title: Inhibitory effects of glycolipids fraction from spinach on mammalian DNA polymerase activity and human cancer cell proliferation.
abstract: We succeeded in purifying the fraction containing the major glycolipids in monogalactosyl diacylglycerol, digalactosyl diacylglycerol and sulfoquinovosyl diacylglycerol (SQDG) from dried vegetables. This glycolipids fraction was an inhibitor of DNA polymerase alpha (pol alpha) in vitro and also the proliferation of human cancer cells. In this study, eight common vegetables were investigated in terms of the glycolipids fraction, the amounts of major glycolipids, mammalian DNA polymerase inhibitory activity and antiproliferative activity toward human cancer cells. Green tea possessed the largest amount of glycolipids overall. Spinach contained the largest amount of SQDG, followed by parsley, green onion, chive, sweet pepper, green tea, carrot and garlic. Spinach had the strongest inhibitory effect on pol alpha activity and human cancer cell proliferation. A significant correlation was found between SQDG content and inhibition of DNA polymerase. Therefore, the inhibition of pol alpha activity by SQDG may lead to cell growth suppression. Of the six subspecies of spinach (Spinacia oleracea) tested, "Anna" had the largest amount of SQDG, strongest inhibitory activity toward DNA polymerase and greatest effect on human cancer cell proliferation. Based on these results, the glycolipids fraction from spinach is potentially a source of food material for a novel anticancer activity.
authors.affiliation: Department of Nutritional Science, Laboratory of Food and Nutritional Sciences, Kobe-Gakuin University, Kobe, Hyogo 651-2180, Japan.
authors.forename: Isoko
authors.initials: I
authors.lastname: Kuriyama
authors.forename: Keiichi
authors.initials: K
authors.lastname: Musumi
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yonezawa
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takemura
authors.forename: Naoki
authors.initials: N
authors.lastname: Maeda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Iijima
authors.forename: Takahiko
authors.initials: T
authors.lastname: Hada
authors.forename: Hiromi
authors.initials: H
authors.lastname: Yoshida
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Mizushina
mesh_terms: D000818:Animals; D002417:Cattle; D002455:Cell Division / Q000187:drug effects*; D045744:Cell Line, Tumor; D004256:DNA Polymerase I / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006017:Glycolipids / Q000032:analysis / Q000302:isolation & purification* / Q000494:pharmacology*; D006801:Humans; D009369:Neoplasms / Q000473:pathology*; D018515:Plant Leaves / Q000737:chemistry; D018724:Spinacia oleracea / Q000737:chemistry*; D013274:Stomach Neoplasms; D014675:Vegetables / Q000737:chemistry
chemical_list: D004791:Enzyme Inhibitors; D006017:Glycolipids; D004256:DNA Polymerase I