An In Vitro Study on the Interactions of Pycnogenol® with Cisplatin in Human Cervical Cancer Cells.

OBJECTIVES: In the treatment of cancer, it is intended to increase the anticancer effect and decrease cytotoxicity using various plant-derived phenolic compounds with chemotherapeutic drugs. Pycnogenol® (PYC), a phenolic compound, has been the subject of many studies. Since the mechanisms of the interactions of PYC with cisplatin need to be clarified, we aimed to determine the effects of PYC on cisplatin cytotoxicity in human cervix cancer cells (HeLa) and to evaluate the genotoxicity of PYC. MATERIALS AND METHODS: The cytotoxicity of cisplatin and PYC was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in HeLa cells for 24 h and 48 h. The effect of PYC against oxidative DNA damage was evaluated using the comet assay. RESULTS: The IC50 values of cisplatin were 22.4 µM and 12.3 µM for 24 h and 48 h, respectively. The IC50 values of PYC were 261 µM and 213 µM for 24 h and 48 h, respectively. For 24 h exposure, PYC significantly reduced the IC50 value of cisplatin at the selected concentrations (15.6-500 µM). For 48 h exposure, PYC did not change the cytotoxicity of cisplatin at concentrations between 15.6 and 125 µM, but significantly reduced it at concentrations of 250 µM and 500 µM. PYC alone did not induce DNA damage at concentrations of 10 µM or 25 µM; however, it significantly induced DNA damage at higher concentrations (50-100 µM). It also significantly reduced H2O2-induced DNA damage at all concentrations studied (10-100 µM). CONCLUSION: Our results suggest that PYC may increase the cisplatin cytotoxicity in HeLa cells at nongenotoxic doses. The results might contribute to the anticancer effect of cisplatin with PYC in cervical carcinoma, but in order to confirm this result further in vitro studies with cancer cell lines and in vivo studies are needed.

Evaluation of the DNA damage in lymphocytes, sperm and buccal cells of workers under environmental and occupational boron exposure conditions.

Industrial production and use of boron compounds have increased during the last decades, especially for the manufacture of borosilicate glass, fiberglass, metal alloys and flame retardants. This study was conducted in two districts of Balikesir; Bandirma and Bigadic, which geographically belong to the Marmara Region of Turkey. Bandirma is the production and exportation zone for the produced boric acid and some borates and Bigadic has the largest B deposits in Turkey. 102 male workers who were occupationally exposed to boron from Bandirma and 110 workers who were occupationally and environmentally exposed to boron from Bigadic participated to our study. In this study the DNA damage in the sperm, blood and buccal cells of 212 males was evaluated by comet and micronucleus assays. No significant increase in the DNA damage in blood, sperm and buccal cells was observed in the residents exposed to boron both occupationally and environmentally (p = 0.861) for Comet test in the sperm samples, p = 0.116 for Comet test in the lymphocyte samples, p = 0.042 for micronucleus (MN) test, p = 0.955 for binucleated cells (BN), p = 1.486 for condensed chromatin (CC), p = 0.455 for karyorrhectic cells (KHC), p = 0.541 for karyolitic cells (KLY), p = 1.057 for pyknotic cells (PHC), p = 0.331 for nuclear bud (NBUD)). No correlations were seen between blood boron levels and tail intensity values of the sperm samples, lymphocyte samples, frequencies of MN, BN, KHC, KYL, PHC and NBUD. The results of this study came to the same conclusions of the previous studies that boron does not induce DNA damage even under extreme exposure conditions.

Preventive role of Pycnogenol® against the hyperglycemia-induced oxidative stress and DNA damage in diabetic rats.

