Carbohydrate Polymers 83 (2011) 1901–1907 Contents lists available at ScienceDirect Carbohydrate Polymers journal homepage: www.elsevier.com/locate/carbpol Cytotoxicity decreasing effect and antimycobacterial activity of chitosan conjugated with antituberculotic drugs Eva Vavˇ ríková a , Jana Mandíková b , Frantiˇ sek Trejtnar b , Kata Horváti c , Szilvia Bösze c , Jiˇ rina Stolaˇ ríková d , Jarmila Vinˇ sová a,∗ a Charles University Faculty of Pharmacy, Department of Inorganic and Organic Chemistry, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic b Charles University Faculty of Pharmacy, Department of Pharmacology and Toxicology, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic c Eötvös Lórand University, Research Group of Peptide Chemistry, Hungarian Academy of Science, Pázmány Péter Sétány 1/A, Budapest H-1117, Hungary d Laboratory for TBC, Regional Institute of Public Health in Ostrava, Partyzánské nám. 7, 702 00 Ostrava, Czech Republic article info Article history: Received 14 June 2010 Received in revised form 7 September 2010 Accepted 25 October 2010 Available online 30 October 2010 Keywords: Chitosan Isoniazid Pyrazinamide Ethionamide In vitro antimycobacterial activity Cytotoxicity abstract Water-soluble chitosan conjugates were prepared by connection with isoniazid, pyrazinamide and ethionamide across the O-carboxymethyl and N-succinyl bridge followed by phosphorylation. Their structures were characterized by FTIR and 1 H NMR spectroscopy. Degree of drug substitution and molec- ular weight of prepared compounds have been investigated. Antimycobacterial activity was determined against Mycobacterium tuberculosis and three non-tuberculosis strains. Chitosan derivatives showed sig- nificant MIC 125 g/mL against all tested strains which can be explained by contribution of the presence of antituberculotic drugs and original structure of chitosan. Cytotoxicity of prepared compounds was evaluated in human liver cell line Hep G2 and human peripheral blood mononuclear cells (PBMC). Tox- icity of antituberculotic drugs on Hep G2 cells were compensated by connection with chitosan and tested compounds have not exhibited significant cytotoxic effect on PBMC cells. Chitosan conjugates with antituberculotic drugs could be potentially effective in the non-toxic chemotherapy of tuberculosis. © 2010 Elsevier Ltd. All rights reserved. 1. Introduction Chitosan is known as a biological active polymer having many interesting properties, low toxicity, biocompatibility, biodegrad- ability and low cost (Uraganu & Tokata, 2006; Vinsova & Vavrikova, 2008). Chitosan is a linear polysaccharide, derived from naturally abundant chitin, composed from d-glucosamine (GluN) and N- acetyl-d-glucosamine (GluNAc) units bonded by -1,4-glycosidic linkages. Degree of deacetylation of commercially prepared chi- tosan is usually in the range between 60 and 100% and has influence on the solubility, swelling index, wound dressing and antimicro- bial properties (Qin, 2008). It is used as a carrier material in various drug delivery systems with a broad range of therapeutic application (Dodane & Vilivalam, 1998). Chemical modifications of chitosan molecule can improve water solubility and connection with drugs. For introduction of carboxylic group there is very useful O-carboxymethylation or N-succinylation. Water solubility of O-carboxymethyl chitosan (OCMC) depends on reaction conditions of carboxymethylation, ∗ Corresponding author. Tel.: +420 495067343; fax: +420 495067166. E-mail addresses: vinsova@faf.cuni.cz, jarmila.vinsova@faf.cuni.cz (J. Vinˇ sová). especially on reaction temperature and ratio of water/propan-2-ol as the reaction solvent (Chen & Park, 2003). N-Succinyl chitosan (NSCS) is well known as a drug carrier with a long circulating effect in the body (Kato, Onishi, & Machida, 2000). Main utilisa- tion of N-succinyl chitosan is in cancer therapy. A conjugate of mitomycin C and N-succinyl chitosan exhibited good antitumor activities against various tumours (Kato, Onishi, & Machida, 2004; Song, Onishi, Machida, & Nagai, 1996). Tuberculosis (TB) is leading infection disease and serious world health problem due to which 1.3 million people died in 2008 (Global tuberculosis control, 2009). Current anti-tuberculosis drugs isoniazid (INH), rifampicin (RIF) and pyrazinamide (PZA) are poten- tial hepatotoxic drugs. They are metabolized and detoxified in the liver. Toxic metabolites develop drug-induced hepatotoxicity (DIH). Antituberculosis drug-induced hepatotoxicity can be fatal when is not recognized at an early stage, after which the therapy should be interrupted. Development of DIH depends on main risk factors as age, sex, ethnic, acetylator phenotype and HIV infection (Sharma, 2004). Incidence of drugs combination can have synergic hepatotoxic effect. It was proved that the in vitro hepatotoxicity of PZA is increased by pre-treatment of cells with INH (Tostmann et al., 2008). On the other hand, INH is able to increase activity of CYP2E1, the enzyme responsible for metabolism of xenobiotics to 0144-8617/$ – see front matter © 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.carbpol.2010.10.053