Carcinogenicity study of γ-oryzanol in F344 rats

Tamagawa, M.; Shimizu, Yasuyoshi; Takahashi, Tsuneo; Otaka, Tadahiko; Kimura, Shota; Kadowaki, H.; Uda, Fumiaki; Miwa, T.

doi:10.1016/0278-6915(92)90135-8

Cited by 15 publications

(9 citation statements)

References 6 publications

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“…Additionally, the potential carcinogenic effect of GO was studied by feeding mice a diet containing GO up to 2 g/kg BW/day for 78 weeks (Tamagawa et al., ) and likewise, in rats during a 2‐year‐long administration (Tamagawa et al., ). No treatment‐related change was found in general condition, food consumption, mortality, organ weight and haematology.…”

Section: Safety Of Gamma‐oryzanol Supplementationmentioning

confidence: 99%

Investigation of nutriactive phytochemical – gamma‐oryzanol in experimental animal models

Szcześniak

Ostaszewski

Ciecierska

et al. 2015

Animal Physiology Nutrition

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SummaryGamma-oryzanol (GO) is an abundant dietary antioxidant that is considered to have beneficial effects in cardiovascular disease, cancer and diabetes. Other potential properties of GO include inhibition of gastric acid secretion and decreased post-exercise muscle fatigue. GO is a unique mixture of triterpene alcohol and sterol ferulates present in rice bran oil, a byproduct of rice processing. GO has been studied by many researchers over the last three decades. In particular, the utility of GO supplementation has been documented in numerous animal models. A large variety of species was examined, and various experimental methodologies and targets were applied. The aim of this study was to summarize the body of research on GO supplementation in animals and to examine possible mechanisms of GO action. Furthermore, while the safety of GO supplementation in animals has been well documented, studies demonstrating pharmacokinetics, pharmacodynamics and efficiency are less clear. The observed differences in these findings are also discussed.

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Section: Safety Of Gamma‐oryzanol Supplementationmentioning

confidence: 99%

Investigation of nutriactive phytochemical – gamma‐oryzanol in experimental animal models

Szcześniak

Ostaszewski

Ciecierska

et al. 2015

Animal Physiology Nutrition

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“…The acute toxic dose of γ-oryzanol is greater than 25 g/kg of body weight in rats and mice [ 11 ]. However, the consumption of γ-oryzanol at a dose of 2 g/kg of body weight per day for two years has been shown to be safe and non-carcinogenic in rats [ 12 ]. Therefore, rice bran oil has been commercialized as a food supplement in many countries.…”

Section: Introductionmentioning

confidence: 99%

Development of Colorectal-Targeted Dietary Supplement Tablets Containing Natural Purple Rice Bran Oil as a Colorectal Chemopreventive

et al. 2018

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Colorectal cancer occurs due to various factors. The important risks are dietary lifestyle and inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis. It has been found that the inhibitory enzyme cyclooxygenase-2 (COX-2) in the colorectal region can potentially reduce the risk of colorectal cancer. The present study investigated rice bran oil from natural purple rice bran, which exhibits antioxidant and anti-inflammatory activity. This study aimed to evaluate the bioactive compound content of natural purple rice bran oil (NPRBO) derived from native Thai purple rice and the anti-inflammatory activity of NPRBO in colorectal cancer cells, and to develop a colorectal delivery platform in the form of film-coated tablets. NPRBO from the rice bran of five different Thai purple rice cultivars, namely Khao’ Gam Leum-Phua (KGLP), Khao’ Gam Boung (KGB), Khao’ Gam Thor (KGT), Khao’ Gam Pah E-Kaw (KGPEK), and Khao’ Niaw Dam (KND), were extracted using the supercritical carbon dioxide extraction technique. The amount of γ-oryzanol (ORY), tocotrienols, and tocopherols present in NPRBOs and the in vitro anti-inflammatory activity of NPRBO were investigated. The highest anti-inflammatory NPRBO was transformed into a dry and free-flowing powder by liquisolid techniques. Then, it was compressed into core tablets and coated with Eudragit®L100 and Eudragit® NE30D. The in vitro release study of the film-coated NPRBO tablets was performed in three-phase simulated gastrointestinal media. The cultivar KGLP was superior to the other samples in terms of the ORY, tocotrienol and tocopherol contents and anti-inflammatory activity. Aerosil® was the most suitable absorbent for transforming NPRBO into a free-flowing powder and was used to prepare the NPRBO core tablets. The in vitro KGLP-NPRBO film-coated tablet release profile showed that no ORY was released at gastric pH while 85% of ORY was released at pH 7.4 after 6 h; this would be expected to occur in the colorectal area. Therefore, this study demonstrates the potential of KGLP-NPRBO to prevent colorectal cancer via a specific colorectal dietary supplement delivery system.

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“…In the Ames test, γ-oryzanol did not exhibit any mutagenicity for Salmonella and Escherichia Coli strains under conditions with and without S9 mix [28] . With regard to in vivo studies, Tamagawa et al [29] , [30] reported that oral administration of γ-oryzanol (200–2000 mg/kg body weight/day) for 79 weeks did not promote tumorigenesis in female mice (B6C3F1). Similarly, they confirmed that oral administration of γ–oryzanol for 105 weeks had no negative effects in F344 male rats Tamagawa et al [29] , [30] .…”

Section: Discussionmentioning

confidence: 99%

“…With regard to in vivo studies, Tamagawa et al [29] , [30] reported that oral administration of γ-oryzanol (200–2000 mg/kg body weight/day) for 79 weeks did not promote tumorigenesis in female mice (B6C3F1). Similarly, they confirmed that oral administration of γ–oryzanol for 105 weeks had no negative effects in F344 male rats Tamagawa et al [29] , [30] . The administration periods and doses exceeded those used in the current study for examination of subacute toxicity and these previous studies demonstrated that γ-oryzanol does not show carcinogenicity.…”

Section: Discussionmentioning

confidence: 99%

Ninety-day oral toxicity study of rice-derived γ-oryzanol in Sprague-Dawley rats

Moon¹,

Kim²,

Shimizu

et al. 2017

Toxicology Reports

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A 90-day oral toxicity study of γ-oryzanol, a rice-derived triterpenoid ferulate, was performed by oral gavage administration to male and female Sprague-Dawley rats at doses of 0, 1000, and 2000 mg/kg body weight/day. All rats administered γ-oryzanol survived throughout the study period. Both male and female rats showed no toxicologically significant changes of the general signs, examination findings, body weight, food consumption, functional observational battery results, ophthalmological findings, urinalysis, hematology tests, clinical chemistry tests, organ weights, and necropsy findings. Moreover, there were no histopathological changes related to administration of γ-oryzanol in males and females from the 2000 mg/kg body weight/day group. In conclusion, the no observed adverse effect level (NOAEL) of γ-oryzanol exceeded 2000 mg/kg body weight/day for both male and female rats under the conditions of this study.

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Carcinogenicity study of γ-oryzanol in F344 rats

Cited by 15 publications

References 6 publications

Investigation of nutriactive phytochemical – gamma‐oryzanol in experimental animal models

Investigation of nutriactive phytochemical – gamma‐oryzanol in experimental animal models

Development of Colorectal-Targeted Dietary Supplement Tablets Containing Natural Purple Rice Bran Oil as a Colorectal Chemopreventive

Ninety-day oral toxicity study of rice-derived γ-oryzanol in Sprague-Dawley rats

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