Avaliação dos antioxidantes presentes em diferentes extratos de lúpulo in vitro e sua ação moduladora sobre os efeitos carcinogênicos da doxorrubicina in vivo

Abstract

Humulus lupulus, popularly known as hops, has lupulin glands that are responsible for secreting a powder rich in resins, polyphenols and essential oils, which provide characteristics such as aroma, bitterness and antioxidant properties. In addition to being used in the beer industry, hops can play an important role in combating cellular oxidative stress through their antioxidant activity. Thus, the objective of this study was to evaluate the in vitro antioxidant and in vivo modulating activity of extracts from three varieties of hops (El Dorado, Ekuanot and Hércules). Hops have medicinal properties of interest, standing out for their richness in phytochemical compounds. Research has shown high levels of flavonoids, giving them this antioxidant action, in addition to their antitumor potential. However, there is little knowledge about the benefits of phytochemicals that hops can provide to human health. Then, the extracts obtained by the cold extraction methods, by magnetic agitation and by ultrasound, were analyzed for their in vitro antioxidant capacity. The results of the DPPH tests showed that the extracts of the El Dorado and Ekuanot varieties, obtained by the cold extraction and ultrasound methods, presented greater antioxidant activity (p<0.05), while the extract of the Hércules variety, extracted by magnetic agitation, demonstrated lower antioxidant activity. Similar results were obtained in the ABTS test. Regarding the quantification of total phenolic compounds, the Ekuanot variety (37.06 mg EAGg-1) in the ultrasound extraction presented the best result found. When analyzing the results obtained from the phosphomolybdenum complex and the reducing power, it was possible to establish a similarity between the two methods, highlighting the greater antioxidant activity in the Ekuanot extract, obtained by ultrasound extraction, and the lower antioxidant activity for the Hércules variety, extracted by magnetic agitation. Although the extracts demonstrated antioxidant activity in all analyses performed, the Ekuanot and Eldorado varieties showed greater antioxidant potential, and considering the extraction methodology, the ultrasonic wave extraction method stood out for providing the greatest extraction of the analyzed compound. Furthermore, the epithelial tumor test in Drosophila melanogaster showed the absence of carcinogenic effect of the three hop extracts obtained through the different methods. Likewise, inhibition of the formation of epithelial tumor clones in D. melanogaster and modulation of the carnogenic effect of doxorubicin were verified in all three extracts. Through the same test, the protective activity of the extracts against the somatic cells of D. melanogaster was demonstrated.