Tempeh and microalgae-fortified tempeh exhibit anticancer potential through S-phase arrest and EGFR/PI3K/AKT/mTOR pathway modulation in BT-474 breast cancer cells

Tempeh, a traditional fermented soybean product, is valued for its nutritional and functional properties. Its health benefits can be enhanced through fortification. The diverse anticancer activities of microalgae pose a promising option for tempeh fortification. This study investigated the anticancer potential of tempeh and algae-fortified tempeh against BT-474 luminal B breast cancer cells. Phytochemical analysis of the 96% ethanol extracts revealed the presence of flavonoids, alkaloids, and high phenolic content. Algae-fortified tempeh reduced the cell viability by up to 60%, surpassing conventional tempeh. Mechanistically, all extracts suppressed EGFR expression, elevated HIF-1α gene, induced S-phase arrest, and reprogrammed PI3K/AKT/mTOR pathway. Spirulina fortification demonstrated a relative predominance of EGFR suppression and PI3K/AKT modulation, potentially influenced by its pinocembrin content, while Euglena fortification uniquely amplified HIF-1α-mediated metabolic stress through compound triad targeting FABP4, AHCY, and BACE1. Flow cytometry confirmed a strong cytostatic effect in a non-lethal manner. These findings highlight algae fortification as a food-biotechnology strategy for pathway-targeted cancer prevention and complementary health applications.