Formosanin C‐induced apoptosis requires activation of caspase‐2 and change of mitochondrial membrane potential

Abstract

(1) The plant has been used as a folk remedy for snake-bite inflammation and tumors. The crude extract of Paris formosana Hayata (Liliaceae) has also been revealed to inhibit the growth of various cultured cancer cell lines.(2) Formosanin C, a diosgenin saponin, a major constituent in the methanol extract of Paris formosana Hayata (Liliaceae), has already been shown to exert a cytotoxic effect on the mouse hepatocellular MH134 cell line injected subcutaneously in C3H/HeN mice, especially in combination with 5-FU.(1) However, the underlying mechanisms remain unknown. Formosanin C was also proved to augment the effect of concanavalin A on lymphocyte proliferation.(3) In addition, intraperitoneal injection of formosanin C was found to induce production of interferon in C3H/HeN mice.(1)Apoptosis is an organized and energy-dependent process, which controls the cell cycle and finally leads to the death of cells.(4) Induction of apoptosis in cancer cells is a potentially promising approach for cancer treatment.(5) Typical morphological features of apoptotic cell death are condensed chromatin in the nucleus, DNA fragmentation, phosphatidylserine externalization, and generation of apoptotic bodies.(6) The process of apoptosis can be regulated by caspases and members of the Bcl-2 family.Mitochondria also play an important role in apoptosis.In the present study, we demonstrated that formosanin C induced apoptosis of human colorectal cancer HT-29 cells. Activation of caspase-2 and change of Δψ m contributed to the translocation of cytochrome c and Smac/DIABLO, which in turn caused the activation of caspase-9 and -3, and fragmentation of DNA. Materials and MethodsReagents. Ammonium acetate was purchased from Merck (Darmstadt, Germany). Cyclosporine A, MTT, PI, NP-40, rhodamine 123, Hoechst 33258, and endothelial cell growth factor were purchased from Sigma (St. Louis, MO, USA). Z-VDVAD-fmk and Z-LEHD-fmk were purchased from Santa Cruz Biotechnology (Santa Cruz, CA, USA). Protein assay reagents were obtained from Bio-Rad Laboratories (Hercules, CA, USA). Other reagents were obtained from the following sources: Annexin V-FITC (BD Pharmingen, San Jose, CA, USA), RNase A (Amresco, Solon, OH, USA), proteinase K (Clontech, Palo Alto, CA, USA), agarose (FMC BioProducts, Rockland, ME, USA), and Tris (American Biorganics, Niagara Falls, NY, USA). Antibodies to various proteins were obtained from the following sources: anticapase-3 mouse monoclonal and anti-Smac/ DIABLO rabbit polyclonal antibodies were purchased from Imgenex (San Diego, CA, USA); anticaspase-9 mouse monoclonal antibody was purchased from Upstate (Lake Placid, NY, USA); anticytochrome c mouse monoclonal antibody was purchased from BD Pharmingen; anti-β-actin monoclonal antibody was purchased from Sigma; anti-X-linked apoptosis-inhibiting protein (XIAP) mouse monoclonal antibody was purchased from BD Transduction Laboratories (Lexington, KY, USA); antipoly(ADPribose) polymerase (PARP) rabbit polyclonal antibody was purchased from Cell Signaling (Beverly, MA, USA); Endo...

Paris Saponin II of Rhizoma Paridis – A novel inducer of apoptosis in human ovarian cancer cells

“…While future studies will further determine the nature of PSII-induced apoptosis in ovarian cancer tumor cells, data from the present studies suggest that PSII treatment affects the mitochondrial apoptotic pathways. Indeed, these findings are supported by a study by Lee et al showing PSII-formosanin C induces mitochondria membrane potential collapse and the activation of essential components of the intrinsic apoptosis pathway (17).…”

“…However, the field investigating the antitumor properties of Paris saponin has only become more active in the past five years. Multiple model systems ranging from murine lung adenocarcinoma (22), human colon adenocarcinoma grade II (17), mouse lung adenocarcinoma (23) to zebrafish embryos have demonstrated that several Paris saponins can induce programmed cell death, inhibit cell migration, and inhibit tumor cell growth. Studies from our laboratories have also unraveled PSI mechanisms of action on ovarian cancer cells (5,24,33,36,39).…”

“…Because of the crucial roles of Rhizoma Paridis in traditional herbal medicines, the pharmacologically active components of Rhizoma Paridis, i.e., saponins, have been isolated. Phytochemical and pharmacological studies have further unlocked a novel therapeutic role as an anticancer agent for these steroid saponins (6,(11)(12)(13)(14)(15)(16)(17). Interestingly, like several other traditional herbal products that have gradually been used in conjunction with modern medicine in cancer treatment (18), evidence-based research into the mechanism underlying the cytotoxic effects of Paris saponin (PS) remains undefined.…”

Cyclooxygenase-2 and 5-lipoxygenase pathways in diosgenin-induced apoptosis in HT-29 and HCT-116 colon cancer cells

“…Caspase activation leads to proteolytic cleavage of specific cell substrates, including PARP (27), lamins, histone H1, as well as proteins involved in cell growth, survival and death (28). Many natural components of plant extracts induce apoptosis in HT-29 cells with caspase-3 activation and PARP cleavage (29,30). However, diosgenin-induced apoptosis in HT-29 cells was PARP-independent in comparison with HCT-116 cells where PARP cleavage was present as previously described (10).…”

Formosanin C-inhibited pulmonary metastasis through repression of matrix metalloproteinases on mouse lung adenocarcinoma

“…3 All these effects depended on the sugar moiety in the structure of formosanin C. Meanwhile, FC induced apoptosis of HT-29 cells through activation of caspase-2 and the dysfunction of mitochondria. 4 Our preliminary drug screening revealed that RPS extracted from Paris polyphylla had strong anti-lung cancer activity. [5][6][7] Formosanin C acting as the main effective constituent in RPS should be studied in detail including its antitumor and antimetastatic effects.…”