title: Dietary beta-cryptoxanthin inhibits N-butyl-N-(4-hydroxybutyl)nitrosamine-induced urinary bladder carcinogenesis in male ICR mice.
abstract: Recent epidemiological studies have indicated that high dietary consumption of fruit and vegetables results in lower risk of bladder cancer. To confirm these findings, we investigated in the current study the effects of dietary administration with beta-cryptoxanthin extracted from Citras unshiu oranges on N-butyl-N-(4-hydroxybutyl)nitrosamine (OH-BBN)-induced urinary bladder carcinogenesis in mice. Male ICR mice were divided into 6 experimental and control groups. Groups 1 through 4 were given OH-BBN (500 ppm) in drinking water for 6 weeks to induced urinary bladder neoplasms. Mice in groups 2, 3 and 4 were fed the diets mixed with 1, 5 and 25 ppm of beta-cryptoxanthin, respectively, starting 1 week after the cessation of OH-BBN exposure, and kept on these diets for 24 weeks until the termination of the study. Group 5 was treated with the diet containing the test compound (25 ppm) alone, and group 6 served as an untreated control. All animals were sacrificed at week 32 for histopathology and immunohistochemistry (cyclin D1). Feeding with beta-cryptoxanthin decreased the incidence and multiplicity of preneoplastic and neoplastic lesions of urinary bladder. Notably, the highest dose (25 ppm) of the test chemical significantly lowered the occurrence of bladder carcinoma, in conjunction with reducing the cyclin D1-positive cell ratio. These findings suggest that beta-cryptoxanthin is able to prevent OH-BBN-induced bladder carcinogenesis in mice.
authors.affiliation: Department of Urogenital Surgery, Kanazawa Medical University, Ishikawa 920-0293, Japan.
authors.forename: Katsuhito
authors.initials: K
authors.lastname: Miyazawa
authors.forename: Shingo
authors.initials: S
authors.lastname: Miyamoto
authors.forename: Rikako
authors.initials: R
authors.lastname: Suzuki
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Yasui
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Ikeda
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kohno
authors.forename: Masamichi
authors.initials: M
authors.lastname: Yano
authors.forename: Takuji
authors.initials: T
authors.lastname: Tanaka
authors.forename: Kazuya
authors.initials: K
authors.lastname: Hata
authors.forename: Koji
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D002085:Butylhydroxybutylnitrosamine; D002273:Carcinogens; D065366:Cryptoxanthins; D019938:Cyclin D1 / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D001749:Urinary Bladder Neoplasms / Q000139:chemically induced* / Q000188:drug therapy* / Q000517:prevention & control; D024341:Xanthophylls / Q000494:pharmacology*
chemical_list: D016588:Anticarcinogenic Agents; D002273:Carcinogens; D065366:Cryptoxanthins; D024341:Xanthophylls; D019938:Cyclin D1; D002085:Butylhydroxybutylnitrosamine