Moringa oleifera leaf extract lowers high blood pressure by alleviating vascular dysfunction and decreasing oxidative stress in L-NAME hypertensive rats

Ruta Montana Evokes Antihypertensive Activity Through an Increase of Prostaglandins Release in L-NAME-Induced Hypertensive Rats

AIMS

The aim of the study was to experimentally investigate the antihypertensive effect of Ruta Montana.

BACKGROUND

Ruta montana L. is traditionally used in Moroccan herbal medicine to treat hypertension. This study aimed to experimentally evaluate 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 for 6 hours for the acute experiment and for 7 days for the sub-chronic test. In the other set, the vasorelaxant effect of RMAPAE on the contractile response was observed in the isolated thoracic aorta.

RESULTS

The results indicated that the RMAPAE extract significantly decreased SBP, MBP, DBP and heart rate in L-NAME-induced 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 its use as an antihypertensive agent.

Phosphorylation and activation of endothelial nitric oxide synthase by red fruit (Pandanus conoideus Lam) oil and its fractions

ETHNOPHARMACOLOGICAL RELEVANCE

Red fruit (Pandanus conoideus Lam) oil (RFO) is utilized by inhabitants of the Papua Island to treat diseases such as infections, cancer, and cardiovascular disease, but the mechanism of action is unknown.

AIM OF THE STUDY

We have recently shown that RFO stimulates nitric oxide (NO) production in endothelial cells. The present study was conducted to investigate the molecular mechanism of endothelial NO synthase (eNOS) activation by RFO.

MATERIALS AND METHODS

NO production by endothelial cells was determined with electron paramagnetic resonance. The vascular function of isolated mouse aorta was examined using a wire myograph system. Phosphorylation of eNOS was studied with Western blot analyses.

RESULTS

RFO induced concentration-dependent vasodilation in isolated mouse aorta. The vasodilator effect of RFO was lost in endothelium-denuded aorta and in aorta from mice deficient in eNOS. Treatment of human EA.hy 926 endothelial cells with RFO led to an enhancement of eNOS phosphorylation at serine 1177 and NO production. The RFO-induced eNOS phosphorylation and NO production were reduced by inhibitors of Akt or AMPK, but not by an inhibitor of CaMKII. The effects of RFO were decreased by pharmacological inhibition of PI3K, indicating an involvement of the PI3K-Akt pathway. Moreover, acetone-soluble fractions and oily fractions of RFO showed higher efficacies than the RFO polar fraction in activating eNOS.

CONCLUSIONS

RFO contains highly active compounds that enhance NO production through Akt- or AMPK-mediated eNOS phosphorylation. The increase in endothelial NO production is likely to represent one of the molecular mechanisms responsible for the therapeutic effects of RFO.

Effects of hydrogen sulphide on oxidative stress, inflammatory cytokines, and vascular remodelling in l-NAME-induced hypertension

This study was designed to evaluate the protective effects of hydrogen sulphide (H₂ S) against NG-Nitro l-Arginine Methyl Ester (l-NAME)-induced hypertension and its possible effects on the inflammatory process, oxidative stress, and vascular remodelling in rats. Forty male Wistar Albino rats were assigned to four equal groups: the control group, the H₂ S control group, the hypertensive group, and the treated group, which received concomitant treatment with sodium hydrosulphide (NaHS) and l-NAME. Systolic blood pressure (SBP) was measured weekly. Serum levels of nitric oxide (NO), total peroxide, and total antioxidant capacity (TAC) were measured and the oxidative stress index (OSI) was calculated. Aortic weight and length were measured and the aortic weight/length ratio determined. Aortic fold expression of interferon-γ (IFN-γ) and vascular cell adhesion molecule-1 (VCAM-1) mRNA was measured using qPCR. Aortic media thickness and elastin content were measured morphometrically. l-NAME administration increased SBP, serum levels of total peroxide and OSI, but reduced serum levels of NO and TAC. Aortic fold expression of IFN-γ and VCAM-1 mRNA, aortic weight, aortic weight/length ratio, aortic media thickness, and elastin area percentage were increased in the hypertensive group. Concurrent administration of l-NAME and H₂ S attenuated these changes. Thus, H₂ S could attenuate the increase in ABP through restoration of the NO level, reduction in the oxidative state, and attenuation of the inflammatory process, thereby reduced vascular remodelling.

