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The main objective of this Doctoral Thesis is to study the potential anti-inflammatory and anti-tumor activity of resveratrol and other stilbenes present in Vitis vinifera. To achieve this goal, the anti-inflammatory effect of stilbenes is firstly addressed in a lipopolysaccharide (LPS) -activated murine macrophage model, and secondly, antitumor activity in a model of human hepatocarcinoma is analyzed.The stilbenes used for the analysis of antitumor activity comprise 8 monomers (resveratrol, piceide, piceatannol, astringin A, pterostilbene, oxyresveratrol, isorhapontine and isorhapontigenine), 7 dimers (e-viniferin, w-viniferin, d-viniferin, ampelopsin A escirpusin A, pallidol and vitisinol C), a trimer (miyabenol C) and 4 tetramers (hopeaphenol, isohopeaphenol, R2-viniferin and R-viniferin). All were tested in the LPS-activated murine macrophage line, analyzing both their cytotoxicity and their ability to inhibit NO production. From these experiments, their IC30 or IC50, respectively, were calculated. The stilbenes selected based on the results obtained were piceatanol, e-viniferin, δ-viniferin, hopeaphenol and isohopeaphenol, with which the effect that they exert on the release of inflammatory cytokines and the production of ROS was studied. Hopeaphenol and piceatannol inhibit ROS production, and only δ-viniferin does not decrease the release of cytokines IL-1β and TNF-α. It is concluded that the derivatives of resveratrol piceatanol, -viniferin, hopeaphenol and isohopeaphenol have interesting effects on the inflammatory response produced by the activation that LPS exerts on murine macrophages. This finding justifies continuing the study in more complex models given its possible usefulness in the treatment of diseases with an inflammatory basis.For the study of antitumor activity, the IC50 obtained after treatment with 6 stilbenes from the 2 hepatoma lines were compared with the line of non-transformed hepatocytes. Resveratrol (monomer), ampelopsin A and e-viniferin (dimers) and the tetramers hopeaphenol, isohopeaphenol, R2-viniferin and R-viniferin were analyzed. The R2-viniferin tetramer shows the highest cytotoxic activity in HepG2 (IC50

149 p. Los ciclos de hiperstimulación ovárica controlada son ampliamente utilizados en las técnicas de reproducción asistida debido al mayor número de óvulos que se obtienen por ciclo y al consecuente aumento de las probabilidades de éxito de los tratamientos. Sin embargo, la manipulación hormonal que conllevan estos ciclos puede producir efectos adversos tanto a nivel ovárico como gestacional, entre ellos alteraciones redox. En esta tesis doctoral se ha estudiado el sistema antioxidante del líquido folicular (microambiente del ovocito) de una misma mujer después de un ciclo de ovulación natural y después de un ciclo de hiperestimulación ovárica controlada. Para ello se han utilizado técnicas espectrofotométricas, espectrometría de masas, inmunotransferencia western, técnicas de cultivos celulares y microscopia confocal. Los resultados mostraron que los ciclos de hiperestimulación ovárica provocan una disminución de la protección antioxidante del líquido folicular y por tanto del ovocito, frente a los ciclos naturales en los que el ovocito se encuentra más protegido. Esto se vio reflejado, entre otras cosas, en una disminución de la actividad de los enzimas PON, los cuales hemos caracterizado por primera en las células de la granulosa humanas, lo que nos lleva a sugerir un posible papel en los procesos reproductivos.

195 p. Nowadays there is an increasing interest in finding bioactive compounds which can be used as chemopreventive agents against cancer. In this work, we have studied the antitumoral actions of aqueous extracts from leaves of the Colombian Amazonian Vismia baccifera plant on the human hepatocellular carcinoma HepG2 cell line. Our results showed that V. baccifera induced a cytotoxic response to HepG2, increasing the levels of mitochondrial O2- and intracellular ROS (particularly hydrogen peroxide), inducing depletion of GSH, cell cycle arrest at G2/M phase, endoplasmic reticulum stress, autophagy and apoptosis. Interestingly, the cytotoxic actions exerted by V. baccifera are exclusive of cancer cells. Hydrogen peroxide, whose intracellular accumulation was early induced by the extract, mediated the cytotoxic response. V. baccifera promoted deregulation of antioxidant enzymes, this effect being secondary to the accumulation of ROS. The intracellular GSH depletion was not the cause, but the consequence of V. baccifera-induced toxicity. The plant extract also affected HepG2 signaling by activating and inhibiting specific pathways. Moreover, we validated the experimental approach we have used to study the toxic response under conditions of 21% atmospheric pO2, ruling out any possible superimposed oxidative stress derived from the culture conditions. Our results highlight the importance of analyzing in depth the actions of this plant to generate knowledge that can lay the bases for coadjuvant or anti-cancer therapy.