Antihypertensive effect of a standardized aqueous extract of Cecropia glaziovii Sneth in rats: An in vivo approach to the hypotensive mechanism
Introduction
Cecropia glaziovii Sneth (Cecropiaceae) and more than 70 other species of the genus are widespread in America's tropical regions. Their crude extracts have been used in Brazilian's phytotherapy (Matta, 1913; Braga, 1960) and in other Latin America's countries (Gupta, 1995) as cardiotonic, diuretic and as relief for cough, bronchitis and asthma. A pharmacological account of C. glaziovii cardiovascular activity aiming its therapeutic relevance for public healthcare was presented in 1997 (Lapa et al., 1999). Other pharmacological screening of standardized Cecropia extracts, if any, past unnoticed, but studies using intravenous (i.v.) injection of crude extracts and in vitro studies of several species extract are found in the literature. For example, i.v. injection of a Cecropia adenopus crude extract produced bradycardia in dogs (Sivori, 1933) and hypotension in rats (Consolini and Migliori, 2005); cardiotonic effect was described in vitro (Consolini et al., 2006); the extract of C. carbonara produced intestinal relaxation in vitro (Vieira et al., 1968); the i.v. injection of Cecropia obtusifolia crude extracts induced hypotension in rats either anesthetized (Vidrio et al., 1982) or conscious (Salas et al., 1987a, Salas et al., 1987b), whereas slight increase in urinary flow occurred after intragastric administration (Vargas Howell and Ulate Montero, 1996). Mechanistically it has been suggested that the extract of C. glaziovii might block noradrenergic and serotoninergic receptors (Nicolau et al., 1988); the extract of C. obtusifolia inhibited binding to angiotensin and endothelin receptors (Caballero-George et al., 2001) or inhibited the central sympathetic tonus (Consolini and Migliori, 2005); Cecropia lyratiloba extract stimulated the release of endothelial NO (Almeida et al., 2006) and C. glaziovii extracts inhibited the angiotensin converting enzyme (ACE) (Castro Braga et al., 2000; Lacaille-Dubois et al., 2001).
Chemical studies of the genus Cecropia detected aminoacids and sugars (Neidlein and Koch, 1980), 8-methyl-azabicyclo (1,2,3) octane (Villar et al., 1988) and isovitexin (Della Monache et al., 1988), flavonoids, catechins and procyanidins (Lacaille-Dubois et al., 2001) all of them putatively related to Cecropia effects. However, correlation of specific pharmacological effects and plant constituents is lacking.
Therefore, the aim of the present paper was to compare the antihypertensive activity of a standardized aqueous extract (AE) of C. glaziovii and of its purified fraction on validated models of hypertension seeking for a definition of the mechanism of action after per os (p.o.) administration.
Section snippets
Botanical material
C. glaziovii Sneth was cultivated from a germoplasm kept at CPQBA's (Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agronômicas) farm, a research center at the University of Campinas, São Paulo, Brazil (Magalhães, 2000). A specimen voucher is deposited at that Center Herbarium under the number CPQBA 78.
Extraction and purification
To obtain the tea used in folk medicine, the ground dried leaves were extracted in hot water (2.0%, 72 °C) for 30 min (yield 20%). The AE was concentrated under vacuum to a fifth of
General effects
Mice and rats treated with the AE (0.1 and 1.0 g/kg, i.p. or p.o.) were slightly more reactive than controls to auditory stimulus. One hour after injection, the animals were less active than controls but without ataxia or other signs of CNS depression. After 8 h they did not differ from control animals. Intraperitoneal injection of AE was followed by evident writhing upon the higher doses but no treatment was lethal within 24 h.
Effect of Cecropia extracts on BP of non-anesthetized normotensive rats
Administration of AE (0.15–0.5 g/kg/day, p.o.) for 3 months to
Acknowledgments
The technical assistance of C.M. Dores, M.C. Gonçalo, and J. F. R. Santos is acknowledged. The authors also thank T.M.A. Lima for the help with some of the blood pressure recordings. This work was supported by grants from Central de Medicamentos (CEME – MS), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP).