Restoring strategy of ethanolic extract of Moringa oleifera leaves against Tilmicosin-induced cardiac injury in rats: Targeting cell apoptosis-mediated pathways

Tilmicosin (Til), an effective macrolide antibiotic, is widely used against respiratory diseases in livestock; however, its treatment is associated with cardiac tissue impairments. In this study, the ethanolic extract of Moringa oleifera (MO) leaves was investigated at two doses (400 and 800 mg/kg body weight [bw], orally) to determine its role in counteracting the effects of Til treatment (75 mg/kg bw) on the cardiac tissue in rats, exploring the oxidative stress-mediated damage and apoptosis. A high dose of MO ethanolic extract elicits considerable changes in the body weight, reduces the mortality rate, neutralizes the impaired cardiac injury markers, improves antioxidant endpoints (total antioxidant capacity, superoxide dismutase, catalase activity, and reduced glutathione level). Also it attenuates the oxidative stress indices (total reactive oxygen species, 8-hydroxy-2-deoxyguanosine, lipid peroxides [malondialdehyde], and protein carbonyl levels) that are associated with Til injection. The co-administration of MO ethanolic extract with Til considerably modulates the expression of apoptosis pathway-encoding genes (Bcl-2, caspase-3, Bax, p53, apoptosis-inducing factor, and Apaf-1), particularly in the high-dose group. Our results support that the concurrent administration of MO ethanolic extract with Til at a dose of 800 mg/kg bw increases the protective activity of the antioxidant system and delays or slows the pathological development of cardiotoxicity mediated by Til injection.

Study of Antihypertensive Activity of Anvillea radiata in L-Name-Induced Hypertensive Rats and HPLC-ESI-MS Analysis

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.

Pharmacological evaluation of the hydro-alcoholic extract of Campomanesia phaea fruits in rats

Campomanesia phaea (Myrtaceae), popularly known as cambuci, is one of several species of plants producing comestible fruits, largely used in human nutrition. Despite its consumption and economic potential, limited scientific research is available on the Campomanesia, especially those related to its therapeutic benefits. It is reported by traditional medicine the use of the plant in the treatment of different disorders, such as cardiovascular and nervous system disturbances. So, the aim of this study was to carry out the pharmacological evaluation of the hydro-alcoholic extract (HAE) of Campomanesia fruits in rats by screening consisting of tests: a) neuropharmacological observation, b) test on the cardiovascular system. The HAE, prepared from the extraction of fruits with water/ethanol, was concentrated and freeze-dried. Behavioral responses in rats were investigated in open field test and the cardiovascular actions were investigated by a register of indirect blood pressure and the register of spontaneous beating rate right atrium. The results revealed that HAE induced grooming, hypotension and bradycardia. So, this study identified an action on the central nervous system, represented by grooming, and a cardiovascular activity of Campomanesia. The hypotension, attributed in part to bradycardia, was not related to a cholinergic effect, discarding a possible cholinomimetic action of the plant that could justify both cardiovascular and central actions.

Consumption of Moringa oleifera Lam Leaves Lowers Postprandial Blood Pressure

Objective: This clinical study monitored the effect of eating cooked Moringa oleifera leaves on the blood pressure (BP) of healthy participants in view of the perception that consumption of Moringa is associated with an increase in blood pressure, which is contradictory to the findings from the literature.Methods: A random sample of 41 healthy participants were enrolled in this prospective, placebo-controlled clinical study. Participants in the case study consumed 120 g of cooked M. oleifera leaves while the control group did not eat Moringa leaves. BP was measured at baseline before the meal and followed up at regular intervals over 24 hours for both groups. Baseline (T0) mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) and postprandial follow-up (T2-T24) were measured for both groups. Participants recorded their diet for a week and this led to an estimation of the total salt consumption per day.Results: A significant difference was observed between DBP at baseline and two hours postprandial (T2) for the case group (p = 0.013). Moreover, in the case group, despite high consumption of salt (7 g/d) during the week preceding the clinical study, there was a significant decrease in both the SBP and DBP. In the control group, participants with prior high consumption of salt (7 g/d) during the week had elevated SBP and DBP.Conclusions: These findings in human subjects indicated the lowering effect of Moringa oleifera leaves consumption on the 2 hours postprandial BP and showed a potential lowering effect on both SBP and DBP despite prior high consumption of salt (7 g/d).

Nobiletin alleviates vascular alterations through modulation of Nrf-2/HO-1 and MMP pathways in l-NAME induced hypertensive rats

Nobiletin alleviates l-NAME-induced vascular dysfunction and remodeling and superoxide production in rats.