Chemical composition, vasorelaxant, antioxidant and antiplatelet effects of essential oil of Artemisia campestris L. from Oriental Morocco

BACKGROUND

Artemisia campestris L. (Asteraceae) is a medicinal herb traditionally used to treat hypertension and many other diseases. Hence, this study is aimed to analyze the essential oil of A. campestris L (AcEO) and to investigate the antiplatelet, antioxidant effects and the mechanisms of its vasorelaxant effect.

METHODS

The chemical composition of AcEO was elucidated using GC/MS analysis. Then, the antioxidant effect was tested on DPPH radical scavenging and on the prevention of β-carotene bleaching. The antiplatelet effect was performed on the presence of the platelet agonists: thrombin and ADP. The mechanism of action of the vasorelaxant effect was studied by using the cellular blockers specified to explore the involvement of NO/GC pathway and in the presence of calcium channels blockers and potassium channels blockers.

RESULTS

AcEO is predominated by the volatiles: spathulenol, ß-eudesmol and p-cymene. The maximal antioxidant effect was obtained with the dose 2 mg/ml of AcEO. The dose 1 mg/ml of AcEO showed a maximum antiplatelet effect of, respectively 49.73% ±9.54 and 48.20% ±8.49 on thrombin and ADP. The vasorelaxation seems not to be mediated via NOS/GC pathway neither via the potassium channels. However, pretreatment with calcium channels blockers attenuated this effect, suggesting that the vasorelaxation is mediated via inhibition of L-type Ca2+ channels and the activation of SERCA pumps of reticulum plasma.

CONCLUSION

This study confirms the antioxidant, antiplatelet and vasorelaxant effects of A.campestris L essential oil. However, the antihypertensive use of this oil should be further confirmed by the chemical fractionation and subsequent bio-guided assays.

Antihypertensive and vasorelaxant effects of aqueous extract of Artemisia campestris L. from Eastern Morocco

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia campestris L. (Asteraceae) has many traditional uses, among which treatment of diabetes and hypertension.

AIM OF THE STUDY

This study was conducted in order to confirm the antihypertensive and hypotensive effects of A. campestris L. aqueous extract (AcAE) and to explore the underlying mechanism of action of its vasorelaxant effect, besides the acute toxicity. Also, the chemical composition of AcAE was investigated.

MATERIAL AND METHODS

the chemical content of AcAE was determined by using HPLC and NMR techniques. The antihypertensive effect was assessed indirectly by tail-cuff method on L-NAME induced hypertensive rats, while the hypotensive action was monitored intravenously by invasive method on normotensive rats. The vasorelaxant effect and vascular mechanism of action were studied in the presence of antagonists and blockers on aorta isolated from normotensive rats. On the other side, the acute toxicity was studied by oral feeding of extract to the mice.

RESULTS

The global phytochemical profile of AcAE reveals the presence of several polyphenols as main components. A. campestris L. infusion was characterized by mono- and di-cinnamoyl compounds, with 3,5-dicaffeoylquinic (isochlorogenic A) acid being the main compound, followed by 5-caffeoylquinic (chlorogenic) acid. Vicenin-2 (apigenin 6,8-di-C-glucoside) appeared to be the most abundant compound among flavonoids. The daily treatment with AcAE at 150mg/kg/day prevented the installation of hypertension on L-NAME hypertensive rats, and reduced SBP from 172mmHg up to 144mmHg. At the dose 40mg/kg, AcAE provoked reduction of systolic (SBP), diastolic (DBP) and mean arterial pressure (MAP), without affecting the heart rate. Also, AcAE (10^-2-2mg/ml) relaxed the precontracted aorta by 95.8±1.3%. The denudation and preincubation of aorta with atropine, calmidazolium, L-NAME, hydroxycobalamin, ODQ, 8-RP-Br-PET-cGMP, thapsigargin and verapamil attenuated the vasorelaxant response, while the pre-treatment with 4-AP, TEA, glibenclamide and BaCl₂ did not alter this effect. The oral administration of AcAE (0-6g/kg) reveals no mortality or toxicity.

CONCLUSIONS

our study proved that AcAE possess an important antihypertensive, hypotensive and vasorelaxant effect, which is mediated via calmodulin-NO-cGC-PKG pathway, and via inhibition of calcium influx through voltage-operated calcium channels and activation of intracellular calcium mobilization into sarcoplasmic reticulum. Therefore, our findings give first evidence about the traditional use of A. campestris L. as antihypertensive plant.

Hypotensive property of Chenopodium ambrosioides in anesthetized normotensive rats

BACKGROUND

The leaves of Chenopodium ambrosioides L. (Chenopodiaceae) are widely used in Moroccan traditional medicine to treat diabetes and hypertension. The goal of the present work is to investigate the hypotensive properties of different extract and fractions of the plant in anesthetized normotensive rats and to elucidate the mechanism underlying this effect.

METHODS

The hypotensive effect of aqueous extract (AqE) of the leaves of C. ambrosioides L., methanolic (MF), ethyl acetate (AcF), and aqueous (AqF) Soxhlet fractions, administrated intravenously, was evaluated in anesthetized rats. The recorded signals of blood pressure and heart rate were visualized and analyzed by using an acquisition card "National Instrument" and software Labview 6.1.