Diabetes mellitus, a complex progressive metabolic disorder, leads to some oxidative stress related complications. Pycnogenol® (PYC), a plant extract obtained from Pinus pinaster, has been suggested to be effective in many diseases including diabetes, cancer, inflammatory and immune system disorders. The mechanisms underlying the effects of PYC in diabetes need to be elucidated. The aim of this study was to determine the effects of PYC treatment (50 mg/kg/day, orally, for 28 days) on the DNA damage and biochemical changes in the blood, liver, and kidney tissues of experimental diabetic rats. Changes in the activities of catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase enzymes, and the levels of 8-hydroxy-2'-deoxyguanosine, total glutathione, malondialdehyde, insulin, total bilirubin, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, high density lipoprotein, low density lipoprotein, total cholesterol, and triglyceride were evaluated. DNA damage was also determined in the whole blood cells and the liver and renal tissue cells using the alkaline comet assay. PYC treatment significantly ameliorated the oxidative stress, lipid profile, and liver function parameters as well as DNA damage in the hyperglycemic rats. The results show that PYC treatment might improve the hyperglycemia-induced biochemical and physiological changes in diabetes.

Effects of cinnamic acid on complications of diabetes

Background/aim: Diabetes mellitus (DM) is a major health problem worldwide. Cinnamic acid (CA) and its derivatives are synthesized in plants and increasing attention has been given to them in recent years due to the high number of beneficial health properties attributed to their consumption. The aim of this study was to investigate the effects of CA on streptozotocin-induced diabetes in Wistar albino rats. Materials and methods: DNA damage was evaluated in the blood, liver, and kidney cells of rats by the alkaline comet assay. Oxidative stress parameters such as catalase, superoxide dismutase, glutathione reductase, glutathione-S-transferase, and glutathione peroxidase activities and 8-hydroxy-2-deoxyguanosine, total glutathione, and malondialdehyde levels; biochemical parameters including insulin, total bilirubin, and BCA protein levels; hepatic enzyme levels such as alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyl transferase; and lipid profile parameters including high-density lipoprotein, low-density lipoprotein, total cholesterol, and triglyceride levels were also evaluated. Results: DM caused genotoxic damage and alterations in lipid profiles, oxidative stress parameters, and hepatic enzymes levels. CA treatment ameliorated these effects. Conclusion: It seems that CA might have a role in the prevention of the complications of diabetes.

Protective Effects of Ursolic Acid in the Kidneys of Diabetic Rats.

OBJECTIVES: Diabetes, a heteregenous metabolic and chronic disease, is a growing health problem in most countries. It has been claimed that diabetes is associated with the increased formation of free radicals and decreased in antioxidant potential. Oxidative stress formed in diabetes may cause DNA damage in the tissues. Ursolic acid, a well-known pentacylic triterpene, is commonly used in traditional Chinese medicine due to its beneficial health effects such as antioxidant, anticancer, and antiulcer properties. The aim of this study was to investigate the effects of ursolic acid in the kidneys of Wistar albino rats with streptozotocin-induced diabetes. MATERIALS AND METHODS: DNA damage was evaluated in the kidney cells of rats using alkaline comet assays. Oxidative stress parameters such as CAT, SOD, GR, and GSH-Px enzyme activities and total GSH and MDA levels were also evaluated. RESULTS: Ursolic acid treatment was found to significantly decrease DNA damage, GR enzyme activities, and MDA levels, and significantly increase GSH levels and CAT, SOD and GSH-Px enzyme activities in diabetic rats. CONCLUSION: According to our results, it seems that ursolic acid may be beneficial against diabetes-induced renal damage.

d-limonene ameliorates diabetes and its complications in streptozotocin-induced diabetic rats.

