~~ Along the bank of the river, on this side and that, will grow all kinds of trees used for food. Their leaves will not wither, and their fruit will not fail. They will bear fruit every month because their water flows from the sanctuary. Their fruit will be for food, and their leaves for healing. Ez 47:12 ~~
Physicians are notorious for the dismissive line: "There's no evidence for that natural therapy!" I heard this today from a physician (an orthopedic surgeon) about the use of olive leaf extract. Unfortunately, this statement most often is a reflection of their own lack of knowledge of the scientific literature and over-reliance on summary articles for their information.
In terms of olive leaf extract ... go to PubMed. Type "oleuropein" which is one the main active ingredients of olive leafs and click on "Clinical Trials". As of the time of writing of this article, there are 580 clinical trials involving this olive leaf extract.
Effects of the olive-derived polyphenol oleuropein on human health.
Int J Mol Sci. 2014 Oct 14;15(10):18508-24. doi: 10.3390/ijms151018508.
The use of the products derived from the olive tree on human health dates back centuries. In several civilizations, the olive tree had and still has a very strong cultural and religious symbolism. Notably, the official seal and emblem of the World Health Organization features the rod of Asclepius over a world map surrounded by olive tree branches, chosen as a symbol of peace and health. Recently, accumulating experimental, clinical and epidemiological data have provided support to the traditional beliefs of the beneficial effect provided by olive derivates. In particular, the polyphenols present in olive leaves, olives, virgin (unrefined) olive oil and olive mill waste are potent antioxidant and radical scavengers with anti-tumor and anti-inflammatory properties. Here, we review the positive impact on human health of oleuropein, the most prevalent polyphenol present in olives. In addition, we provide data collected in our laboratory on the role of oleuropein in counteracting lipid accumulation in a mouse model of non-alcoholic fatty liver disease.
Memorial Sloan Kettering Cancer Center - Integrative Medicine
Derived from the olive plant, both leaves and the extract have been used to treat infections, inflammation, diabetes, and hypertension. A major component of olive leaf, oleuropein, has antioxidant properties (1). Because of its hypoglycemic effects, the leaf extract can induce insulin release and improve peripheral uptake of glucose (2). Further, the leaf extracts demonstrated antimicrobial properties (3) (22), anti-HIV (4), and anticancer (13) (14) (15) (18) (19) properties. Animal studies showed antiarrhythmic, spasmolytic, diuretic (5), antihypertensive (6), analgesic (20) (21), and cholesterol-lowering (7) effects.
Small studies have shown effectiveness of olive leaf extract in reducing blood pressure in patients with hypertension (16) (17). The anticancer effects of olive leaf extract in humans are not known.
- Montilla MP, Agil A, Navarro MC, Jimenez MI, Garcia-Granados A, Parra A et al. Antioxidant activity of maslinic acid, a triterpene derivative obtained from Olea europaea. Planta Med 2003;69:472-4.
- Gonzalez M, Zarzuelo A, Gamez MJ, Utrilla MP, Jimenez J, Osuna I. Hypoglycemic activity of olive leaf. Planta Med 1992;58:513-5.
- Markin D, Duek L, Berdicevsky I. In vitro antimicrobial activity of olive leaves. Mycoses 2003;46:132-6.
- Lee-Huang S, Zhang L, Huang PL, Chang YT, Huang PL. Anti-HIV activity of olive leaf extract (OLE) and modulation of host cell gene expression by HIV-1 infection and OLE treatment. Biochem.Biophys.Res Commun. 2003;307:1029-37.
- PDR for Herbal Medicines. Montvale, NJ: Medical Economics, 1998.
- Somova LI, Shode FO, Ramnanan P, Nadar A. Antihypertensive, antiatherosclerotic and antioxidant activity of triterpenoids isolated from Olea europaea, subspecies africana leaves. Journal of Ethnopharmacology.Vol.84(2-3)()(pp 299-305), 2003. 2003;299-305.
