Mutation Research 497 (2001) 213–222 Antioxidative and antimutagenic activity of yeast cell wall mannans in vitro L´ ıvia Križková a,∗ , Zdena ˇ Duraˇ cková b , Jozef Šandula c , Vlasta Sasinková c , Juraj Krajˇ coviˇ c a a Institute of Cell Biology, Faculty of Natural Sciences, Comenius University, Odborárske námestie 5, 811 07 Bratislava, Slovak Republic b Department of Medical Chemistry, Biochemistry and Clinical Biochemistry, Faculty of Medicine, Comenius University, Sasinkova 2, 813 72 Bratislava, Slovak Republic c Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 842 38 Bratislava, Slovak Republic Received 10 April 2001; received in revised form 19 June 2001; accepted 26 June 2001 Abstract Antioxidative and antimutagenic effect of yeast cell wall mannans, in particular, extracellular glucomannan (EC-GM) and glucomannan (GM-C.u.) both from Candida utilis, mannan from Saccharomyces cerevisiae (M-S.c.) and mannan from Candida albicans (M-C.a.) was evaluated. Luminol-dependent photochemical method using trolox as a standard showed that EC-GM, GM-C.u., M-S.c. and M-C.a. have relatively good antioxidative properties. EC-GM exhibited the highest antioxidative activity, followed by GM-C.u. and M-S.c. M-C.a. showed the least antioxidative activity. These mannans were experimentally confirmed to exhibit different, statistically significant antimutagenic activity in reducing damage of chloroplast DNA of the flagellate Euglena gracilis induced by ofloxacin and acridine orange (AO). We suggest that the antimutagenic effect of EC-GM, GM-C.u., M-S.c. and M-C.a. against ofloxacin is based on their ability to scavenge reactive oxygen radicals. With AO, the reduction of the chloroplast DNA lession could be a result of the absorptive capacity of the mannans. The important characteristics of mannans isolated from the yeast cell walls, such as good water solubility, relatively small molecular weight (15–30 kDa), and antimutagenic effect exerted through different mode of action, appear to be a promising features for their prospective use as a natural protective (antimutagenic) agents. © 2001 Elsevier Science B.V. All rights reserved. Keywords: Yeast cell wall mannans; Candida utilis; Candida albicans; Saccharomyces cerevisiae; Euglena gracilis; Ofloxacin; Acridine orange; Antioxidant; Antimutagenicity 1. Introduction There is consistent experimental and epidemiologi- cal evidence that naturally occurring compounds have the ability to protect against certain types of muta- gens and carcinogens. Polysaccharides isolated from the cell wall of various yeasts are one such cate- ∗ Corresponding author. Tel.: +42-1-7-55577476; fax: +42-1-7-55424902. E-mail address: krizkova@m2.fedu.uniba.sr (L. Križkov´ a). gory of naturally occurring agents. The cell wall of yeasts is composed of complex polymers of -glucans, -mannans, mannoproteins and a minor component of chitin. The main constituents are -glucans accounting for 50–60% of the cell wall weight. They form a rigid skeleton, responsible for the shape of the cell and its physical strength and show a wide range of immunode- termining activity [1,2]. The mannans and mannopro- teins represent 30–40% of the cell wall and determine the cell surface properties. They have not only im- portant physiological functions but their carbohydrate 1383-5718/01/$ – see front matter © 2001 Elsevier Science B.V. All rights reserved. PII:S1383-5718(01)00257-1