the receptors mediating 5-hydroxytryptamine (5-HT)-induced contraction in arteries of deoxycorticosterone acetate (DOCA)-salt-hypertensive rats. Specifically, contraction to 5-HT is mediated primarily by 5-HT2A receptors in arteries from normotensive sham rats and by both 5-HT2A and 5-HT2B receptors in arteries from hypertensive rats. We hypothesized that the 5-HT2B receptor may play a role in maintaining the high blood pressure of DOCA-salt-hypertensive rats, and herein we provide data connecting in vitro and in vivo findings. The endothelium-denuded isolated superior mesenteric artery of DOCA-salt rats displayed a marked increase in maximum contraction to the newly available 5-HT2B-receptor agonist BW-723C86 compared with that of arteries from sham rats, confirming that the 5-HT2B receptor plays a greater role in 5-HT-induced contraction in arteries from DOCA-salt rats. In chronically instrumented rats, the 5-HT2B-receptor antagonist LY-272015 (0.3, 1.0, and 3.0 mg/kg iv at 30-min intervals) was given cumulatively 1 time/wk during 4 wk of continued DOCA-salt treatment. LY-272015 did not reduce blood pressure of the sham-treated rats at any time or dose. However, LY-272015 (1.0 and 3.0 mg/kg) significantly reduced mean blood pressure in a subgroup of week 3 (−20 mmHg) and week 4 DOCA-salt (−40 mmHg) rats that had extremely high blood pressure (mean arterial blood pressure ∼200 mmHg). Blockade of 5-HT2Breceptors by in vivo administration of LY-272015 (3.0 mg/kg) was verified by observing reduced 5-HT-induced contraction in rat stomach fundus, the tissue from which the 5-HT2B receptor was originally cloned. These data support the novel hypothesis that 5-HT2B-receptor expression is induced during the development of DOCA-salt hypertension and contributes to the maintenance of severe blood pressure elevations.


1987 ◽  
Author(s):  
M Rampart ◽  
H Bult ◽  
A G Herman ◽  
P J Jose ◽  
T J Williams

Injection of endotoxin (LPS) in animals, a model for gram-negative septic shock, leads to intravascular activation of the complement system, and is one of the few conditions in which 6-oxo-PGF]CX and thromboxane (TX) B2 (non-enzymic metabolites of PGI2 and TXA2) can be detected in arterial blood. Previously we reported associations between complement activation, PGI2 biosynthesis and LPS-induced hypotension in rabbits. As C5a and C5adesArg trigger endothelial PGI2 formation in vitro, we have now measured the plasma levels of immunoreactive (ir) C5a in relation to generation of PGI2 and changes in arterial blood pressure in LPS shock. Pentobarbitone anaesthethized rabbits received LPS (E. coli 0111:B4, 0.5 mg/kg) or saline via the marginal ear vein. A catheter in the left carotid artery was used to collect blood and to monitor mean arterial blood pressure (MABP). Platelet and leukocyte numbers, haemolytic complement titre (CH50), and plasma ir6-oxo-PGFioc , irTXB2 and irC5a were measured 15 min before and at different times after saline or LPS injection. LPS caused a dose- and time-dependent formation of irC5a in rabbit serum in vitro, predominantly via the classical pathway. LPS also activated complement in vivo, as indicated by about 20 % reduction of CH50 titre (measured after 3h) and a marked increase of arterial irC5a (20-120 ng/ml) in the first 2 to 5 min. After 30 min, irC5a had returned to baseline levels (< 2-5 ng/ml) and remained so up to 3h after injection of LPS. This irC5a peak correlated with a shortlasting initiation of PGI2 release (from < 20 pg/ml up to 550 pg/ml) and a drop in MABP (from about 95 mmHg to 50 mmHg) 2-5 min after LPS. None of these changes occurred after saline injection.In conclusion, LPS activates complement in vivo with concomitant formation of C5a. This peptide may trigger -either directly or after phagocyte activation - endothelial PGI2 biosynthesis, leading to arterial hypotension. This is supported by the suppression of the initial rise of arterial ir6-oxo-PGF1α and hypotension in complement-depleted rabbits. Inhibition of C5a formation or activity may prove to be a meaningful approach to the treatment of septic circulatory shock.


