The current landscape of indole hybrids with in vivo antitumor potential

Cancer has emerged as a major cause of death throughout the world, leading to around 10 million deaths annually. Anticancer therapeutics play a pivotal role in cancer therapy, but they fail to fully meet the escalating, diverse, and critical needs of patients, underscoring the urgent need for innovative anticancer chemotherapeutics. Indole hybrids can simultaneously modulate multiple targets within cancer cells, potentially addressing drug resistance and adverse events associated with single-component therapies while enhancing therapeutic efficacy and improving pharmacokinetic properties. Diverse indole hybrids, including indole-azoles, indole-chalcones, indole-sulfonamides, indole-sulfones, indole-ureas, and indole-hydrazides, have been designed, synthesized, and evaluated for their in vivo antitumor potential, metabolic stability, pharmacokinetic properties, toxicity, and modes of action since 2021. This review aims to provide insights into the in vivo antitumor therapeutic potential of indole hybrids developed from 2021 to pave the way for future rational design.