Targeting the breast tumor microenvironment by plant-derived products and their nanoformulations

Breast cancer is one of the considerable prevalent neoplasms worldwide. It is an intricate disorder and various modalities alone or in combination have been suggested for the control of this malignancy. In the recent decade, scientists have explored the interactions among tumor cells and the surrounding environment for finding new targets for better elimination of cancer cells and reducing non-targeted effects in normal tissues. The tumor microenvironment (TME) consists of miscellaneous cell kinds, including stromal cells, endothelial cells, immune cells, and vascular system. Targeting the TME has been suggested as a promising strategy for different solid cancers. Phytochemicals, natural compounds seen in plants, have been revealed to have antitumor effects in breast cancer. Emerging evidence indicates that phytochemicals can influence the function of various cells in TME, thus, rendering the suppression of tumors. In this review, we discuss the different interactions within the breast TME and the impact of phytochemicals on these interactions. Targeting the TME with some phytochemicals may improve breast cancer treatment outcomes. We also review the effects of nanomaterials on the efficacy of phytochemicals in breast TME. The limitations and future directions for the clinical translation of phytochemicals and nanoparticles loaded with phytochemicals will also be discussed.