Interaction between hypertension and periodontitis.

OBJECTIVE: The possible association between hypertension and periodontitis and the effect of hypertension on periodontal treatment were investigated by evaluating salivary and gingival crevicular fluid (GCF) interleukin (IL)-6 and C reactive protein (CRP) levels. METHODS: Forty-two healthy individuals without any previously diagnosed systemic disease [10 periodontally healthy (control) and 10 periodontitis (CP)] and subjects with hypertension [13 periodontally healthy (HP) and 9 with periodontitis (CP + HP)] participated in the study. GCF and saliva samples were obtained at baseline and 4 weeks after Phase I periodontal treatment. Biochemical parameters were analyzed using ELISA. RESULTS: Before the periodontal treatment, significantly higher GCF IL-6 and CRP levels were detected in CP + HP and CP groups compared to HP and control groups (p < 0.01). Salivary CRP level in CP + HP group was found to be higher than the control group (p < 0.05). Statistically significant gingival and plaque index measurements (p < 0.01) might suggest a possible effect of hypertension on periodontal status. Periodontal treatment significantly improved the clinical indices; however, biochemical parameters did not change after the treatment. CONCLUSION: The association of hypertension with periodontitis through local salivary and GCF inflammatory mediators might be possible in disease process.

Evaluation of periodontal status and cytokine levels in saliva and gingival crevicular fluid of patients with inflammatory bowel diseases.

BACKGROUND: Periodontal diseases and inflammatory bowel diseases (IBD, ulcerative colitis [UC] and Crohn disease [CD]) have been reported to present with increased salivary and gingival crevicular fluid (GCF) concentrations of cytokines. The aim of this study was to evaluate the salivary and GCF levels of TNF-α, IL-1ß, IL-10, and IL-17A and their associations with the periodontal statuses of UC, CD, and non-IBD patients, and to analyze the interrelationships among these cytokines, IBD conditions, and periodontal diseases. METHODS: This cross-sectional study was performed with a total of 131 patients (62 women and 69 men, mean age 42.96±13.02 years). Patients were divided into three groups: UC, CD, and non-IBD. Periodontal status was defined according to the 2017 World Workshop Disease Classification. Salivary and GCF cytokine levels were analyzed using ELISA. RESULTS: UC and CD patients diagnosed as having periodontitis and gingivitis presented with significantly higher levels of TNF-α and lower levels of IL-10 as compared with non-IBD patients (p<0.05). UC patients diagnosed with periodontitis exhibited significantly higher scores of bleeding on probing (p = 0.011) and increased salivary and GCF IL-1ß levels as compared with CD patients (p = 0.005, and 0.012, respectively). Considering the active and remission status of IBD, salivary IL-1ß was found to be correlated with the parameters representing the severity of periodontal diseases in active UC and CD patients. CONCLUSION: In the presence of periodontal diseases, UC and CD patients showed different expression levels of TNF-α, IL-1ß, and IL-10 in oral secretions as compared with non-IBD patients.

Ubiquinone Levels as a Marker of Antioxidant System in Children with Attention Deficit Hyperactivity Disorder.

The aims of this study are to compare serum ubiquinone levels in children with attention deficit hyperactivity disorder (ADHD) with healthy controls and to investigate the correlation between ubiquinone levels of children with ADHD and their ADHD symptoms. Twenty-seven children who are 6-12 years old age with attention deficit hyperactivity disorder having clinically normal intelligence and 23 children with clinically normal intelligence and no psychiatric disorder of similar age and sex who referred to Ankara University School of Medicine Department of Child and Adolescent Psychiatry were included in this study. All children were diagnosed by same researcher using the Semi-Structured Clinical Interview for DSM-IV Scale for Affective Disorders and Schizophrenia Interview for School Children-Now and for the Life-Long Version (K-SADS-PL). Parents and teachers of the children completed the Conners Parent Rating Scale Revised Long Form (CPRS-LF) and Conners Teacher Rating Scale Revised Long Form (CTRS-LF). There were no statistically significant differences regarding the age, gender, and sociodemographic data of the groups. Serum ubiquinone levels of the ADHD group were significantly lower than the control group. We did not find any correlation between ubiquinone levels and clinical values. Since ubiquinone levels are lower in children with ADHD compared with controls, we suggest that decreased antioxidant levels may play a role in ADHD pathogenesis by disrupting oxidative balance.

Serum activities of dipeptidyl peptidase-4 and adenosine deaminase in polycystic ovary syndrome: association with obesity.

