Blood pressure lowering effect of an olive leaf extract (Olea europaea) in L-NAME induced hypertension in rats.
A specially prepared olive leaf extract (EFLA 943) has been tested for its blood pressure lowering activity in rats rendered hypertensive by daily oral doses of L-NAME (NG-nitro-L-arginine methyl ester, 50 mg/kg) for at least 4 weeks. Oral administration of the extract at different dose levels at the same time as L-NAME for a period of 8 weeks showed a dose dependent prophylactic effect against the rise in blood pressure induced by L-NAME, best effects being induced by a dose of 100 mg/kg of the extract. In rats previously rendered hypertensive by L-NAME for 6 weeks and then treated with that dose of the extract for a further 6 weeks without discontinuation of L-NAME, normalisation of the blood pressure was observed. The findings confirm previous reports on the hypotensive effects of olive leaf. The special extract, EFLA 943, was shown to give consistent results with little individual variability. The antihypertensive effect of the extract may be related to a variety of factors involving reversal of vascular changes involved in the L-NAME induced hypertension.
Khayyal
Mohamed T
MT
Department of Pharmacology, Faculty of Pharmacy, Cairo University, Cairo, Egypt. mtkhayyal@hotmail.com
el-Ghazaly
Mona A
MA
Abdallah
Dalal M
DM
Nassar
Noha N
NN
Okpanyi
Samuel N
SN
Kreuter
Matthias-Heinrich
MH
D000818:Animals; D000959:Antihypertensive Agents / Q000737:chemistry* / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D004791:Enzyme Inhibitors; D006973:Hypertension / Q000139:chemically induced* / Q000188:drug therapy* / Q000517:prevention & control; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D052250:Nitric Oxide Synthase Type III; D031658:Olea / Q000737:chemistry*; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar
D000959:Antihypertensive Agents; D004791:Enzyme Inhibitors; D010936:Plant Extracts; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D019331:NG-Nitroarginine Methyl Ester