Research
Oleuropein
33 peer-reviewed studies curated from PubMed and Semantic Scholar.
Studies
Sorted by quality and recency
Metabolic and inflammatory effects of oleuropein and olive leaf extract: a systematic review and meta-analysis.
Systematic review and meta-analysis of 11 RCTs evaluating the effects of olive leaf extract and oleuropein on glucose metabolism, lipid profile, and inflammatory markers. The analysis found no statistically or clinically significant effects on glycemic or lipid outcomes, and evidence regarding inflammatory markers was scarce and of low certainty.
Efficacy of olive leaf extracts in controlling blood pressure in hypertensive patients: a double-blind randomized clinical trial.
This multicenter randomized, double-blind, placebo-controlled trial assessed the effects of olive leaf extract (OLE) on blood pressure control in 621 hypertensive patients. OLE significantly reduced 24-hour systolic blood pressure, blood pressure load, and diastolic blood pressure variability, and improved lipid profile, systemic inflammation, and body weight without significant adverse events.
Olive leaf extract effect on cardiometabolic risk factors: a systematic review and meta-analysis of randomized clinical trials.
Systematic review and meta-analysis of 12 RCTs involving 703 adults assessing the impact of olive leaf extract on cardiometabolic risk factors. Positive correlations were found with glucose metabolism, blood pressure, lipid profile, and inflammatory markers. Fasting glycemia showed significant results favoring the control group.
Effects of a combination of olive leaf extract and potassium on blood pressure in participants with mild to moderate hypertension: A double blind, randomized, placebo-controlled trial.
RCT of 70 adults with mild to moderate hypertension comparing an olive leaf extract and potassium supplement to placebo for 12 weeks. The supplement group showed significant reductions in morning systolic BP, total cholesterol, LDL-cholesterol, triglycerides, and oxidized LDL, with improved insulin sensitivity. No significant changes in fasting glucose, HbA1c, or hs-CRP were observed.
Phenolic-rich extract of olive leaf with a hypocaloric diet alleviates oxidative stress in obese females: a randomized double-blind placebo controlled trial.
This randomized controlled trial investigated the effect of olive leaf extract (OLE) added to a calorie-restricted diet on oxidative stress markers in 70 obese women. The OLE group showed a significant reduction in serum malondialdehyde levels compared to the placebo group, indicating improved oxidative stress.
Effects of olive leaf extract supplementation on systemic markers of tissue aging and remodeling in postmenopausal women: a randomized controlled trial with exploratory skin outcomes.
This randomized, double-blind, placebo-controlled trial studied the effects of 12 weeks of olive leaf extract (OLE) supplementation on systemic markers of tissue aging and remodeling in 65 postmenopausal women. While no statistically significant effects on systemic markers were observed, exploratory skin analyses showed a reduction in pore number and surface skewness in the OLE group, suggesting potential localized effects on skin structure.
Beneficial Effect of Olive Leaf Extract as an Adjunct to Standard Antifungal Therapy in Treating-Related Oral Diseases.
RCT evaluating olive leaf extract (OLE) as an adjunct to standard antifungal therapy in 59 subjects with oral diseases. OLE combined with nystatin increased salivation rate, and with miconazole, decreased tongue burning. No significant reduction in colony number or salivary IL-17A levels was observed.
Olive Leaf Extract Supplementation Improves Postmenopausal Symptoms: A Randomized, Double-Blind, Placebo-Controlled Parallel Study on Postmenopausal Women.
RCT of 60 postmenopausal women comparing 250 mg/day olive leaf extract to placebo for 12 weeks. Olive leaf extract improved postmenopausal symptoms, bone mineral density in the right arm, and decreased triglyceride concentrations and TG/HDL-C ratio.
Olive Leaves as a Potential Phytotherapy in the Treatment of COVID-19 Disease; A Mini-Review.
This mini-review explores the potential of olive leaves as a co-therapy supplement for COVID-19 treatment. Olive leaves contain phenolic compounds and triterpenoids with reported anti-SARS-CoV-2, anti-inflammatory, analgesic, antipyretic, immunomodulatory, and antithrombotic activities, suggesting their potential benefit in managing COVID-19 symptoms.
Olive Leaf Extract Supplementation Combined with Calorie-Restricted Diet on Reducing Body Weight and Fat Mass in Obese Women: Result of a Randomized Control Trial
An 8-week randomized, placebo-controlled trial evaluated the effects of olive leaf extract (OLE) supplementation combined with a calorie-restricted diet on obese women. The OLE group showed significant decreases in BMI, fat mass, and body weight compared to the placebo group. Improvements were also observed in glycemic indices, lipid profile, and adipokine levels.
The efficacy of olive leaf extract on healing herpes simplex virus labialis: A randomized double-blind study.
This randomized double-blind clinical trial compared the effects of 2% olive leaf extract (OLE) cream and 5% acyclovir cream on HSV-1 in 66 patients. Both treatments were effective, but the OLE group experienced less bleeding, itching, pain, irritation, and color change, and had a shorter treatment course compared to the acyclovir group.
