Bioatividade de extratos fenólicos de maçã (Malus domestica Borkh cv. Gala)

Abstract

Introduction: The consumption of apple, fruit rich in phenolic compounds, is associated with several health benefits. Its bioactive compounds are related to the reduction of glycaemia in diabetic individuals and the prevention of several types of cancers. In addition to being potential antibacterial agents. Material and methods: In this study, acetoethanolic extracts of apple Gala cultivar, harvested in Vacaria, RS, Brazil, in the year 2018, were concentrated by extraction in solid phase to obtain a purified extract and four phenolic fractions. To evaluate the potential use of these extracts; (1) individual and total phenolic composition, (2) phenolic profile, (3) thermostability, (4) photostability, (5) stability at pH changes, (6) antioxidant activity, (7) antimicrobial activity against pathogenic bacteria, (8) antidiabetic activity, (9) potential for preventing cell death in fibroblasts and (10) anticarcinogenic potential against melanoma cells (murine and human). Main results: A purified extract and four fractions were obtained where flavonoids and phenolic acids were found. Among these, 5 subclasses of phenolic compounds among hydrocinnamic acids, flavonols, flavanols, anthocyanin and dihydrochalcone were identified. Fractions III, IV and purified extract showed similar compounds and high antioxidant activity correlated to phenolic content in each one. Their stability was maintained, especially among the extracts in the optimum storage condition. The purified extract was able to reduce damage to the genetic material by up to 34 %, with the ability of the product to reduce the fragmentation of DNA induced by ultraviolet radiation in human fibroblast culture, as well as fraction II reduced by up to 19% fraction III reduced 17 % and IV 22 % damage. Fractions III and IV showed anticancer activity for melanoma cells. Fraction IV and the purified extract effectively inhibited the growth of gram-positive bacteria (Listeria monocytogenes and S. aureus). Especially the purified extract inhibited the action of the α-glycosidase enzyme. Conclusions: It is concluded that the purified extract and apple fractions cv. gala can be further studied for use 11 of active ingredients in the protection of skin against photoaging and cancer, on antidiabetic activity and also in the preservation, sanity and functionality of foods.