Olive Leaf extract has anti-viral, anti-bacterial and anti-fungal effects. Oleuropein and hydroxytyrosol are considered as main polyphenolic compounds in olive leaf. Oleuropein is converted into elenolic acid in the body which may prevent  bacteria and viruses  from replicating. Olive leaf extract has been shown to be effective against herpes, flu and colds, bacterial infections, vaginal yeast infections, malaria, and hepatitis. In 1969 scientists showed olive leaf constituents are strong in vitro inhibitors of numerous viruses, including parainfluenza, pseudorabies, herpes, and some forms of polio. Almost every virus tested, including several cold and influenza viruses, was inactivated when exposed to a constituent of olive leaf extracts (OLE), calcium elenolate. Olive leaf extract (Oleuropein) has been patented in the United States for antiviral activity against viral diseases, including hepatitis and herpes.

Antiviral and Antibacterial Activity

First researches by the pharmaceutical company Upjohn found extracts from olive leaves to be effective in treating infection caused by a large number of viruses as well as bacteria and parasitic protozoans. Oleuropein is able to stop viruses in their tracks, by neutralizing the enzymes that are important for the virus to replicate itself and spread. The major constituent of olive leaf is the phytochemical oleuropein, which is broken down to elenolic acid, has a potent anti-bacterial activity, and the ability to interfere with critical amino acid production essential for viruses. Investigators have showed olive leaf  constituents, especially elenolic acid and its salt, calcium elenolate, are effective in vitro against many viruses investigated, including parainfluenza, pseudorabies, Herpes simplex, Varicella zoster, coxsackie virus, myxoviruses, rhinoviruses, encephalomyocarditis, 2 strains of  leukemia virus and some forms of polio.

Olive leaf extract interacts with the protein in cold and flu virus particles to halt infection, according to a research reported in “Alternative Medicine Review“. In lab experiments, olive leaf extract has shown virucidal effect like herpes simplex 1 and 2 and herpes zoster. Research conducted in 1969, proved that a compound of oleuropein from the olive leaf could kill all viruses, including the herpes, against which it was investigated. In 1992 French scientists found that all of the herpes viruses were inhibited or killed by extracts from olive leaf.

Lab studies have a shown that olive leaf extracts can influence proteins that prevent cell death that may prove effective against the HIV (Human Immunodeficiency Virus).  Anti-HIV effects of  leaf extract include up-regulation of the expression of apoptosis inhibitor proteins as well as protein kinase signaling molecules. Cell-to-cell transmission of HIV was inhibited in a  dose-dependent manner with EC50s of 0.2 µg/ml, and HIV replication was inhibited in an in vitro experiment. The olive leaf extract indicates antiviral effect against viral haemorrhagic septicaemia rhabdovirus (VHSV). A study in reported 2003 edition of  Biochemical and Biophysical Research communications concluded that oleuropein helped the prevent the adherence of the hemorrhagic septicaemia virus to normal healthy cells, and reduce the infectivity of the virus by up to 30%.  Oleuropein, inhibited the in vitro infectivity of the viral haemorrhagic septicaemia virus. Incubation of virus with oleuropein before infection reduced the viral infectivity to 10 and 30%, respectively.

Olive leaf extracts has been found to kill a number of microorganisms including, yeasts, bacteria and fungi. Olive leaf extract (oleuropein) has been shown to have strong antimicrobial effect against both Gram Negative and Gram-positive bacteria as well as mycoplasma. Research reported by the “American Society for Microbiology“, found that OLE (olive leaf extract) inhibited the growth of every virus, bacteria, fungi and protozoa it was tested against.