- Pasquale RD, Monforte A, Trozzi A, Raccuia S, Tommasini S, Ragusa S. Effects of leaves and shoot of Olea europaea L. and oleuropien on experimental hypercholesterolemia in rat. Plantes Med Phytother 1991;25:134-40.
- Horn C. Olive leaf to fight infection. Natural Health 2000;30:40.
- Zarzuelo A, Duarte J, Jimenez J, Gonzalez M, Utrilla MP. Vasodilator effect of olive leaf. Planta Med 1991;57:417-9.
- Pieroni A, Heimler D, Pieters L, van Poel B, Vlietinck AJ. In vitro anti-complementary activity of flavonoids from olive (Olea europaea L.) leaves. Pharmazie 1996;51:765-8.
- Brinker F. Herb Contraindications And Drug Interactions. Sandy, OR: Eclectic Medical Publications, 2001.
- Liccardi G, D’Amato M, D’Amato G. Oleaceae pollinosis: a review. Int Arch.Allergy Immunol. 1996;111:210-7.
- Kimura Y, Sumiyoshi M. Olive leaf extract and its main component oleuropein prevent chronic ultraviolet B radiation-induced skin damage and carcinogenesis in hairless mice. J Nutr. 2009 Nov;139(11):2079-86.
- Anter J, Fernández-Bedmar Z, Villatoro-Pulido M, et al. A pilot study on the DNA-protective, cytotoxic, and apoptosis-inducing properties of olive-leaf extracts. Mutat Res. 2011 May 20. [Epub ahead of print].
- Mijatovic SA, Timotijevic GS, Miljkovic DM, et al. Multiple antimelanoma potential of dry olive leaf extract. Int J Cancer. 2011 Apr 15;128(8):1955-65.
- Perrinjaquet-Moccetti T, Busjahn A, Schmidlin C, et al. Food supplementation with an olive (Olea europaea L.) leaf extract reduces blood pressure in borderline hypertensive monozygotic twins. Phytother Res. 2008 Sep;22(9):1239-42.
- Susalit E, Agus N, Effendi I, et al. Olive (Olea europaea) leaf extract effective in patients with stage-1 hypertension: comparison with Captopril. Phytomedicine. 2011 Feb 15;18(4):251-8.
- Abaza L, Talorete TP, Yamada P, et al. Induction of growth inhibition and differentiation of human leukemia HL-60 cells by a Tunisian gerboui olive leaf extract. Biosci Biotechnol Biochem. 2007 May;71(5):1306-12.
- Anter J, Fernández-Bedmar Z, Villatoro-Pulido M, et a. A pilot study on the DNA-protective, cytotoxic, and apoptosis-inducing properties of olive-leaf extracts. Mutat Res. 2011 Aug 16;723(2):165-70.
- Kaeidi A, Esmaeili-Mahani S, Sheibani V, et al. Olive (Olea europaea L.) leaf extract attenuates early diabetic neuropathic pain through prevention of high glucose-induced apoptosis: in vitro and in vivo studies. J Ethnopharmacol. 2011 Jun 14;136(1):188-96.
- Esmaeili-Mahani S, Rezaeezadeh-Roukerd M, Esmaeilpour K, et al. Olive (Olea europaea L.) leaf extract elicits antinociceptive activity, potentiates morphine analgesia and suppresses morphine hyperalgesia in rats. J Ethnopharmacol. 2010 Oct 28;132(1):200-5.
- Pereira AP, Ferreira IC, Marcelino F, et al. Phenolic compounds and antimicrobial activity of olive (Olea europaea L. Cv. Cobrançosa) leaves. Molecules. 2007 May 26;12(5):1153-62.
Here is another set of references:
1. Aziz NH, Farag SE, Mousa LA, Abo-Zaid MA. Comparative antibacterial and antifungal effects of some phenolic compounds. Microbios. 1998;93:43–54.