Dipeptidyl peptidase-4 (DPP-4) plays a role in metabolic and inflammatory diseases. Increased adenosine deaminase (ADA) has been suggested to induce insulin resistance and inflammation. We measured serum DPP-4 and ADA activities. Serum ADA activity was significantly higher in PCOS group (p = .006), whereas there was no difference in serum DPP-4 activity between the groups (p > .05). When the study subjects were divided into four groups in terms of obesity; an increasing trend in serum ADA activity between the groups was observed and ADA activity was significantly higher in overweight and obese patients with PCOS than nonobese controls (p = .016), there were no significant differences between the other groups (p > .05). A positive correlation was found between ADA and BMI in the whole group (p = .022). Multivariate regression analyses revealed that significant determinants were diastolic blood pressure, ADA, and the presence of PCOS for DPP-4 (R2 = 0.344, F = 9.079, p < .001); the presence of PCOS and DPP-4 for ADA (R2 = 0.123, F = 6.302, p = .003). We demonstrated increased serum ADA activity as well as its association with obesity in PCOS, while there was no change in serum DPP-4 activity in women with PCOS.

Levels of Cytokines in Gingival Crevicular Fluid during Rapid Maxillary Expansion and the Subsequent Retention Period.

OBJECTIVE: To monitor the effects of rapid maxillary expansion (RME) on bone metabolic activities during and after 3 months of retention. STUDY DESIGN: Fifteen patients with a mean age of 12.9 ± 0.6 years were treated with a bonded expansion device, activated 2 turns per day. The retention period was 3 months. Clinical periodontal parameters were recorded at baseline and after retention. Gingival crevicular fluid (GCF) samples were collected from maxillary first molars from the compression sides at baseline, then at 1 and 10 days and after retention. Tension side samples were obtained at baseline and after retention. Interleukin-1beta (IL-1ß), transforming growth factor beta1 (TGF-ß1), prostaglandin E2 (PGE2) and nitric oxide (NO) levels were specifically measured. RESULTS: Periodontal parameters increased significantly after retention relative to baseline values. Levels of IL-1ß, TGF-ß1 and PGE2 increased on day 10, and decreased after retention on the compression side. NO levels were elevated on day 10, and remained higher after retention on the compression side. Tension side cytokine levels remained higher relative to baseline values after retention. CONCLUSIONS: The results of this study indicate the importance of ongoing adaptive bone activities after 3 months of retention with RME, which should be considered questionable as an effective retention period.

Nitric oxide and arginase levels in peri-implant tissues after delayed loading.

OBJECTIVE: Nitric oxide (NO) is synthesized from the conversion of L-arginine to L-citrulline by NO synthase (NOS). Arginase can compete with NOS for the common substrate L-arginine, and thus inhibit NO production. NO levels and arginase ezyme might affect the bone remodeling cycle around implants. The aim of this studywas to investigate NO and arginase levels in gingival crevicular fluid (GCF), peri-implant sulcular fluid (PISF), and saliva. MATERIALS AND METHODS: Twenty patients with one or more implants (Straumann®; Institute Straumann AG, Basel, Switzerland) restored with fixed crown prostheses were included in the study. Plaque index (PI), gingival index (GI), probing depth (PD), and bleeding on probing (BOP) were recorded from six sites of each tooth and implant at baseline and at months 1, 3, and 6 after loading. The saliva, GCF, and PISF were collected at baseline and at months 1, 3, and 6 after loading. NO level and arginase enzyme were evaluated in GCF, PISF, and saliva. RESULTS: Arginase and NO levels in saliva did not change significantly from baseline to months 1, 3, and 6. However, both PISF NO and arginase levels showed an increased pattern from baseline to month 6. NO levels were significantly higher at months 3 and 6, compared to baseline, while PISF arginase levels increased significantly from baseline to months 3 and 6. CONCLUSION: NO and arginase enzyme measurements in saliva, GCF, and PISF may be beneficial in the determination of current peri-implant tissues. In particular, PISF might provide more information than saliva.

The effect of light-emitting diode photobiomodulation on implant stability and biochemical markers in peri-implant crevicular fluid.

