Bufotalin from Venenum Bufonis inhibits growth of multidrug resistant HepG2 cells through G(2)/M cell cycle arrest and apoptosis.
ABSTRACT Venenum Bufonis, a traditional Chinese medicine, is widely used in the treatment of liver cancer in modern Chinese medical practices. In our search for anti-hepatoma constituents in Venenum Bufonis, bufotalin, bufalin, telocinobufagin and cinobufagin were obtained. Bufotalin was the most potent active compound among these four bufadienolides, and it exerted stronger inhibitory effect on the viability of doxorubicin-induced multidrug resistant liver cancer cells (R-HepG2) than that of their parent cells HepG2. Structure-activity relationship analysis indicated that the acetyl group linked to C-16 of bufadienolides might be useful for increasing anti-hepatoma activity. Further mechanistic studies revealed that bufotalin treatment induced cell cycle arrest at G(2)/M phase through down-regulation of Aurora A, CDC25, CDK1, cyclin A and cyclin B1, as well as up-regulation of p53 and p21. Bufotalin treatment also induced apoptosis which was accompanied by decrease in mitochondrial membrane potential, increases in intracellular calcium level and reactive oxygen species production, activations of caspase-9 and -3, cleavage of poly ADP-ribose polymerase (PARP) as well as changes in the expressions of bcl-2 and bax. It was also found that the inhibition of Akt expression and phosphorylation was involved in apoptosis induction, and specific Akt inhibitor LY294002 or siRNA targeting Akt can synergistically enhanced bufotalin-induced apoptosis. In vivo study showed that bufotalin significantly inhibited the growth of xenografted R-HepG2 cells, without body weight loss or marked toxicity towards the spleen. These results indicate that bufotalin has a promising potential to become a novel anti-cancer agent for the treatment of liver cancer with multidrug resistance.
- Oncogene 06/2013; · 7.36 Impact Factor
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ABSTRACT: Copper(II) mixed-ligand complex, [Cu3(p-3-bmb)2Cl4 (CH3OH)2]n (Cu(II) compound), where p-3-bmb=1-((2-(pyridine-3-yl)-1H-benzoimidazol-1-yl) methyl)-1Hbenzotriazole, has been recently found to possess potent anti-tumor activities both in vivo and in vitro. In this study, we demonstrated that Cu(II) compound significantly inhibited tumor growth in mice that inoculated with S180 cells. Meanwhile, the viabilities of HeLa and SGC-7901 cells were inhibited by Cu(II) compound with IC50 values in the range of 5 to 30μM. Further mechanistic studies revealed that Cu(II) compound treatment induced cell cycle arrested at G1 phase through p53, p21, cyclinD1, cdk4, pRb and E2F1. Cu(II) compound treatment also induced apoptosis of HeLa and SGC-7901 cells which were accompanied with decrease in mitochondrial membrane potential, increase in reactive oxygen species production, release of cytochrome C, cleavage of caspase-9, caspase-3 and poly ADP-ribose polymerase (PARP) as well as activations of bcl-2 and bax. These results indicate that Cu(II) compound has a promising potential to become a novel anti-cancer agent.European journal of pharmacology 12/2013; · 2.59 Impact Factor
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ABSTRACT: Cardiac glycosides, also known as cardiotonic steroids, are a group of natural products that share a steroid-like structure with an unsaturated lactone ring and the ability to induce cardiotonic effects mediated by a selective inhibition of the Na(+)/K(+)-ATPase. Cardiac glycosides have been used for many years in the treatment of cardiac congestion and some types of cardiac arrhythmias. Recent data suggest that cardiac glycosides may also be useful in the treatment of cancer. These compounds typically inhibit cancer cell proliferation at nanomolar concentrations, and recent high-throughput screenings of drug libraries have therefore identified cardiac glycosides as potent inhibitors of cancer cell growth. Cardiac glycosides can also block tumor growth in rodent models, which further supports the idea that they have potential for cancer therapy. Evidence also suggests, however, that cardiac glycosides may not inhibit cancer cell proliferation selectively and the potent inhibition of tumor growth induced by cardiac glycosides in mice xenografted with human cancer cells is probably an experimental artifact caused by their ability to selectively kill human cells versus rodent cells. This paper reviews such evidence and discusses experimental approaches that could be used to reveal the cancer therapeutic potential of cardiac glycosides in preclinical studies.BioMed Research International 01/2014; 2014:794930. · 2.88 Impact Factor