Selenium biotransformation and phenolic compound extraction from seleniumenriched Wolffia globosa: antioxidant potential and anti-proliferative effects on human ovarian cancer cells

Wolffia globosa is an aquatic plant rich in proteins and bioactive compounds. Selenium (Se), an essential micronutrient that is essential for cellular utilization and provides significant health benefits. This study investigated the extraction of phenolic compounds from Se-enriched W. globosa using ultrasonic-assisted extraction (UAE), as well as the antioxidant and anti-proliferative activities on human cancer cells of the Se-enriched W. globosa extract. The results showed the optimal Se-enrichment condition was achieved using sodium selenite at 20 ppm during an 8-day germination period, providing higher growth and Se accumulation in the plant cells with no observed toxicity. The optimal extraction condition was 60% methanol, 32% amplitude, and 10 min of extraction time, resulting in higher total phenolic content and enhanced antioxidant activity. Se-enriched W. globosa extract showed upregulation of bioactive compounds, including indole-3- acryloylglycine (I3AG) and spiculosine (ES-285), which contributed to the higher antioxidant activity observed in Se-enriched samples compared to non-enriched controls. Moreover, Se-enriched W. globosa extract exhibited anticancer activity, significantly reducing the proliferation of human ovarian cancer cells (A2780), while showing no toxicity to normal cells. These findings suggested that Se-enriched W. globosa could serve as a valuable bioactive ingredient with antioxidant and anticancer properties for functional food supplements and therapeutic applications.