The Japan Radiation Research Society NII-Electronic Library Service The JapanRadiationResearch Society J. RadiaL Res., 48, 241-245 (2007) ShortCommunication Effect of Curcumin and Curcumin Copper Complex (1:1) Radiation-induced Changes of Anti-oxidant Enzymes Levels inthe Livers of SwissAlbinoMice on Prabhakar R. KOIRAMi, Veeresh P, VEERAPURi, Amit KUNWAR2, Beena MISHRA2, Atanu BARIK2, IndiraK. PRIYADARSINI2 and Unnikrishnan K. MAZHUVANCHERRYi" RadiationlAntioxidantenzymestCurcumin/CurcumincoppercomplextGSH. The et:fect of mononuclear copper (II) complex of curcumin in 1:1 stoiehiometry (hereafter referred to as complex) administered 30 min before y-irradiation (4.5 Gy) on alterations in antioxidant and Thiobarbituric acid reactive substances (TBARS) levelsin iiverswas studied in comparison to curcumin at a doseof 50 mgfkg. The different antioxidants likeGSH, GST, catalase, SOD, TBARS and total thiois were estimated in the liverhomogenates excised at different time intervals (1, 2 and 4 h) post irradiation using colorimetric methods. There wus a radiation-induced decrease in the levels of all the studied enzymes at 1 h post irradiation, while an increase was observed at latertime points. Both curcumin and complex treatment in sham-irradiated mice decreased the levels of GSH and total thiols, whereas there was an increasein the levels of catalasc, GST and SOD compared to normal contre]. Under the infiuenceof irradiation, both curcumin and complex treatment protected the deelinein the levelsof GSH, GST, SOD, catalase and total thiols, and inhibitedradiation-induced lipid peroxidation. Further,the complex was found to be more effective in protecting the enzymes at 1 h post irradiation compared to curcumin treated group. This may be due to the higher rate constants of the complex compared to curcumin fbrtheir reac- tionswith various free radicals. INTRODUCTION Dietary antioxidants are known to strengthen the physio- logical antioxidant defensesystem either by scavenging reactive oxygen free radicals (ROS) or by protectinglelevat- ing endogenous antioxidant enzymes. They also decrease the risk of many chronic discases such as cancer and cardiovas- cular disordcrs.i} The antioxidant activity of curcumin, a nat- ural polyphenol, found inthe rhizomes of Cureuma tonga (turmeric), exhibits anti-inflammatory, antineoplastic, anti- oxidant and chemopreventive activities.24)Curcumin and its analogues are known to proteet biomembranesagainst per- oxidative damage. Peroxidation of lipidsis known to be a free radica]-mediated chain reaction leading to the damage of the cell membrane. Superoxide, an important member of 'Correspondingauthor:Phone/+918202S72195. Fax:+91S202570061, E-mail:mkunnikrishnan@gmail.eom iDepartmenl ot' Pharmacology, Manipal College of PharmaceuticalSci- ences, Manipal - 576 1e4; 2Radiation & PhotochemistryDivision, Bhabha Atomic Research Center, Mumbai - 400 085, doi/le,1269ijrr.06103 the ROS, also participates inHaber-Weiss reaction and gen- erates more damaging hydroxyl radicals.S) Superoxide dis- muatase (SOD) is one of the most important antioxidant enzymes thatcatalyze superoxide neutralization by convert- ingit to hydrogen peroxide and oxygen.6J) SODs are being exp]ored as usefu] pharmacological agents.S'9) The native enzyme, however, has several limitations, such as a short shelf life, low lipid solubility, and low penetration into cells.7)Several copper and manganese complexes of impor- tant compounds have been shown to ecacient]y catalyze superoxide dismutation.]O) Inthis aspect, we had synthesized a mononuclear copper (II) complex of curcumin in1:1 sto- ichiometry (hereafter referred to as complex). The complex has been eva]uated for its abi]ity to aet as an SOD mimic and was found to exhibit free radical seavenging ability and inhibits vradiation-induced lipid peroxidation inmodel sys- tems better than curcumin.ii) These studies encouraged us to study the effect of the complex on time-dependent changes in liver antiox'idant levels of irradiated Swissalbino mice. J.Radiat,Res,,VoL48,No,3{20e7);http:lijrrjstage.jst.go.jp