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Oleanolic acid (OA) and its derivatives are widely found in diverse plants and are naturally effective pentacyclic triterpenoid compounds with broad prophylactic and therapeutic roles in various diseases such as ulcerative colitis, multiple sclerosis, metabolic disorders, diabetes, hepatitis and different cancers. This review assembles and presents the latest in vivo reports on the impacts of OA and OA derivatives from various plant sources and the biological mechanisms of OA activities. Thus, this review presents sufficient data proposing that OA and its derivatives are potential alternative and complementary therapies for the treatment and management of several diseases.

WOS: 000424646600026, In this study we report that amino acridine intermediates 7 and 8 were obtained from the reduction of nitro acridine derivatives 5 and 6 that were synthesized via the condensation of dimedone, p-nitrobenzaldehyde with various amine derivatives, respectively. Then acridine sulfonamide hybrid compounds (9-18) were synthesized by the reaction of amino acridine 7, 8 with sulfonyl chlorides. The new hybrid compounds were characterized by FT-IR, H-1-NMR, C-13-NMR, and HRMS analyzes. The evaluation of in vitro anticholinesterase action of the synthesized compounds against AChE showed that some of them are potent inhibitors. Among them, compound 17 showed the most potent activity against AChE with an IC50 of 0.14 A mu M.

WOS: 000396702900011, In the last decade, hydroxycinnamic acids (HCA) have gained increasing attention from researchers due to their antioxidant potential. The aim of this study was to examine in detail the impact of dietary HCA on particular types of P450 and also selected phase II and antioxidant enzymes in Wistar rat. HCA (10 mu M/kg/day, i.p.) was administered for ten continuous days. Examination of the activities and mRNA and protein levels revealed that CYP2B, 2C6 and 3A enzyme activities were not altered significantly, with Western blot and qRT-PCR results corroborating this result. While treatment with HCA led to a significant reduction in CYP1A1/CYP1A2-associated enzyme activities, CYP1A1 protein, and mRNA levels were found to be unchanged. Aromatase (CYP19) activity, as well as protein and mRNA levels, were significantly reduced with HCA treatment. On the other hand, the NAD(P) H: quinone oxidoreductase 1 (NQO1), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferases (GSTs) activities were increased significantly. Also, HCA treatment significantly increased the GST-mu and GST-theta mRNA levels., Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [109R012], This study was supported by a grant from The Scientific and Technological Research Council of Turkey (109R012).

In the present study, the possible role of ellagic acid (EA) on antioxidant potential of Epilobium hirsutum (EH) in rat liver was investigated. Wistar rats were intraperitoneally treated with 37.5 mg/kg of EH and 10 mg/kg of EA for 9 days. Effects of EH and EA on antioxidant [glutathione peroxidase (GPx) and superoxide dismutases (SOD)] and Phase II [NADPH quinone oxidoreductase 1 (NQO1) and glutathione S-transferases (GSTs)] enzyme activities, as well as protein and mRNA expressions of those, were investigated. Polyphenolic content of EH was determined by LC-MS/MS analysis. EH and EA injection to rats resulted in a significant increase of NQO1 (3.6-fold and 4.7-fold), GPx (1.45-fold), and SOD (1.34-fold and 1.27-fold) enzyme activities, whereas total GST (46% and 57%) and its isoforms,and GST mu (57% and 72%), and GST theta (60% and 68%) activities were significantly decreased. Western-blot and qRT-PCR analysis showed that NQO1 and GPx protein and mRNA expressions were increased significantly (P < 0.0001), whereas GST mu and GST theta were significantly decreased (P < 0.0001). © 2016 Taylor & Francis Group, LLC.

