scholarly journals Oleuropein-Enriched Olive Leaf Extract Affects Calcium Dynamics and Impairs Viability of Malignant Mesothelioma Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Carla Marchetti ◽  
Marco Clericuzio ◽  
Barbara Borghesi ◽  
Laura Cornara ◽  
Stefania Ribulla ◽  
...  

Malignant mesothelioma is a poor prognosis cancer in urgent need of alternative therapies. Oleuropein, the major phenolic of olive tree (Olea europaeaL.), is believed to have therapeutic potentials for various diseases, including tumors. We obtained an oleuropein-enriched fraction, consisting of 60% w/w oleuropein, from olive leaves, and assessed its effects on intracellular Ca2+and cell viability in mesothelioma cells. Effects of the oleuropein-enriched fraction on Ca2+dynamics and cell viability were studied in the REN mesothelioma cell line, using fura-2 microspectrofluorimetry and MTT assay, respectively. Fura-2-loaded cells, transiently exposed to the oleuropein-enriched fraction, showed dose-dependent transient elevations of cytosolic Ca2+concentration (Ca2+i). Application of standard oleuropein and hydroxytyrosol, and of the inhibitor of low-voltage T-type Ca2+channels NNC-55-0396, suggested that the effect is mainly due to oleuropein acting through its hydroxytyrosol moiety on T-type Ca2+channels. The oleuropein-enriched fraction and standard oleuropein displayed a significant antiproliferative effect, as measured on REN cells by MTT cell viability assay, with IC50of 22 μg/mL oleuropein. Data suggest that our oleuropein-enriched fraction from olive leaf extract could have pharmacological application in malignant mesothelioma anticancer therapy, possibly by targeting T-type Ca2+channels and thereby dysregulating intracellular Ca2+dynamics.

Author(s):  
Mustafa Bayram ◽  
Semra Topuz ◽  
Cemal Kaya

Olive leaves which is one of the by-products of olive tree cultivation and olive processing industry, have been used in traditional folk medicine for centuries. In recent studies, it has been determined that olive leaf has many bioactivities and these effects have been associated with high phenolic compound content. The most dominant phenolic compound of olive leaf is oleuropein, which is the heterosidic ester of elenolic acid and 3,4-dihydroxyphenylethanol. Therefore, some studies have been carried out for extracting high value added compounds from olive leaves in recent years. Antioxidant and antimicrobial activities of crude phenolic extract and oleuropein have been investigated. Moreover, some studies have been carried out to increase the possibility of using olive leaf extract and oleuropein in food industry due to increasing suspicion of side effects and toxicity of synthetic food preservatives. In this review, it was aimed to investigate phenolic compounds of olive leaf extract, phenolic compound extraction from olive leaf as well as antioxidant, antimicrobial activity of olive leaf extract and oleuropein and possibilities of use in foods.


2021 ◽  
Vol 11 (9) ◽  
pp. 4006
Author(s):  
Jose Gustavo De la Ossa ◽  
Alessandra Fusco ◽  
Bahareh Azimi ◽  
Jasmine Esposito Salsano ◽  
Maria Digiacomo ◽  
...  

Olive tree is a well-known source of polyphenols. We prepared an olive leaf extract (OLE) and characterized it via high performance liquid chromatography (HPLC) analysis. OLE was blended with different polyhydroxyalkanoates (PHAs), namely, poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) and polyhydroxybutyrate/poly(hydroxyoctanoate-co-hydroxydecanoate) (PHB/PHOHD), to produce fiber meshes via electrospinning: OLE/PHBV and OLE/ (PHB/PHOHD), respectively. An 80–90% (w/w%) release of the main polyphenols from the OLE/PHA fibers occurred in 24 h, with a burst release in the first 30 min. OLE and the produced fiber meshes were assayed using human dermal keratinocytes (HaCaT cells) to evaluate the expression of a panel of cytokines involved in the inflammatory process and innate immune response, such as the antimicrobial peptide human beta defensin 2 (HBD-2). Fibers containing OLE were able to decrease the expression of the pro-inflammatory cytokines at 6 h up to 24 h. All the PHA fibers allowed an early downregulation of the pro-inflammatory cytokines in 6 h, which is suggestive of a strong anti-inflammatory activity exerted by PHA fibers. Differently from pure OLE, PHB/PHOHD fibers (both with and without OLE) upregulated the expression of HBD-2. Our results showed that PHA fiber meshes are suitable in decreasing pro-inflammatory cytokines and the incorporation of OLE may enable indirect antibacterial properties, which is essential in wound healing and tissue regeneration.


