title: Synergistic effects of combined phytochemicals and skin cancer prevention in SENCAR mice.
abstract: The purpose of our study was to determine the inhibitory effect of combined phytochemicals on chemically induced murine skin tumorigenesis. Our hypothesis was that concurrent topical and dietary treatment with selected compounds would lead to more efficient prevention of skin cancer. We tested ellagic acid and calcium D-glucarate as components of diets, while resveratrol was applied topically; grape seed extract was applied topically or in the diet. The 4-week inflammatory-hyperplasia assay based on the 7,12-dimethylbenz[a]anthracene (DMBA)-induced skin carcinogenesis model in SENCAR mice was used. We have found that all the selected combinations caused a marked decrease of epidermal thickness compared with the DMBA-treated group and also with groups treated with a single compound and DMBA. All combinations of resveratrol with other compounds showed a synergistic effect on hyperplasia and Ha-ras mutations. Skin tissue of mice receiving the combinations showed decreased cell proliferation and Bcl2 expression; decreased p21, a regulator of cell cycle; and decreased marker of inflammation cyclooxygenase-2. All the selected combinations diminished the DMBA-induced mRNA expression of the CYP1B1 level, and also caused a marked decrease of proto-oncogenes c-jun and c-fos, components of transcription factor activator protein. In conclusion, all combinations showed either additive or synergistic effects and their joint actions allowed for decreasing the doses of the compounds. Especially, resveratrol combinations with ellagic acid, grape seed extract, and other phytochemicals are very potent inhibitors of skin tumorgenesis, based on the suppression of epidermal hyperplasia as well as on the modulation of intermediate biomarkers of cell proliferation, cell survival, inflammation, oncogene mutation, and apoptosis.
authors.affiliation: Department of Pharmacology, University of Texas Health Science Center at San Antonio, 78229, USA.
authors.forename: Magdalena C
authors.initials: MC
authors.lastname: Kowalczyk
authors.forename: Piotr
authors.initials: P
authors.lastname: Kowalczyk
authors.forename: Olga
authors.initials: O
authors.lastname: Tolstykh
authors.forename: Margaret
authors.initials: M
authors.lastname: Hanausek
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Walaszek
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Slaga
mesh_terms: D000287:Administration, Topical; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D018890:Chemoprevention / Q000379:methods; D004032:Diet; D004195:Disease Models, Animal; D004357:Drug Synergism; D004610:Ellagic Acid / Q000008:administration & dosage; D005260:Female; D011905:Genes, ras / Q000187:drug effects; D005937:Glucaric Acid / Q000008:administration & dosage; D056604:Grape Seed Extract / Q000008:administration & dosage; D051379:Mice; D018632:Mice, Inbred SENCAR; D009154:Mutation; D008517:Phytotherapy / Q000379:methods*; D000077185:Resveratrol; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012878:Skin Neoplasms / Q000517:prevention & control*; D013267:Stilbenes / Q000008:administration & dosage
chemical_list: D016588:Anticarcinogenic Agents; D000972:Antineoplastic Agents, Phytogenic; D056604:Grape Seed Extract; D013267:Stilbenes; D004610:Ellagic Acid; D000077185:Resveratrol; D005937:Glucaric Acid