The present study was designed to evaluate different doses of ellagic acid (EA)in vivoin rats for its potential to modulate hepatic phases I, II, and antioxidant enzymes. EA (10 or 30 mg/kg/day, intragastrically) was administered for 14 consecutive days, and activity, protein, and mRNA levels were determined. Although the cytochrome P450 (CYP) 2B and CYP2E enzyme activities were decreased significantly, the activities of all other enzymes were unchanged with the 10 mg/kg/day EA. In addition, western-blot and qRT-PCR results clearly corroborated the above enzyme expressions. On the other hand, while the NAD(P)H:quinone oxidoreductase 1 (NQO1), catalase (CAT), glutathione peroxidase (GPX), and glutathione S-transferase (GST) activities were increased significantly, CYP1A, 2B, 2C, 2E, and 19 enzyme activities were reduced significantly with 30 mg/kg/day EA. In addition, CYP2B, 2C6, 2E1, and 19 protein and mRNA levels were substantially decreased by the 30 mg/kg/day dose of EA, but the CYP1A protein, and mRNA levels were not changed. CYP3A enzyme activity, protein and mRNA levels were not altered by neither 10 nor 30 mg/kg/day ellagic acid. These results indicate that EA exerts a dose-dependent impact on the metabolism of chemical carcinogens and drugs by affecting the enzymes involved in xenobiotics activation/detoxification and antioxidant pathways.

Epilobium hirsutum (EH) is a medicinal plant for treating various diseases. Despite its wide usage, there is no available information about its potential influences on drug metabolism. The present study was undertaken to determine the in vivo effects of EH on hepatic CYP2B, CYP2C, CYP2D, and CYP3A enzymes that are primarily involved in drug metabolism. Male Wistar rats were injected intraperitoneally with EH water extract (EHWE) and ellagic acid (EA) at a daily dose of 37.5 and 20 mg/kg, respectively, for 9 days and hepatic drug-metabolizing enzymes were assessed at activity, protein and mRNA levels. Erythromycin N-demethylase activity was inhibited by 53 and 21 % in EHWE- and EA-treated rats, respectively. Benzphetamine N-demethylase and 7-benzyloxyresorufin-O-debenzylase activities were decreased by 53 and 43 %, and 57 and 57 % in EHWE-and EA-treated rats, respectively. Moreover, protein levels of CYP2B1, CYP2C6, CYP2D2, and CYP3A1 also decreased by 55, 15, 33, and 82 % as a result of EHWE treatment of rats, respectively. Similarly, CYP2B1, CYP2C6, CYP2D2, and CYP3A1 protein levels decreased by 62, 63, 49, and 37 % with EA treatment, respectively. qRT-PCR analyses also showed that mRNA levels of these enzymes were significantly inhibited with bothEHWE and EA treatments. In conclusion, inhibition of drug clearances leading to drug toxicity because of the lowered activity and expression of drug-metabolizing enzymes might be observed in the people who used EH as complementary herbal remedy that might be contributed by its EA content. © 2014 Springer International Publishing Switzerland.

Dwarf nettle (Urtica urens) seed extract was examined in vivo in the rat for its potential to modulate drug metabolizing enzymes including aminopyrine N-demethylase (APND; CYP2C6), aniline 4-hydroxylase (A4H; CYP2E1), nitrosodimethylamine N-demethylase (NDMA-ND; CYP2E1) erythromycin N-demethylase (ERND; CYP3A1) CYP2D1/2 and glutathione S-transferase (GST). RT-PCR data and western blotting studies clearly demonstrated that CYP2C6 and CYP2E1 mRNA levels were substantially increased after Urtica treatment, while the level of CYP3A1 mRNA decreased and that of CYP2D1/2 remained unchanged. Urtica treatment significantly induced GST activity in the liver, lung and kidney (66-, 46- and 31-fold, respectively) while decreasing that of APND (35-, 61- and 94-fold) and NDMA-ND (23, 28 and 54-fold). ERND activity in liver was reduced 45-fold, but increased in the lung and kidney (78- and 144-fold) after Urtica treatment. These results indicate that Urtica seed extract may have the potential to inhibit and/or induce the metabolism of certain co-administered drugs.

