Osman Ciftci

Antioxidative effects of curcumin, β-myrcene and 1,8-cineole against 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced oxidative stress in rats liver.

The aim of this study was to investigate the effectiveness of curcumin, β-myrcene (myrcene) and 1,8-cineole (cineole) on antioxidant defense system in rats given a persistent environmental pollutant (2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD). Rats (n = 112) were divided randomly into 8 equal groups. One group was kept as control and given corn oil as carrier. TCDD was orally administered at the dose of 2 μg/kg/week. Curcumin, myrcene and cineole were orally administered at the doses of 100 mg/kg/day, 200 mg/kg/day and 100 mg/kg/ day, respectively, by gavages dissolved in corn oil with and without TCDD. The liver samples were taken from half of all rats on day 30 and from the remaining half on day 60 for the determination of thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), catalase (CAT), glutathione peroxidase (GSH-Px) and CuZn-SOD levels by spectrophotometric method. The results indicated that although TCDD significantly (p ≤ 0.01) increased formation of TBARS, it caused a significant decline in the levels of GSH, CAT, GSH-Px and CuZn-SOD in rats. In contrast, curcumin, myrcene and cineole significantly increased GSH, CAT, GSH-Px and CuZn-SOD levels but decreased formation of TBARS. Additionally, the antioxidative effects of curcumin, myrcene and cineole were increased at day 60 compared to day 30. In the TCDD groups given curcumin, myrcene and cineole, oxidative stress decreased by time. In conclusion, curcumin, myrcene and cineole showed antioxidant activity and eliminated TCDD-induced oxidative stress in rats in a time-dependent manner.

Beneficial effects of chrysin on the reproductive system of adult male rats.

In this study, the beneficial effect of chrysin, a natural flavonoid currently under investigation due to its important biological activities, on reproductive system of rats was investigated. Rats (n = 16) were divided randomly into two equal groups. Rats in control group were given corn oil as carrier. Chrysin was orally administered at the dose of 50 mg kg−1 per day by gavages, and it was dissolved in corn oil for 60 days. Tissue thiobarbituric acid reactive substances (TBARS) and glutathione (GSH) levels, antioxidant enzyme activity (CAT, SOD and GSH‐Px), sperm parameters (motility, concentration and abnormal sperm rate), reproductive organ weight (testes, epididymis, vesicula seminalis, prostate) and serum testosterone levels were determined in the rats. Our results indicated that chrysin significantly increased GSH, CAT, GSH‐Px and CuZn‐SOD levels, but did not change the formation of TBARS significantly. In addition, sperm motility, sperm concentration and serum testosterone levels significantly increased, whereas abnormal sperm rate significantly decreased with chrysin treatment. In conclusion, it is suggested that treatment with chrysin can positively affect the reproductive system in rats, and it can be used for the treatment of male infertility.

Ameliorative effects of curcumin against acute cadmium toxicity on male reproductive system in rats

The aim of the present study was to investigate the ameliorative effect of curcumin (CMN) against acute cadmium chloride (CdCl2) toxicity on male reproductive system in rats. CdCl2 is known to be a heavy metal and potential environmental pollutant. For this purpose, 28 rats were equally divided into four groups; the first group was kept as control and given distilled water and corn oil as carrier. In second and third groups, CdCl2 and CMN were administered at the dose with 1 mg kg−1 day−1 and 100 mg kg−1 for 3 days respectively. CdCl2 and CMN were given together at the same doses in the fourth group. It was determined that acute CdCl2 exposure caused a significant reproductive damage via increased oxidative stress (increased TBARS levels and decreased SOD, CAT, GPx and GSH levels), histological alterations (necrosis, oedema etc.) and spermatological damage (decreased sperm motility and sperm concentration and increased abnormal sperm rate) in male rats. However, CMN treatment partially reversed these toxic effects of CdCl2 on the reproductive system. In conclusion, our results show that acute exposure of CdCl2 may lead to infertility, and CMN could prevent and reverse hazardous effects of CdCl2 to some degree. Thus, CMN may be useful for the prevention of CdCl2‐induced reproductive damage.

Comparison of reproductive toxicity caused by cisplatin and novel platinum-N-heterocyclic carbene complex in male rats.

