The Mediterranean diet and olive oil as its quintessential part are almost synonymous with a healthy way of eating and living nowadays. This kind of diet has been highly appreciated and is widely ...recognized for being associated with many favorable effects, such as reduced incidence of different chronic diseases and prolonged longevity. Although olive oil polyphenols present a minor fraction in the composition of olive oil, they seem to be of great importance when it comes to the health benefits, and interest in their biological and potential therapeutic effects is huge. There is a growing body of in vitro and in vivo studies, as well as intervention-based clinical trials, revealing new aspects of already known and many new, previously unknown activities and health effects of these compounds. This review summarizes recent findings regarding biological activities, metabolism and bioavailability of the major olive oil phenolic compounds-hydroxytyrosol, tyrosol, oleuropein, oleocanthal and oleacein-the most important being their antiatherogenic, cardioprotective, anticancer, neuroprotective and endocrine effects. The evidence presented in the review concludes that these phenolic compounds have great pharmacological potential, however, further studies are still required.
Cancer presents one of the leading causes of death in the world. Current treatment includes the administration of one or more anticancer drugs, commonly known as chemotherapy. The biggest issue ...concerning the chemotherapeutics is their toxicity on normal cells and persisting side effects. One approach to the issue is chemoprevention and the other one is the discovery of more effective drugs or drug combinations, including combinations with polyphenols. Olive oil polyphenols (OOPs), especially hydroxytyrosol (HTyr), tyrosol (Tyr) and their derivatives oleuropein (Ole), oleacein and oleocanthal (Oc) express anticancer activity on different cancer models. Recent studies report that phenolic extract of virgin olive oil may be more effective than the individual phenolic compounds. Also, there is a growing body of evidence about the combined treatment of OOPs with various anticancer drugs, such as cisplatin, tamoxifen, doxorubicin and others. These novel approaches may present an advanced strategy in the prevention and treatment of cancer.
This review article describes studies published over the past five years on the combination of polyphenols, which are the most studied in the field of anticancer effects (curcumin, quercetin, ...resveratrol, epigallocatechin gallate, and apigenin) and chemotherapeutics such as cisplatin, 5-fluorouracil, oxaliplatin, paclitaxel, etc. According to WHO data, research has been limited to five cancers with the highest morbidity rate (lung, colorectal, liver, gastric, and breast cancer). A systematic review of articles published in the past five years (from January 2018 to January 2023) was carried out with the help of all Web of Science databases and the available base of clinical studies. Based on the preclinical studies presented in this review, polyphenols can enhance drug efficacy and reduce chemoresistance through different molecular mechanisms. Considering the large number of studies, curcumin could be a molecule in future chemotherapy cocktails. One of the main problems in clinical research is related to the limited bioavailability of most polyphenols. The design of a new co-delivery system for drugs and polyphenols is essential for future clinical research. Some polyphenols work in synergy with chemotherapeutic drugs, but some polyphenols can act antagonistically, so caution is always required.
Olive oil phenols are recognized as molecules with numerous positive health effects, many of which rely on their antioxidative activity, i.e., the ability to transfer hydrogen to radicals. ...Proton-coupled electron transfer reactions and hydrogen tunneling are ubiquitous in biological systems. Reactions of olive oil phenols, hydroxytyrosol, tyrosol, oleuropein, oleacein, oleocanthal, homovanillyl alcohol, vanillin, and a few phenolic acids with a DPPH• (2,2-diphenyl-1-picrylhydrazyl) radical in a 1,4-dioxane:water = 95:5 or 99:1 v/v solvent mixture were studied through an experimental kinetic analysis and computational chemistry calculations. The highest rate constants corresponding to the highest antioxidative activity are obtained for the ortho-diphenols hydroxytyrosol, oleuropein, and oleacein. The experimentally determined kinetic isotope effects (KIEs) for hydroxytyrosol, homovanillyl alcohol, and caffeic acid reactions are 16.0, 15.4, and 16.7, respectively. Based on these KIEs, thermodynamic activation parameters, and an intrinsic bond orbital (IBO) analysis along the IRC path calculations, we propose a proton-coupled electron transfer mechanism. The average local ionization energy and electron donor Fukui function obtained for the phenolic compounds show that the most reactive electron-donating sites are associated with π electrons above and below the aromatic ring, in support of the IBO analysis and proposed PCET reaction mechanism. Large KIEs and isotopic values of Arrhenius pre-exponential factor AH/AD determined for the hydroxytyrosol, homovanillyl alcohol, and caffeic acid reactions of 0.6, 1.3, and 0.3, respectively, reveal the involvement of hydrogen tunneling in the process.
