153 research outputs found
Time related inhibition by methylguanidine in LPS-stimulated J774A.1 macrophages
Methylguanidine (MG) is a nitrogen compound deriving from protein catabolism that accumulates in
Chronic kidney disease (CKD). Changes in monocyte functions have been recognised as one of the most
important key factor responsible for the immunological disorders associated with uremia and it has been
demonstrated that high blood concentrations of nitrogen compounds, as MG, could be responsible of
immunodisfunctions associated to uremic syndrome. Inducibie nitric oxide synthase (iNOS) and
cycloxygenase-2 (COX-2) and their respective metabolites, nitric oxide and prostaglandins, are a crucial step
both in the activation of immunoresponsive cells and in the mechanism of citotoxicity, NO mediated. It has
been previously reported the ability of MG to inhibit iNOS activity and expression both in vitro and in vivo.
The aim of this study is to evaluate if MG could interfere with macrophagic immunoresponses also modulating
iNOS and COX-2 at different time of incubation in J774A.1 stimulated with Lipopolysahharide from E.coli.
Our results demonstrated that MG exerted inhibitory effect on iNOS and COX-2. These effects are related to
incubation time thus highliting the detrimental effect of immune system by MG in uremic conditions
Synthesis, structural aspects and cytotoxicity of the natural cyclopeptides yunnanins A, C and phakellistatins 1, 10
Yunnanins A and C, two cyclic heptapeptides occurring in the roots of Stellaria yunnanensis, and phakellistatins 1 and 10, a
hepta- and an octacyclopeptide first isolated from marine sponges of the genus Phakellia, were efficiently synthesized using a combination of
solid and solution-phase techniques. Structural analysis on the synthetic members of the yunnanin series showed that the synthetic sample of
yunnanin A exhibited a configurational pattern at the Pro peptide linkages identical to the natural product (trans-Pro3, trans-Pro5), while
yunnanin C was obtained as a complex mixture of geometric/conformational isomers; the major isomer (trans-Pro3) was indistinguishable
from the natural cyclopeptide and co-occurred along with lower amounts of a mixture (1:1 ratio) of two different rotamers, both displaying cis
geometry at the Pro3 linkage. In the phakellistatin series, the synthetic phakellistatin 1 (determined as cis-Pro1, cis-Pro3, cis-Pro5) was
identical to the natural one, while two different isomeric products of phakellistatin 10 could be obtained: a major one (trans-Pro1, trans-Pro4,
trans-Pro6) showing spectral properties superimposable with the natural metabolite, and a minor geometric isomer of the natural
cyclopeptide. Interestingly, the synthetic cyclopeptides, although found to be chemically identical with their natural counterparts, did not
display the same biological properties (in vitro cytotoxicity against a panel of cancer cell lines), leaving presently open the question whether
or not the potent bioactivity reported in the literature should really be attributed to these natural cyclic peptides.
q 2003 Elsevier Ltd. All rights reserved
Cytotoxic Activity and Composition of Petroleum Ether Extract from Magydaris tomentosa (Desf.) W. D. J. Koch (Apiaceae).
The petroleum ether extract of Magydaris tomentosa flowers (Desf.) W. D. J. Koch has been analyzed by GC-MS. It is mainly constituted by furanocoumarins such as xanthotoxin, xanthotoxol, isopimpinellin, and bergaptene. Other coumarins such as 7-methoxy-8-(2-formyl-2-methylpropyl) coumarin and osthole also occurred. The antiproliferative activity of Magydaris tomentosa flower extract has been evaluated in vitro on murine monocyte/macrophages (J774A.1), human melanoma (A375) and human breast cancer (MCF-7) tumor cell lines, showing a major activity against the latter
Citrus sinensis and Vitis vinifera Protect Cardiomyocytes from Doxorubicin-Induced Oxidative Stress: Evaluation of Onconutraceutical Potential of Vegetable Smoothies
The interest towards nutraceuticals able to counteract drug side effects is continuously growing in current chemotherapeutic protocols. In the present study, we demonstrated that smoothies containing mixtures of Citrus sinensis and Vitis vinifera L. cv. Aglianico N, two typical fruits of the Mediterranean diet, possess bioactive polyphenols that protect cardiomyocytes against
doxorubicin-induced oxidative stress. The polyphenolic extracts isolated from Citrus sinensis- and Vitis vinifera-based functional smoothies were deeply characterized by Liquid Chromatography-Mass Spectrometry methods. Subsequently, the functional smoothies and relative mixtures were tested to verify their ability to affect cellular viability and oxidative stress parameters in embryonic cardiomyocyte cells (H9c2), and human breast adenocarcinoma cell line (MCF-7) exposed to doxorubicin. Interestingly, we found that the mix resulting from Citrus sinensis and Vitis vinifera association in ratio 1:1 was able to reduce cardiomyocytes damage induced by anthracyclines, without significantly interfering with the pro-apoptotic activity of the drug on breast cancer cells. These results point out the potential use of vegetable smoothies as adjuvants functional foods for chemotherapeutic anticancer protocols
Potential Role of Natural Antioxidant Products in Oncological Diseases
Nutrition has a significant effect and a crucial role in disease prevention. Low consumption
of fruit and vegetables and a sedentary lifestyle are closely related with the onset and development of many types of cancer. Recently, nutraceuticals have gained much attention in cancer research due to their pleiotropic effects and relatively non-toxic behavior. In fact, although in the past there
have been conflicting results on the role of some antioxidant compounds as allies against cancer,
numerous recent clinical studies highlight the efficacy of dietary phytochemicals in the prevention and treatment of cancer. However, further investigation is necessary to gain a deeper understanding of the potential anticancer capacities of dietary phytochemicals as well as the mechanisms of their
action. Therefore, this review examined the current literature on the key properties of the bioactive
components present in the diet, such as carotenoids, polyphenols, and antioxidant compounds, as
well as their use in cancer therapy. The review focused on potential chemopreventive properties,
evaluating their synergistic effects with anticancer drugs and, consequently, the side effects associated
with current cancer treatments
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