An aqueous extract of olive leaf was bactericidal against Klebsiella pneumoniae, Pseudomonas aeruginosa, E. coli, and Staphylococcus aureus. Researches in Israel found the extract efficacious against Streptococcus by damaging the cell membrane of the bacteria, and therefore allowing intercellular substances like potassium, phosphorus and glutamate toleak out, disabling the bacteria. A study reported in the Apr 2003 edition of  “Mycoses” explored the effects of olive leaf extract against strains of various bacteria and fungi in vitro. Within 3 hours, olive leaf extracts killed nearly all bacteria, and within 24 hours, it completely destroyed candida, the yeast-like fungus responsible for vaginal yeast infections. New researches demonstrated the antimicrobial activity of olive leaf extracts against Campylobacter jejuni, H. pylori and MRSA (methicillin-resistant Staphylococcus aureus). According to a study reported in in May 2009  in the International Journal of Antimicrobial Agents OLE (olive leaf extract) may reduce levels of the bacteria H. pylori and Campylobacter jejuni in the digestive tract.

Olive leaves come from the olive tree (Olea europae), which is native to the Mediterranean. Oleuropein is a non-toxic secoiridoid found in the leaves and fruits of olive. One of these bioactive compounds is the secoiridoid oleuropein, which can constitute up to 6-9% of dry matter in the leaves.

Olive Leaf Hypertension and Heart Health Effects

Olive leaf extracts and their oleuropein constituents are best known for their blood pressure-lowering properties. Hypertension thought to be responsible for 50% of all heart attacks and strokes. Oleuropein, favorably modulates arterial resistance or stiffness, high blood pressure’s core mechanism. Research found that olive leaf extract causes relaxation of the arterial walls and reduces high blood pressure. It is oleuropein that is largely responsible for the useful effect on high blood pressure. The oleuropeoside, which was isolated from olive leaf during the twenties, caused important hypotension in rats, due to prolonged peripheral vasodilatation of  isolated aorta. Olive leaf water extract proposed property as an inhibitor of the ACE (angiotensin converting enzyme) has been showed in vitro.

Scientists designed a study to compare its effects to Captopril, a blood pressure medication known as an ACE-inhibitor. A study reported in the Feb 2011 edition of  Phytomedicine sought to compare the effects of  OLE (olive leaf extract) against captopril. For 8 weeks, subjects either took the medication or 500 mg of  olive leaf extracts twice a day. All subjects experienced important drops in both systolic and diastolic blood pressure. Although they utilize different mechanisms of action, both olive leaf extracts (oleuropein) and captopril function inside the vasculature to lessen the tension in the walls of blood vessels and promote widening of the vessels, eventually lowering blood pressure. This study demonstrate olive leaf extract may be as effective as captopril for treating Stage 1 high blood pressure.

Taking 1000mg of a specific olive leaf extract (EFLA®943) can lower blood pressure in people with mild hypertension. To test this in humans, scientists from Germany and Switzerland carried a pilot study with 20 identical (monozygotic) twin pairs who had an increased blood pressure. Identical twins were used to help keep the data consistent, because genetic differences can make people respond differently to the same therapies. Participants were either given placebo capsules or capsules containing doses of 500mg or 1000mg of leaf extract EFLA®943. At the study’s conclusion, those who took the highest daily dosage of  EFLA®943 (1000 mg) received the highest benefits. At the end of the 8-week study, the group that took 1000 mg per day had dropped their systolic blood pressure by an average of 11 points.

Preliminary research findings demonstrate that compounds in olive leaf may help by assisting normal platelet aggregation, which may in turn play a role in helping to prevent the formation of clots. Olive leaf extracts appears to lower levels of deleterious blood fats, called triglycerides, known to raise the risk of  heart attacks and strokes. In a study, participants who took the olive leaf pill for 8 weeks saw a significant reduction in blood pressure readings and triglyceride levels.  Oleuropein shows anti-atherogenic activity. In 2003, researchers reported that oleuropein reduces monocytoid cell adhesion to stimulated endothelium as well as vascular cell adhesion molecule-1 (VCAM-1) mRNA and protein. Compounds found in olive leaves have been shown to help directly avoid the formation of arterial plaques in 2 ways. 1) They reduces the production and activity of a series of adhesion molecules. 2) they reduce platelet aggregation by multiple mechanisms, which reduces the risk that tiny clots will form at sites of plaque to produce a stroke or heart attack.

