Acute and chronic antihypertensive effects of Cinnamomum zeylanicum stem bark methanol extract in L-NAME-induced hypertensive rats

Abstract

BackgroundPrevious study showed that the aqueous extract of the stem bark of Cinnamomum zeylanicum possesses antihypertensive and vasodilatory properties. The present work investigates the acute and chronic antihypertensive effects of the methanol extract of Cinnamomum zeylanicum stem bark (MECZ) in L-NAME-induced hypertensive rats.MethodsThe acute antihypertensive effects of MECZ (5, 10 and 20 mg/kg) administered intravenously were evaluated in rats in which acute arterial hypertension has been induced by intravenous administration of L-NAME (20 mg/kg). For chronic antihypertensive effects, animals were treated with L-NAME (40 mg/kg/day) plus the vehicle or L-NAME (40 mg/kg/day) in combination with captopril (20 mg/kg/day) or MECZ (300 mg/kg/day) and compared with control group receiving only distilled water. All drugs were administered per os and at the end of the experiment that lasted for four consecutive weeks, blood pressure was measured by invasive method and blood samples were collected for the determination of the lipid profile. The heart and aorta were collected, weighed and used for both histological analysis and determination of NO tissue content.ResultsAcute intravenous administration of C. zeylanicum extract (5, 10 and 20 mg/kg) to L-NAME-induced hypertensive rats provoked a long-lasting decrease in blood pressure. Mean arterial blood pressure decreased by 12.5%, 26.6% and 30.6% at the doses of 5, 10 and 20 mg/kg, respectively. In chronic administration, MECZ and captopril significantly prevented the increase in blood pressure and organs’ weights, as well as tissue histological damages and were able to reverse the depletion in NO tissue’s concentration. The MECZ also significantly lower the plasma level of triglycerides (38.1%), total cholesterol (32.1%) and LDL-cholesterol (75.3%) while increasing that of HDL-cholesterol (58.4%) with a significant low atherogenic index (1.4 versus 5.3 for L-NAME group).ConclusionMECZ possesses antihypertensive and organ protective effects that may result from its ability to increase the production of the endogenous NO and/or to regulate dyslipidemia.

UHPLC-DAD characterization of bioactive secondary metabolites from Ocimum americanum and Pupalia lappacea extracts: Antioxidant activity and antihypertensive effects on L-NAME-induced hypertensive rats

“…The increase in blood pressure could be explained by inhibition of nitric oxide (NO) synthesis by L-NAME (Kimura et al, 2017). Thus, a sufficient amount of NO is associated with normal vasodilatation and normal blood pressure, whereas inhibition of NO production may lead to hypertension (Nyadjeu et al, 2013;Sung et al, 2013). These data clearly justify the significant increase in SBP, DBP and MBP after L-NAME administration in our study.…”

Clerodendrum Chinensis Extracts;AeC and EeC Exerts Rapid Antihypertensive Effects in L-NAME Hypertensive Experimental Models

“…Table 1 shows that the control groups were adequate as controls as the saline group did not show any significant increments or decrease in the parameters of importance while the L-NAME control group should an increase in the parameters. It is well known that L-NAME, administered either acutely by intravenous route or chronically by the oral means induce sustained hypertension (Nyadjeu et al, 2013, Chaswal et al, 2011.…”

Antihypertensive Effect of Rutin: Pharmacological and Computational Approach

“…Group V received the standard drug captopril at a dose of 60 mg/kg after 60-90 min of L-NAME hydrochloride administration. Systolic blood pressure (SBP) and heart rate (HR) were measured by the noninvasive blood pressure amplifier system (PowerLab, ADInstruments, Australia) on days 0, 7, 14 and 21 [10].…”