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Bioactive substances from the Chinese daffodil, Narcissus tazetta
Author(s) -
Chiu K. W.,
Lee Y. C.,
Yung K. H.
Publication year - 1992
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.2650060502
Subject(s) - chronotropic , cholinergic , histaminergic , chemistry , pharmacology , in vivo , adrenergic , acetylcholine , endocrinology , medicine , inotrope , biology , biochemistry , receptor , histamine , heart rate , blood pressure , microbiology and biotechnology
The cardiovascular activity of the aqueous (A) and 30% MeOH (B) fractions of an ethanol extract of the daffodil bulbs ( Narcissus tazetta ) was examined using in vivo and in vitro preparations of normotensive rats and in the presence/absence of various blockers: α, β‐adrenergic, cholinergic, ganglionic, histaminergic, enzyme converson inhibitor, calcium channel. These fractions (A and B) produced similar dose‐dependent hypotensive responses in the anesthetized animals. The responses induced by fraction B might be mediated via adrenergic and cholinergic receptor activation. In isolated atrial preparations, fraction A increased the atrial rate (+ ve chronotropism) but not the atrial tension (inotropism). Fraction B, however, produced negative chronotropic but positive inotropic responses. Fraction B had no effect on the untreated tail vascular smooth muscle but increased the tension on AVP‐preconstricted helical strips. It is suggested that the daffodil bulb contains cardiovascular active substances, the sum total of the effects produced accounts for the hypotensive action. It is further shown that these substances are distinct from those of well‐documented antimitotic narciclasine.