Brain tumor incidence shows an upward trend in recent years; brain tumors account for 5% of adult tumors, while in children, this figure has increased to 70%. Moreover, 20%–30% of malignant tumors will eventually metastasize into the brain. Both benign and malignant tumors can cause an increase in intracranial pressure and brain tissue compression, leading to central nervous system(CNS) damage which endangers the patients' lives. Despite the many approaches to treating brain tumors and the progress that has been made, only modest gains in survival time of brain tumor patients have been achieved. At present, chemotherapy is the treatment of choice for many cancers, but the special structure of the blood–brain barrier(BBB) limits most chemotherapeutic agents from passing through the BBB and penetrating into tumors in the brain. The BBB microenvironment contains numerous cell types, including endothelial cells, astrocytes, peripheral cells and microglia, and extracellular matrix(ECM). Many chemical components of natural products are reported to regulate the BBB microenvironment near brain tumors and assist in their treatment. This review focuses on the composition and function of the BBB microenvironment under both physiological and pathological conditions, and the current research progress in regulating the BBB microenvironment by natural products to promote the treatment of brain tumors.
Xiao ZhaoRujing ChenMei LiuJianfang FengJun ChenKaili Hu
Desmoplastic tumors have an abundance of stromal cells and the extracellular matrix which usually result in therapeutic resistance.Current treatment prescriptions for desmoplastic tumors are usually not sufficient to eliminate the malignancy.Recently,through modulating cancer-associated fibroblasts(CAFs)which are the most abundant cell type among all stromal cells,natural products have improved chemotherapies and the delivery of nanomedicines to the tumor cells,showing promising ability to improve treatment effects on desmoplastic tumors.In this review,we discussed the latest advances in inhibiting desmoplastic tumors by modeling CAFs using natural products,highlighting the potential therapeutic abilities of natural products in targeting CAFs for cancer treatment.