2013 ◽  
Vol 67 (5-6) ◽  
pp. 303-315
Author(s):  
Zoran Miloradovic ◽  
Maja Gvozdenov ◽  
Djurdjica Jovovic ◽  
Nevena Mihailovic-Stanojevic ◽  
Milan Ivanov ◽  
...  

Hypertension is one of the main causes of cardiovascular disorders and since ancient times olive tree leaves have been used in its therapy. However the mechanisms of their atihypertensive effect have not been sufficiently explained yet. The main objective of our study was to investigate acute effect of olive tree leaves extract on haemodynamics and lipid peroxidation in rats with congenital hypertension under normal and blocked synthesis of nitric oxide. For the purpose of our research, there were used olive tree leaf extract EFLA? 943 as well as inhibitor of nitric oxide synthase enzyme L-NAME. Nitric oxide synthesis inhibition led to statistically significant increase of mean arterial pressure, reducing heart rate and cardiac output, increase of total vascular resistance and lipid peroxidation in plasma. Treatment by olive leaf extract led to decrease of mean arterial pressure, reducing the frequency and cardiac output, without change in lipid peroxidation. Olive leaf extract under blockade of nitric oxide led to decrease of mean arterial pressure, total peripheral resistance remained high, cardiac output low, and lipid peroxidation significantly increased. General conclusion is that olive leaf extract has a strong antihypertensive effect, decreases cardiac pre and after load and does not influence lipid peroxidation. Under blockade of nitric oxide synthesis, this extract keeps antihypertensive properties, but due to strong endothelial dysfunction, it is unable to regulate increased total peripheral resistance and marked lipid peroxidation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Toshio Mikami ◽  
Jimmy Kim ◽  
Jonghyuk Park ◽  
Hyowon Lee ◽  
Pongson Yaicharoen ◽  
...  

AbstractObesity is a risk factor for development of metabolic diseases and cognitive decline; therefore, obesity prevention is of paramount importance. Neuronal mitochondrial dysfunction induced by oxidative stress is an important mechanism underlying cognitive decline. Olive leaf extract contains large amounts of oleanolic acid, a transmembrane G protein-coupled receptor 5 (TGR5) agonist, and oleuropein, an antioxidant. Activation of TGR5 results in enhanced mitochondrial biogenesis, which suggests that olive leaf extract may help prevent cognitive decline through its mitochondrial and antioxidant effects. Therefore, we investigated olive leaf extract’s effects on obesity, cognitive decline, depression, and endurance exercise capacity in a mouse model. In physically inactive mice fed a high-fat diet, olive leaf extract administration suppressed increases in fat mass and body weight and prevented cognitive declines, specifically decreased working memory and depressive behaviors. Additionally, olive leaf extract increased endurance exercise capacity under atmospheric and hypoxic conditions. Our study suggests that these promising effects may be related to oleanolic acid’s improvement of mitochondrial function and oleuropein’s increase of antioxidant capacity.


2021 ◽  
Vol 134 ◽  
pp. 111139
Author(s):  
Reyes Benot-Dominguez ◽  
Maria Grazia Tupone ◽  
Vanessa Castelli ◽  
Michele d’Angelo ◽  
Elisabetta Benedetti ◽  
...  

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Ying Shen ◽  
Su Jin Song ◽  
Narae Keum ◽  
Taesun Park

The present study aimed to investigate whether olive leaf extract (OLE) prevents high-fat diet (HFD)-induced obesity in mice and to explore the underlying mechanisms. Mice were randomly divided into groups that received a chow diet (CD), HFD, or 0.15% OLE-supplemented diet (OLD) for 8 weeks. OLD-fed mice showed significantly reduced body weight gain, visceral fat-pad weights, and plasma lipid levels as compared with HFD-fed mice. OLE significantly reversed the HFD-induced upregulation of WNT10b- and galanin-mediated signaling molecules and key adipogenic genes (PPARγ, C/EBPα, CD36, FAS, and leptin) in the epididymal adipose tissue of HFD-fed mice. Furthermore, the HFD-induced downregulation of thermogenic genes involved in uncoupled respiration (SIRT1, PGC1α, and UCP1) and mitochondrial biogenesis (TFAM, NRF-1, and COX2) was also significantly reversed by OLE. These results suggest that OLE exerts beneficial effects against obesity by regulating the expression of genes involved in adipogenesis and thermogenesis in the visceral adipose tissue of HFD-fed mice.


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