Olive leaves as a main byproduct of olive oil and fruit industry are a valuable source of phytochemicals such as polyphenols, with multiple biomedical effects. Apart from leaves, olive branches and ...stems make up a significant amount of olive waste. It is well known that the drying process and long-term storage affect the stability and concentration of polyphenols present in raw materials. For that matter, two different means of storing olive waste, at room temperature and +4 °C, were compared by determining the content of the polyphenol oleuropein (OLE) in olive leaf, branch, and stem extracts (LE, BE, and SE) by HPLC-DAD method. Total phenols (TPC),
-diphenols (
-DPC), and total flavonoids (TFC) content in extracts were assessed by UV-Vis measurements. LE prepared from leaves stored at +4 °C had the highest OLE content, 30.7 mg g
of dry extract (DE). SE from stems stored at +4 °C was the richest in TPC and TFC (193 mg GAE/g DE and 82.9 mg CE/g DE, respectively), due to the higher purity of the extract. The biological activity of extracts was determined on cervical cancer (HeLa), melanoma (A375), metastatic melanoma (A375M) tumor cell lines, and on spontaneously immortalized cell line of keratinocytes (HaCaT), using the MTT assay. The data show that all extracts had a similar dose-dependent effect on cell viability in HeLa cells, while the effect of LE on melanoma A375 and A375M, and HaCaT cells was cell-line dependent.
Recent experimental studies of kinetic isotope effects (KIE-s) and hydrogen tunnelling comprising three proton-coupled electron transfer (PCET) oxidations of ascorbate monoanion, (a) in aqueous ...reaction solutions, (b) in the mixed water-organic cosolvent systems, (c) in aqueous solutions of various salts and (d) in fairly diluted aqueous solutions of the various partial hydrophobes are reviewed. A number of new insights into the wealth of the kinetic isotope phenomena in the PCET reactions have been obtained. The modulation of KIE-s and hydrogen tunnelling observed when partially hydrophobic solutes are added into water reaction solution, in the case of fairly diluted solutions is revealed as the strong linear correlation of the isotopic ratios of the Arrhenius prefactors
h/
d and the isotopic differences in activation energies Δ
(D,H). The observation has been proposed to be a signature of the involvement of the collective intermolecular excitonic vibrational dynamics of water in activation processes and aqueous chemistry.
Our study of tunnelling in proton-coupled electron transfer (PCET) oxidation of ascorbate with hexacyanoferrate(III) follows the insights obtained from ultrafast 2D IR spectroscopy and theoretical ...studies of the vibrational water dynamics that led to the proposal of the involvement of collective intermolecular excitonic vibrational water dynamics in aqueous chemistry. To test the proposal, the hydrogen tunnelling modulation observed in the PCET reaction studied in the presence of low concentrations of various partial hydrophobic solutes in the water reaction system has been analyzed in terms of the proposed involvement of the collective intermolecular vibrational water dynamics in activation process in the case. The strongly linear correlation between common tunnelling signatures, isotopic values of Arrhenius prefactor ratios ln
/
and isotopic differences in activation enthalpies ΔΔ
(H,D) observed in the process in fairly diluted water solutions containing various partial hydrophobic solutes (such as dioxane, acetonitrile, ethanol, and quaternary ammonium ions) points to the common physical origin of the phenomenon in all the cases. It is suggested that the phenomenon can be rooted in an interplay of delocalized collective intermolecular vibrational dynamics of water correlated with vibrations of the coupled transition configuration, where the donor-acceptor oscillations, the motions being to some degree along the reaction coordinate, lead to modulation of hydrogen tunnelling in the reaction.
