Of humans and hamsters: a comparative evaluation of carcinogen activation, DNA damage, cell proliferation, apoptosis, invasion, and angiogenesis in oral cancer patients and hamster buccal pouch carcinomas.

The hamster buccal pouch (HBP) carcinogenesis model is one of the most well characterized animal systems for analyzing the development of oral squamous cell carcinoma (OSCC), a common malignancy worldwide. HBP carcinomas that closely mimic human OSCC are useful in understanding the molecular mechanisms of neoplastic transformation. The present study is a comparative evaluation of markers of carcinogen activation, oxidative stress, cell proliferation, apoptosis, invasion, and angiogenesis in human and hamster OSCCs.

In vitro antioxidative potential of lactoferrin and black tea polyphenols and protective effects in vivo on carcinogen activation, DNA damage, proliferation, invasion, and angiogenesis during experimental oral carcinogenesis.

The present study was designed to evaluate the in vitro antioxidant potential of bovine lactoferrin (bLF) and black tea polyphenols [Polyphenon-B (P-B)] as well as in vivo inhibitory effects on the development of 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinomas. Antioxidant activity was screened using a panel of assays including 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), hydroxyl radical anion (OH*), superoxide anion (O2*-), and nitric oxide (NO) radical scavenging assays as well as assay for reducing power. The chemopreventive potential of bLF and P-B was assessed in the HBP model based on the modulatory effects on DMBA-induced oxidative DNA damage as well as the expression of proteins associated with carcinogen activation (CYP1A1, CYP1B1), cell proliferation [cyclin D1, proliferating cell nuclear antigen (PCNA), glutathione S-transferase pi (GST-P)], angiogenesis [vascular endothelial growth factor (VEGF), VEGF receptor 1 (VEGFR1)], and invasion and metastasis [matrix metalloproteinase-9 (MMP-9) and tissue inhibitors of MMP-2 (TIMP-2)].

Evaluation of Azadirachta indica leaf fractions for in vitro antioxidant potential and in vivo modulation of biomarkers of chemoprevention in the hamster buccal pouch carcinogenesis model.

We evaluated the chemopreventive potential of Azadirachta indica (neem) leaf fractions based on in vitro antioxidant assays, and in vivo inhibitory effects on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. In addition we also identified the major constituents in neem leaf fractions by HPLC. Analysis of the free radical scavenging activities and reducing potential of crude ethanolic extract (CEE), ethyl acetate fraction (EAF) and methanolic fraction (MF) of neem leaf revealed a concentration-dependent increase in antioxidant potential that was in the order EAF>MF>CEE.

Combination chemoprevention of hamster buccal pouch carcinogenesis by bovine milk lactoferrin and black tea polyphenols.

Combination chemoprevention is a promising approach for oral cancer prevention. The authors evaluated the combined chemopreventive effects of bovine milk lactoferrin (bLF) and black tea polyphenols (Polyphenon-B) in a clinically relevant in vivo model of 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Although dietary administration of bLF and Polyphenon-B alone significantly reduced the tumor incidence, combined administration of bLF and polyphenon-B was more effective in inhibiting DMBA-induced genotoxicity and development of HBP carcinomas by modulation of carcinogen-metabolizing enzymes and cellular redox status.

Comparative evaluation of antiproliferative, antiangiogenic and apoptosis inducing potential of black tea polyphenols in the hamster buccal pouch carcinogenesis model.

Background: To evaluate the relative chemopreventive efficacy of two black tea polyphenols, Polyphenon-B [P-B] and BTF-35 on 7,12-dimethylbenz [a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis.

Methods: Hamsters were divided into 6 groups. The right buccal pouches of animals in groups 1-3 were painted with 0.