Oleuropein is the most important phenolic compound in the fruit of olive tree. In-vitro studies show that oleuropein induces apoptosis in numerous cancers, including leukemia, breast cancer and colon cancer, and inhibits proliferation and metastasis. Scientists demonstrated that oleuropein aglycone is the most strong phenolic compound in decreasing breast cancer cell viability. Although oleuropein has shown strong anticancer activity the underlying action mechanism remains largely unknown.

Olive Leaf Extract and Cancer

Oleuropein, is a potent antioxidant and anti-angiogenic agent. Oleuropein inhibit the proliferation and migration of advanced-grade tumor cell lines in a dose-responsive manner. Olive-leaf extracts were found to inhibit cell proliferation of human breast adenocarcinoma (MCF-7), and human urinary bladder carcinoma. Oleuropein exhibits specific cytotoxicity against breast cancer cells, with higher effect on the basal-like MDA-MB-231 cells than on the luminal MCF-7 cells. Latterly, researchers reported that 200 lg/mL of oleuropein remarkably decreases  the viability of MCF-7 cells and reduces  the number of  MCF-7 cells by inhibiting the rate of cell proliferation and inducing cell apoptosis.

When oleuropein was administered orally to mice that had developed tumors, it regressed the tumors in 9 to 12 days. In an experiment, oleuropein irreversibly rounded cancer cells, preventing their replication, motility, and invasiveness; these effects were reversible in normal cells. When administered orally to mice that developed spontaneous tumors, oleuropein completely regressed tumors in 9-12 days. This experiment; reported by Biochemical and Biophysical Research Communications. A version of oleanolic acid, found in olive leaf, substantially reduced the growth of liver tumors in lab animals, according to scientists from “Johns Hopkins University and Dartmouth Medical School“. In their study, the use of small amounts of the  OLE (olive leaf extract), a triterpenoid analog called CDDO-Im, yielded a greater than 85% diminution in the volume of liver tumors.“Even at low-doses, CDDO-Im induces cell protecting genes, inhibits DNA damage by aflatoxin and dramatically blocks development of liver tumors,” according to Melinda Yates lead author of the study.

Prostatitis is inflammation of the prostate. Usually causes painful or difficult urination. Quercetin has anti-inflammatory and antioxidant properties and may decrease symptoms of chronic prostatitis. It is occasionally coupled with papain and bromelain, have anti-inflammatory effect, but also help to improve the absorption of quercetin.

Quercetin Prostatitis Benefits

Quercetin is a polyphenolic flavonoid that may benefit men with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) through antioxidant and anti inflammatory  mechanisms. In vitro and animal studies have shown quercetin to improve symptoms of chronic nonbacterial prostatitis in mice. According to “Mount Sinai Hospital“, quercetin is an effective cure for chronic prostatitis. The studies shows symptoms begin to disappear after a few months of daily use. Current Urology Reports in July 2007 reported an article pointed out that the new method of therapy of prostatitis have some findings of efficacy include compounds such as quercetin phytotherapeutic.

A study showed that 500 mg of quercetin twice daily for at least 2 weeks significantly improved symptoms in 59% of men with chronic prostatitis. The results of an clinical trial reported in the Dec 1999 edition of  “Urology” shows that quercetin helps to reduce chronic pelvic pain in men with chronic prostatitis. In this study, investigated the effects of 500 mg of quercetin, taken twice daily, in thirty men with chronic prostatitis. After the one-month, study was over, 67% of the men taking the quercetin reported a measurable improvement in symptom. Papain and bromelain promote absorption of quercetin and have anti-inflammatory effects as well. Investigators at the “Institute for Male Urology” gave men with prostatitis 1000 mg of quercetin daily for 1 month. Two-thirds of the men had at least a 25% diminution in symptoms. When the  researchers added papain and bromelain to enhance quercetin absorption, 82% of the patients got better.

