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