Recent significant strides of natural compounds in
immunomodulation have highlighted their great potential against
cancer. Despite many attempts being made for
cancer immunotherapy, the biomedical application of natural compounds encounters a bottleneck because of their unclear mechanisms, low solubility and bioavailability, and limited efficacy. Herein, we summarize the immune regulatory mechanisms of different natural compounds at each step of the
cancer-immunity cycle and highlight their anti-
tumor potential and current limitations. We then propose and present various drug delivery strategies based on nanotechnology, including traditional nanoparticles (NPs)-based delivery strategies (
lipid-based NPs,
micelles, and
polysaccharide/peptide/
protein-based NPs) and novel delivery strategies (cell-derived NPs and carrier-free NPs), thus providing solutions to break through existing bottlenecks. Furthermore, representative applications of nature-inspired nanomedicines are also emphasized in detail with the advantages and disadvantages discussed. Finally, the challenges and prospects of natural compounds for
cancer immunotherapy are provided, hopefully, to facilitate their far-reaching development toward clinical translation.