In vitro evaluation of goldfish (Stachys byzantina K. Koch) extracts obtained using natural deep eutectic solvents (NADES)

Chronic diseases are one of the main causes of death worldwide, and the search for antioxidant compounds to prevent these diseases is crucial. These compounds can be extracted using conventional solvents but can pose chemical hazards. Therefore, the research seeks safer and more sustainable alternatives. An unconventional plant called goldfish from the garden (Stachys byzantina K. Koch) has a high antioxidant potential due to its richness of vitamin A, iron, calcium, and total phenolics. In this study, different combinations of natural solvents were proposed to extract antioxidant compounds from the leaves of this plant, comparing them to conventional solvents. The extracts obtained were evaluated for their phenolic and flavonoid content and their antioxidant capacity using DPPH, ABTS, and FRAP methods. The results showed that the levels of bioactive compounds varied according to the combination of solvents, ranging from 0.308 to 0.811 mg EAG.g(-1) for total phenolics and from 0.030 to 1.162 mg EQ.g(-1) for total flavonoids. The antioxidant capacity of the extracts also varied according to the method used. Through statistical analyses, the LP-Ale-50 % solvent was identified as the best combination for the recovery of bioactive compounds of the species. The results indicate the superiority of NADES over conventional solvents and show that the extracts can be applied in the food and pharmacological industries.