OBJECTIVE: The purpose of this study was to determine the effect of light-emitting diode photomodulation (LED PBM) on implant osseointegration by measuring implant stability changes by resonance frequency analysis (RFA) and measuring interleukin-1ß (IL-1ß), transforming growth factor-ß (TGF-ß), prostaglandin-E2 (PGE2), and nitric oxide (NO) levels in peri-implant crevicular fluid (PICF). BACKGROUND DATA: Light therapy modulates various biological events and allows improved wound healing in ischemic and wounded tissues. METHODS: Fifteen patients (8 control, 7 LED) participated in the study. In the LED group, LED device at a wavelength of 626 nm in the near-infrared (NIR) region (treatment array area: 4.80 cm2; average intensity: 38.5 mW/cm2; total power: 185 mW; total energy: 222 J; average density: 46.2 J/cm2) was applied for 20 min over the surgical area during 3 weeks, three times in a week, starting from the operation day. Implant stability quotient (ISQ) values were recorded at the time of operation, and 2, 4, 8, and 12 weeks postoperatively. PICF samples were collected in postoperative weeks 4 and 12 and IL-1ß, TGF-ß, PGE2, and NO levels were evaluated. Clinical indices were recorded around implants in postoperative weeks 4 and 12. RESULTS: In the control group, significant reduction of ISQ values from week 2 to week 12 were demonstrated. In the LED group, baseline ISQ values were maintained during the study and no significant changes were observed. Changes in biochemical parameters were found to be similar between groups over time. However, in the LED group, a negative correlation was found between PGE2 and ISQ values. CONCLUSIONS: LED application to surgical area has a positive effect on the osseointegration process, and implant stability can be maintained.

Immunohistopathologic demonstration of deleterious effects on growing rat testes of radiofrequency waves emitted from conventional Wi-Fi devices.

OBJECTIVE: To investigate effects on rat testes of radiofrequency radiation emitted from indoor Wi-Fi Internet access devices using 802.11.g wireless standards. METHODS: Ten Wistar albino male rats were divided into experimental and control groups, with five rats per group. Standard wireless gateways communicating at 2.437 GHz were used as radiofrequency wave sources. The experimental group was exposed to radiofrequency energy for 24 h a day for 20 weeks. The rats were sacrificed at the end of the study. Intracardiac blood was sampled for serum 8-hydroxy-2'-deoxyguanosine levels. Testes were removed and examined histologically and immunohistochemically. Testis tissues were analyzed for malondialdehyde levels and prooxidant-antioxidant enzyme activities. RESULTS: We observed significant increases in serum 8-hydroxy-2'-deoxyguanosine levels and 8-hydroxyguanosine staining in the testes of the experimental group indicating DNA damage due to exposure (p < 0.05). We also found decreased levels of catalase and glutathione peroxidase activity in the experimental group, which may have been due to radiofrequency effects on enzyme activity (p < 0.05). CONCLUSIONS: These findings raise questions about the safety of radiofrequency exposure from Wi-Fi Internet access devices for growing organisms of reproductive age, with a potential effect on both fertility and the integrity of germ cells.

Periodontal nitric oxide pathway alteration due to precompetition anxiety in handball players.

BACKGROUND: Psychologic and physical stress is known to be related with periodontal disorders. The objective of this study is to investigate salivary and gingival crevicular fluid (GCF) nitric oxide (NO) metabolism and its association with the periodontal reaction to precompetition anxiety in competitive athletes. METHODS: A total of 18 elite male handball players participated in this study. The anxiety level of participants was determined by using a competitive state anxiety inventory-2 (CSAI-2). Periodontal clinical measurements, saliva, and GCF samples were obtained before the application of the CSAI-2 during the half-season break and just before the league championship match. NO-level, arginase, and NO synthase (NOS) activities were analyzed in saliva samples; NO and basic fibroblast growth factor (FGF-b) levels were analyzed in GCF samples. RESULTS: The CSAI-2 was significantly different between the two evaluation time points. GCF NO and FGF-b levels increased before the championship match, whereas saliva levels did not change. The plaque index and gingival index (GI) increased at the evaluation just before the championship match. The difference in the GI was statistically significant. CONCLUSION: The competitive stress of athletes may lead to a gingival/periodontal disturbance accompanied by an altered NO metabolism in saliva and GCF.

Arginine-nitric oxide-polyamine metabolism in periodontal disease.