Cisplatin and other platinum complexes are important chemotherapeutic agents and useful in the treatment for several cancers such as prostate, ovarian and testis. However, severe side effects including reproductive toxicity of cisplatin and other platinum complex cause limitations in their clinical usage. In this context, we aimed to compare the damage in testis caused by cisplatin and a novel platinum-N-heterocyclic carbene complex (Pt-NHC). To this end, 35 Sprague-Dawley rats were divided randomly into five equal groups (n = 7 in each group). Cisplatin and Pt-NHC were intraperitoneally administered as a single dose of 5 mg/kg or 10 mg/kg, and the rats were then killed 10 days after this treatment. The testicular tissues and serum samples were taken from all rats for the determination of reproductive toxicity. The results showed that cisplatin and Pt-NHC caused toxicity on the reproductive system via increased oxidative and histological damage, decreased serum testosterone levels and negatively altered sperm characteristics in a dose-dependent manner (p < 0.05). At the same dose levels, cisplatin generally caused lower toxicity on the reproductive system compared with Pt-NHC. In conclusion, these results suggest that Pt-NHC has more toxic effects on the male reproductive system than cisplatin, and in terms of clinical usage, Pt-NHC may be unsafe compared with cisplatin.

Protective effects of quercetin and chrysin against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced oxidative stress, body wasting and altered cytokine productions in rats

The aim of this study is to investigate the effects of the quercetin (Q) and chrysin (CH) on oxidative stress, cytokines levels and body weights in rats induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Rats were divided randomly into six equal groups. TCDD, Q and CH were administered by gavages dissolved in corn oil at the doses of 2 µg/kg/week, 20 mg/kg/day and 50 mg/kg/day, respectively. The blood samples were taken from all rats at 60th days to be analyzed for the determination of thiobarbituric acid reactive substances (TBARS), tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). The results indicated that although TCDD increased significantly TBARS and TNF-α levels, it caused a decline in the levels of IFN-γ and body weight. In contrast, these effects of TCDD on TBARS, TNF-α, IFN-γ levels and body weight were significantly prevented by treatments of Q and CH. In conclusion, it was determined that TCDD caused the adverse effects on immune functions, body weight and oxidative stress in rats. However, Q and CH administered with TCDD eliminated these adverse effects. These results suggest that Q and CH may play a protective role against TCDD toxicity.

Hesperidin protects brain and sciatic nerve tissues against cisplatin-induced oxidative, histological and electromyographical side effects in rats

In the present study, the beneficial effect of hesperidin (HP), a citrus flavonoid, on cisplatin (CP)-induced neurotoxicity was investigated. A total of 28 rats were equally divided into four groups; the first group was kept as control. In the second and third groups, CP and HP were given at the doses of 7 and 50 mg/kg/day, respectively. In the fourth group, CP and HP were given together at the same doses. The results indicated that although CP caused significant induction of lipid peroxidations and reduction in the antioxidant defense system potency in the brain and sciatic nerve, HP prevented these effects of CP. Besides, CP led to histopathological damage, mainly apoptosis, as well as electromyographical (EMG) changes in sciatic nerve. On the other hand, HP treatment reversed histopathological and EMG effects of CP. In conclusion, CP had severe dose-limiting neurotoxic effects and these effects of CP can be prevented by HP treatment. Thus, it appears that coadministration of HP with CP may be a useful approach to attenuate the negative effects of CP on the nervous system.

Ameliorating effects of quercetin and chrysin on 2,3,7,8-tetrachlorodibenzo- p-dioxin-induced nephrotoxicity in rats

The aim of this study is to investigate the beneficial effects of the quercetin (Q) and chrysin (CH) against nephrotoxicity induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a persistent environmental contaminant, in rats. Rats were divided randomly into six equal groups. TCDD, Q and CH were administered by gavages dissolved in corn oil at the doses of 2 µg/kg/week, 20 mg/kg/day and 50 mg/kg/day, respectively. The kidney samples were taken from all rats on day 60 for the determination of thiobarbituric acid reactive substances (TBARS), glutathione (GSH), catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) levels by spectrophotometric method. The results indicated that TCDD significantly induced lipid peroxidation and reduced antioxidant activities in rats. In contrast, Q and CH significantly prevented toxic effects of TCDD via increased GSH, CAT, GPx and SOD levels but decreased formation of TBARS. Also, it was determined that exposure to TCDD leads to significant histological damage in kidney tissue, and these effects can be eliminated with Q and CH treatment. In conclusion, the current study showed that exposure to TCDD can exert nephrotoxicity in rats. When Q and CH were given together with TCDD, they prevented nephrotoxic effects of TCDD. Their preventive effect lends more support to the role of oxidative and histological damage in the overall toxicity of TCDD.