Effect of olive leaf extract on glucose levels in diabetes-induced rats: A systematic review and meta-analysis.
Systematic review and meta-analysis of randomized controlled trials on olive leaf extract in diabetic rats. OLE significantly increased insulin levels and reduced blood glucose, total cholesterol, and triglyceride levels, indicating benefits for glycemic control and lipid profile.
Oleuropein Supplementation Increases Resting Skeletal Muscle Fractional Pyruvate Dehydrogenase Activity but Does Not Influence Whole-Body Metabolism: A Randomized, Double-Blind, and Placebo-Controlled Trial in Healthy, Older Males.
RCT in 40 healthy older males examining the effects of oleuropein supplementation on muscle energy metabolism and whole-body metabolism. Chronic supplementation increased skeletal muscle fractional PDH activity but did not affect mitochondrial respiration, muscle strength, fatigue resistance, or whole-body substrate metabolism.
Efficacy and safety of olive leaf extract (Olea europaea L.) for glycaemic control in adults with type 2 diabetes mellitus (ESOLED): A pilot randomised controlled trial.
The ESOLED trial is a pilot, randomised, placebo-controlled trial assessing the efficacy and safety of olive leaf extract (OLE) for glycaemic control in adults with type 2 diabetes. Thirty-one participants were randomized to receive OLE or placebo for 24 weeks. The trial found no statistically significant differences in HbA1c, diabetes-related distress, or quality of life between groups, though OLE showed greater improvements in insulin sensitivity. OLE was well-tolerated with no severe adverse events.
Evaluating the effectiveness of topical olive leaf extract emulgel in managing recurrent herpes labialis: a randomized controlled clinical study.
This randomized, triple-blinded study compared the effectiveness of olive leaf extract (OLE) emulgel to acyclovir cream in managing recurrent herpes labialis (RHL) lesions in 40 patients. While there were no significant differences in pain intensity between the two groups, OLE showed a statistically significant advantage in the timing of lesion crust fall-off.
Effect of chitosan-oleuropein nanoparticles on dentin collagen cross-linking.
The study developed chitosan oleuropein nanoparticles (CS-OL-NPs) and tested their effect on dentin collagen cross-linking. CS-OL-NPs enhanced the dentin's mechanical properties and resistance to enzymatic degradation, showing good biocompatibility and potential for clinical application.
Effects of Olive Leaf Extract on Metabolic Response, Liver and Kidney Functions and Inflammatory Biomarkers in Hypertensive Patients.
RCT of 60 hypertensive patients evaluating the effects of olive leaf extract (OLE) on metabolic response, liver and kidney functions, and inflammatory biomarkers. OLE significantly decreased inflammatory biomarkers interleukin-6, interleukin-8, and tumor necrosis factor alpha compared to placebo, but had no significant effect on glucose metabolism or liver and kidney function parameters.
Olive leaf tea is beneficial for lipid metabolism in adults with prediabetes: an exploratory randomized controlled trial.
This exploratory randomized controlled trial studied the effects of olive leaf tea (OLT) on lipid metabolism in adults with prediabetes. The study found that OLT significantly decreased serum levels of triglycerides and low-density lipoprotein cholesterol compared to low-concentration OLT, although effects on abdominal obesity and glucose metabolism were unclear.
Nutritional implications of olives and sugar: attenuation of post-prandial glucose spikes in healthy volunteers by inhibition of sucrose hydrolysis and glucose transport by oleuropein.
The study explored the potential of oleuropein, prepared from olive leaves, to inhibit digestive enzymes and lower glucose uptake. Seven crossover, controlled, randomized intervention studies on healthy volunteers assessed the effect of oleuropein on post-prandial blood glucose. Oleuropein inhibited intestinal maltase and sucrase, and glucose transport in vitro, but only attenuated post-prandial blood glucose after consumption of 25g sucrose, not with higher doses or with glucose.
Impact of phenolic-rich olive leaf extract on blood pressure, plasma lipids and inflammatory markers: a randomised controlled trial.
RCT of 60 pre-hypertensive males examining the effects of phenolic-rich olive leaf extract (OLE) on blood pressure, plasma lipids, and inflammatory markers. OLE intake significantly lowered systolic and diastolic blood pressure, plasma total cholesterol, LDL cholesterol, triglycerides, and interleukin-8 levels compared to control.
Effects of dietary oleuropein supplementation on growth performance, serum lipid concentrations and lipid oxidation of Japanese quails.
In vivo experiment on Japanese quails to assess dietary supplementation with oleuropein and/or α-tocopheryl acetate. Oleuropein at 150 or 200 mg/kg delayed lipid oxidation in quail meat and increased polyunsaturated and omega-3 fatty acid contents in thigh meat compared to control and vitamin E diets.
Efficacy of oleuropein against UVB irradiation: preliminary evaluation.