1987 ◽  
Author(s):  
F Hermán ◽  
P Hadházy ◽  
K Magyar

Iloprost (Schering A.G.) is a chemically stable derivative of prostacyclin. We compared the hypotensive and antiaggregatory effects of PGI2 and Iloprost. The concentration producing 50% inhibition (IC50) of ADP-induced platelet aggregation in vitro was 0.35±0.15 nmol/1 for PGI2 and 0.56±0.2 nmol/1 for Iloprost (n=5). The in vivo antiaggregatory activity was measured with a modified filtration pressure technique (F.Hermán et al.Thromb. Res.44 /1986/, 575) in anaesthetized beagle dogs; the change in arterial blood pressure was recorded simultaneously. Using this technique, the dose-response relationship and the duration of action of prostacyclin and Iloprost following bolus administration have been determined. PGI2 was equipotent with Iloprost in inhibiting platelet aggregation in vivo (ED25: 0.25±0.04 nmol/kg; 0.28±0.05 respectively). At the same time PGI2 was two times as potent as Iloprost in decreasing the mean arterial blood pressure (ED25: 0.41±0.12 nmol/kg; 0.87±0.14 nmol/kg respectively). The antiaggregatory and hypotensive effects of Iloprost last longer in each experiment than that of PGI2, but did not reach the level of significance probably due to the considerable interindividual differences. The in vivo selectivity ratios (hypotensive potency/antiaggregatory potency) of Iloprost and PGI2 were 0.32 and 0.6 respectively. These results show that in anesthetized beagles Iloprost is somewhat more selective than PGI2 in inhibiting platelet aggregation.


1984 ◽  
Vol 247 (6) ◽  
pp. F975-F981 ◽  
Author(s):  
R. A. Stahl ◽  
U. Helmchen ◽  
M. Paravicini ◽  
L. J. Ritter ◽  
P. Schollmeyer

In vitro prostaglandin (PG) and thromboxane B2 (TXB2) formation by isolated glomeruli from normotensive (N) and two-kidney, one-clip hypertensive (2K,1C) rats was determined. When calculated on the basis of glomerular protein content, PGE2, 6-keto-PGF1 alpha and TXB2 production of glomeruli from clipped kidneys was significantly greater than PG and TXB2 formation of glomeruli from the untouched kidneys. When PG and TXB2 formation was calculated per amount of glomeruli, only PGE2 formation was found to be significantly greater in clipped kidneys. No severe damage of glomerular structure was found in the kidneys when studied by light microscopy. In additional in vivo studies, the effect of the cyclooxygenase inhibitor indomethacin on blood pressure and glomerular filtration rate (GFR) was evaluated. Following indomethacin GFR in 7 of 13 clipped kidneys of 2K,1C rats decreased from 363 +/- 77 to 188 +/- 51 microliter/100 g body wt, whereas six kidneys developed anuria. No effect of cyclooxygenase inhibition on GFR was found in N rats and in untouched kidneys of 2K,1C rats. Mean arterial blood pressure in 2K,1C hypertension fell significantly, from 158 +/- 10 to 135 +/- 7 mmHg, after cyclooxygenase inhibition. No effect was seen in N rats. The data suggest that increased glomerular PG formation in the clipped kidneys of 2K,1C rats is involved in the pathogenesis of hypertension in this animal model.


2020 ◽  
Vol 20 (7) ◽  
pp. 1059-1072
Author(s):  
Mourad Akdad ◽  
Mohammed Ajebli ◽  
Andrea Breuer ◽  
Farid Khallouki ◽  
Robert W. Owen ◽  
...  