It is known that diabetes causes some complications including alterations in lipid profile, hepatic enzyme levels but also it causes oxidative stress. Limonene, a major component of Citrus oils, has important health beneficial effects in lowering the level of oxidative stress due to its antioxidant activity. The aim of this study was to investigate the effects of D-limonene on streptozotocin (STZ)-induced diabetes in Wistar albino rats. For this purpose, DNA damage was evaluated by alkaline comet assay. Changes in the activities of catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR) and glutathione peroxidase (GSHPx) and the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), total glutathione (GSH), malondialdehyde (MDA), insulin, total bilirubin and BCA protein, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT), high density lipoprotein (HDL), low density lipoprotein (LDL), total cholesterol and triglyceride were also evaluated. D-limonene treatment was found to significantly decrease DNA damage, GR enzyme activities and MDA levels and significantly increase GSH levels and CAT, SOD and GSH-Px enzyme activities and altered lipid and liver enzyme parameters in diabetic rats. According to our results, it seems that D-limonene might have a role in the prevention of the complication of diabetes in rats.

Antigenotoxic properties of Paliurus spina-christi Mill fruits and their active compounds.

BACKGROUND: Paliurus spina-christi Mill. (PS) fruits are widely used for different medical purposes in Turkey. Like in many medicinal herbs the studies concerning their activity, the activities of PS are also not well clarified. The aim of this study is to evaluate the antigenotoxicity of the compounds isolated and identified from the extracts of PS fruits. METHODS: The active compounds were separated, isolated, and determined by chromatographic methods and their structural elucidation was performed by Nuclear Magnetic Resonance (NMR) methods. The compounds were obtained from either ethyl acetate (EA) or n-butanol extracts. The cytotoxicities of the compounds using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the antigenotoxic activities of the compounds using the alkaline single cell gel electrophoresis techniques (comet assay) were evaluated in Chinese hamster lung fibroblast (V79) cell lines. RESULTS: The isolated major compounds were identified as (+/-) catechins and gallocatechin from EA fraction and rutin from n-butanol fraction of PS fruits. Their chemical structures were identified by 1H-NMR, 13C-NMR, HMBC, and HMQC techniques. Half-maximal inhibitory concentration of catechins, gallocatechin, and rutin were found to be 734 µg/mL, 220 µg/mL, and 1004 µg/mL, respectively. The methanolic extract of PS (1-100 µg/mL) alone did not induce DNA single-strand breaks while catechins (1-100 µg/mL), gallocatechin (1-50 µg/mL), and rutin (1-50 µg/mL) significantly reduced H2O2-induced DNA damage. CONCLUSION: It has been suggested that PS fruits and their compounds catechins, gallocatechin and rutin may have beneficial effects in oxidative DNA damage. It seems that PS fruits may be used in protection of the disorders related to DNA damage.

Assessment of Genotoxic Effects of Pendimethalin in Chinese Hamster Over Cells by the Single Cell Gel Electrophoresis (Comet) Assay.

OBJECTIVES: Pendimethalin (N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzeneamine) is a dinitroaniline herbicide compound which selectively controls weeds. It is a cell division and growth inhibitor. It descends plants in a short time after seedling. It is a soil and water pollutant due to the widespread use of formulations in Turkey and around the world. Pendimethalin is manufactured in and imported by Turkey. Pendimethalin is a slightly toxic compound that is classified in toxicity class 3 by the United States Environmental Protection Agency (USEPA). Even though it is classified as group C (human possible carcinogen) compound by the USEPA, there are limited number of studies about its genotoxic effects. The aim of this study was to evaluate in vitro genotoxic effects of different concentrations of pendimethalin in Chinese hamster over (CHO) cells by the single cell gel electrophoresis (comet) assay. MATERIALS AND METHODS: The cells are incubated with 1, 10, 100, 1000 and 10000 µM concentrations of pendimethalin for 30 min at 37°C and DNA damage was compared with CHO cells untreated with pendimethalin. 50 µM hydrogen peroxide was used as positive control. RESULTS: No significant cytotoxic effects were observed within the concentration ranges studied. The DNA damage in CHO cells was significantly increased in the pendimethalin concentrations of 1, 100, 1000 and 10000 µM, however, a significant decrease was observed in 10 µM pendimethalin concentration. CONCLUSION: Our results show that 1-10000 µM concentrations of pendimethalin induce DNA damage in CHO cells, which was assessed by comet assay.