BACKGROUND: Arginine is converted to nitric oxide (NO) via NO synthase and to ornithine via arginase. Ornithine decarboxylase (ODC) catalyzes the conversion of ornithine to polyamines. Arginase can inhibit NO production, and NO can inhibit ODC activity as part of an early inflammatory response. This study examines the arginine-NO-polyamine pathway alteration in saliva and gingival biopsy samples of patients with gingivitis or periodontitis and healthy controls and evaluates the response to periodontal treatment. METHODS: This study includes nine gingivitis patients, 15 chronic periodontitis patients, and 11 healthy age-matched controls. Periodontal clinical measurements, gingival biopsies, and saliva samples were obtained before treatment (BT) and 1 month after periodontal treatment (AT). Arginase and ODC activities and NO levels were determined spectrophotometrically. RESULTS: The BT salivary and gingival NO levels were found to be highest in the gingivitis group, followed by the healthy and the periodontitis groups, respectively. Salivary NO levels significantly increased in the periodontitis group and decreased in the gingivitis group AT (P <0.05). Gingival NO levels decreased significantly in the periodontitis and the gingivitis groups AT (P <0.05). Arginase levels were detected highest in the gingivitis group and lowest in the periodontitis group, both in saliva and gingiva. Only gingival arginase levels significantly increased AT (P <0.05). ODC activity was highest in saliva, and lowest in the gingiva of the periodontitis patients BT. It was found to be significantly higher in the periodontitis group AT (P <0.05). CONCLUSIONS: In this study, regarding arginine-NO-polyamine metabolism, gingival tissue seems to be more informative about periodontal pathogenesis than saliva. At early phase of periodontal inflammation, NO arginase and ODC levels were measured as higher than at an established lesion of periodontitis.

Impact of chlorhexidine mouth rinse use on postextraction infection via nitric oxide pathway.

OBJECTIVE AND DESIGN: Nitric oxide (NO) has been linked to inflammatory reactions, tissue destruction, host defense, and wound healing in oral diseases. It is known that arginase enzyme controls the synthesis of NO through arginine depletion. This study evaluated the arginase-NO pathway alteration in response to tissue injury after dental extraction surgery and the effect of postoperative use of 0.2% chlorhexidine gluconate rinse (CHX). MATERIALS AND METHODS: This study included 28 individuals who had impacted mandibular third molars. They were randomly divided into two groups. Group A was comprised of 13 individuals who used postoperative CHX (0.2%) rinse, while group B included 15 individuals who did not use postoperative CHX rinse. For each patient, periodontal inflammatory status was evaluated. Salivary and gingival tissue samples were obtained before and 1 h and 1 week after the surgery to determine the NO level and arginase activity using spectrophotometric methods. RESULTS: NO level of tissue samples displayed an insignificant decrease in both groups postoperatively. However, arginase activity of tissue samples was significantly higher in group B compared to group A 1 week after surgery (p

Concurrent measurement of adenosine deaminase and dipeptidyl peptidase IV activity in the diagnosis of tuberculous pleural effusion.

Measurement of pleural fluid adenosine deaminase (ADA) levels aids diagnosing tuberculous pleural effusion (TPE). Dipeptidyl peptidase IV (DPP) enzyme is closely related to ADA. Our aim was to determine the value of concurrent measurement of these T-cell-associated enzymes, ADA and DPP levels in the diagnosis of TPE. Patients with pleural effusion were grouped as TPE, parapneumonic, malignant, congestive heart failure related, and miscellaneous pleural effusions. Pleural and serum ADA and DPP levels were measured. Pleural and serum levels of ADA and pleural DPP were higher in TPE group than the rest. In 7 patients, pleural biopsy revealed granulomatous pleuritis. All of these patients had TPE and had elevated serum and pleural ADA levels. Serum and pleural ADA or DPP levels and pleural ADA and DPP levels correlated with each other. Selecting cutoff values of 40 and 27 IU/L for pleural ADA and DPP, respectively, the sensitivity of concurrent measurement of both enzymes was 77%, specificity 94%, and diagnostic efficiency 91%. ADA and DPP play an important role in tuberculous immunopathogenesis. The utility of DPP in the diagnosis of TPE has never been determined before. Concurrent measurement of ADA-DPP can aid in diagnosing TPE with higher specificity, sensitivity, and efficiency.

The role of oxidative mechanisms in the etiopathogenesis of pterygium: a preliminary study.

BACKGROUND: To evaluate the role of light-induced oxidative mechanisms in the pathogenesis of primary pterygium. METHODS: Pterygium specimens were obtained from 18 eyes of 18 patients undergoing pterygial removal (group A), and normal conjunctival specimens were obtained from 18 eyes of 18 patients undergoing cataract surgery (group B). In all specimens, malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activities were studied and compared. RESULTS: In group A, the mean SOD activity was lower, and the mean MDA level was higher when compared to group B. However, these differences did not reach clinical significance (p > 0.05). On the other hand, the mean CAT activity was statistically significantly higher in group A when compared to controls (p = 0.017). CONCLUSION: This preliminary study indicates that oxidative mechanisms seem to play a role in the pathogenesis of pterygium. These mechanisms are apparently activated by ultraviolet irradiation. Further studies are required to establish the role of oxidative mechanisms in the pathogenesis of primary or recurrent pterygia.