The study evaluated the cosmetic properties of oleuropein against UVB-induced erythema in healthy volunteers. Oleuropein formulations showed lenitive efficacy by reducing erythema, transepidermal water loss, and blood flow by 22%, 35%, and 30% respectively, suggesting its potential use in cosmetics to repair UV damage.
The Effect of Olive Leaf Extract on Upper Respiratory Illness in High School Athletes: A Randomised Control Trial.
RCT of 32 high school athletes comparing olive leaf extract (OLE) to placebo over nine weeks. OLE did not significantly reduce upper respiratory illness incidence but decreased the duration of sick days by 28%, potentially aiding return to play.
Indirect Chronic Effects of an Oleuropein-Rich Olive Leaf Extract on Sucrase-Isomaltase In Vitro and In Vivo.
The study investigated the chronic effects of oleuropein-rich olive leaf extract (OLE) on sucrase-isomaltase expression in vitro and in vivo. In a cell model, OLE lowered SI mRNA, protein, and activity, but in a human pilot study with 11 women, OLE did not change post-prandial blood glucose levels compared to placebo.
Oleuropein, a component of extra virgin olive oil, lowers postprandial glycaemia in healthy subjects.
RCT with 20 healthy subjects using a cross-over design to test 20mg oleuropein versus placebo before lunch. Oleuropein significantly lowered postprandial blood glucose and DPP-4 activity, and increased insulin and glucagon-like peptide-1 levels compared to placebo. It also reduced oxidative stress markers, suggesting oleuropein improves postprandial glycaemic profile by reducing Nox2-derived oxidative stress.
Human Intervention Study to Assess the Effects of Supplementation with Olive Leaf Extract on Peripheral Blood Mononuclear Cell Gene Expression.
Double-blinded placebo-controlled trial assessing the effects of olive leaf extract on gene expression in peripheral blood mononuclear cells from 29 healthy male volunteers. OLE consumption resulted in downregulation of genes involved in inflammatory pathways, lipid metabolism, and cancer, suggesting potential health benefits.
Secoiridoids delivered as olive leaf extract induce acute improvements in human vascular function and reduction of an inflammatory cytokine: a randomised, double-blind, placebo-controlled, cross-over trial.
A randomised, double-blind, placebo-controlled, cross-over trial with 18 healthy volunteers investigated the effects of olive leaf extract (OLE) on vascular function and inflammation. OLE consumption significantly reduced DVP-stiffness index and IL-8 production compared to control, with phenolic metabolites detected in urine.
Olive (Olea europaea L.) leaf polyphenols improve insulin sensitivity in middle-aged overweight men: a randomized, placebo-controlled, crossover trial.
Randomized, placebo-controlled, crossover trial in 46 middle-aged overweight men assessing the effects of olive leaf polyphenols on insulin sensitivity. Supplementation with olive leaf extract improved insulin sensitivity by 15% and pancreatic β-cell responsiveness by 28% compared to placebo.
Human absorption and metabolism of oleuropein and hydroxytyrosol ingested as olive (Olea europaea L.) leaf extract.
RCT studying the bioavailability and metabolism of oleuropein and hydroxytyrosol from olive leaf extract (OLE) in nine volunteers. The study found that liquid OLE resulted in higher peak oleuropein concentrations in plasma compared to capsules, and males showed greater bioavailability of conjugated hydroxytyrosol.
Analysis of Antioxidant and Antiviral Effects of Olive (Olea europaea L.) Leaf Extracts and Pure Compound Using Cancer Cell Model
The study assessed the antioxidant and antiviral effects of olive leaf extracts and oleuropein using in vitro assays and human HeLa cells. Olive leaf extracts protected cells from lipid peroxidation and increased antioxidant enzyme levels. Oleuropein inhibited HSV-1 replication and stimulated phosphorylation of certain proteins, suggesting potential health benefits.
Stability of oleuropein in the human proximal gut.
The study assessed the intralumenal stability of oleuropein in human gastric and small intestinal contents under fasted and fed state conditions. Oleuropein degraded in the fasted state but was stable in the fed state, with a zero-order degradation half-life of at least 12 hours in the fed small intestine.
Oleuropein-enriched chocolate by extra virgin olive oil blunts hyperglycaemia in diabetic patients: Results from a one-time 2-hour post-prandial cross over study.
Cross-over study evaluating the effects of oleuropein-enriched chocolate on glycemia and insulin levels in 25 T2DM patients and 20 healthy subjects. Oleuropein-enriched chocolate was associated with a significantly less increase in blood glucose in T2DM patients compared to control chocolate, and no change in healthy subjects.
Oleuropein Decreases Cyclooxygenase-2 and Interleukin-17 Expression and Attenuates Inflammatory Damage in Colonic Samples from Ulcerative Colitis Patients.
The study investigated the effects of oleuropein on colonic mucosa from ulcerative colitis patients. Oleuropein treatment reduced the expression of COX-2 and IL-17 and ameliorated inflammatory damage in colonic biopsies, suggesting its potential role in UC treatment.