Toad venom-derived bufadienolides and their therapeutic application in prostate cancers: Current status and future directions

Abstract

Cancer is the second leading cause of death worldwide. Specially, the high incidence rate and prevalence of drug resistance have rendered prostate cancer (PCa) a great threat to men’s health. Novel modalities with different structures or mechanisms are in urgent need to overcome these two challenges. Traditional Chinese medicine toad venom-derived agents (TVAs) have shown to possess versatile bioactivities in treating certain diseases including PCa. In this work, we attempted to have an overview of bufadienolides, the major bioactive components in TVAs, in the treatment of PCa in the past decade, including their derivatives developed by medicinal chemists to antagonize certain drawbacks of bufadienolides such as innate toxic effect to normal cells. Generally, bufadienolides can effectively induce apoptosis and suppress PCa cells in-vitro and in-vivo, majorly mediated by regulating certain microRNAs/long non-coding RNAs, or by modulating key pro-survival and pro-metastasis players in PCa. Importantly, critical obstacles and challenges using TVAs will be discussed and possible solutions and future perspectives will also be presented in this review. Further in-depth studies are clearly needed to decipher the mechanisms, e.g., targets and pathways, toxic effects and fully reveal their application. The information collected in this work may help evoke more effects in developing bufadienolides as therapeutic agents in PCa.

Isolation, Identification and Chemical Modification of Bufadienolides from Bufo melanostictus Schneider and Their Cytotoxic Activities against Prostate Cancer Cells

“…Toad venom, known as Venenum bufonis, has been utilized for therapeutic purposes for many centuries in modern China as well as other Asian nations including South Korea and Japan, following it being appropriately dried and formulated [1,2]. Toad venom plays a central role as the primary constituent in various therapeutic formulations or Chinese patent medicines [3].…”

“…1 H NMR (400 MHz) and13 C NMR (100 MHz) data for compounds 1 and 2 in CD3OD a . Position 1 2 δC δH (J in Hz) δC δ H (J in Hz) 1 24.9, CH2 1.82 a , 1.42 a 24.7, CH2 1.80 a , 1.46 a 2 25.7, CH2 1.68 a 27.5, CH2 1.82 a , 1.26 a 3 72.1, CH 5.05, br s 67.1, CH 4.06, (br.…”

“…;1 H NMR (400 MHz, MeOD) and13 C NMR (100 MHz, MeOD), see Table 1; HR-ESI-MS m/z 467.2391 [M + Na] + (calcd for C 26 H 36 O 6 Na, 467.2410). ; 1 H NMR (400 MHz, MeOD) and 13 C NMR (100 MHz, MeOD), see Table 1; HR-ESI-MS m/z 467.2319 [M + Na] + (calcd for C 26 H 36 O 6 Na, 467.2410).…”

Pharmacological Effects of Cinobufagin

“…It is prepared from the dried white secretion of the auricular glands and the skin glands of Bufo gargarizans Cantor or Bufo melanostictus Schneider [ 3 ]. According to the theory of traditional Chinese medicine, it has efficacy in providing detoxification, pain relief, resuscitation, and refreshment [ 4 , 5 ]. The chemical constituents of toad venom mainly include bufadienolides, indole alkaloids, sterols, polysaccharides, amino acids, and organic acids, among which bufadienolides and indole alkaloids are considered to be the main active ingredients [ 6 – 8 ].…”

“…The chemical constituents of toad venom mainly include bufadienolides, indole alkaloids, sterols, polysaccharides, amino acids, and organic acids, among which bufadienolides and indole alkaloids are considered to be the main active ingredients [ 6 – 8 ]. Modern pharmacological studies have demonstrated that toad venom possesses a multitude of pharmacological activities, including antitumor, cardiac, antibacterial, and analgesic activities effects [ 4 , 9 , 10 ].…”