References (34)
- et al.
Biological screening of selected medicinal Panamanian plants by radioligand-binding techniques
Phytomedicine
(2001) - et al.
Screeening the Brazilian flora for antihypertensive plant species for in vitro angiotensin I-converting enzyme inhibiting activity
Phytomedicine
(2000) - et al.
Cardiovascular effects of the South American medicinal plant Cecropia pachystachya (ambay) on rats
J. Ethnopharmacol.
(2005) - et al.
Cardiotonic and sedative effects of Cecropia pachystachya Mart. (ambay) on isolated rat hearts and conscious mice
J. Ethnopharmacol.
(2006) - et al.
Search for potential angiotensin converting enzyme (ACE)-inhibitors from plants
Phytomedicine
(2001) - et al.
Animal models of hypertension: an overview
J. Lab. Clin. Med.
(2005) - et al.
Role of angiotensin receptor blockade as monotherapy in reaching blood pressure goals
Am. J. Physiol.
(2005) - et al.
Antihypertensive action of a procyanidin glycoside from Rhamnus lycioides
J. Ethnopharmacol.
(1991) - et al.
Hypotensive activity of Cecropia obtusifolia
J. Pharm. Sci.
(1982) - et al.
Renal change in malignant hypertension
Lancet
(1939)
Activity of Cecropia lyratiloba extract on contractility of cardiac and smooth muscles in Wistar rats
Clin. Exp. Pharmacol. Physiol.
Plantas do Nordeste especialmente do Ceará
Cecropia pathystachya Mart
A topic on new antihypertensive drug research
Cited by (38)
The mechanisms of calcium mobilization by procyanidins, flavonols and flavonoids from Cecropia glaziovii Sneth in pulmonary endothelial cell cultures endorse its popular use as vasodilator phytomedicine
2021, Biomedicine and PharmacotherapyCitation Excerpt :While the antidepressant activity of ButF was measured in rat models [2], the anxiolytic effect of AE was observed in mice [4]. Hypotensive activity occurs when the relaxation of smooth muscles takes place, which can be stimulated by several mechanisms [5–15] such as the following: blockage of L-type calcium channels [7–20], action on β-2 adrenergic receptors [21], and/or participation of the nitric oxide pathway [20–23]. Previous studies carried out in our laboratory have demonstrated the hypotensive and antihypertensive activities of the aqueous extract (AE) and the butanolic fraction (ButF) isolated from Cecropia glaziovii Sneth.
Ethnopharmacological investigations of the leaves of Cecropia pachystachya Trécul (Urticaceae): A native Brazilian tree species
2021, Journal of EthnopharmacologyHypotensive effect of Eugenia dysenterica leaf extract is primarily related to its vascular action: The possible underlying mechanisms
2020, Journal of EthnopharmacologyDevelopment of Caco-2 cells-based gene reporter assays and evaluation of herb-drug interactions involving CYP3A4 and CYP2D6 gene expression
2019, Chemico-Biological InteractionsVasorelaxant effect of standardized extract of Cecropia glaziovii Snethl encapsulated in PLGA microparticles: In vitro activity, formulation development and release studies
2018, Materials Science and Engineering CCitation Excerpt :In folk medicine, the leaves of Cecropia glaziovii Snethl are used in the treatment of various diseases, including the control of blood pressure [1]. Some literature studies have reported a hypotensive effect for plant preparations [2, 3], which has been attributed to a synergism between C-glycosylflavonoids and proanthocyanidins as these compounds showed to be inactive when tested separately [4]. Preliminary phytochemical studies have reported the presence of catechins, procyanidins and flavonoids in standardized aqueous extracts of C. glaziovii [5].
Manufacture and characterization of chitosan/PLGA nanoparticles nanocomposite buccal films
2017, Carbohydrate Polymers