ISOLATION OF ARISTOLOCHIC ACIDS FROM ARISTOLOCHIA ALBIDA (DUCH) AND SOME STUDIES OF THEIR BIOLOGICAL ACTIONS (FAMILY: ARISTOLOCHIACEAE

No Thumbnail Available
Date
2000-05
Authors
OYEBANJO, OMOTAYO OLADIPUPO
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Aristolochia albida (Duch) [Family: Aristolochiaceae] is a shrub abundantly available in Nigeria and very much used by the traditional herbalist for a variety of purposes. The plant is used extensively to treat abdominal colic and is also claimed to be beneficial in the treatment and management of snake bites. The chloroform extract of the rhizomes of the plant gave a mixture of pale yellow micro needle-like fluorescent crystal through chromatographic separation which after crystallization in CHCl3MeOH (4:1) revealed two spots coded as CA1 and CA2. CA1 and CA2 were characterized as aristolochic (4,5-methylene dioxy-ll-methoxy-14- nitrophenanthrene-1-carboxylic acid), C17H21O7N [M+, 341] and aristoloside (aristolochic acid with glucosyl residue attached to C-9), C23H21O13N [M+, 519] on the basis of their m.p 191-194 °C and 280 - 283 °C. Spectral analysis (UV, 1R, NMR, MS) and comparison with reference aristolochic acids respectively. The biological actions of the crude aqueous extract of the plant rhizomes showed a dose-dependent relaxation of the frog rectus abdominis and antagonised the action of acetylcholine on the same tissue in the same manner like atropine. This effect is beneficial in the management of gastrointestinal disorders thus justifying the use of the plant for stomach disorders in traditional medicine. The anti-snake venom studies of rhizomes of Aristolochia albida showed that the extract could safely be useful in the treatment of snake bites especially those involving N. nigricollis, a cobra snake. The extract (4 mg/ml) antagonised the effective concentration of venom of N. nigricollis (0.16 mg/ml) dose dependently and occupy the muscarinic receptors thereby changing the conformation of the receptors thus preventing the snake venom access to these receptors to cause toxic and lethal reactions, which suggests that the extract might consists of agents capable of suppressing the effect of the venom. The biological test on rat phrenic nerve diaphragm revealed that the aqueous extract of the plant reduced slightly the inhibition effect of the venom even though the phrenic nerve diaphragm is a weak tissue in explaining the basis for neurochemical transmission. The use of this plant in traditional medicine is thus justified by the results of these tests in the treatment and management of snakebites.
Description
A THESIS SUBMITTED TO THE POSTGRADUATE SCHOOL, AHMADU BELLO UNIVERSITY, ZAR1A. IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE AWARD OF THE DEGREE OF MASTER OF SCIENCE, AHMADU BELLO UNIVERSITY, ZAR1A - NIGERIA. MAY, 2000.
Keywords
ISOLATION,, ARISTOLOCHIC,, ACIDS,, ARISTOLOCHIA ALBIDA,, (DUCH), BIOLOGICAL,, (FAMILY: ARISTOLOCHIACEAE)
Citation
Collections