Chlorophyllin abrogates canonical Wnt/β-catenin signaling and angiogenesis to inhibit the development of DMBA-induced hamster cheek pouch carcinomas.

Background: Chlorophyllin, a water soluble semi-synthetic food-grade derivative is reported to exhibit a wide range of beneficial health effects. We investigated the effect of chlorophyllin supplementation on Wnt/β-catenin and vascular endothelial growth factor (VEGF) signaling in the 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis model.

Methods And Results: Hamsters were divided into 4 groups.

Investigation of the chemopreventive potential of neem leaf subfractions in the hamster buccal pouch model and phytochemical characterization.

Chemoprevention by medicinal plants has evolved as a practical strategy to control the incidence of cancer. Azadirachta indica (neem) containing various bioactive components is a promising candidate for chemoprevention. The present study was undertaken to evaluate the chemopreventive efficacy of the bioactive subfractions ethyl acetate chloroform insoluble fraction (ECIF) and the methanol ethyl acetate insoluble fraction (MEIF) following activity-guided fractionation of neem leaf extract.

Gene expression signature of DMBA-induced hamster buccal pouch carcinomas: modulation by chlorophyllin and ellagic acid.

Chlorophyllin (CHL), a water-soluble, semi-synthetic derivative of chlorophyll and ellagic acid (EA), a naturally occurring polyphenolic compound in berries, grapes, and nuts have been reported to exert anticancer effects in various human cancer cell lines and in animal tumour models. The present study was undertaken to examine the mechanism underlying chemoprevention and changes in gene expression pattern induced by dietary supplementation of chlorophyllin and ellagic acid in the 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis model by whole genome profiling using pangenomic microarrays. In hamsters painted with DMBA, the expression of 1,700 genes was found to be altered significantly relative to control.

Nimbolide, a neem limonoid abrogates canonical NF-κB and Wnt signaling to induce caspase-dependent apoptosis in human hepatocarcinoma (HepG2) cells.

Nuclear factor kappa B (NF-κB), an oncogenic signaling factor plays a critical role in the development and progression of various cancers. The objective of this study was to investigate the effect of nimbolide, a neem derived tetranortriterpenoid on NF-κB signaling and its downstream events - Wnt/β-catenin activation and apoptosis evasion in human hepatocarcinoma (HepG2) cells by evaluating NF-κB family members (NF-κB-p50, p65, IκB-α, p-IκB-α, and IKKβ), members of Wnt signaling (GSK-3β and β-catenin), and intrinsic apoptosis (Bcl-2, Bax, cytochrome c, Smac/DIABLO, caspase-3, and caspase-9). Our results demonstrate that nimbolide concurrently abrogates canonical NF-κB and Wnt signaling and induces intrinsic apoptosis in HepG2 cells.

Ellagic acid coordinately attenuates Wnt/β-catenin and NF-κB signaling pathways to induce intrinsic apoptosis in an animal model of oral oncogenesis.

Purpose: Constitutive activation of the Wnt signaling pathway and its downstream effectors plays a key role in neoplastic transformation. The objective of this study was to investigate the effect of ellagic acid, a plant-derived polyphenol on Wnt/β-catenin signaling and its downstream circuits- NF-κB and mitochondrial apoptosis in the 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis model.

Methods: Hamsters were divided into six groups.

Quercetin suppresses cytochrome P450 mediated ROS generation and NFκB activation to inhibit the development of 7,12-dimethylbenz[a]anthracene (DMBA) induced hamster buccal pouch carcinomas.

Increased production of reactive oxygen species (ROS) has long been recognized to play a pivotal role in carcinogenesis. Quercetin, a naturally occurring dietary flavonoid is known for its ROS scavenging properties. The present study was designed to investigate the chemopreventive and chemotherapeutic effects of quercetin based on cytochrome P450 (CYP) mediated ROS generation, ROS-induced cellular damage and activation of the NFκB signalling circuit during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis.

Aberrant activation of Wnt/β-catenin signaling pathway contributes to the sequential progression of DMBA-induced HBP carcinomas.

Wnt signaling pathway mediated via interactions between β-catenin and members of the TCF/LEF-1 family of transcription factors plays a central role in the regulation of epithelial cell proliferation, apoptosis, differentiation, adhesion, epithelial-mesenchymal transition, and invasion. Aberrant activation of the Wnt/β-catenin signaling pathway with overexpression of Wnt and Fz, mutations of APC, β-catenin, and axin 1, and cytoplasmic accumulation of β-catenin have been frequently reported in a broad spectrum of human malignancies including oral squamous cell carcinomas (OSCCs). However, changes in the components of the Wnt signaling pathway have not been documented during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis, a paradigm for oral oncogenesis and chemointervention.

Cancer chemoprevention by dietary phytochemicals: promises and pitfalls.

Research over the past decade has provided convincing evidence to support the premise that phytochemicals from the diet offer protection against cancer risk. A large number of dietary phytochemicals have been demonstrated to exhibit anticancer activities by interfering with multiple signaling pathways aberrant in cancer. These agents target a plethora of cellular molecules and molecular pathways including xenobiotic-metabolizing enzymes, reactive oxygen species, inflammation, cell cycle, apoptosis, invasion, angiogenesis, transcription factors, and protein kinases.

The flavonoid quercetin modulates the hallmark capabilities of hamster buccal pouch tumors.

Epidemiological studies have consistently demonstrated the protective effects of dietary phytochemicals against cancer risk. Quercetin, a ubiquitous dietary flavonoid, has attracted considerable attention owing to its potent antioxidant and antiproliferative activities. The present study was designed to investigate the chemopreventive as well as the therapeutic ability of quercetin to modulate the key hallmark capabilities of 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinomas.

Eugenol induces apoptosis and inhibits invasion and angiogenesis in a rat model of gastric carcinogenesis induced by MNNG.

Aims: Combining apoptosis induction with anti-invasive and anti-angiogenic treatment is gaining increasing attention as a promising strategy for cancer chemoprevention. In the present study, eugenol (4-allyl-2-methoxyphenol) was evaluated for its chemopreventive effects on N-methyl-N(')-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis in Wistar rats by analyzing markers of apoptosis, invasion and angiogenesis.

Main Methods: The expressions of markers of apoptosis (Bcl-2, Bcl-xL, Bax, Apaf-1, cytochrome C, caspase-9, caspase-3 and poly(ADP-ribose)polymerase; PARP), invasion (matrix metalloproteinase-2; MMP-2, matrix metalloproteinase-9; MMP-9, reversion-inducing cysteine rich protein with Kazal motifs; RECK and tissue inhibitors of metalloproteinase-2; TIMP-2) and angiogenesis (vascular endothelial growth factor; VEGF and VEGF receptor1; VEGFR1) in stomach tissue of experimental and control animals were measured by gelatin zymogram, immunohistochemical, Western blot and RT-PCR analysis.

The neem limonoids azadirachtin and nimbolide inhibit hamster cheek pouch carcinogenesis by modulating xenobiotic-metabolizing enzymes, DNA damage, antioxidants, invasion and angiogenesis.

The neem tree has attracted considerable research attention as a rich source of limonoids that have potent antioxidant and anti-cancer properties. The present study was designed to evaluate the chemopreventive potential of the neem limonoids azadirachtin and nimbolide based on in vitro antioxidant assays and in vivo inhibitory effects on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis. Both azadirachtin and nimbolide exhibited concentration-dependent anti-radical scavenging activity and reductive potential in the order: nimbolide > azadirachtin > ascorbate.