98 research outputs found

    Diet supplementation for 5 weeks with polyphenol-rich cereals improves several functions and the redox state of mouse leucocytes

    Get PDF
    BACKGROUND: Cereals naturally contain a great variety of polyphenols, which exert a wide range of physiological effects both in vitro and in vivo. Many of their protective effects, including an improvement of the function and redox state of immune cells in unhealthy or aged subjects come from their properties as powerful antioxidant compounds. However, whether cereal-based dietary supplementation positively affects the immune function and cellular redox state of healthy subjects remains unclear. AIM OF THE STUDY: To investigate the effects of supplementation (20% wt/wt) for 5 weeks with four different cereal fractions on healthy mice. METHODS: Several parameters of function and redox state of peritoneal leukocytes were measured. The cereals, named B (wheat germ), C (buckwheat flour), D (fine rice bran) and E (wheat middlings) contained different amounts of gallic acid, p-hydroxybenzoic acid, vanillic acid, sinapic acid, p-coumaric acid, ferulic acid, quercetin, catechin, rutin and oryzanol as major polyphenols. RESULTS: In general, all cereal fractions caused an improvement of the leukocyte parameters studied such as chemotaxis capacity, microbicidal activity, lymphoproliferative response to mitogens, interleukin-2 (IL-2) and tumor necrosis factor (TNFα) release, as well as oxidized glutathione (GSSG), GSSG/GSH ratio, catalase (CAT) activity and lipid oxidative damage. We observed similar effects among the cereal fractions. CONCLUSIONS: The results suggest that some of these effects may due, at least partially, to the antioxidant activity of the polyphenols naturally present in cereals. Since an appropriate function of the leukocytes has been proposed as marker of the health state, a short-term intake of cereals seems to be sufficient to exert a benefit in the health of the general population. However, further studies are needed to assess the optimal doses and to find out which active polyphenols are able to mediate the observed physiological effects before recommending their regular consumption

    What Is New for an Old Molecule? Systematic Review and Recommendations on the Use of Resveratrol

    Get PDF
    Stilbenes are naturally occurring phytoalexins that generally exist as their more stable E isomers. The most well known natural stilbene is resveratrol (Res), firstly isolated in 1939 from roots of Veratrum grandiflorum (white hellebore) (1) and since then found in various edible plants, notably in Vitis vinifera L. (Vitaceae) (2). The therapeutic potential of Res covers a wide range of diseases, and multiple beneficial effects on human health such as antioxidant, anti-inflammatory and anti-cancer activities have been suggested based on several in vitro and animal studies (3). In particular, Res has been reported to be an inhibitor of carcinogenesis at multiple stages via its ability to inhibit cyclooxygenase, and is an anticancer agent with a role in antiangiogenesis (4). Moreover, both in vitro and in vivo studies showed that Res induces cell cycle arrest and apoptosis in tumor cells (4). However, clinical studies in humans evidenced that Res is rapidly absorbed after oral intake, and that the low level observed in the blood stream is caused by a fast conversion into metabolites that are readily excreted from the body (5). Thus, considerable efforts have gone in the design and synthesis of Res analogues with enhanced metabolic stability. Considering that reduced Res (dihydro- resveratrol, D-Res) conjugates may account for as much as 50% of an oral Res dose (5), and that D-Res has a strong proliferative effect on hormone-sensitive cancer cell lines such as breast cancer cell line MCF7 (6), we recently devoted our synthetic efforts to the preparation of trans-restricted analogues of Res in which the E carbon-carbon double bond is embedded into an imidazole nucleus. To keep the trans geometry, the two aryl rings were linked to the heteroaromatic core in a 1,3 fashion. Based on this design, we successfully prepared a variety of 1,4-, 2,4- and 2,5-diaryl substituted imidazoles including Res analogues 1, 2 and 3, respectively, by procedures that involve transition metal-catalyzed Suzuki-Miyaura cross-coupling reactions and highly selective N-H or C-H direct arylation reactions as key synthetic steps. The anticancer activity of compounds 1–3 was evaluated against the 60 human cancer cell lines panel of the National Cancer Institute (NCI, USA). The obtained results, that will be showed and discussed along with the protocols developed for the preparation of imidazoles 1–3, confirmed that a structural optimization of Res may provide analogues with improved potency in inhibiting the growth of human cancer cell lines in vitro when compared to their natural lead. (1) Takaoka,M.J.Chem.Soc.Jpn.1939,60,1090-1100. (2) Langcake, P.; Pryce, R. J. Physiological. Plant Patology 1976, 9, 77-86. (3) Vang, O.; et al. PLoS ONE 2011, 6, e19881. doi:10.1371/journal.pone.0019881 (4) Kraft, T. E.; et al. Critical Reviews in Food Science and Nutrition 2009, 49, 782-799. (5) Walle, T. Ann. N.Y. Acad. Sci. 2011, 1215, 9-15. doi: 10.1111/j.1749-6632.2010.05842.x (6) Gakh,A.A.;etal.Bioorg.Med.Chem.Lett.2010,20,6149-6151

    Primary, Adaptive, and Acquired Resistance to Cancer Immunotherapy

    Full text link
    Cancer immunotherapy can induce long lasting responses in patients with metastatic cancers of a wide range of histologies. Broadening the clinical applicability of these treatments requires an improved understanding of the mechanisms limiting cancer immunotherapy. The interactions between the immune system and cancer cells are continuous, dynamic, and evolving from the initial establishment of a cancer cell to the development of metastatic disease, which is dependent on immune evasion. As the molecular mechanisms of resistance to immunotherapy are elucidated, actionable strategies to prevent or treat them may be derived to improve clinical outcomes for patients

    mean-variance portfolio optimization

    No full text
    Portfolio optimization is the process of determining the best combination of securities and proportions with the aim of having less risk and obtaining more profit in an investment. Utilizing covariance as a risk measure, mean-variance portfolio optimization model has brought a revolutionary approach to quantitative finance. Since then, along with the advancements in computational power and algorithmic enhancements, a lot of efforts have been made on improving this model by considering real-life conditions and solving model variants with various methodologies tested on various data and performance measures. A comprehensive literature review of recent and novel papers is crucial to establish a pattern of the past, and to pave the way on future directions. In this paper, a total of 175 papers published in the last two decades are selected within the scope of operations research community and reviewed in detail. Thus, a comprehensive survey on the deterministic models and applications suggested for mean-variance portfolio optimization in which several variants of this model as well as additional real-life constraints are studied. The review classifies the approaches according to exact and approximate attempts and analyzes the proposed algorithms based on various data and performance indicators in depth. Areas of future research are outlined. (C) 2019 Elsevier Ltd. All rights reserved.C1 [Kalayci, Can B.; Ertenlice, Okkes; Akbay, Mehmet Anil] Pamukkale Univ, Fac Engn, Dept Ind Engn, TR-20160 Kinikli, Denizli, Turkey
    corecore