Mutagenic activity of peloids in the Salmonella Ames test Katalin Szendi ⁎, Gellért Gerencsér, Edit Murányi, Csaba Varga Department of Environmental Health, Institute of Public Health Medicine, University of Pécs, Hungary abstract article info Article history: Received 6 October 2010 Received in revised form 27 September 2011 Accepted 30 September 2011 Available online xxxx Keywords: Peloid Genotoxicity Salmonella Ames test Toxicological risk The mechanism of action of peloids (medicinal muds) applied in spa therapy has been mostly unknown, especially in aspect of chemical features. Recently, several organic compounds have been detected from spa waters using gas chromatographic methods, without exact knowledge on biological activity. They may have important roles in therapy, but may possess carcinogenic and other toxic properties, as well. This aim requires severe methodological developments in this field. In the present paper two peloid samples from Hévíz (West-Hungary) and Kolop (East-Hungary) were tested. We performed two types of experiments on peloids, at first without any pre-treatment (in toto), and in the second set of experiment aqueous, hydrochloric acidic, methanol and toluene extracts of peloids were prepared for mutagenicity testing. The solvent extraction study was repeated twice. The objective of this study was to detect complex genotoxic effects of peloids, the risk assessment and protection of the exposed population. In the in toto experiment there was no statistically significant mutagenicity. The solvent extraction studies represented statistically significant mutagenicity in several fractions. Mutagenicity in samples was fluctuating. In the first study more mutagenic fractions were found. In the repeated experiment the mutagenic pattern was almost completely different, only minimal overlapping occurred. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Mud treatment is a very popular part of spa therapy. Medical muds (peloids) are fine granular materials having good water binding and heat retaining capacity, making them suitable for preparation of peloid wraps, mud baths and packs. These treatments may be recom- mended for wide range of diseases, including osteoarthritis, gyneco- logical disorders, sciatica, skin diseases, trauma, but preferably for rheumatic disorders, and other different afflictions and ailments (Bender et al., 2002, 2005). Balneotherapy is an integrated part of clinical medicine in several European countries. Although these treat- ments are frequently used in therapy or prevention, the side-effects of spa waters and peloids are mostly unknown. We also have limited evidence of the positive, healing effects of muds. However, many of the studies suffer from methodological biases, and so may not be entirely reliable (Verhagen et al., 1997). During the last decades several organic compounds were detected using gas chromatography, high pressure liquid chromatography (HPLC) and mass spectrometry. We have, however, limited information on their presence in medical muds, interactions or biological activity in- volving carcinogenicity and other specific toxicity (Varga, 2010). In our present study the potential toxic and genotoxic effects of peloids were investigated for the first time. It is a crucial step in lifting balneology and balneotherapy up to the evidence-based level. The objective was to collect data on medical muds – used in therapy and prevention – to assess their health risks, and to develop a new ex- perimental method of detecting possible genotoxic effects of muds in their original state without any treatment. 2. Materials and methods Two peloid samples mined from mud tailings of Hévíz (H) (supplied by Spa Hévíz and St. Andrew Rheumatology Hospital, Hungary) and Kolop (K) (supplied by Harkány Spa, Hungary), re- spectively were tested both in toto and with standard soil extrac- tion procedure (Lassu, 1998). Published physical and chemical data on peloid samples were summarized in Tables 1–3 (http://www.wellness- centrum.hu/heviz.php, http://www.halinaansa.hu/termeszetes-es-osi- gyogymodok/kolopi-gyogyiszap-kompressz.html). 2.1. Experiment in toto Two TA strains of genetically modified mutant Salmonella typhimurium with suppressed histidine synthesis were used (Maron and Ames, 1983). Bacterial strains were kindly provided by Dr. B.N. Applied Clay Science xxx (2011) xxx–xxx ⁎ Corresponding author at: Department of Environmental Health, Institute of Public Health Medicine, University of Pécs, Szigeti str. 12, 7624 Pécs, Hungary. Tel.: + 36 72 536 394; fax: +36 72 536 395. E-mail addresses: szkata82@yahoo.co.uk (K. Szendi), gellert82@freemail.hu (G. Gerencsér), muranyiedit@yahoo.co.uk (E. Murányi), chemsafety@freemail.hu (C. Varga). CLAY-02317; No of Pages 5 0169-1317/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.clay.2011.09.015 Contents lists available at SciVerse ScienceDirect Applied Clay Science journal homepage: www.elsevier.com/locate/clay Please cite this article as: Szendi, K., et al., Mutagenic activity of peloids in the Salmonella Ames test, Appl. Clay Sci. (2011), doi:10.1016/ j.clay.2011.09.015