[Levels of adenosine deaminase and dipeptidyl peptidase IV in patients with panic disorder]. / Panik bozuklugunda adenozin deaminaz ve dipeptidil peptidaz IV enzim düzeyleri.

OBJECTIVE: Adenosine deaminase and dipeptidyl peptidase IV are enzymes connected to T cells that play an important role in immune system functioning. In this study, in order to understand the immune processes in panic disorder, we determined the serum levels of adenosine deaminase and dipeptidyl peptidase IV in medication-free panic disorder patients and compared them to those of healthy controls. METHOD: Enzymes levels were determined in blood samples of 24 healthy controls and 33 panic disorder patients diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders-IV that were medication free during the previous month and medically healthy. RESULTS: Levels of both enzymes were significantly higher in panic disorder patients than in the controls (P<0.001 for adenosine deaminase and P<0.05 for dipeptidyl peptidase IV). The levels of the enzymes did not correlate with sociodemographic variables, duration of the disorder, presence of agoraphobia, presence of stressors, number of panic attack symptoms, and Hamilton depression and anxiety rating scale scores. In addition, the 2 enzymes? levels did not correlate with each other. There was a correlation between Hamilton anxiety rating scale score and the number of panic attack symptoms (P<0.001); however, Hamilton anxiety rating scale scores were not correlated with the other variables. CONCLUSION: Our results suggest that there may be a primary or secondary impaired immune state in the course of panic disorder, as there is in many other psychiatric disorders, such as major depression. Future studies with larger samples are needed to clarify the relationship between the immune system and panic disorder.

Effectiveness of scaling and root planing versus modified Widman flap on nitric oxide synthase and arginase activity in patients with chronic periodontitis.

BACKGROUND: Nitric oxide (NO) is synthesized from the conversion of L-arginine to L-citrulline by NO synthase (NOS). Arginase, which is an arginine-depleting enzyme, can compete with NOS for the common substrate L-arginine and thus inhibit NO production. OBJECTIVES: In the present study, we aimed to examine the correlation between the arginase and NOS activity in patients with chronic periodontitis and to compare the effects of scaling and root planing and modified Widman flap procedures on enzyme activity. MATERIAL AND METHODS: The study included 13 patients diagnosed with chronic periodontitis. Using a split-mouth design, the defects showing>or=7 mm of attachment loss were treated either with scaling and root planing or with modified Widman flap. Gingival biopsies from both sites were obtained at baseline and 2 months after periodontal treatment. Immunohistochemical staining was performed for evaluating NOS expression and specific arginase activity was determined spectrophotometrically. RESULTS: Although inflamed periodontal tissues demonstrated a strong inducible NOS (iNOS) expression at baseline, immunostaining decreased after periodontal treatment. iNOS expression intensity and the number of inflammatory cells showing iNOS expression were found to be higher in the scaling and root planing group compared to the modified Widman flap group. The specific activity of arginase was measured as 0.18+/-0.07 IU/mg protein in the modified Widman flap group and 0.25+/-0.11 IU/mg protein in the scaling and root planing group at baseline. After periodontal therapy, the enzyme level was increased to 0.68+/-0.14 IU/mg protein in the modified Widman flap and to 1.10+/-0.23 IU/mg protein in the scaling and root planing group. CONCLUSION: This study was the first report of evaluating the involvement of the arginine-NO pathway in chronic periodontitis and this might be considered to be of value in understanding the periodontal disease mechanisms.

Cyclosporine reduces hepatic antioxidant capacity: protective roles of antioxidants.

The immunosuppressive agent cyclosporine A (CsA) has been reported to exert measurable hepatotoxic effects. One of the causes leading to hepatotoxicity is thought to be reactive oxygen radical formation. Therefore, this study was designed to elucidate possible relation between cyclosporine A treatment and antioxidant capacity (AOC) of hepatic tissue and, to determine if antioxidant supplementation is beneficial. Cyclosporine A was given to 20 rabbits orally for 10 days. Vitamins E and C combination were given intramuscularly. Vitamin therapy was started 3 days before cyclosporine A treatment and continued for 10 days. In each group (control, cyclosporine A, cyclosporine A+vitamin, and vitamin only) there were five animals. After the animals were sacrificed, their livers were removed to be used in the AOC measurement. AOC was found to be lower in cyclosporine A group compared to control and vitamin groups. Results suggest that reduced antioxidant capacity may play part in the cyclosporine A-induced hepatotoxicity and use of some antioxidants may give beneficial results.

