Inhibitory Effects\nof Royal Jelly and Its Functional\nComponents on the Proliferation of MKN-28 Gastric Cancer Cells

Royal jelly (RJ) is a natural food product with nutritional\nvalue\nand anticancer activity. However, their effects on gastric cancer\nare unclear. Here, we show that treatment with 5–320 μg/mL\nof RJ, ethanol extract (RJEE), and protein hydrolyzate (RJPH) decreased\nthe viability of MKN-28 gastric cancer cells, with a half-maximal\ninhibitory concentration of 123.22 μg/mL for RJEE. RJ, RJEE,\nand RJPH increase the lactate dehydrogenase release rate and change\nthe morphology of the cells, resulting in cell shrinkage, nucleoplasm\ncondensation, and the formation of apoptotic bodies. RJ and its functional\ncomponents stagnated the cell cycle in the G0/G1 phase, accompanied\nby the accumulation of reactive oxygen species, decreased mitochondrial\nmembrane potential, and increased expression levels of p53 and p21\nproteins, caspase-3 activation, and apoptosis. Therefore, RJ, RJEE,\nand RJPH have potential inhibitory effects on the proliferation of\ngastric cancer cells.