SEARCH FOR NATURAL ANTIOXIDANT PRODUCTS FROM BIOACTIVE AUTOCHTHONOUS SPECIES

BUAY, ANA SOL; ORTEGA, MARIA GABRIELA; BUSTOS, PAMELA SOLEDAD

Minas Gerais

Congreso; II INTERNATIONAL CONGRESS ON SCIENCE, BIODIVERSITY AND SUSTAINABILITY; 2023

Universidade Federal de Minas Gerais (UFMG)

Reactive oxygen species (ROS) include free radicals and non-radical molecules derivedfrom oxygen that are easily converted to radicals. These are responsible for the oxidativedamage to biomolecules such as DNA, lipids and proteins, producing alterations in theirstructure, favoring tumoral and inflammatory processes, and many degenerative diseases.An important group of natural products found in plants are phenols, to which antioxidantactivity and free radical scavenging capacity are attributed; and within them we findflavonoids, which have numerous biological properties such as antimicrobials, antiinflammatory, anticarcinogenic, highlighting its antioxidant activity. In this sense, thespecies Gaillardia megapotamica (Spreng.) Baker (GA) popularly known as "Topasaire"or "Botón de oro", and Physalis viscosa L. (PHY) commonly known as "Camambu" or"Tomatillo", both distributed in the central zone of our country and widely used in popularmedicine are promising given that other species of the same genera have shownsignificant antioxidant activity. GA is used as an antimigraine, anticephalalgic,antineuralgic, antiseborrheic, antialopedic, antiflu and decongestant, while PHY is usedin gastric and throat conditions, conjunctivitis, as febrifuge, analgesic and antiinflammatory. So far, there are few reports of chemical content and antioxidant activityof these species. The aim was to determine the content of total polyphenols, quantify totalflavonoids and evaluate the antioxidant activity. The ground and dried aerial parts of GAand PHY were extracted with Soxhlet using ethanol as solvent. Two ethanolic extractswere obtained: GA extract (EGA) and PHY extract (EPHY) respectively. From each ofthem, 3 aliquots were taken to perform the experiments of total polyphenols using theFolin Ciocalteau reagent, total flavonoids with the AlCl3 method, and antioxidant activityby the TEAC method (Antioxidant Capacity in Trolox equivalents). A high content oftotal phenols was determined in EGA and EPHY, finding values of 140.3±2.9 and135.5±5.1 equivalent milligrams of gallic acid/gram of extract; significant flavonoidcontent 12.37±0.09 and 12.18±0.91 equivalent milligrams of quercetin/gram of extract;and good antioxidant activity, noted by the discoloration of a blue/green radical solutionof ABTS•+ radical, determining an IC50 of 50.3±1.6 and 52.92±1.2 μg/ml, respectively.We conclude that the presence of phenols and flavonoids could be responsible for theantioxidant activity in both plant species and possibly for the popular use of thesemedicinal plants.