Can Forage Grasses inhibit Prion Replication ?
Tomofumi Miyamoto^ Rie Sadatomi\ Hiroyuki Tanaka^ Ryuichi Higu- chi\ Satoshi Kawatake^ and Katsumi Doh-ura^
^Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 Japan ^Dept. of Prion Re- search, Tohoku University School of Medicine
<e-mail> miyamoto@phar.kyushu-u.ac.jp
Abstract
Prion diseases are a group of fatal neurodegenerative disorders, and thought to be caused by the accumulation of an infectious prote- ase-resistant isoform of prion protein (PrP^^). Mysteriously, the cattle exposed to infectious feed do not necessarily catch bovine spongiform en- cephalopathy (BSE). For one reason, we assumed that some constituents in forage grasses inhibit the infection of BSE. We therefore investigated whether some forage grasses show inhibitory effects on the formation of PrP^^
We collected six common forage grasses, Italian ryegrass (Lolium mul- tiflorum). Eastern gamagrass (Tripsacum dactyloides). Reed canarygrass (Phalaris arundinacea), Kikuyugrass (Pennisetum dandestinum), Bahia grass (Paspalum notatum), and Bermuda grass (Cynodon dactylon), and then prepared their EtOH extract.
First, we examined whether each extract show the affinity for endoge- nous cellular prion protein (PrP^) with the competitive enzyme-linked im- munosorbent assay (ELISA). In consequence, Italian ryegrass extract showed the potent affinity for PrP*^.
We then investigated with prion-infected neuroblastoma cells (ScN2a and F3) whether Italian ryegrass extract inhibits the formation of PrP^^.
In a preliminary examination, we found that EtOH extract of Italian rye- grass inhibited the PrP^^ formation in a dose-dependent manner. These findings suggest that some constituents in forage grasses might be useful for the prevention of prion diseases.
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