Oxidative stress in patients with chronic renal failure: effects of hemodialysis.

OBJECTIVE: To investigate blood oxidative status of patients with chronic renal failure (CRF) and possible effects of hemodialysis on the development of oxidative stress in blood. MATERIALS AND METHODS: The levels of malondialdehyde (MDA) and oxidation resistance (OR) values were measured in blood plasma, erythrocyte hemolysate and erythrocyte membrane fractions of 33 patients with CRF and of 12 healthy controls. Of the 33 patients, 17 subjects were under hemodialysis treatment. RESULTS: MDA levels were found to be increased in all blood fractions of the patients. OR values were unchanged in erythrocyte hemolysates but decreased in plasma and erythrocyte membrane fractions of the CRF patients. Moreover, erythrocyte MDA levels were determined to be higher in hemodialyzed patients compared with both controls and non-hemodialyzed patients. OR values were lower in all blood fractions of the hemodialyzed patients relative to controls and non-hemodialyzed patients. CONCLUSION: Results suggest that there is a significant oxidative stress (expressed as peroxidation) in blood samples from patients with CRF, which is further exacerbated by hemodialysis.

Effects of cigarette smoking with different tar content on erythrocyte oxidant/antioxidant status.

In this study, the effects of cigarettes with differing tar content on erythrocyte oxidant/antioxidant status was investigated. Malondialdehyde (MDA) as an indicator of oxidant status and superoxide radical scavenger activity (SSA) as an indicator of antioxidant status were measured in erythrocytes from 20 smokers and 10 non-smoker controls. Ten of the 20 smoking subjects smoked five cigarettes with full flavour low tar (FFLT with 12 mg tar) and the others smoked five cigarettes with full flavour high tar (FF with 23 mg tar) over 1 hour. Initial blood samples from both groups at fasting, followed by further samples from smokers at 1.5 hours and 3 hours after smoking. Initial erythrocyte MDA level and SSA activity were found to be higher in the smoking groups compared to non-smokers. Furthermore, both parameters were significantly higher at the 1.5-hour and 3-hour erythrocyte samples when compared to initial values in the FFLT group. However, there were no statistically significant differences between SSA values established at different times in FF group. Results suggest that smoking causes oxidant load in the erythrocytes. Although a compensatory mechanism (i.e. increased SSA activities) develops in the FFLT group after smoking, this cannot prevent peroxidation reactions (i.e. increased MDA levels) in the erythrocytes. As to the types of cigarettes, both seem to have oxidant potential, but oxidation degree in the FFLT group is higher than that of FF group. These results suggest that antioxidant supplementation to smokers might be beneficial to decrease cellular oxidation damages.

The effects of cyclosporine on antioxidant enzyme activities and malondialdehyde levels in rabbit hepatic tissues.

Possible molecular mechanisms leading to cyclosporine-induced hepatotoxicity has not been cleared yet. Therefore, investigation of antioxidant status of hepatic tissues exposed to cyclosporine A (CsA) and of free radical involvement in the CsA-induced hepatotoxicity seems of importance. For this aim, 20 rabbits were used in the study. In each group (control, CsA, CsA plus vitamin and, vitamin only) there were 5 animals. CsA was given orally (25 mg/kg/day) for 10 days. Vitamins E (100 mg/kg/ day) and C (200 mg/kg/day) combination was injected intramuscularly. After 10th day, animals were killed, and livers were prepared for the enzymatic assays. Activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and, malondialdehyde (MDA) levels were determined in the supernatant fractions. Lowered SOD, unchanged GSH-Px and, increased CAT activities and MDA levels were detected in hepatic tissues of rabbits treated with CsA as compared with controls. In the CsA plus vitamin group, SOD activity was found to be higher, GSH-Px and CAT activities unchanged and MDA levels lower than the CsA group. In the vitamin-treated group, all of the enzyme activities were higher than the controls but MDA levels were unchanged. Correlation analysis revealed some significant differences between the groups. Results suggest that cyclosporine impairs the antioxidant defense system and thus, leads to oxidant stress and peroxidation in rabbit hepatic tissues. It has been established that this process can be prevented by antioxidant vitamin supplementation.