Effects of extracts of Portulaca oleracea on skeletal muscle in vitro.
Extracts of Portulaca oleracea inhibited twitch tension due to direct (MS) and indirect electrical stimulation via the phrenic nerve (NS) of the rat hemidiaphragm muscle. The rank order of potency was dialysable extract greater than or equal to methanol extract greater than diethylether extract, although all exhibited equal efficacy. The non-dialysable extract did not inhibit twitch tension due to MS or NS. The dialysable, methanol and diethylether extracts inhibited tetanus tension, and attenuated the area under the K+- and caffeine-induced contracture. The contracture induced by nicotinic agonists and K+ on the rectus abdominis muscle was significantly inhibited by these extracts.
Department of Pharmacology, University of Jos, Nigeria.
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F
Okwuasaba
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C
Ejike
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O
Parry
D000818:Animals; D001001:Anura; D002110:Caffeine / Q000494:pharmacology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009132:Muscles / Q000187:drug effects*; D010791:Phrenic Nerve / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012132:Respiratory Muscles / Q000187:drug effects; D012997:Solvents
D010936:Plant Extracts; D012997:Solvents; D002110:Caffeine; D011188:Potassium