Oleuropein as an inhibitor of peroxisome proliferator-activated receptor gamma

As the beneficial effects of the Mediterranean diet on human health are well established, the phenolic compounds in olive oil have been gaining interest. Oleuropein, a major phenolic compound in olives, is known to reduce the blood glucose levels in alloxan-induced diabetic rats and rabbits, however, its effect on type 2 diabetes caused by obesity is not clear. The purpose of this study is clarifying the effect of oleuropein on the glucose tolerance in skeletal muscle under the condition of lipotoxicity caused by type 2 diabetes. Oleuropein enhanced glucose uptake in C2C12 cells without insulin. Translocation of glucose transporter 4 (GLUT4) into the cell membrane was promoted by activation of adenosine monophosphate-activated protein kinase (AMPK) but not protein kinase B (Akt). Physiological concentration of oleuropein (10 µM) was sufficient to express beneficial effects on C2C12 cells. Oleuropein prevented palmitic acid-induced myocellular insulin resistance. Furthermore, in gastrocnemius muscles of mice fed a high fat diet, oleuropein also induced the GLUT4 localization into cell membrane. These results suggest the possibility of oleuropein to be effective for type 2 diabetes by reducing insulin resistance in skeletal muscles.

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“…Some studies suggest that oleuropein inhibits PPARγ expression. ( 26 , 27 ) Further study on the molecular target of oleuropein is essential.…”

Section: Discussionmentioning

confidence: 99%

Oleuropein improves insulin resistance in skeletal muscle by promoting the translocation of GLUT4

Fujiwara

Tsukahara

Ikeda

et al. 2017

J. Clin. Biochem. Nutr.

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“…Sirt induction by CR, resveratrol or other plant polyphenols [ 36 ] results in many cellular outcomes and is considered responsible for the epigenetic effects of these molecules [ 5 ] (see below). In particular, it has been reported that Sirt induction (i) counteracts elevated inflammation and lowers cholesterol and triglyceride synthesis [ 37 ]; (ii) reduces oxidative damage markers and increases expression of Nrf2-dependent genes that modulates antioxidant factors in mice fed with a diet rich in olive oil phenolics [ 38 ]; (iii) activates Nrf2 thus attenuating oxidative stress with endothelium protection in mice fed with resveratrol [ 39 ]; (iv) downregulates the pro-inflammatory agent NFκB thus inhibiting the inflammatory response in rat heart subjected to myocardial ischemia and reperfusion [ 40 ]; and (v) inhibits directly the transcriptional activity of PPARγ, with ensuing anti-adipogenic effects [ 41 ]. In addition, a cross-talk does exist between Sirt1 and AMP-activated protein kinase (AMPK), a sensor of the energy state of the cell.…”

Section: Biochemical Effects Of Olive Polyphenols Considered As Camentioning

confidence: 99%

Nutraceutical Properties of Olive Oil Polyphenols. An Itinerary from Cultured Cells through Animal Models to Humans

Rigacci

Stefani

2016

IJMS

217

170

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The increasing interest in the Mediterranean diet hinges on its healthy and anti-ageing properties. The composition of fatty acids, vitamins and polyphenols in olive oil, a key component of this diet, is considered a key feature of its healthy properties. Therefore, it is of significance that the Rod of Asclepius lying on a world map surrounded by olive tree branches has been chosen by the World Health Organization as a symbol of both peace and well-being. This review travels through most of the current and past research, recapitulating the biochemical and physiological correlations of the beneficial properties of olive tree (Olea europaea) polyphenols and their derivatives found in olive oil. The factors influencing the content and beneficial properties of olive oil polyphenols will also be taken into account together with their bioavailability. Finally, the data on the clinical and epidemiological relevance of olive oil and its polyphenols for longevity and against age- and lifestyle-associated pathologies such as cancer, cardiovascular, metabolic and neurodegenerative diseases are reviewed.

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“…It is a polyphenolic constituent with high antioxidant capacity [7], [8], [9] comparable to a hydrosoluble analog of α-tocopherol or vitamin E [10]. Various studies shown that oleuropein has many biological benefits in animals and human beings including antioxidant [9], [11], [12], anti-inflammatory [13], antidiabetic [7], [14], anticancer [15], [16], hypoglycemic [17], hypolipidemic [17]. Almost all previous studies attribute the beneficial biological effects of olive leaf extracts to oleuropein [9], [14], [19], [20], [21], [22].…”

Section: Introductionmentioning

confidence: 99%

Effect of oleuropein on myocardial dysfunction and oxidative stress induced by ischemic-reperfusion injury in isolated rat heart

Esmailidehaj

Bajoovand

Rezvani

et al. 2016

Journal of Ayurveda and Integrative Medicine

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BackgroundStudies have reported antioxidant effect of oleuropein in isolated rat heart.ObjectiveThis study was conducted to investigate whether perfusion of isolated rat heart with oleuropein, before induction of ischemia or at the onset of reperfusion, had any effect on the hemodynamic parameters, infarct size and biochemical factors following ischemic – reperfusion injury.Materials and methodsForty-eight male Wistar rats were divided into 6 groups: the control groups (Con-P and Con-T groups), O10-P and O50-P groups perfused with 10 and 50 μg/g heart oleuropein 5 min before the induction of ischemia and O10-T and O50-T groups perfused with 10 and 50 μg/g heart oleuropein at the beginning of the reperfusion, respectively. All hearts were subjected to 30 min global ischemia and 90 min reperfusion. Hemodynamic parameters were monitored throughout the experiment. The creatine kinase (CK) and malondialdehyde (MDA) level of coronary outflow were assayed and the infarct size measured at the end of reperfusion.ResultsWe found hemodynamic parameters namely heart rate, left ventricular end diastolic pressure (LVEDP), left ventricular developed pressure (LVDP), ±dp/dt and coronary outflow significantly improved in all groups that received oleuropein compared to the control groups. Also, the infarct size was smaller and the coronary outflow levels of CK and MDA were lower in the oleuropein groups compared to the control groups.ConclusionsThe findings suggest that perfusion of isolated rat heart with oleuropein would lead to improved myocardial dysfunction following ischemic-reperfusion injury. Our findings confirm the antioxidant potential of oleuropein.

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Oleuropein as an inhibitor of peroxisome proliferator-activated receptor gamma

Cited by 26 publications

References 21 publications

Oleuropein improves insulin resistance in skeletal muscle by promoting the translocation of GLUT4

Oleuropein improves insulin resistance in skeletal muscle by promoting the translocation of GLUT4

Nutraceutical Properties of Olive Oil Polyphenols. An Itinerary from Cultured Cells through Animal Models to Humans

Effect of oleuropein on myocardial dysfunction and oxidative stress induced by ischemic-reperfusion injury in isolated rat heart

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