The muscle relaxant properties of Portulaca oleracea are associated with high concentrations of potassium ions

S Habtemariam, A L Harvey, P G Waterman

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

The juice and aqueous extracts from the plant Portulaca oleracea have been used in West Africa for a variety of medical purposes, and extracts were previously shown to have muscle relaxant properties on isolated nerve-muscle preparations. We have attempted to characterise the components responsible for this activity. Ethanolic extracts caused an initial augmentation of twitch height in chick biventer cervicis preparations and then blockade which appeared to be mediated by an action directly on muscle fibres rather than on neuromuscular transmission. Solvent fractionation of the crude ethanolic extract followed by bioassay on the chick biventer cervicis preparation showed that muscle paralysis increased with increasing polarity: i.e. water fraction > butanol > ethyl acetate approximately equal to crude extracts. These fractions contained 28%, 18%, 12.2% and 9%, respectively, of potassium by weight of dried extract. Similar concentrations of KCl reproduced the same effect as the extracts on muscle activity, and when the most active fraction (water fraction) was desalted, it had no neuromuscular activity even at 10 times higher concentration than used previously. We conclude that the neuromuscular activity of extracts of Portulaca oleracea is caused by high concentrations of potassium ions.
LanguageEnglish
Pages195-200
Number of pages6
JournalJournal of Ethnopharmacology
Volume40
Issue number3
DOIs
Publication statusPublished - Dec 1993

Fingerprint

Portulaca
Potassium
Ions
Muscles
Complex Mixtures
Butanols
Western Africa
Water
Neuromuscular Junction
Plant Extracts
Paralysis
Biological Assay
Weights and Measures

Keywords

  • animals
  • calcium
  • chemical fractionation
  • chickens
  • drug dose-response relationship
  • african traditional medicine
  • muscle relaxation
  • muscles
  • plant extracts
  • medicinal plants
  • potassium

Cite this

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title = "The muscle relaxant properties of Portulaca oleracea are associated with high concentrations of potassium ions",
abstract = "The juice and aqueous extracts from the plant Portulaca oleracea have been used in West Africa for a variety of medical purposes, and extracts were previously shown to have muscle relaxant properties on isolated nerve-muscle preparations. We have attempted to characterise the components responsible for this activity. Ethanolic extracts caused an initial augmentation of twitch height in chick biventer cervicis preparations and then blockade which appeared to be mediated by an action directly on muscle fibres rather than on neuromuscular transmission. Solvent fractionation of the crude ethanolic extract followed by bioassay on the chick biventer cervicis preparation showed that muscle paralysis increased with increasing polarity: i.e. water fraction > butanol > ethyl acetate approximately equal to crude extracts. These fractions contained 28{\%}, 18{\%}, 12.2{\%} and 9{\%}, respectively, of potassium by weight of dried extract. Similar concentrations of KCl reproduced the same effect as the extracts on muscle activity, and when the most active fraction (water fraction) was desalted, it had no neuromuscular activity even at 10 times higher concentration than used previously. We conclude that the neuromuscular activity of extracts of Portulaca oleracea is caused by high concentrations of potassium ions.",
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author = "S Habtemariam and Harvey, {A L} and Waterman, {P G}",
year = "1993",
month = "12",
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The muscle relaxant properties of Portulaca oleracea are associated with high concentrations of potassium ions. / Habtemariam, S; Harvey, A L; Waterman, P G.

In: Journal of Ethnopharmacology, Vol. 40, No. 3, 12.1993, p. 195-200.

Research output: Contribution to journalArticle

TY - JOUR

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AU - Habtemariam, S

AU - Harvey, A L

AU - Waterman, P G

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N2 - The juice and aqueous extracts from the plant Portulaca oleracea have been used in West Africa for a variety of medical purposes, and extracts were previously shown to have muscle relaxant properties on isolated nerve-muscle preparations. We have attempted to characterise the components responsible for this activity. Ethanolic extracts caused an initial augmentation of twitch height in chick biventer cervicis preparations and then blockade which appeared to be mediated by an action directly on muscle fibres rather than on neuromuscular transmission. Solvent fractionation of the crude ethanolic extract followed by bioassay on the chick biventer cervicis preparation showed that muscle paralysis increased with increasing polarity: i.e. water fraction > butanol > ethyl acetate approximately equal to crude extracts. These fractions contained 28%, 18%, 12.2% and 9%, respectively, of potassium by weight of dried extract. Similar concentrations of KCl reproduced the same effect as the extracts on muscle activity, and when the most active fraction (water fraction) was desalted, it had no neuromuscular activity even at 10 times higher concentration than used previously. We conclude that the neuromuscular activity of extracts of Portulaca oleracea is caused by high concentrations of potassium ions.

AB - The juice and aqueous extracts from the plant Portulaca oleracea have been used in West Africa for a variety of medical purposes, and extracts were previously shown to have muscle relaxant properties on isolated nerve-muscle preparations. We have attempted to characterise the components responsible for this activity. Ethanolic extracts caused an initial augmentation of twitch height in chick biventer cervicis preparations and then blockade which appeared to be mediated by an action directly on muscle fibres rather than on neuromuscular transmission. Solvent fractionation of the crude ethanolic extract followed by bioassay on the chick biventer cervicis preparation showed that muscle paralysis increased with increasing polarity: i.e. water fraction > butanol > ethyl acetate approximately equal to crude extracts. These fractions contained 28%, 18%, 12.2% and 9%, respectively, of potassium by weight of dried extract. Similar concentrations of KCl reproduced the same effect as the extracts on muscle activity, and when the most active fraction (water fraction) was desalted, it had no neuromuscular activity even at 10 times higher concentration than used previously. We conclude that the neuromuscular activity of extracts of Portulaca oleracea is caused by high concentrations of potassium ions.

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