engleski

In vitro and In vivo Antioxidant Activity of Anthocyanins

During the past decades, a lot of research has been focused on antioxidants and their effects on health. The balance between oxidation and anti-oxidation is critical in maintaining a healthy biologic system and although low doses of antioxidants may be favourable to this system, high quantities may disrupt this balance. At cellular level, there is enough evidence to confirm that the oxidative stress occurs due to the normal physiological processes and environmental interactions, and complex antioxidative defence mechanisms counteract oxidative damages. However, an in- depth understanding of the biochemical events occurring at a molecular level is needed to elucidate pathways of oxidative damages and to guide future advances in medicine. Polyphenols are the largest antioxidant group of plant origin which are particularly present in fruits and vegetables. This enormous group of molecules is classified into several sub- groups, as flavonoids, in which the anthocyanins highlights. Anthocyanins have been pointed out by their biological properties, such as anti-inflammatory, cardiovascular protector, antidiabetic, anti-obesity, anticarcinogenic properties due to the suppression of oxidative stress and inflammatory markers. Owing to these effects, the use of anthocyanins as functional food or nutritional complement have become very relevant over the last few years. The ability of anthocyanins as antioxidant in vivo depends on many factors that should be considered during evaluation, and antioxidant in vitro methods are used as first approach. Usually antioxidant in vitro methods give quantitative data about anthocyanins, however they do not provide information on absorption, transportation and distribution through biological fluids, tissues and cells. Beyond this, clinical and epidemiologic estimations should be taken into consideration, because this information can indicate how much of that content is useful to the body, as high content of antioxidants in vitro does not imply in vivo antioxidant activity. Additionally, the method of administration (food vs. supplements) and defined dosage should be investigated in detail, because although true that anthocyanins are beneficial and display usefulness in the homeostasis, they can also act as prooxidants. This chapter examines all issues exposed previously, as well as the main methods for assessment of total anthocyanins content, extraction and identification in order to obtain an anthocyanin profile. Moreover, the fundamental in vitro and in vivo antioxidant activity assays, from pure anthocyanins and those extracted from plant extracts published in the last years are also reviewed.

oxidative stress ; antioxidant methods ; natural antioxidants ; lipid oxidation ; bioavailability ; anthocyanins

Inozemne ustanove koautora na radu: University of Santiago de Compostela, Santiago de Compostela, Spain ; Universidade Católica Portuguesa, CBQF-Centro de Biotecnologia e Química Fina–Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal ; University of Vigo (Campus Ourense), As Lagoas, Ourense, Spain ; Meat Technology Center, Ourense, Spain