Although humans are exposed to o-coumaric acid (OCA) in their diet, there is no available literature related to drug interaction and the carcinogen-activating potential of OCA in the HepG2 cell line.This study was undertaken to determine the effects of OCA on the cytochrome P450 (CYP) 1A2, CYP2E1, CYP2C9, and CYP3A4 enzymes, which are primarily involved in carcinogen and drug metabolism.The cytotoxicity of OCA in HepG2 cells was investigated by measuring the cleavage of WST-1. The protein and mRNA levels of CYPs were determined by western blotting and RT-PCR, respectively.The EC10, EC25, and EC50 values of OCA were calculated to be 1.84, 3.91 and 7.39 mM, respectively. A sublethal dose of 5 mM was used throughout this study. The CYP1A2 protein and mRNA levels were increased by 52 and 40% (p 0.05), as were the CYP2E1 levels by 225 and 424%, respectively (p 0.05). However, OCA treatment caused 52 and 60% decreases in the levels of CYP3A4 protein and mRNA (p 0.05), respectively. In contrast to CYP3A4, the CYP2C9 protein and mRNA levels increased by 110 and 130%, respectively.Co-administration of OCA with some drugs may lead to undesirable food-drug interactions due to modulatory effects on CYP isozymes involved in drug metabolism. Moreover, exposure to OCA may cause an increase in carcinogenicity and toxicity due to the induction of the CYP isozymes involved in chemical carcinogenesis. Therefore, serious precautions should be taken when using OCA as a supplement.

Cladribine (2-CdA) is used as an anti-cancer drug but is currently studied as a potential treatment for use in relapsing-remitting multiple sclerosis (MS). In this study, we computer designed, synthesized, and characterized two novel derivatives of 2-CdA, K1-5d and K2-4c, and investigated their underlying mechanism of beneficial effect using the CCRF-CEM and RAJI cell lines. For this purpose, we first determined their effect on MS and DNA damage and repair-related gene expression profiles using custom arrays along with 2-CdA treatment at non-toxic doses. Then, we determined whether cells underwent apoptosis after treatment with 2-CdA, K1-5d, and K2-4c in CCRF-CEM and RAJI cells, using the DNA fragmentation assay. It was found that both derivatives modulated the expression of the pathway-related genes that are important in inflammatory signaling, apoptosis, ATM/ATR, double-strand break repair, and the cell cycle. Furthermore, 2-CdA, K1-5d, and K2-4c significantly activated apoptosis in both cell lines. In summary, our data demonstrate that although both derivatives act as anti-inflammatory and apoptotic agents, inducing the accumulation of DNA strand breaks and activating the ultimate tumor suppressor p53 in T and B lymphocytes, the K1-5d derivative has shown more promising activities for further studies.

In this study, the degree of induction of cytochrome P4501A-associated 7-ethoxyresorufin O-deethylase (EROD) activity and immunochemical detection of cytochrome P4501A in leaping mullet (Liza saliens) and common sole (Solea vulgaris) were used as biomarker for assessment of polycyclic aromatic hydrocarbon (PAH) or/and polychlorinated biphenyl (PCB) type organic pollutants along the Izmir Bay on the Aegean Sea coast, Turkey. Fish were captured in May 1995 and February and June 1996. Mullet caught from Pasaport, a highly urbanized and industrial section of the Bay, had approximately 62 times more EROD activity than the feral fish sampled from an uncontaminated site in the Outer Bay. Mullet caught along the pollutant gradient at the three other sites in the Bay exhibited less but highly significant induced EROD activity. An inverse relationship was found between the EROD activity in the fish and the distance between the catch point and the discharge region of polluted rivers and of industrial and domestic wastes into the Harbour. Studies using the polyclonal antibodies produced against mullet cytochrome P4501A showed a similar trend. In addition, EROD activities of benthic fish, common sole, captured from three different sites of the Bay also confirmed and extended the results obtained with those of mullet. Except that, common sole caught from site 5, the edge of Gediz river, exhibited higher EROD activity than that of fish caught from site 4, Tuzla. Although, detailed qualitative and quantitative analyses of organic chemicals in the waters and sediments of Izmir Bay are not available, the results of this study indicate that Inner and Middle Bays of Izmir Bay are highly contaminated with PAH and/or PCB type organic pollutants.

