Antioxidant Activity Composition Research Articles

ANTIOXIDANT PROPERTIES OF THE DIHYDROQUERCETIN WITH ALPHA-TOCOPHEROL COMBINATIONS IN FREE RADICAL OXIDATION

Introduction. A significant factor in the manifestation of the compound antioxidant ability is a pattern of its interaction with other antioxidants, which affects the demonstrated final antioxidant effect. Flavonoids display different antioxidant capacities along with a wide range of biological activity, dihydroquercetin in particular. The role of the regenerating component in the cycles of mutual transformations in antioxidant systems is assumed for dihydroquercetin as it's a compound with a high profile of antiradical capacity. Here we focused on the nature of the antioxidant activity presentation in a composition consisting of dihydroquercetin and the essential antioxidant α-tocopherol. The combination was studied in a wide ratio range of the dihydroquercetin-α-tocopherol composition components from 1:1 to 1:20, based on the assumption that the concentration of the second component in living systems is excessive. Aim. The work aimed to determine the nature of the dihydroquercetin-α-tocopherol composition antioxidant activity in vitro, both in general and in terms of the individual component’s action. Material and methods. The antioxidant effects of the composition were studied within the framework of decolorization and kinetic methods based on the inhibition of model radical cations of 2,2'-azino-bis-(3-ethylbenzthiosoline-6-sulfonic acid) diammonium salt. To determine the nature of the individual components' action, high-resolution mass spectrometry was used, based on the analysis of the spectra of which kinetic curves of the consumption of the components of the composition were constructed. Results. A study of the interaction of dihydroquercetin with α-tocopherol by the decolorization method showed that a slight subadditive effect was observed for all ratios of the components of the compositions. The kinetic method revealed a two-stage nature of the antioxidant activity manifestation of the composition, with the first stage of the induction period being attributed to the α–tocopherol action, and the second to dihydroquercetin. In support of the hypothesis expressed, it was shown by high-resolution mass spectrometry that a decrease in the concentration of dihydroquercetin in the composition begins only after almost complete α-tocopherol consumption. Conclusions. α-Tocopherol prevents the oxidation of dihydroquercetin by radical cations ABTS•+ when acting together in the composition, and regeneration of one antioxidant by another does not occur.

Correlation Study of Antioxidant Activity with Phenolic and Flavonoid Compounds in 12 Indonesian Indigenous Herbs.

The antioxidant activity (AA), total phenolic content (TPC), and total flavonoid content (TFC) of selected Indonesian Zingiberaceae herbs were determined. An optimization extraction procedure was conducted by using Taguchi L16 orthogonal array. Four chemical assays were applied, including 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity assay, H2O2 scavenging activity assay, Folin–Ciocalteau (F–C) assay, and NaNO2-AlCl3-NaOH assay, which revealed remarkable differences in AA, TPC, and TFC. The result indicated the diversity of AA composition among the herbs, and C. longa exhibited the highest AA. HPLC-PAD analysis revealed that curcumin was present in five high antioxidant herbs, and the highest amount was in C. longa. Pearson correlation analysis indicated that the identified TPC and TFC were significant contributors to AA, and curcumin was likely the main contributing antioxidant compound. Our approach concluded that C. longa is the greatest source of natural antioxidants among 12 Indonesian indigenous Zingiberaceae herbs. The use of a mixed-method approach to augment the findings of solitary methods might facilitate future researchers to uncover deeper and hidden meanings.

Research progress on biological activities of Olea europaea leaf extract

Olea europaea oil is one of the most important part of the "Mediterranean dietary pattern", and a lot of epidemiological evidences showed that people with the Mediterranean diet having a lower morbidity of the cardiovascular system diseases, skin cancer and colon cancer. The health benefits of a Mediterranean diet not only attributed to monounsaturated fatty acids and vitamins and other nutrients in O. europaea oil, but also the phenolic compounds named as antioxidant effect. Studies have shown that O. europaea leaf contains much more antioxidant activity composition than the fruit, and oleuropein, flavonoids such polyphenols are the main active ingredients in O. europaea leaf. A small amount of O. europaea was introduced into China in 1956, after widely cultivated in Fujian, Guangdong, Taiwan, Sichuan, Shaanxi, Yunnan, and Longnan in Gansu province is the biggest O. europaea planting area in the country. In every winter pruning O. europaea will produce a large number of the leaves, which could be a high added value products (phenolic compounds) of rich source. This article through consulting the literature at home and abroad, classified and summarized the biological activity research status of O. europaea leaf extract and the possible mechanisms, including antimicrobial, antitumor, antioxidation, and on the function of brain, cardiovascular system, anti-diabetes, anti-inflammatory and analgesia and so on. At the same time looked ahead to its development prospects of O. europaea leaf extract, it has variety and high content of active ingredients, and antioxidant synergy, which provide a theoretical basis for the further development and utilization of O. europaea leaf. And O. europaea leaf extract has a rich cheap source and good bioavailability, which provided a broad space in the application of medical and health care.