The determination of oxidative damage in heart tissue of rats caused by ruthenium(II) and gold(I) N-heterocyclic carbene complexes

In the present study, we aimed to determine the oxidative damage in rat heart tissue induced by ruthenium(II)-NHC (Ru) and gold(I)-NHC (Au) complexes which have anticarcinogenic effects and not used clinically yet. For this purpose, 35 Sprague-Dawley rats were randomly divided into 5 equal groups. In the control group, rats treated with saline, Ru and Au complexes were intraperitoneally given high (10 mg/kg) and low (5 mg/kg) doses as only one administration. The animals were killed, and heart tissues were taken on day 10 of the drug administration for the determination of the biochemical parameters (malondialdehyde, superoxide dismutase, reduced glutathione and catalase levels). It was determined that both Ru and Au complexes treatment significantly caused oxidative damage compared to the control group. Additionally, it was shown that Au treatment caused more adverse effects than Ru treatment. Also, it was clearly found that the occurred effects were generally determined in a dose-dependent manner. In conclusion, when these compounds synthesized for the treatment of cancer were used, they caused oxidative damage in heart tissue. However, Ru complex could be preferred for cancer treatment in terms of user safety.

Quercetin prevents docetaxel-induced testicular damage in rats

The protective effect of quercetin on docetaxel – an anticancer agent – induced testicular damage in rats was investigated. Thirty‐two rats were randomly divided into four groups: group 1 – control, carrier solutions were given; group 2 – quarcetin 20 mg kg−1 day−1 was given orally; group 3 – docetaxel 5 mg kg−1 was given intraperitoneally as single dose; group 4 – docetaxel and quarcetin were given together. The histopathological changes; the specific biochemical markers, including antioxidants; and the sperm characteristics were evaluated. Docetaxel caused a significant increase in TBARS level and a significant decrease in SOD, GPX, CAT and GSH levels in the testicular tissues compared with the control group, whereas quercetin led to a significant decrease in lipid peroxidation, which was caused by docetaxel, via reducing TBARS level and increasing the levels of SOD, CAT, GPX and GSH. In addition, after docetaxel administration, sperm motility, sperm concentration, testicular and epididymis weights were significantly decreased and abnormal sperm rate and histopathological changes were increased. However, these effects of docetaxel on sperm parameters, histological changes and the tissue weights were eliminated by quercetin treatment. Our results show that the administration of docetaxel induced the testicular damage (oxidative stress, testes tissue damage and sperm parameters), and quercetin prevented docetaxel‐induced testicular damage in rats.

Effects of quercetin and chrysin on 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin induced hepatotoxicity in rats

The objective of current study is to investigate the effects of the administration of chrysin (CH) and quercetin (Q) on rat liver in which oxidative and histological damage had been induced by 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD). Rats were randomly divided into six equal groups. TCDD was orally administered at the dose of 2 μg/kg/week, and Q and CH were orally administered at the doses of 20 mg/kg day and 50 mg/kg/day, respectively, by gavages dissolved in corn oil. The liver samples to be analyzed for the determination of oxidative and histological alternations were taken from rats at 60 days. The results indicated that although 2,3,7,8‐TCDD significantly induced (P ≤ 0.01) lipid peroxidation (increase of MDA levels), it positively affected oxidant/antioxidant system (a decline in the levels of GSH, CAT, GSH‐Px, and CuZn‐SOD) in rats significantly. The histological changes observed in the liver correlated with the biochemical findings. However, these effects of TCDD on oxidative and histological changes were eliminated by Q and CH treatment. In conclusion, TCDD caused an adverse effect on rats liver. When Q and CH were given together with TCDD, they prevented hepatotoxicty induced by TCDD. Thus, it is thought that Q and CH may be useful as a new category of anti‐TCDD toxicity agent.