Phenethyl Isothiocyanate from Watercress By-Products: A Novel Green Extraction and Its Potential Health Benefits

Description

Introduction: Cruciferous vegetables are gaining popularity as “superfoods” containing exceptionally high phytochemicals content, particularly isothiocyanates, that bring health-promoting effects beyond basic nutrients. Phenethyl isothiocyanate (PEITC) is one of the most interesting isothiocyanates, showing antioxidant, anti-inflammatory, antimicrobial, and anticancer effects. This makes PEITC suitable for nutraceuticals and functional foods as an adjuvant against oxidative and inflammatory-related disorders, especially in the gastrointestinal tract, which is increasingly burdening the healthcare system globally1. Furthermore, as a widely consumed vegetable, crucifers are highly wasted in the supply chain process. PEITC can be obtained from watercress by-products. This commitment to reducing food waste can help achieve circularity and sustainability in agricultural production2. Extracting isothiocyanates traditionally involves harmful solvents. Microwave gravity hydrodiffusion (MHG) is a promising solvent-free extraction technique. Following this idea, this work is innovative as it is the first to apply MHG to extract PEITC. Methodology: MHG extraction of PEITC was developed and optimized. The phenolic profile of MHG extracts and their bioactivities, including antioxidant, anti-diabetic, and antihypertensive (IC50) and antimicrobial activities against gastrointestinal pathogens, were evaluated. Furthermore, this work begins investigating the concept of hormesis applied to the PEITC and its effects on intestinal cells (Caco-2 and HT29-MTX), including anti-inflammatory activity and the ability to neutralize ROS. Results: MHG successfully extracted the PEITC (1818 μg/g watercress DB). The optimized MHG extraction was also applied to turnip. This innovation resulted in a patent application where freezing is the key novelty. One obtained extract was a stable suspension with a zeta-potential of -12.6 mV. Ferulic acid was one of the main phenolic compounds. Besides, the extracts provided antioxidant, antihypertensive, and anti-diabetic activity and inhibited the growth of pathogens. Low concentrations of PEITC inhibited cellular metabolism compared to higher concentrations in the first few hours, but higher concentrations exhibited cytotoxic effects after 24h. Besides, PEITC reduced IL-8 secretion cells and the basal level of ROS in the cells. Conclusion: This study demonstrates that MHG is a green technique for extracting PEITC with potential bioactivities for enhancing gastrointestinal tract health. Besides, it highlights the importance of upcycling vegetable waste from the agricultural industry to create high-valueadded products.

Period	4 Sept 2024
Held at	University of Coahuila, Mexico