The Ameliorative Effects of Pycnogenol® on Liver Ischemia-Reperfusion Injury in Rats.

OBJECTIVES: Pycnogenol® (PYC®), a standardized extract from the bark of Pinus maritima, consists of different phenolic compounds. PYC® has shown to have protective effects on chronic diseases such as diabetes, asthma, cancer, and immune disorders. The aim of this study was to determine the effects of PYC® against the DNA damage and biochemical changes in blood, liver, and lung tissues of ischemia-reperfusion (IR)-induced Wistar albino rats. MATERIALS AND METHODS: A sham group, IR injury-induced group, and IR+PYC® group were formed. Ischemia was induced and sustained for 45 min, then the ischemic liver was reperfused, which was sustained for a further 120 min at the end of this period. After anesthesia and before the IR inducement, 100 mg/kg PYC® was given to the IR+PYC® group through intraperitoneal injections. The total oxidant (TOS) and total antioxidant status (TAS), total thiol levels (TTL), advanced oxidation protein products (AOPP), and biochemical parameters [myeloperoxidase (MPO), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH)] in the rats were analyzed using spectrophotometric methods and DNA damage was assessed using single-cell gel electrophoresis. RESULTS: The levels of TOS, TTL, MPO, AOPP, ALT, AST, and LDH were significantly decreased in the IR+PYC® group compared with the IR group (p<0.05). The levels of TAS were significantly increased in the IR+PYC® group compared with the IR group (p<0.05). PYC® reduced the DNA damage when compared with the IR group (p<0.05). CONCLUSION: The present results suggest that PYC® treatment might have a role in the prevention of IR-induced oxidative damage by decreasing DNA damage and increasing antioxidant status.

Resveratrol Protects Sepsis-Induced Oxidative DNA Damage in Liver and Kidney of Rats.

BACKGROUND: The increases of free radicals have been proposed to be involved in the pathogenesis of sepsis, which leads to multiple-organ dysfunction syndromes. The uses of antioxidants as a complementary tool in the medical care of oxidative stress-related diseases have attracted attention of researchers. Resveratrol (RV) has suggested being antioxidant, anti-proliferative, and anti-inflammatory effects in various experimental models and clinical settings. AIMS: This study was undertaken to evaluate the protective effects of RV on oxidative DNA damage induced by sepsis in the liver and kidney tissues of Wistar albino rats. STUDY DESIGN: Animal experimentation. METHODS: Four experimental groups consisting of eight animals for each was created using a total of thirty-two male Wistar albino rats. Sham group was given 0.5 mL of saline intra-peritoneal (ip) only following laparatomy. Sepsis group was given 0.5 mL saline ip only following the induction of sepsis. RV-treated group was given a dose of 100 mg/kg ip RV in 0.5 mL saline following laparatomy. RV-treated sepsis group was given 100 mg/kg ip RV in 0.5 mL saline following the induction of sepsis. A model of sepsis was created by cecal ligation and puncture technique. In the liver and kidney tissues, oxidative stress parameters (malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPX)) and a proinflammatory cytokine (tumor necrosis factor alpha (TNF-alpha)), were evaluated spectrophotometrically and DNA damage was determined by the alkaline single cell gel electrophoresis (comet assay) technique using formamidopyrimidine DNA glycosylase protein. RESULTS: In the RV-treated sepsis group, the levels of MDA and TNF-alpha were lower and GSH levels, SOD and GPX activities were higher than in the septic rats (p<0.05). RV treatment significantly reduced the sepsis-induced oxidative DNA damage in the liver and kidney cells (p<0.05). CONCLUSION: It is suggested that RV treatment might reduce the sepsis-induced oxidative DNA damages in sepsis-related diseases; however, there is a need for more studies to clear up the protective mechanisms of RV against sepsis.

