scholarly journals Olive leaf extract activity against Candida albicans and C. dubliniensis – the in vitro viability study

2016 ◽  
Vol 66 (3) ◽  
pp. 411-421 ◽  
Author(s):  
Nataša Zorić ◽  
Nevenka Kopjar ◽  
Klara Kraljić ◽  
Nada Oršolić ◽  
Siniša Tomić ◽  
...  

Abstract Olive leaf extract is characterized by a high content of polyphenols (oleuropein, hydroxytyrosol and their derivatives), which is associated with its therapeutic properties. The objective of the present research was to evaluate the antifungal activity of olive leaf extract against Candida albicans ATCC 10231 and C. dubliniensis CBS 7987 strains. Minimum inhibitory concentrations (MIC) of the extract were determined by several in vitro assays. The extract showed a concentration depended effect on the viability of C. albicans with MIC value of 46.875 mg mL-1 and C. dubliniensis with MIC value 62.5 mg mL-1. Most sensitive methods for testing the antifungal effect of the extracts were the trypan blue exclusion method and fluorescent dye exclusion method while MIC could not be determined by the method according to the EUCAST recommendation suggesting that herbal preparations contain compounds that may interfere with this susceptibility testing. The fluorescent dye exclusion method was also used for the assessment of morphological changes in the nuclei of treated cells. According to the obtained results, olive leaf extract is less effective against the tested strains than hydroxytyrosol, an olive plant constituent tested in our previous study.

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 255 ◽  
Author(s):  
Palmeri ◽  
Parafati ◽  
Trippa ◽  
Siracusa ◽  
Arena ◽  
...  

An olive leaf extract (OLE) has been tested in vitro for its antibacterial activity and ability to inhibit α-glucosidase enzyme. OLE was also evaluated for its potential, when added to pasteurized milk, to preserve nutritional parameters and to limit microbial growth, thus prolonging shelf life. In vitro assays demonstrated a strong antibacterial efficacy of OLE mainly against Bacillus cereus and the capacity to inhibit α-glucosidase enzyme (IC50) when used at 0.2 mg oleuropein/mL. The milk fortification with OLE at 3.6 mg of oleuropein/mL of milk reduced total mesophilic bacteria at undetectable level after 6 d (expiration date) and by 1 log CFU/mL after 10 d. Moreover, OLE addition at 1.44 and 3.6 mg of oleuropein/mL of milk significantly reduced fat and lactose losses up to 10 d. The results motivate the use of the OLE to make a new functional milk with an extended shelf life.


2017 ◽  
Vol 12 (2) ◽  
pp. 33-44 ◽  
Author(s):  
Shaimaa Helmy El-Sayed ◽  
Neimat Amer ◽  
Soad Ismail ◽  
Iman Ali ◽  
Enas Rizk ◽  
...  

2011 ◽  
Vol 1 (11) ◽  
pp. 472 ◽  
Author(s):  
Mona Boaz ◽  
Eyal Leibovitz ◽  
Yosefa Bar Dayan ◽  
Julio Wainstein

Almost 30% of US residents ages 65 and older have diabetes. The cost of diabetes care was estimated at $174 billion in 2007, including $116 billion in additional medical costs, and $58 billion in reduced productivity. Globally, the estimated cost of diabetes care was $376 billion in 2010, representing 12% of health expenditures. Many individuals with diabetes make use of functional foods, nutritional supplements, and/or herbal remedies to manage their disease. The functional foods olive leaf extract, turmeric, and fenugreek are commonly used in traditional medicine systems to manage diabetes. All three of these functional foods have antioxidant and anti-inflammatory properties as well as specific insulin sensitizing qualities. In vitro studies offer proof of mechanism, and animal studies consistently show treatment efficacy for all three foods. The few human studies that have been conducted, however, use surrogate rather than clinical endpoints. The establishment of these and other functional foods as evidence based interventions for diabetes requires well designed, adequately powered, and randomized controlled pivotal trials with clinical endpoints.Keywords: type 2 diabetes, olive leaf extract, turmeric, and fenugreek


2019 ◽  
Vol 279 ◽  
pp. 40-48 ◽  
Author(s):  
Estefanía González ◽  
Ana María Gómez-Caravaca ◽  
Begoña Giménez ◽  
Rubén Cebrián ◽  
Mercedes Maqueda ◽  
...  

