Dietary supplement of isohumulones inhibits the formation of aberrant crypt foci with a concomitant decrease in prostaglandin E2 level in rat colon
✍ Scribed by Hajime Nozawa; Wakako Nakao; Feng Zhao; Keiji Kondo
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 488 KB
- Volume
- 49
- Category
- Article
- ISSN
- 1613-4125
No coin nor oath required. For personal study only.
✦ Synopsis
Male Fischer 344 rats were subcutaneously injected with azoxymethane (AOM) twice weekly at a dose of 15 mg/kg and were fed with freeze-dried (FD) samples of beer brewed without hops (nonhops beer), beer with hops at 4 times the amount of regular lager beer (64-hops beer), and isomerized hop extract (IHE) for the whole experimental period (I/PI) or for the post-initiation period (PI) only. Feeding FD beer samples at a dose of 1% significantly decreased the number of aberrant cryp foci (ACF) in the PI protocol over five weeks.64-hops beer showed stronger inhibitory effects on the development of the numbers of aberrant crypts per focus and large ACF with four or more crypts than non-hops beer. Feeding IHE to rats at a dose of 0.01% or 0.05% in either the I/PI or PI experiment significantly reduced the numbers of ACF. Prostaglandin E2 (PGE2) levels in colonic mucosa of AOM-treated rats were significantly reduced by feeding of IHE. PGE2 production induced by lipopolysaccharide/interferon-c (LPS/IFN-c) in RAW264.7 cells was also reduced by treatment with IHE and isohumulone in a dose-dependent manner. These observations suggest that isohumulones show chemopreventive effects on ACF formation in rat colon by inhibiting the production of PGE2.