MCM3AP and POMP Mutations Cause a DNA-Repair and DNA-Damage-Signaling Defect in an Immunodeficient Child.

Immunodeficiency patients with DNA repair defects exhibit radiosensitivity and proneness to leukemia/lymphoma formation. Though progress has been made in identifying the underlying mutations, in most patients the genetic basis is unknown. Two de novo mutated candidate genes, MCM3AP encoding germinal center-associated nuclear protein (GANP) and POMP encoding proteasome maturation protein (POMP), were identified by whole-exome sequencing (WES) and confirmed by Sanger sequencing in a child with complex phenotype displaying immunodeficiency, genomic instability, skin changes, and myelodysplasia. GANP was previously described to promote B-cell maturation by nuclear targeting of activation-induced cytidine deaminase (AID) and to control AID-dependent hyperrecombination. POMP is required for 20S proteasome assembly and, thus, for efficient NF-κB signaling. Patient-derived cells were characterized by impaired homologous recombination, moderate radio- and cross-linker sensitivity associated with accumulation of damage, impaired DNA damage-induced NF-κB signaling, and reduced nuclear AID levels. Complementation by wild-type (WT)-GANP normalized DNA repair and WT-POMP rescued defective NF-κB signaling. In conclusion, we identified for the first time mutations in MCM3AP and POMP in an immunodeficiency patient. These mutations lead to cooperative effects on DNA recombination and damage signaling. Digenic/polygenic mutations may constitute a novel genetic basis in immunodeficiency patients with DNA repair defects.

The protective role of ferulic acid on sepsis-induced oxidative damage in Wistar albino rats.

Oxidative stress has an important role in the development of sepsis-induced multiorgan failure. Ferulic acid (FA), a well-established natural antioxidant, has several pharmacological activities including anti-inflammatory, anticancer and hepatoprotective. This study aimed to investigate the effects of FA on sepsis-induced oxidative damage in Wistar albino rats. Sepsis-induced DNA damage in the lymphocytes, liver and kidney cells of rats were evaluated by comet assay with and without formamidopyrimidine DNA glycosylase (Fpg). The oxidative stress parameters such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and total glutathione (GSH) and malondialdehyde (MDA) levels were also measured. It is found that DNA damage in sepsis+FA-treated group was significantly lower than the sepsis group. FA treatment also decreased the MDA levels and increased the GSH levels and SOD and GSH-Px activities in the sepsis-induced rats. It seems that FA might have ameliorative effects against sepsis-induced oxidative damage.

Modulation of the poly (ADP-ribose) polymerase inhibitor response and DNA recombination in breast cancer cells by drugs affecting endogenous wild-type p53.

Synthetic lethal interactions between poly (ADP-ribose) polymerase (PARP) and homologous recombination (HR) repair pathways have been exploited for the development of novel mono- and combination cancer therapies. The tumor suppressor p53 was demonstrated to exhibit indirect and direct regulatory activities in DNA repair, particularly in DNA double-strand break (DSB)-induced and replication-associated HR. In this study, we tested a potential influence of the p53 status on the response to PARP inhibition, which is known to cause replication stress. Silencing endogenous or inducibly expressing p53 we found a protective effect of p53 on PARP inhibitor (PARPi)-mediated cytotoxicities. This effect was specific for wild-type versus mutant p53 and observed in cancer but not in non-transformed cell lines. Enhanced cytotoxicities after treatment with the p53-inhibitory drug Pifithrinα further supported p53-mediated resistance to PARP inhibition. Surprisingly, we equally observed increased PARPi sensitivity in the presence of the p53-activating compound Nutlin-3. As a common denominator, both drug responses correlated with decreased HR activities: Pifithrinα downregulated spontaneous HR resulting in damage accumulation. Nutlin-3 induced a decrease of DSB-induced HR, which was accompanied by a severe drop in RAD51 protein levels. Thus, we revealed a novel link between PARPi responsiveness and p53-controlled HR activities. These data expand the concept of cell and stress type-dependent healer and killer functions of wild-type p53 in response to cancer therapeutic treatment. Our findings have implications for the individualized design of cancer therapies using PARPi and the potentially combined use of p53-modulatory drugs.

