Exploring the Anticancer Mechanisms of Dendrobium officinale Polysaccharides in Colorectal Cancer: Apoptosis and Autophagy Interactions

Dendrobium officinale polysaccharides (DOP) exhibit anticancer potential against colorectal cancer (CRC), yet their mechanisms remain unclear. This study investigated DOP's effects on HCT-116 cells. DOP dose- and time-dependently inhibited proliferation and induced apoptosis, evidenced by elevated cleaved caspase-3/-9, poly ADP-ribose polymerase (PARP), Bax, and reduced Bcl-2. Concurrently, DOP activated autophagy (increased LC3-II/I, Beclin-1; decreased p62) via phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) suppression. Combining DOP with the autophagy inhibitor chloroquine enhanced apoptosis (higher cleaved PARP, Bax; lower Bcl-2) and reactivated PI3K/Akt/mTOR signaling. These findings demonstrate DOP inhibits CRC by dual induction of apoptosis and autophagy blockade through PI3K/Akt/mTOR inhibition, with autophagy suppression synergistically augmenting apoptosis. The study highlights DOP's translational potential as a functional food or adjuvant therapy, proposing a novel combinatorial strategy for CRC treatment.