Phytochemical profile, in vitro activities, and toxicity of optimized Eugenia uniflora extracts

Abstract

In this study, we investigated the influence of mixture design on the chemical profile of Eugenia uniflora leaves, evaluating the antioxidant and antimicrobial activities, the toxic and hemolytic potential, with the focus on the improvement of the polyphenol’s extraction for incorporation of the extract in semi-solid forms with antifungal action. The chemical analysis was evaluated by UV-Vis and HPLC. The antimicrobial, antioxidant, and hemolytic activities were monitored. The flavonoid content ranged from 2.63-7.98 %w/w and tannins from 5.42-18.29 %w/w. The extract consisted of gallic acid (0.09-1.29%; w/w), ellagic acid (0.09-0.37%; w/w), and myricitrin (0.18-1.20%; w/w). The most successful solvent system with the highest level of active extract was water: ethanol: propylene glycol. The extracts showed fungicidal properties (3.9 µg/mL), high antioxidant activity (IC50: 9.50 µg/mL), and low toxicity. These solvent mixtures can improve the in vitro bioactivities when compared to pure solvents and this result demonstrates the importance of mixture designs as useful tools for creating high-quality herbal products and elucidate the potential of E. uniflora glycolic extracts as active herbal pharmaceutical ingredients in topical delivery systems.