Among hydroxycinnamic acids, caffeic, ferulic and p-coumaric acids have received considerable attention due to their biological activities. However, studies related to the biological activities of o-coumaric acid (OCA) are limited. In this regard, this study was designed to determine the chemopreventive potential of OCA in human breast cancer cells (MCF-7). The EC50 value of OCA was found to be 4.95 mM and was used throughout the study. Caspase-3 protein and mRNA levels increased by 59% and 72%. Similarly, protein and mRNA levels of Bax were increased by 115% and 152%. However, OCA treatment caused 48% and 35% decreases in Bcl-2 protein and mRNA levels. Cyclin D1 and cyclin dependent kinase-2 protein and mRNA levels decreased significantly. Moreover, p53 protein and mRNA levels increased by 178% and 245%, respectively. In addition to p53, PTEN protein and mRNA levels were induced. Although, CYP1A1, CYP1A2 and CY2E1 mRNA levels increased, CYP3A4 and CYP2C9 mRNA levels decreased in response to OCA treatment. These results suggest that OCA demonstrates anticarcinogenic activity on MCF-7 cells by activating multiple pathways. However, it also has high carcinogen activating and drug interaction potential. Therefore, serious precautions must be taken before using OCA.

Context: Natural products have attracted increasing interests due to their use in flavoring, nutrition, cosmetics, pharmacy and medicine. Epilobium hirsutum L. (Onagraceae) is known for its analgesic, antimicrobial, and antiproliferative activity. CYP1A1 and CYP2E1, xenobiotic metabolizing enzymes, serve as a metabolic activation route yielding reactive metabolites that are eliminated by the action of NQO1 and glutathione peroxidase (GPx) enzymes. Objective: This study investigated in vivo effects of Epilobium hirsutum (EH) on CYP2E1, CYP1A1, NQO1 and GPx activities, protein and mRNA expressions in liver. Materials and methods: Male Wistar Albino rats were injected with EH at a dose of 37.5mg/kg i.p. daily for 9d. CYP2E1, CYP1A1, NQO1 and GPx activities, protein and mRNA levels were determined by enzyme assays, Western blotting and qPCR, respectively. Results: CYP1A1 associated ethoxyresorufin-O-deethylase activity of control and EH-treated animals were found as 6.54±1.21 and 4.48±1.67nmol/min/mg, respectively. CYP2E1 associated aniline 4-hydroxylase of control and EH group were 0.537±0.011 and 0.109±0.01nmol/min/mg, respectively. However, EH treatment increased the GPx and NQO1 activities from 0.069±0.015 to 0.107±0.026nmol/min/mg and from 163.34±92 to 588.3±14nmol/min/mg, respectively. Furthermore, protein and mRNA expression analysis revealed that CYP1A1 and CYP2E1 levels were decreased while those of NQO1 and GPx increased after EH treatment. Discussion and conclusion: Our current data suggest that the metabolism of xenobiotics, including drugs, may be altered due to changes in the expression and activity of these proteins by EH. © 2013 Informa Healthcare USA, Inc.

The aim of this study was to investigate the possible effects of sulphite oxidase (SOX, E.C. 1.8.3.1) deficiency on xenobiotic metabolism. For this purpose, SOX deficiency was produced in rats by the administration of a low molybdenum diet with concurrent addition of 200 ppm tungsten to their drinking water. First, hepatic SOX activity in deficient groups was measured to confirm SOX deficiency. Then, aminopyrine N-demethylase, aniline 4-hydroxy-lase, aromatase, caffeine N-demethylase, cytochrome b5 reductase, erythromycin N-demethylase, ethoxyresorufin O-deethylase, glutathione S-transferase, N-nitrosodimethylamine N-demethylase and penthoxyresorufin O-deethylase activities were determined to follow changes in the activity of drug metabolizing enzymes in SOX-deficient rats. Our results clearly demonstrated that SOX deficiency significantly elevated A4H, caffeine N-demethylase, erythromycin N-demethylase and N-nitrosodimethylamine N-demethylase activities while decreasing ethoxyresorufin O-deethylase and aromatase activities. These alterations in drug metabolizing enzymes can contribute to the varying susceptibility and response of sulphite-sensitive individuals to different drugs and/or therapeutics used for treatments. ©2012 JCBN.

