Suppression of glutathione S-transferase placental form-positive foci development in rat hepatocarcinogenesis by Chlorella pyrenoidosa.
The modifying effects of dietary administration of dried Chlorella pyrenoidosa powder (C. pyrenoidosa) on the development of glutathione S-transferase placental form-positive foci (GST-P-positive foci), which are putative preneoplastic lesions, in male F344 rats were investigated using a medium-term liver bioassay system. In rats given 10% C. pyrenoidosa in a basal diet, the number and area of GST-P-positive foci in the rat livers, which diethylnitrosamine (DEN) initiated and 2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline (MeIQx) promoted, were significantly decreased compared with those fed a basal diet not containing C. pyrenoidosa. The inhibition percentage of the number and area of GST-P-positive foci > or =0.2 mm in diameter was 67.6 and 74.2%, respectively (p<0.01). Furthermore, C. pyrenoidosa significantly decreased the number of GST-P-positive foci induced by MeIQx alone. The inhibition percentage of the number of GST-P-positive foci <0.2 mm in diameter was 52% (p<0.01). These results suggest that C. pyrenoidosa has chemopreventive effects against hepatocarcinogenesis in rats. C. pyrenoidosa appears to be a promising chemopreventive agent for human liver neoplasia and carcinogenesis induced by heterocyclic amines such as MeIQx.
Takekoshi
Hideo
H
Sun Chlorella Corp., 369 Osaka-cho, Karasuma-dori Gojo, Shimogyo-ku, Kyoto 600-8177, Japan. htakekoshi@sunchlorella.co.jp
Mizoguchi
Toru
T
Komasa
Yoko
Y
Chubachi
Hirofumi
H
Inoue
Yukari
Y
Imanishi
Hideyo
H
Nakano
Masuo
M
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002708:Chlorella; D004032:Diet; D004052:Diethylnitrosamine / Q000008:administration & dosage / Q000633:toxicity; D004435:Eating; D005982:Glutathione Transferase / Q000378:metabolism*; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D008113:Liver Neoplasms / Q000139:chemically induced / Q000201:enzymology / Q000517:prevention & control*; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011810:Quinoxalines / Q000008:administration & dosage / Q000633:toxicity; D051381:Rats; D011916:Rats, Inbred F344; D016896:Treatment Outcome
D007527:Isoenzymes; D011810:Quinoxalines; D004052:Diethylnitrosamine; C036990:2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline; D005982:Glutathione Transferase