2. Bisignano G, Tomaino A, Lo Cascio R, Crisafi G, Uccella N, Saija A. On the in-vitro antimicrobial activity of oleuropein and hydroxytyrosol. J Pharm Pharmacol. 1999;51:971–4.
3. Elliott GA, Buthala DA, DeYoung EN. Preliminary safety studies with calcium elenolate, an antiviral agent. Antimicrobial Agents Chemother. 1969;9:173–6.
4. Fleming HP, Walter WM Jr, Etchells JL. Antimicrobial properties of oleuropein and products of its hydrolysis from green olives. Appl Microbiol. 1973;26:777–82.
5. Heinze JE, Hale AH, Carl PL. Specificity of the antiviral agent calcium elenolate. Antimicrob Agents Chemother. 1975;8:421–5.
6. Hirschman SZ. Inactivation of DNA polymerases of murine leukaemia viruses by calcium elenolate. Nat New Biol. 1972;238:277–9.
7. Juven B, Henis Y, Jacoby B. Studies on the mechanism of the antimicrobial action of oleuropein. J Appl Bacteriol. 1972;35:559–67.
8. Lee-Huang S, Zhang L, Huang PL, Chang YT, Huang PL. Anti-HIV activity of olive leaf extract (OLE) and modulation of host cell gene expression by HIV-1 infection and OLE treatment. Biochem Biophys Res Commun. 2003;307:1029–37.
9. Renis HE. Inactivation of myxoviruses by calcium elenolate. Antimicrob Agents Chemother. 1975;8:194–9.
10. Renis HE. In vitro antiviral activity of calcium elenolate. Antimicrobial Agents Chemother. 1969;9:167–72.
11. Walter WM Jr, Fleming HP, Etchells JL. Preparation of antimicrobial compounds by hydrolysis of oleuropein from green olives. Appl Microbiol. 1973;26:773–6.
12. Cherif S, Rahal N, Haouala M, et al.A clinical trial of a titrated Olea extract in the treatment of essential arterial hypertension. J Pharm Belg. 1996;51:69–71.
13. Fehri B, Aiache JM, Memmi A, Korbi S, Yacoubi MT, Mrad S, Lamaison JL. Hypotension, hypoglycemia and hypouricemia recorded after repeated administration of aqueous leaf extract of Olea europaea L. J Pharm Belg. 1994;49:101–8.
14. Khayyal MT, el-Ghazaly MA, Abdallah DM, Nassar NN, Okpanyi SN, Kreuter MH. Blood pressure lowering effect of an olive leaf extract ( Olea europaea) in L-NAME induced hypertension in rats. Arzneimittelforschung. 2002;52:797–802.
15. Ribeiro Rde A, Fiuza de Melo MM, De Barros F, Gomes C, Trolin G. Acute antihypertensive effect in conscious rats produced by some medicinal plants used in the state of Sao Paulo. J Ethnopharmacol. 1986;15:261–9.
16. Zarzuelo A, Duarte J, Jimenez J, Gonzalez M, Utrilla MP. Vasodilator effect of olive leaf. Planta Med. 1991;57:417–9.
17. Fehri B, Aiache JM, Memmi A, et al. Hypotension, hypoglycemia and hypouricemia recorded after repeated administration of aqueous leaf extract of Olea europaea L [in French]. J Pharm Belg. 199449:101–8.
18. Gonzalez M, Zarzuelo A, Gamez MJ, Utrilla MP, Jimenez J, Osuna I. Hypoglycemic activity of olive leaf. PlantaMed. 1992;58:513–5.
19. Onderoglu S, Sozer S, Erbil KM, Ortac R, Lermioglu F. The evaluation of long-term effects of cinnamon bark and olive leaf on toxicity induced by streptozotocin administration to rats. J Pharm Pharmacol. 1999;51:1305–12.
20. Susalit E, Agus N, Effendi I, et al. Olive (Olea europaea) leaf extract effective in patients with stage-1 hypertension: comparison with Captopril. Phytomedicine. 2011;18(4):251-258.