Quercetin (3,4,5,7-pentahydroxylflavone) belongs to a class of water-soluble plant coloring substances called bioflavonoids. It is found in many often-consumed foods, including especially red onions, apple, tea, berries, and brassica vegetables, as well as many seeds, flowers, barks, and leaves. It is also found in medicinal botanicals, including Hypericum perforatum, Ginkgo biloba, Sambucus canadensis, and many others, and is usually a component of the therapeutic activity of the plant.

Quercetin Antiviral Activity

Studies indicate that quercetin may improve immune function and inhibit viral replication. Quercetin’s antiviral effect may be related to its ability to bind viral protein coat and to interfere with viral nucleic acid synthesis. Italian investigators demonstrated that they could use a quercetin-rich extract to up-regulate the antiviral immune response in cells infected with herpes viruses. Quercetin may exert antiviral effect against different types of viruses including herpes simplex virus type, polio virus type 1, reverse transcriptase of  HIV and other retroviruses. Quercetin exerts antiviral activity against reverse transcriptase of  HIV and other retroviruses, and was shown to lessen the infectivity and cellular replication of  herpes simplex virus type 1, polio-virus type, parainfluenza virus type 3, and RSV (respiratory syncytial virus). In an study, quercetin inhibited hepatitis C virus replication. Another study demonstrated that quercetin and quercetrin both have an inhibitory activity on the HIV reverse transcriptase and on casein kinase 2, an enzyme responsible for the transcription of several hiv genes. Quercetin has a triple action to fight viruses; 1- Reduces the ability of a virus to infect cells. 2- Inhibiting the ability of infected cells to replicate and reproduce. 3-Reducing resistance of infected cells to medication treatment.

Influenza viruses are major pathogens that cause respiratory infections in humans and animals. Findings from cell culture experiments provide potent evidence that quercetin may be efficacious as an anti-infective agent, reducing the  infectivity and replication of a variety of respiratory viruses.A new research demonstrated that quercetin and isoquercetin (a glucoside form of quercetin), substantially reduced the replication of influenza viruses in vitro and in vivo. In one study, quercetin inhibited influenza A virus replication in the lab more effectively than the anti-flu medication Tamiflu.

Quercetin, has been reported to inhibit infectivity and replication of a broad spectrum of viruses and may offset the increase in susceptibility to infection associated with stressful exercise. A study demonstrated that quercetin could decrease flu when animals were intentionally exposed. In this study mice were exposed to the flu virus under various conditions, including increased stress from exercise. The mice given quercetin offset the unfavorable effects of stress and demonstrated much less susceptibility to the flu. This study builds on an earlier human study where quercetin reduced ailment and maintained mental performance in physically stressed people. Trained cyclists consumed 1000 mg per day of quercetin (also vitamin C and niacin) for 5 weeks. After 3 weeks, subjects rode a bicycle three hours per day for 3 days to the point of exhaustion. After the exercise period,  45% of the placebo-consuming cyclists became ill, while just 5% of the quercetin group suffered any illness.

In another animal study found that quercetin inhibits both influenza A and B viruses, and viruses were not able to develop resistance to quercetin cure. When quercetin was used with anti-viral medications the anti-viral activity was even stronger, and the quercetin prevented the development of resistance to the medications that otherwise occurs. In studies with flu-infected mice, quercetin’s antioxidant effects were shown to play a role. Quercetin doses of 1-mg/day substantially decreased production of harmful superoxide free radicals by a type of white blood cell in the lung.

Rhinovirus, which is responsible for the majority of common colds, moreover causes exacerbations in people with asthma and chronic obstructive pulmonary disease. According to a research presented at the American Thoracic Society 2010 International Conference held, quercetin could be a cure for rhinovirus (RV)-caused infections. Hepatitis C is an important cause of  liver failure and liver cancers. In Aug 2009 cell study demonstrated that quercetin interfered with the gene signals that enable hepatitis C virus production. The researchers showed  that the Quercetin inhibits hepatitis C viral production in tissue culture, at least partially through its inhibition of heat shock protein expression. Therapy with quercetin reduced the infectious particle production to nontoxic concentrations of HCV.