Vitamin D (VitD) plays various roles, promotes musculoskeletal health, maintains parathyroid hormone levels and supports the immune processes. Vitamin D deficiency is common among cancer patients ...including thyroid cancer. Since some data indicate that preoperative VitD levels in cancer patients correlate with the further prognosis of the disease. Therefore, it is worthwhile to investigate this in the most common cancer of the thyroid gland, papillary thyroid cancer (PTC). The aim of this study was to evaluate serum VitD levels in patients with PTC concerning age, gender, body mass index (BMI), cancer stage, thyroid hormone levels, thyroglobulin concentration and the efficiency of VitD3 supplementation in these patients.
Our cross-sectional study included 105 patients, and 34 healthy subjects in the control group. After 12 weeks of VitD3 supplementation (insufficient patients received1000IJ/day, deficient patients 2000IJ/day, severe deficient patient 5000IJ/day) along with the lifestyle and dietary management, the response was evaluated according to the personal characteristics, levels of VitD, free thyroxine (FT4), freetriiodothyronine (FT3) hormones and thyroglobulin (TG).
The responders whose median age was 61-year-old, were mostly women (94%), with BMI below 23.7kg/m
, which indicates that most of the patients were normally nourished. 70% of patients were in the first stage of PTC, 76% had a vitamin D deficiency, while musculoskeletal disorders were present in 30% patients. VitD supplementation improved serum VitD status, FT3 discretely elevated and the TG levels significantly decreased in our PTC patients.
It should be noted that VitD deficiency is presented in 70% of patients with PTC in our study sample. Dietary recommendation applied as lifestyle changes along with oral VitD3 supplementation, corrected VitD status to the recommended serum level. Although the data from our study is not sufficient to evaluate the VitD level as a prognostic factor for cancer, we have shown that it is necessary to examine its level along with an individual dietary approach for each patient with PTC.
The roles of phenolics from olive oils as effective anticancer agents have been documented in various in vitro studies of different cancer cells lines, but the relationship between the phenolic ...profile of olive oil and its biological activity needs more elucidation. In this study, we analysed phenolic profiles of extra virgin olive oils (EVOOs) from different autochthonous cultivars from Croatia (Oblica, Bjelica, Buža, Žižolera) and investigated the biological effect of EVOO phenolic extracts (EVOO-PEs) on human cervical (HeLa) and human colon (SW48) cancer cell lines alone and in combination with cisplatin (cDDP), carboplatin (CBP), 5-fluorouracil (5-FU) and irinotecan. The quantitative evaluation of olive oil polyphenols was performed by HPLC-DAD and spectrophotometric analysis. The biological effect of EVOO-PEs alone and in combination with anticancer drugs was measured by MTT assay. Analysed EVOO-PEs differ in phenolic profile and inhibited HeLa and SW48 cells in a dose-dependent manner. Further, it is shown that EVOO-PEs (Oblica-Sea, Buža and Žižolera), in combination with anticancer drugs, increase the metabolic activity of HeLa and SW48 cells and have a protective role. These data imply careful consummation of olive oil during chemotherapy of cancer patients.
This paper provides an overview of the process of bibliotherapy and suggests some techniques that can be used in implementing it. Before this, autor underlines the differences between clinical and ...developmental bibliotherapy, and presents a short historical overview of development of this discipline of psychotherapy. Author also quotes a various deffinitions of this term in both meanings and concludes that all of these deffinitions contains a common denominator which is using books in order to helping people. Various chapters of the paper discuss the topics such as: bibliotherapy and children needs, the bibliotherapeutic process, the skills and attributes of a good bibliotherapist, and the limitations of bibliotherapy.
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