Nutrients ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1505
Author(s):  
Alison Pyner ◽  
Shuk Yan Chan ◽  
Sarka Tumova ◽  
Asimina Kerimi ◽  
Gary Williamson

Consumption of dietary bioactives is an avenue to enhancing the effective healthiness of diets by attenuating the glycaemic response. The intestinal brush border enzyme sucrase-isomaltase (SI) is the sole enzyme hydrolysing consumed sucrose, and we previously showed the acute effects of olive leaf extract (OLE) on sucrase activity when given together with sugars both in vitro and in vivo. Here we tested whether OLE could affect sucrase expression when pre-incubated chronically, a “priming” effect not dependent on competitive interaction with SI, in both a cell model and a human intervention. Using differentiated Caco-2/TC7 cells, long-term pre-treatment with oleuropein-rich olive leaf extract (OLE) lowered SI mRNA, surface protein and activity, and attenuated subsequent sucrose hydrolysis. Based on these results, a randomised, double-blinded, placebo-controlled, crossover pilot study was conducted. OLE (50 mg oleuropein) was consumed in capsule form 3 times a day for 1 week by 11 healthy young women followed by an oral sucrose tolerance test in the absence of OLE. However this treatment, compared to placebo, did not induce a change in post-prandial blood glucose maximum concentration (Glcmax), time to reach Glcmax and incremental area under the curve. These results indicate that changes in SI mRNA, protein and activity in an intestinal cell model by OLE are not sufficient under these conditions to induce a functional effect in vivo in healthy volunteers.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4069
Author(s):  
Sarah Albogami ◽  
Aziza  Hassan

Cancer is one of the most serious public health issues worldwide, ranking second only to cardiovascular diseases as a cause of death. Numerous plant extracts have extraordinary health benefits and have been used for centuries to treat a variety of ailments with few side effects. Olive leaves have a long history of medicinal and therapeutic use. In this study, the anti-cancer properties of an olive leaf extract were investigated in vitro using colorectal and prostate cancer cell lines (HT29 and PC3, respectively). A high-performance liquid chromatography analysis showed that the olive leaf extract contained a high chlorogenic acid content. Accordingly, chlorogenic acid may be related to the observed effects of the aqueous extract on cancer cells, including increased inhibition of cancer cell growth, migration, DNA fragmentation, cell cycle arrest at the S phase, reactive oxygen species (ROS) production, and altered gene expression. The effects of the extracts were greater in HT29 than in PC3 cells. These results suggest that chlorogenic acid, the main constituent in the olive extract, is a promising new anti-cancer agent. Further analyses should focus on its in vivo effects on colorectal tumor models, both alone and in combination with established agents.


Planta Medica ◽  
2018 ◽  
Vol 84 (12/13) ◽  
pp. 886-894
Author(s):  
Katlego Mmopele ◽  
Sandra Combrinck ◽  
Josias Hamman ◽  
Clarissa Willers ◽  
Weiyang Chen ◽  
...  

AbstractThe African wild olive (Olea europaea subsp. africana) is traditionally used as a hypotensive agent. Herb-drug interactions may result from the concurrent use of herbal medicines and conventional prescription drugs. This aspect was investigated by determining the effect of the extract on the in vitro intestinal epithelial permeation of selected hypotensive drugs using the Caco-2 cell culture model. The phytochemical profiles of leaf extracts of African wild olive from different localities in South Africa were compared, since efficacy is determined by the chemical composition. Extracts were analysed using ultra-performance liquid chromatography. The oleuropein concentration varied considerably from below the detection limit (4.94 µg/mL) to 59.4 mg/g dry weight. Chemometric models constructed from the aligned chromatographic data indicated only quantitative differences between the profiles. The leaf extract was found to increase the permeability of propranolol in the absorptive direction (Papp = 8.93 × 10−6 cm/s) across Caco-2 cell monolayers, but considerably decreased transport in the secretory direction (Papp = 3.68 × 10−6 cm/s). The permeation of diltiazem was enhanced by the extract in both the absorptive (Papp = 7.33 × 10−6 cm/s) as well as in the secretory direction (Papp = 7.16 × 10−6 cm/s), but a decrease in the efflux ratio was observed. The extract therefore caused a net increase in the transport of both drugs in the absorptive direction due to an inhibition effect on their efflux. This suggests a potential increase in the blood levels of these drugs when taken simultaneously with African wild olive leaf extract, indicating potential adverse effects that must be verified in vivo.


2014 ◽  
Vol 28 (3) ◽  
pp. 451-456 ◽  
Author(s):  
Andrea Čabarkapa ◽  
Lada Živković ◽  
Dijana Žukovec ◽  
Ninoslav Djelić ◽  
Vladan Bajić ◽  
...  

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