Inhibitory effect of conjugated eicosapentaenoic acid on mammalian DNA polymerase and topoisomerase activities and human cancer cell proliferation.

Conjugated eicosapentaenoic acid (cEPA) selectively inhibited the activities of mammalian DNA polymerases (pols) and human DNA topoisomerases (topos) [Yonezawa Y, Tsuzuki T, Eitsuka T, Miyazawa T, Hada T, Uryu K, et al. Inhibitory effect of conjugated eicosapentaenoic acid on human DNA topoisomerases I and II. Arch Biochem Biophys 2005;435:197-206].

Structural analysis of isosteviol and related compounds as DNA polymerase and DNA topoisomerase inhibitors.

Isosteviol (ent-16-ketobeyeran-19-oic acid) is a hydrolysis product of stevioside, which is a natural sweetener produced in the leaves of Stevia rebaudiana (Bertoni) Bertoni. In this report, we prepared isosteviol and related compounds from stevioside by microbial transformation and chemical conversion and assayed the inhibitory activities toward DNA metabolic enzymes and human cancer cell growth. Among twelve compounds obtained, only isosteviol (compound 3) potently inhibited both mammalian DNA polymerases (pols) and human DNA topoisomerase II (topo II), and IC50 value for pol alpha was 64.

Effects of DNA polymerase inhibitory and antitumor activities of lipase-hydrolyzed glycolipid fractions from spinach.

We succeeded in purifying the major glycolipid fraction in the class of sulfoquinovosyl diacylglycerol, monogalactosyl diacylglycerol and digalactosyl diacylglycerol (DGDG) from a green vegetable, spinach (Spinacia oleracea L.). This glycolipid fraction was an inhibitor of DNA polymerases and a growth inhibitor of NUGC-3 human gastric cancer cells, and, interestingly, the activities were much stronger when the fraction was hydrolyzed by lipase.

Inhibitory effect of conjugated eicosapentaenoic acid on human DNA topoisomerases I and II.

DNA topoisomerases (topos) and DNA polymerases (pols) are involved in many aspects of DNA metabolism such as replication reactions. We reported previously that long chain unsaturated fatty acids such as polyunsaturated fatty acids (PUFA) (i.e.

The effects of dehydroaltenusin, a novel mammalian DNA polymerase alpha inhibitor, on cell proliferation and cell cycle progression.

As described previously, a natural product isolated from fungus (Acremonium sp.), dehydroaltenusin, is an inhibitor of mammalian DNA polymerase alpha in vitro [Y. Mizushina, S.