Konposatu fenolikoak eta osasuna

Abstract

Phenolic compounds make up a wide group of different substances that can be grouped together by its chemical structure. They are synthesized by plants as sec-ondary metabolites in response to aggressions such as ultraviolet radiation, pathogens, oxidative damage and rough climatic conditions. For this reason, they can be found in plant based foodstuffs, such as fruits, vegetables, nuts, oils, teas and wines. The major-ity of the phenolic compounds present on food are found as esters, glycosides or polymers, which have to be hydrolyzed in the gut before being absorbed. By the action of the so called phase II enzymes, the phenolic compounds are metabolized in the small bowel and in the liver. Some of the metabolites produced in the liver are secreted to the small bowel through the bile duct, where they will be either deconjugated to be reab-sorbed or reach the colon. Once in the large bowel, the phenolic compounds are further metabolized by the gut microbiota. As a consequence of all these processes, the bioa-vailability of the phenolic compounds is low. The excretion of the phenolic compounds and their metabolites is basically done through the urine. They are bioactive com-pounds with high antioxidant capacity. In the last years, different beneficial effects against the development of some illnesses (cancer, cardiovascular and neurodegenera-tive diseases) were attributed to these compounds, in part because of their antioxidant effect, and also due to other different mechanisms.; Konposatu fenolikoak, egitura kimikoaren arabera sailkatu daitezkeen zenbait sustantziaz osatutako talde zabal bat dira. Landareek ekoizten dituzte bigarren mailako metabolito gisa, erantzun modura erradiazio ultramorea, patogenoak, kalte oxidatiboa eta ingurumen baldintza zailak bezalako erasoei aurre egiteko. Hori dela eta, modu naturalean daude landare jatorriko elikagaietan, hala nola frutetan, barazkie-tan, fruitu lehorretan, olioetan, tean eta ardoan. Konposatu fenoliko gehienak ester, glu-kosido edo polimero gisa aurkitzen dira elikagaietan, eta ondorioz hestean hidrolizatu behar dira xurgatuak izan baino lehen. Gibelean eta heste meharrean konposatu fenoli-koak metabolizatzen dira II faseko entzimen eraginez. Gibelean eratzen diren metabo-litoen zati bat, heste meharrera jariatuko da behazun bideetatik, eta bertan berriro xur-gatuak izateko dekonjugatu egingo dira, edota kolonerako bidea jarraituko dute. Behin heste lodian, hesteko mikrobiotak konposatu fenolikoak metabolizatuko ditu. Prozesu hauen ondorioz, konposatu fenolikoen bioerabilgarritasuna txikia da. Konposatu fe-nolikoen eta beren metabolitoen iraizpena, gernu bidez gertatzen da nagusiki. Antio-xidazio-ahalmen handia duten konposatu bioaktiboak dira. Azken urteetan, eragiten dituzten antioxidazio efektuengatik, eta beste mekanismo batzuengatik, hainbat gaixo-tasunen garapenaren aurkako efektu onuragarriak egotzi zaizkie: minbizia, gaixotasun kardiobaskularrak eta neuroendekapenezko gaixotasunak.