The study, published in Phytomedicine, found an olive leaf extract (EFLA 943 from Frutarom, Switzerland) to be as effective in treating high-blood pressure as a common medication blood pressure medication (Captopril/Dexacap from Dexa Medica).
The researchers also found that unlike the drug, olive leaf extract also significantly reduced plasma triglyceride levels.
“Olive leaf extract, at the dosage regimen of 500 mg twice daily, was similarly effective in lowering systolic and diastolic blood pressures in subjects with stage-1 hypertension as Captopril, given at its effective dose of 12.5–25 mg twice daily,” said the authors, led by Prof Endang Susalit, from the University of Indonesia.
The authors declared that their research was supported by PT Dexa Medica and Frutarom Switzerland Ltd.
The authors said that hypertension affects approximately 50 million individuals in the United States, and approximately 1 billion individuals worldwide.
They noted that it is possible to lower blood pressure with several classes of currently available anti-hypertensive drugs, including angiotensin converting enzyme inhibitors (such as Captopril), angitoensin-receptor blockers, and calcium channel blockers.
“Nevertheless, most patients with hypertension will require two or more anti-hypertensive medications to achieve their blood pressure goals … [which] also mean the increment of risks of adverse drug reaction and medication costs,” said the authors.
Susalit and colleagues noted that one alternative may be the use of herbal medicines. They explained that the leaves of the olive tree (Olea europaea L.) “have been used since ancient times to combat high blood pressure, atherosclerosis and diabetes and for other medicinal purposes.”
Olive leaf contains active substances including oleuropein, oleacein and oleanolic acid. They said that the olive lead extract EFLA 943 (from Frutarom) has been previously studied for its safety and anti-hypertensive effects.
At a dose of 1000 mg daily, the extract “was clearly superior to recommendations for life-style changes in reducing mean blood pressure levels from baseline,” said the authors.
“Based on the positive results observed in the pre-clinical and human studies, the current clinical trial was designed to primarily confirm the anti-hypertensive effect of the Olive leaf extract EFLA 943 in comparison with Captopril as one of the standard therapy for hypertension in patients with stage-1 hypertension,” said the authors.
The authors conducted a double-blind, randomized, parallel and active-controlled clinical study to evaluate the anti-hypertensive effect as well as the tolerability of olive leaf extract in comparison with Captopril in patients with stage-1 hypertension.
Olive leaf extract (EFLA 943) was given orally at the dose of 500 mg twice daily for eight weeks, whilst Captopril was given at the dosage regimen of 12.5 mg twice daily at start.
Evaluation of blood pressure was performed every week during the trial, whilst lipid profiles were recorded at four week intervals.
Susalit and his co-workers reported that after eight weeks of treatment, both treatment groups experienced significant reductions in systolic and diastolic blood pressure from baseline. They added that such reductions were not significantly different between groups.
However, they reported that a significant reduction of triglyceride level was observed for the group receiving olive leaf extract, but not in Captopril group.
The researchers said that the mechanism of action by which the olive leaf extract exerts its anti-hypertensive effects remains unknown “and is continuously being studied.”
They speculated that the anti-hypertensive activity “lies probably in its content of oleuropein acting synergistically with other active substances to exert both ACE inhibitory and calcium channel blocking activities.”
The authors concluded that “the anti-hypertensive activity of the extract was comparable to that of Captopril, given at its effective dose of 12.5–25 mg twice daily.”
“Additionally, the beneficial effects of the extract on lipid profile, particularly in reducing plasma LDL-, total-cholesterol and triglyceride levels were strongly indicated by this trial,” said the researchers.
Volume 18, Issue 4, Pages 251-258, doi: 10.1016/j.phymed.2010.08.016
“Olive (Olea europaea) leaf extract effective in patients with stage-1 hypertension: Comparison with Captopril"
Authors: E. Susalit, N. Agus, I. Effendi, R.R. Tjandrawinata, D. Nofiarny, et al