Objective: This study aimed to evaluate the effect of the aqueous extract of Anvillea radiate (A. radiata) aerial parts (AEAR) on arterial blood pressure in normotensive and hypertensive rats. Methods: The effect of the acute and sub-chronic administration of AEAR on the following blood pressure parameters: systolic blood pressure (SBP), mean blood pressure (MBP), diastolic blood pressure (DBP), and heart rate (HR) was evaluated in normotensive and L-NAME induced hypertensive rats. In the second experiment, the vasorelaxant effect of AEAR was assessed in isolated aortic rings from rats with functional endothelium pre-contracted with epinephrine (EP) or KCl, and six antagonists/ inhibitors were used to explore the mechanisms of action involved in the vasorelaxant effect. In order to determine the phytochemical contents of Anvillea radiata, HPLC-ESI-MS analysis was conducted. Results: Daily oral administration of AEAR (100 mg/kg) provoked a significant decrease in SBP, MBP, and DBP without affecting HR in hypertensive rats. In addition, AEAR (0.08-0.64 mg/ml) revealed a vasorelaxant effect in thoracic aortic rings pre-contracted by EP (10 μM) or KCl (80 mM). This effect was reduced in the presence of Nifedipine, L-Name or Methylene blue. The polyphenolic compounds of AEAR were determined. Conclusion: This study revealed that AEAR possesses a potent antihypertensive activity and its vasorelaxant activity seems to be mediated through Ca2+ channels, direct nitric oxide (NO), and NO/cGMP pathways. Chlorogenic acid and caffeic acid identified in A. radiata could be at least partially responsible for the antihypertensive activity of this extract.


2020 ◽  
Vol 20 (5) ◽  
pp. 736-744
Author(s):  
Fadwa El-Ouady ◽  
Mohamed Eddouks

Objective: The objective of the study was to evaluate the antihypertensive activity of Asteriscus graveolens. Methods: L-NAME hypertensive and normotensive rats have received orally the aqueous extract of Asteriscus graveolens aerial parts (AGAPE) (100 mg/kg) during six hours for the acute experiment and during seven days for the sub-chronic treatment. Thereafter, blood pressure parameters were evaluated. Concerning the in vitro investigation, the vasorelaxant effect of AGAPE was tested in isolated thoracic aortic rings. Results: AGAPE extract significantly decreased the blood pressure parameters in hypertensive rats. Moreover, the results revealed that AGAPE exhibited antihypertensive effect through its vasorelaxant properties. More interestingly, this vasorelaxant activity seems to be probably mediated through activation of K+ ATP-sensitive (KATP) channels. Conclusion: The study demonstrates the antihypertensive activity of aqueous Asteriscus graveolens extract in hypertensive rats through activation of vascular KATP channels. This finding supports the use of this plant for the management of hypertension in Morocco.


1992 ◽  
Vol 133 (2) ◽  
pp. R1-R4 ◽  
Author(s):  
C. Bjenning ◽  
Y. Takei ◽  
T.X. Watanabe ◽  
K. Nakajima ◽  
S. Sakakibara ◽  
...  

ABSTRACT The effects of an elasmbranch cardiac C-type natriuretic peptide (dogfish CNP-22) on arterial blood pressure were investigated in vivo in chronically cannulated dogfish Scyliorhinus canicula and in vitro by a myographic technique using the distal part of the first branchial artery. In-vivo dogfish CNP-22 caused a dose-dependent reduction in mean arterial blood pressure which was much more potent than that of α-human ANP. In-vitro dogfish CNP-22 also caused a dose-dependent relaxation which was independent of the endothelium. These results are in marked contrast to those obtained in similar studies on other vertebrate species in which CNP exhibited only mild hypotensive effects compared to both atrial and brain natriuretic peptides. This study indicates the importance of using homologous peptides in determing the physiological role of natriuretic peptides in non-mammalian vertebrates.


Sign in / Sign up

Export Citation Format

Share Document