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ACE activity during the hypotension produced by standardized aqueous extract of Cecropia glaziovii Sneth: a comparative study to captopril effects in rats.
Phytomedicine. 2007 May; 14(5):321-7.P

Abstract

To evaluate the effect of the standardized aqueous extract (AE) of Cecropia glaziovii Sneth on the plasma angiotensin I converting enzyme (ACE-EC 3.4.15.1) activity, rats were treated with a single dose of AE (1 g/kg, p.o.) or repeatedly (0.5 g/kg/bid, p.o.) for 60 days. Captopril (50 mg/kg, p.o.) was used as positive control on the same animals. The effects on the blood pressure were recorded directly from the femoral artery (single dose), or indirectly by the tail cuff method (repeated doses) in conscious rats. The plasma ACE activity was determined spectrofluorimetrically using Hypuril-Hystidine-Leucine as substrate. The arterial blood pressure, heart rate and plasma ACE activity were not significantly modified within 24 h after a single dose administration of AE. Comparatively, blood pressure in captopril treated rats was reduced by 7-16% and heart rate was increased by 10-20% from 30 min to 24 h after drug administration. ACE activity after captopril presented a dual response: an immediate inhibition peaking at 30 min and a slow reversal to 32% up-regulation after 24 h. To correlate the drug effects upon repeated administration of either compound, normotensive rats were separated in three groups: animals with high ACE (48.8+/-2.6 nmol/min/ml), intermediate ACE (39.4+/-1.4 nmol/min/ml) and low ACE (23.5+/-0.6 nmol/min/ml) activity, significantly different among them. Repeated treatment with AE reduced the mean systolic blood pressure (121.7+/-0.5 mm Hg) by 20 mm Hg after 14 days. The hypotension was reversed upon washout 60 days afterwards. Likely, repeated captopril administration decreased blood pressure by 20 mm Hg throughout treatment in all groups. After 30 days treatment with AE (0.5 g/kg/bid, p.o.) the plasma ACE activity was unchanged in any experimental group. After captopril (50 mg/kg/bid, p.o.) administration the plasma ACE activity was inhibited by 50% within 1 h treatment but it was up-regulated by 120% after 12 h in all groups. It is concluded that the hypotension produced by prolonged treatment with AE of C. glaziovii is unrelated to ACE inhibition.

Authors+Show Affiliations

Universidade Federal de São Paulo, Department of Pharmacology, Natural Products Section, 04044-020 São Paulo, SP, Brazil.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article

Language

eng

PubMed ID

17433647

Citation

Ninahuaman, M F M L., et al. "ACE Activity During the Hypotension Produced By Standardized Aqueous Extract of Cecropia Glaziovii Sneth: a Comparative Study to Captopril Effects in Rats." Phytomedicine : International Journal of Phytotherapy and Phytopharmacology, vol. 14, no. 5, 2007, pp. 321-7.
Ninahuaman MF, Souccar C, Lapa AJ, et al. ACE activity during the hypotension produced by standardized aqueous extract of Cecropia glaziovii Sneth: a comparative study to captopril effects in rats. Phytomedicine. 2007;14(5):321-7.
Ninahuaman, M. F., Souccar, C., Lapa, A. J., & Lima-Landman, M. T. (2007). ACE activity during the hypotension produced by standardized aqueous extract of Cecropia glaziovii Sneth: a comparative study to captopril effects in rats. Phytomedicine : International Journal of Phytotherapy and Phytopharmacology, 14(5), 321-7.
Ninahuaman MF, et al. ACE Activity During the Hypotension Produced By Standardized Aqueous Extract of Cecropia Glaziovii Sneth: a Comparative Study to Captopril Effects in Rats. Phytomedicine. 2007;14(5):321-7. PubMed PMID: 17433647.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - ACE activity during the hypotension produced by standardized aqueous extract of Cecropia glaziovii Sneth: a comparative study to captopril effects in rats. AU - Ninahuaman,M F M L, AU - Souccar,C, AU - Lapa,A J, AU - Lima-Landman,M T R, Y1 - 2007/04/12/ PY - 2006/06/23/received PY - 2006/11/07/accepted PY - 2007/4/17/pubmed PY - 2007/6/20/medline PY - 2007/4/17/entrez SP - 321 EP - 7 JF - Phytomedicine : international journal of phytotherapy and phytopharmacology JO - Phytomedicine VL - 14 IS - 5 N2 - To evaluate the effect of the standardized aqueous extract (AE) of Cecropia glaziovii Sneth on the plasma angiotensin I converting enzyme (ACE-EC 3.4.15.1) activity, rats were treated with a single dose of AE (1 g/kg, p.o.) or repeatedly (0.5 g/kg/bid, p.o.) for 60 days. Captopril (50 mg/kg, p.o.) was used as positive control on the same animals. The effects on the blood pressure were recorded directly from the femoral artery (single dose), or indirectly by the tail cuff method (repeated doses) in conscious rats. The plasma ACE activity was determined spectrofluorimetrically using Hypuril-Hystidine-Leucine as substrate. The arterial blood pressure, heart rate and plasma ACE activity were not significantly modified within 24 h after a single dose administration of AE. Comparatively, blood pressure in captopril treated rats was reduced by 7-16% and heart rate was increased by 10-20% from 30 min to 24 h after drug administration. ACE activity after captopril presented a dual response: an immediate inhibition peaking at 30 min and a slow reversal to 32% up-regulation after 24 h. To correlate the drug effects upon repeated administration of either compound, normotensive rats were separated in three groups: animals with high ACE (48.8+/-2.6 nmol/min/ml), intermediate ACE (39.4+/-1.4 nmol/min/ml) and low ACE (23.5+/-0.6 nmol/min/ml) activity, significantly different among them. Repeated treatment with AE reduced the mean systolic blood pressure (121.7+/-0.5 mm Hg) by 20 mm Hg after 14 days. The hypotension was reversed upon washout 60 days afterwards. Likely, repeated captopril administration decreased blood pressure by 20 mm Hg throughout treatment in all groups. After 30 days treatment with AE (0.5 g/kg/bid, p.o.) the plasma ACE activity was unchanged in any experimental group. After captopril (50 mg/kg/bid, p.o.) administration the plasma ACE activity was inhibited by 50% within 1 h treatment but it was up-regulated by 120% after 12 h in all groups. It is concluded that the hypotension produced by prolonged treatment with AE of C. glaziovii is unrelated to ACE inhibition. SN - 0944-7113 UR - https://www.unboundmedicine.com/medline/citation/17433647/ACE_activity_during_the_hypotension_produced_by_standardized_aqueous_extract_of_Cecropia_glaziovii_Sneth:_a_comparative_study_to_captopril_effects_in_rats_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0944-7113(06)00227-3 DB - PRIME DP - Unbound Medicine ER -