title: Dietary feeding of Opuntia humifusa inhibits UVB radiation-induced carcinogenesis by reducing inflammation and proliferation in hairless mouse model.
abstract: It has been validated that ultraviolet B (UVB) irradiation induced both squamous and basal cell carcinomas, as a tumor initiator and promoter. Opuntia humifusa is a member of the Cactaceae family which has been demonstrated in our previous study to have a chemopreventive effect in 7, 12-dimethylbenz[a]anthracene and 12-O-tetradecanoylphorbol-13-acetate induced skin carcinogenesis models. Therefore, this study was designed to determine the protective effects of O. humifusa against photocarcinogenesis. O. humifusa was administrated to mice as a dietary feeding, following exposure to UVB radiation (180 mJ/cm(2)) twice a week of 30 weeks for skin tumor development in hairless mice. Dietary O. humifusa inhibited UVB-induced epidermal hyperplasia, infiltration of leukocytes, level of myeloperoxidase and the levels of proinflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), in UVB exposed skin. Also, O. humifusa significantly inhibited both protein and mRNA expression level of cyclooxygenase-2 (COX-2), nitric oxide synthase (iNOS), proliferating cell nuclear antigen (PCNA) and cyclin D1 compared to the non-O. humifusa treated group. Collectively, these results suggest that O. humifusa could inhibit photocarcinogenesis in mouse skin and that protective effect is associated with the inhibition of not only UVB-induced inflammatory responses involving COX-2, iNOS and proinflammatory cytokines, but also the down-regulation of UVB-induced cellular proliferation.
authors.affiliation: Department of Veterinary Infectious Disease, College of Veterinary Medicine, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Jin-A
authors.initials: JA
authors.lastname: Lee
authors.forename: Bock-Gie
authors.initials: BG
authors.lastname: Jung
authors.forename: Tae-Hoon
authors.initials: TH
authors.lastname: Kim
authors.forename: Su-Gil
authors.initials: SG
authors.lastname: Lee
authors.forename: Young-Seok
authors.initials: YS
authors.lastname: Park
authors.forename: Bong-Joo
authors.initials: BJ
authors.lastname: Lee
mesh_terms: D000818:Animals; D001483:Base Sequence; D063646:Carcinogenesis; D002273:Carcinogens / Q000633:toxicity; D016207:Cytokines / Q000378:metabolism; D017931:DNA Primers; D004195:Disease Models, Animal; D005260:Female; D051379:Mice; D008812:Mice, Hairless; D016328:NF-kappa B / Q000378:metabolism; D009381:Neoplasms, Radiation-Induced / Q000517:prevention & control*; D029747:Opuntia; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D012867:Skin / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D012878:Skin Neoplasms / Q000517:prevention & control*; D013755:Tetradecanoylphorbol Acetate / Q000633:toxicity; D014466:Ultraviolet Rays
chemical_list: D002273:Carcinogens; D016207:Cytokines; D017931:DNA Primers; D016328:NF-kappa B; D013755:Tetradecanoylphorbol Acetate