Antioxidant activity of Humulus lupulus and Vaccinium myrtillus individual and combined extracts

摘要

Oxidative stress, that generates reactive oxygen and nitrogen species, is caused by an imbalance occurred at the cellular level and causes the appearance of several disease, including atherosclerosis, diabetes, neurodegenerative diseases and cancer. We investigated by two methods: DPPH and total antioxidant capacity, antioxidant capacity and free radical scavenger potential of three hydroalcoholic extracts from: Humulus lupulus (cones) and Vaccinium myrtillus (leaves) and a combined extract obtained as a mixture of the two species, compared with the reference substances chlorogenic acid and rutin, highlighting the chemical composition of the extracts in total polyphenolic compounds. Reference substances have a similar behavior in both test methods, meanwhile the studied samples have opposite behaviors. In DPPH assay Vaccinium myrtillus extract has a higher scavenger capacity than Humulus lupus extract at the most concentrations and test times leading to a direct dependence between the inhibition potential of DPPH and composition in total polyphenolic compounds. In phosphomolyb- denum assay Humulus lupulus extract has total antioxidant capacity higher than the Vaccinium myrtillus extract, at all tested concentrations, which may be due to the different reactivity of the extracts compounds with phosphomolybdic reagent, taking into account both time and reaction temperature, as well as the chemical complexity of the extracts. Antioxidant activity of combined extract tends to achieve a balance compared with the results for individual extracts, in the determinations made by the two methods, including in the case of quantitative chemical composition.