In vitro evaluation of the anticancer effect of lactoferrin and tea polyphenol combination on oral carcinoma cells

Abstract

We investigated the anticancer effects of green and black tea polyphenols alone and in combination with bovine milk lactoferrin (bLF) on human tongue squamous carcinoma (CAL-27) and normal human gingival fibroblast (HGF) cells. Both green (Polyphenon-E;P-E) and black tea polyphenols (Polyphenon-B;P-B) preferentially inhibit the growth of CAL-27 cells in a dose-dependent manner. Based on the IC(50) values, P-E was found to be more effective than P-B and the combination of P-E and bLF (1:2 ratio) exhibited synergistic inhibition of CAL-27 cells. Analysis of the mechanism revealed nuclear fragmentation and condensation with appearance of the A(o) peak indicative of apoptosis. Furthermore, tea polyphenols transduced the apoptosis signal via generation of reactive oxygen species and decrease in the Bcl-2/Bax ratio thereby inducing mitochondrial permeability transition with consequent activation of caspase-3. Overall, the potency of cytotoxic and apoptosis inducing effects of dietary agents on CAL-27 cells was in the order P-E and bLF combination (1:2 ratio)>P-E>P-B. These results suggest that a "designer" approach may be useful for oral cancer prevention strategies.

Bcl-2 family proteins and cancer

“…Several chemical inhibitors of antiapoptotic Bcl-2-family proteins based on mimicking BH3 peptides have been described (Wang et al, 2000a, b;Degterev et al, 2001;Enyedy et al, 2001;Tzung et al, 2001;Kutzki et al, 2002;Leone et al, 2003;Becattini et al, 2004;Pellecchia and Reed, 2004;Walensky et al, 2004;Oltersdorf et al, 2005;Mohan et al, 2007;Nguyen et al, 2007;Kitada et al, 2008), and at least three of these agents are currently being tested in human clinical trials for cancer (reviewed by Reed and Pellecchia, 2005). The structural basis for activation of Bax and Bak by BH3 peptides has not yet been reported.…”

Pro-apoptotic and anti-proliferative effects of corn silk extract on human colon cancer cell lines

“…On the second day, the membranes were incubated with the relevant secondary antibodies (1:2,000) for 90 min at room temperature. Finally, the transferred proteins were visualized using diaminobenzidine as previously described (18,19).…”

Antiproliferative Properties of Methanolic Extract of Nigella sativa against the MDA-MB-231 Cancer Cell Line

“…Expression levels of Bax (pro-apoptotic) and Bcl (antiapoptotic) gene level provide further information regarding apoptosis. Some of the natural compounds such as flavonoids and polyphenols have shown a significant induction of Bax and depletion in Bcl-2 for an induction of apoptosis-mediated cell death (Mohan et al, 2007). Thymoquine, a volatile active principle of NS, has shown an induction of apoptosis in colon cancer cells (GaliMuhtasib et al, 2006) and HeLa cells (Shafi et al, 2009).…”