RESULTS

Intravenous administration of AqE of the leaves of C. ambrosioides L. induces a dose-dependent hypotension. A similar effect was obtained with MF, AcF, and AqF. Atropine (1 mg/kg), used to block cholinergic system, significantly reduced the hypotensive response to MF and AcF suggesting the presence of the cholinomimetic-muscarinic components in these fractions. However, the blood pressure lowering effect of MF and AcF in rats pretreated with L-NAME 20 mg/kg was unchanged showing that the release of NO is not implicated in the hypotensive action of this plant.

CONCLUSIONS

The present study demonstrates that extracts from leaves of C. ambrosioides induce hypotensive effect that may be partially associated with its cardiac effects. These results may partly explain the traditional use of leaves of C. ambrosioides L. for the treatment of disorders such as hypertension.

Influence of genetics and non-genetic factors on acenocoumarol maintenance dose requirement in Moroccan patients

WHAT IS KNOWN AND OBJECTIVE

Coumarin derivatives such as acenocoumarol represent the therapy of choice for the long-term treatment and prevention of thromboembolic diseases. Many genetic, clinical and demographic factors have been shown to influence the anticoagulant dosage. Our aim was to investigate the contribution of genetic and non-genetic factors to variability in response to acenocoumarol in Moroccan patients.

METHODS

Our study included 114 adult Moroccan patients, receiving long-term acenocoumarol therapy for various indications. Tests for VKORC1 -1639G>A promoter polymorphism (rs9923231), CYP2C9*2 rs1799853, CYP2C9*3 rs1057910, and CYP4F2 rs2108622 alleles were undertaken using Taq Man(®) Pre-Developed Assay Reagents for allelic discrimination. The statistical analysis was performed using the SAS V9 statistical package.

RESULTS AND DISCUSSION

Genotyping showed that the allele frequencies for the SNPs studied were no different to those found in Caucasians population. A significant association was observed between the weekly maintenance dose and the VKORC1 (P = 0·0027) and CYP2C9 variant genotypes (P = 0·0082). A final multivariate regression model that included the target International Normalized Ratio, VKORC1 and CYP2C9 genotypes explained 36·2% of the overall interindividual variability in acenocoumarol dose requirement.

WHAT IS NEW AND CONCLUSION

Our study shows large interindividual variability in acenocoumarol maintenance dose requirement in our population. VKORC1 and CYP2C9 variants significantly affected acenocoumarol dose, in-line with results in other populations. For the Moroccan population, the SNPs that have the largest effect on acecoumarol dose are CYP2C9 rs1799853, CYP2C9 rs1057910 and VKORC1 rs9923231.

[Isolated left ventricular congenital diverticulum in adult: Report of cardiac imaging]

Cardiac diverticulum is an infrequent congenital malformation, it's even more rare in adulthood. It's often associated with other thoraco-abdominal diverticulums, and rarely isolated. The diagnosis relies on echocardiography. By the way, the magnetic resonance imagery (MRI) allows a finer analysis of the diverticulum, its topography and its situation contributed to vascular and cardiac structures, it has largely replaced the ventriculography. We report in this article the case of a patient of 36 years whose diagnosis of the diverticulum was made by transthoracic echocardiography (TTE) at the time of an assessment of dyspnea, this exam also objectified a mitral insufficiency by deformation and dilatation of the mitral annulus. Radiological assessment was completed by a transoesophageal echocardiography (TOE) and magnetic resonance imagery (MRI). Surgical treatment consisted of surgical closing of the diverticulum and mitral annuloplasty.

Chemical composition, vasorelaxant, antioxidant and antiplatelet effects of essential oil of Artemisia campestris L. from Oriental Morocco

BACKGROUND

Artemisia campestris L. (Asteraceae) is a medicinal herb traditionally used to treat hypertension and many other diseases. Hence, this study is aimed to analyze the essential oil of A. campestris L (AcEO) and to investigate the antiplatelet, antioxidant effects and the mechanisms of its vasorelaxant effect.

METHODS

The chemical composition of AcEO was elucidated using GC/MS analysis. Then, the antioxidant effect was tested on DPPH radical scavenging and on the prevention of β-carotene bleaching. The antiplatelet effect was performed on the presence of the platelet agonists: thrombin and ADP. The mechanism of action of the vasorelaxant effect was studied by using the cellular blockers specified to explore the involvement of NO/GC pathway and in the presence of calcium channels blockers and potassium channels blockers.

RESULTS

AcEO is predominated by the volatiles: spathulenol, ß-eudesmol and p-cymene. The maximal antioxidant effect was obtained with the dose 2 mg/ml of AcEO. The dose 1 mg/ml of AcEO showed a maximum antiplatelet effect of, respectively 49.73% ±9.54 and 48.20% ±8.49 on thrombin and ADP. The vasorelaxation seems not to be mediated via NOS/GC pathway neither via the potassium channels. However, pretreatment with calcium channels blockers attenuated this effect, suggesting that the vasorelaxation is mediated via inhibition of L-type Ca²⁺ channels and the activation of SERCA pumps of reticulum plasma.

CONCLUSION

This study confirms the antioxidant, antiplatelet and vasorelaxant effects of A.campestris L essential oil. However, the antihypertensive use of this oil should be further confirmed by the chemical fractionation and subsequent bio-guided assays.