Humans are exposed to acrylamide in their diet and cigarette smoke. Acrylamide is metabolized into glycidamide by CYP2E1. However, very few studies regarding the effects of acrylamide on cytochrome P450 and Glutathione S-Transferase (GST) isozymes have been pursued. The aim of this study is to elucidate the effects of acrylamide on cytochrome P450 and GST isozymes in HepG2 cell line. Treatment with 1.25 and 2.5 mM acrylamide caused 9.5- and 3.7-fold increases and 4.0- and 3.3-fold increases in CYP1A-associated ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylase (MROD) activities, respectively. These increases were consistent with increases in mRNA and protein levels of these isozymes. Similarly, CYP2E1-associated aniline 4-hydroxylase (ANH) activity, protein levels, and mRNA levels increased 2.1- and 2.6-fold, 2.4- and 3.2-fold, and 1.4- and 1.9-fold following 1.25 and 2.5 mM acrylamide treatments, respectively. In addition, GST-mu activity was increased 2.4- and 5.1-fold by acrylamide. Moreover, GST-mu mRNA and protein levels increased twofold as a result of acrylamide treatment. In contrast, GST-pi protein and mRNA levels decreased significantly. In conclusion, human cell exposure to acrylamide causes an increase in the levels of carcinogenicity and toxicity and a disturbance in drug metabolism, possibly due to complex effects on P450 and GST isozymes. © Springer Science+Business Media B.V. 2012.

1. Treatment of gilthead seabream ( Spams aurata ) with benzene 0.6 ml/kg/day, s.c., for four consecutive days resulted in a marked 78% and 73% decrease in total cytochrome P450 content and 7-ethoxyresorufin O-deethylase activity of liver microsomes, respectively. 2. In contrast, benzene treatment did not affect aniline 4-hydroxylase, ethylmorphine N -demethylase and cytochrome b5 content of fish liver microsomes, significantly. 3. The study revealed a distinct difference in the mixed-function oxidation of xenobiotics in mammalian and fish liver microsomes in response to benzene treatment.

Cholinesterase (ChE) and ethoxyresorufin-O-deethylase (EROD) were of special interest to this study as these biochemical tools have been widely used for the determination of exposure to pollutants. In this study, the freshwater oligochaete Limnodrilus profundicola was tested for its potential as a bioindicator of freshwater pollution. For this purpose, the ChE and EROD activities of L. profundicola and the level of polycyclic aromatic hydrocarbons (PAH) of water samples collected from different sites along the Curuksu stream on the Menderes River (the ancient Meander) running through south-western Turkey were studied. First, these activities were characterized using, as model substrates, acetylthiocholine (ATC), propionylthiocholine (PTC), and butyrylthiocholine (BTC). Then, the in vivo effects of insecticides and pollutants on these activities were investigated. L. profundicola were exposed to various doses of methyl-parathion, methomyl, and deltamethrin. Although significant inhibition of ChE was detected with each of the insecticides, the highest level of inhibition was observed with methyl-parathion. In addition to the inhibition of ChE, the activity of EROD was induced by exposure to oil-contaminated sediments. Thus, although L. profundicola has a reputation for being very resistant to pollution (although it is not insensitive to it), we demonstrated that it may potentially be used as a bioindicator species for contaminant exposure when ChE and EROD are used as biomarkers. © 2010 Wiley Periodicals, Inc.

In this study, feral leaping mullet (Liza saliens) liver microsomal 7-ethoxyresorufin O-deethylase (EROD), and cytosolic glutathione S-transferases (GSTs) activities were investigated using 7-ethoxyresorufin, 1-chloro-2,4-dinitrobenzene (CDNB), and ethacrynic acid (EA) as substrates, respectively. The average EROD activity was found as 1139±175 pmol resorufin/min/mg protein. The average GST activities towards CDNB and EA were found as 1364±41 and 140±19 nmol/min/mg protein, respectively. We have, then, investigated the in vitro effects of some metals and detergents on CYP1A and GST activities in leaping mullet liver. Leaping mullet liver microsomal EROD activity was significantly inhibited by Hg (0.1 mM), Ni (0.1 mM), Cd (0.1 mM), Cu (0.1 mM), Zn (0.1 mM), Sb (0.1 mM), Fe2+ (1 mM), Co (1 mM), Al (1 mM), and Fe3+ (1 mM), with the percent inhibition of 80, 80, 77, 75, 70, 69, 56, 53, 46, and 44, respectively. Similarly, conjugation of CDNB catalyzed by GST was inhibited significantly to lesser extend by Hg (0.1 mM), Sb (0.1 mM), Cd (0.1 mM), Cu (0.1 mM), Zn (0.1 mM), Fe3+ (1 mM), Co (1 mM), and Fe2+ (1 mM), with the percent inhibition of 70, 69, 65, 61, 54, 51, 47, and 43, respectively. The degrees of inhibition observed on GST catalyzed EA conjugation by Hg (0.1 mM), Cd (0.1 mM), Sb (0.1 mM), Cu (0.1 mM), and Zn (0.1 mM) were 86, 78, 69, 51, and 42, respectively. In addition to metals, the effect of various detergents on leaping mullet liver EROD, GST-CDNB, and GST-EA activities were studied. It was found that ionic detergents strongly inhibited the EROD activity, whereas much less inhibitions were observed with GST catalyzed activities. Therefore, the CYP1A inhibition potencies of metals and detergents suggest that their contribution to the overall CYP1A induction in polycyclic aromatic hydrocarbons contaminated environmental samples has to be taken into account for better interpretation of environmental studies. © 2006 Elsevier Inc. All rights reserved.

