The multifaceted antineoplastic effects of arenobufagin against human cancers

Toad-based therapies (Chansu) are a part of traditional Chinese medicine (TCM) in which toad venom is used for the treatment of cancers. Toad venom is a complex mixture of steroid-based compounds called bufadienolides, which have good anticancer potential. Arenobufagin is a toad venom-derived bufadienolide that has been endowed with strong antitumor activity. Most of the studies have demonstrated that arenobufagin shows potent cytotoxicity in cell-based assay systems (IC₅₀ value: <100 nM) and significant antitumor efficacy in preclinical cancer models at lower doses (between 3 and 5 mg/kg). Arenobufagin has been reported to target signaling axes such as the PI3K/Akt/mTOR, Nrf2, ATM/ATR, NF-κB, MAPKs, and Jagged1/Notch in various types of cancer cells. Pharmacokinetic studies have shown that arenobufagin has rapid absorption and gradual elimination from the system compared to many other bufadienolides. In the present article, we have comprehensively reviewed the literature related to the in vitro and in vivo anticancer properties of the arenobufagin. We have discussed the mechanism of the arenobufagin-induced cytotoxicity in different types of cancer cells and xenograft models, pharmacokinetics, and toxicity associated with its administration. Overall, the present article provides up-to-date information about arenobufagin in connection with its anticancer potential.