RESUMO
The number of mushrooms on Earth is estimated at 140,000, of which maybe only 10 % are known. Meanwhile, ca.14, 000 species that we know today, about 50 % are considered to possess varying degrees of edibility, and about 700 species are medicinal mushrooms. Medicinal mushrooms such as Ganoderma lucidum (Reishi, Lingzhi), Lentinus edodes (Shiitake, Xiang gu), Inonotus obliquus (Chaga, Hei hua mo) and many others have been collected and used for hundreds of years in Korea, China, Japan, and eastern Russia. Those practices still form the basis of modern scientific studies of fungal medical activities, especially in the field of stomach, prostrate, and lung cancers. It is notable and remarkable how reliable the facts collected by traditional eastern medicine are in the study of medicinal mushrooms. Mushrooms of their high fiber content, sterols, proteins, microelements and a low calorific value, are almost ideal for diets designed to prevent cardiovascular diseases as first suggested by Traditional Chinese Medicine. Several mushroom species have been studied for anti-inflammatory and antioxidant activities and patents have been established for these usages. Fruit-bodies of Ganoderma lucidum and Lentinus edodes have long been a major factor in folk medicine for the treatment of chronic hepatitis. Polysaccharides belong to a structurally diverse class of macromolecules, in which monosaccharide residues join to each other by glycosidic linkages to form polymer. It is noteworthy that, in comparison with other biopolymers such as proteins and nucleic acids, polysaccharides offer the highest capacity for carrying biological information because they have the greatest potential for structural variability. Mushroom polysaccharides exert their antitumor action mostly via activation of the immune response of the host organism.
RESUMO
Abstract: The beneficial influence of many foodstuffs and beverages including fruits, vegetables, tea, red wine, coffee, and cacao on human health has been recently recognized to originate from the chain-breaking antioxidant activity of natural polyphenols, significant constituent of the above products. Therefore antioxidants have received increasing attention within biological, medical, nutritional, and agrochemical fields and resulted in the requirement of simple, convenient, and reliable antioxidant capacity determination methods. Many methods which differ from each other in terms of reaction mechanisms, oxidant and target/probe species, reaction conditions, and expression of results have been developed and tested in the literature. In this review, the methods most widely used for the determination of antioxidant capacity are evaluated, presenting the general principals, recent applications, and their strengths and limitations. Conclusion: In this review, numerous antioxidant capacity methods, which differ from each other in terms of reaction mechanisms, oxidant and target/probe species, reaction conditions, and expression of results. It is important that analysis conditions, substrate, and concentration of antioxidants should simulate real food or biological systems. The total antioxidant capacity value should include assays applicable to both lipophilic and hydrophilic antioxidants and regards the similarity and differences of both HAT and ET. The assays including various ROS/RNS such as superoxide anion, hydroxyl radical, hydrogen peroxide, singlet oxygen, peroxynitrite, nitric oxide, nitric dioxide have to be designed to comprehensively evaluate the antioxidant capacity of a sample.