In this study, feral leaping mullet (Liza saliens) liver cytosolic glutathione S-transferases (GSTs) were investigated and characterized using 1-chloro-2,4-dinitrobenzene (CDNB) and ethacrynic acid (EA) as substrates. The average GST activities towards CDNB and EA were found to be 1365 +/- 41 and 140 +/- 20 nmol/min per mg protein, respectively. The effects of cytosolic protein amount and temperature ranging from 4 to 70 degrees C on enzyme activities were examined. While both activities towards CDNB and EA showed similar dependence on protein amount, temperature optima were found as 37 and 42 degrees C, respectively. In addition, the effects of pH on GST-CDNB and -EA activities were studied and different pH activity profiles were observed. For both substrates, GST activities were found to obey Michaelis-Menten kinetics with apparent V(max) and K(m) values of 1661 nmol/min per mg protein and 0.24 mM and 157 nmol/min per mg protein and 0.056 mM for CDNB and EA, respectively. Distribution of GST in Liza saliens tissues was investigated and compared with other fish species. Very high GST activities were measured in tissues from Liza saliens such as liver, kidney, testis, proximal intestine, and gills. Moreover, our results suggested that GST activities from Liza saliens would be a valuable biomarker for aquatic pollution.

Liquid–liquid extraction of various alkali, alkaline-earth, and transition metal cations with o-(4-hydroxydiazophenyldiazophenyl)-p-tert-butylphenol (L1), bisdiazo (1-hydroxy-4-tert-butyl-phenyl)benzene (L2), p-(2-hydroxy-5-tert-butylphenylazophenylazo)calix[4]arene (L3), and p-(2-hydroxy-5-tert-butylphenylazophenylazo)calix[6]arene (L4), p-(4-butylphenylazo)calix[6]arene (L5), p-[4-(phenylazo)phenylazo]calix[6]arene (L6), p-(4-hydroxyphenylazo)calix[6]arene (L7), p-{4-[N-(thiazol-2-yl)sulfamoyl]phenylazo}calix[6]arene (L8), p-(4-acetamidophenylazo)calix[6]arene (L9), p-(thiazol-2-ylazo)calix[6]arene (L10), and p-(2-sulfanylphenylazo)calix[6]arene (L11) from the aqueous phase into the organic phase was carried out. For comparison, the corresponding azo calix[n]arene derivatives and two phenol derivatives were also examined. Since Ag +, Hg +, and Hg 2+ cations form complexes with azo groups strongly, the extraction of these metals was found to be highly effective.

Biotransformation of relatively insoluble organic chemicals to more water-soluble compounds is a prerequisite for their detoxification and excretion. The first step in biotransformation is usually the oxidative step, catalyzed by the microsomal cytochrome P450 dependent mixed function oxidase (MFO) system. This “Phase I” metabolism is usu ally followed by “Phase II” in which oxygenated groups of xenobiotics are conjugated with glucuronate, sulfate, acetyl, or glutathione by different families of transferase en zymes. Thus, resulting polar and water-soluble end product can be excreted from the or ganism through bile or urine.1

Three distinct cytochrome P450 isozymes, P4501A1, P4502B and an unidentified P450 isozyme were separated and isolated from beta-NF-treated gilthead seabream liver microsomes. Cytochrome P4501A1 was partially purified from beta-NF-treated gilthead seabream liver microsomes in the presence of detergents Emulgen 913 and cholate and protease inhibitors using two DEAE-cellulose, Porapak Q and two hydroxylapatite column chromatographies. The overall yield of purified P4501A1 was 1.2% with respect to microsomal total P450 with a specific content of 3 nmol/mg protein. The purified P4501A1 was characterized with respect to spectral, electrophoretic, biocatalytic and immunochemical properties, which are found to be similar to P4501A1s purified from other teleost species such as trout, scup, cod and perch suggesting that the P450 we have purified belongs to CYP1A1.

Benzo(a)pyrene [B(a)P] treatment of gilthead seabream, 25 mg/kg, i.p. for 5 consecutive days, did not cause any significant changes in ethylmorphine N -demethylase and aniline 4-hydroxylase activities of liver microsomes. The same treatment did not alter the liver microsomal cytochrome b5 content, NADH-cytochrome b5 reductase and NADPH-cytochrome P450 reductase activities. However, benzo(a)pyrene treatment caused a 2–3-fold increase in 7-ethoxyresorufin O -deethylase (7-EROD) activity of gilthead seabream liver microsomes. Although, upon treatment, total cytochrome P450 content of liver microsomes increased about 1.7-fold in 1990 fall, no such increase was observed in spring 1991. However, a new cytochrome P450 with an apparent M r of 58,000 was observed on SDS-PAGE of liver microsomes obtained from benzo(a)pyrene treated gilthead seabream. Besides, in vitro addition of 0.2 × 10 −6 M benzo(a)pyrene to the incubation mixture inhibited 7-ethoxyresorufin O -deethylase activity by 93%. Gilthead seabream liver microsomal 7-ethoxyresorufin O -deethylase activity was characterized with respect to substrate concentration, amount of enzyme, type of buffer used, incubation period and temperature.

Polycyclic aromatic hydrocarbons (PAHs), dioxins, dibenzofurans, and polychlorinated biphenyls (PCBs) present in polluted environment induce cytochrome P4501A (CYP1A) isozyme in fish, which in turn results in a marked increased production of carcinogenic metabolites from PAHs. The induction of hepatic CYP1A in fish by certain classes of chemicals has been suggested as an early warning system, a "most sensitive biological response" for assessing environmental contamination conditions. This has implications for human fish consumption, as well as for the health status of aquatic organisms. Correlation between elevated CYP1A and altered steroid metabolism and decreased reproductive success has been pointed out. The induction of CYP1A and associated enzyme activities has now been confirmed in a number of field studies. Cases where these biomarkers have been studied in field conditions will be presented. Special emphasis will be given to field studies in which the induction of CYP1A activity, 7-ethoxyresorufin O-deethylase (EROD) activities and immunochemical detection of CYP1A in leaping mullet and common sole are used as a biomarker for PAH- and/or PCB-type pollutants along the Izmir Bay on the Aegean Sea. Organisms are often exposed to complex mixtures of pollutants, including polychlorinated biphe- nyls (PCBs), polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), poly- cyclic aromatic hydrocarbons (PAHs), alkyltin compounds, and metals. Pollutants that bioaccumulate in the organism first cause effects at the molecular and cellular levels. This may lead to adverse effects in the organism, which in turn may cause changes at the population and the community level in the years to come. Fish populations living in highly polluted areas often have high incidences of gross pathological lesions and neoplasms that may be associated with the elevated levels of toxic chemicals in the sediments (1). The high levels of neoplasms in fish collected from a creosote (mixture of petroleum products) polluted site in Puget Sound, WA, USA were reported (2). Even though chemical analyses are able to measure a wide range of pollutants quantitatively and accurately, the complex mixture of chemical pollutants cannot be fully assessed. Furthermore, it does not reveal the impact of chemical pollution on the aquatic environment. The use of biochemical markers fulfills this purpose. Biomarker responses are, broadly speaking, of two kinds: those that measure only