Modulating effects of pycnogenol® on oxidative stress and DNA damage induced by sepsis in rats.

The aim of this study was to evaluate the protective effects of Pycnogenol® (Pyc), a complex plant extract from the bark of French maritime pine, on oxidative stress parameters (superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities and total glutathione (GSH) and malondialdehyde (MDA) levels), an inflammatory cytokine (tumor necrosis factor alpha (TNF-α) level) and also DNA damage in Wistar albino rats. Rats were treated with 100 mg/kg intraperitonally Pyc following the induction of sepsis by cecal ligation and puncture. The decreases in MDA levels and increases in GSH levels, and SOD and GPx activities were observed in the livers and kidneys of Pyc-treated septic rats. Plasma TNF-α level was found to be decreased in the Pyc-treated septic rats. In the lymphocytes, kidney, and liver tissue cells of the sepsis-induced rats, Pyc treatment significantly decreased the DNA damage and oxidative base damage using standard alkaline assay and formamidopyrimidine DNA glycosylase-modified comet assay, respectively. In conclusion, Pyc treatment might have a role in the prevention of sepsis-induced oxidative damage not only by decreasing DNA damage but also increasing the antioxidant status and DNA repair capacity in rats.

Protective effects of curcumin against oxidative stress parameters and DNA damage in the livers and kidneys of rats with biliary obstruction.

Curcumin, a most active antioxidant compound, has been suggested to have potential beneficial effects against most metabolic and psychological disorders, including cholestasis. In the present study, the effects of curcumin against oxidative stress and DNA damage induced by bile duct ligation (BDL) in Wistar albino rats for 14 days were investigated. The rats were divided into three following groups: Sham group, the BDL group and the BDL+curcumin group. A daily dose of 50mg/kg curcumin was given to the BDL+curcumin group intragastrically for 14 days. The biomarkers of hepatocellular damage were decreased in the BDL+curcumin group compared to the BDL group, indicating that curcumin recovered the liver functions. DNA damage as assessed by the alkaline comet assay was also found to be low in the BDL+curcumin group. Curcumin significantly reduced malondialdehyde and nitric oxide levels, and enchanced reduced glutathione levels and catalase, superoxide dismutase, and glutathione S-transferase enzymes activities in the livers and kidneys of BDL group. Curcumin treatment in BDL group was found to decrease tumor necrosis factor-alpha levels in the livers of rats. These results suggest that curcumin might have protective effects on the cholestasis-induced injuries in the liver and kidney tissues of rats.

Assessment of immunotoxicity and genotoxicity in workers exposed to low concentrations of formaldehyde.

Formaldehyde (FA), which is an important chemical with a wide commercial use, has been classified as carcinogenic to humans by International Research on Cancer (IARC). The genotoxic and carcinogenic potential of FA has been documented in mammalian cells and in rodents. A recent evaluation by the E.U. Scientific Committee for Occupational Exposure Limits (SCOEL) anticipated that an 8-h time-weighted average exposure to 0.2 ppm FA would not be irritating and not genotoxic in humans. In order to verify this prediction, a field study was performed that aimed at evaluating immune alterations and genetic damage in peripheral lymphocytes of workers in medium density fiberboard plants exposed to a level of FA equivalent to the OEL recommended by SCOEL (0.2 ppm). Subsets of peripheral lymphocytes, immunoglobulins (IgG, IgA, IgM), complement proteins, and tumor necrosis factor-alpha (TNF-α) levels were evaluated. DNA damage of the workers was assessed by the Comet assay. The absolute numbers and the percentages of T lymphocytes and of natural killer cells, and the levels of TNF-α were higher than the controls, whereas IgG and IgM levels were found to be lower in workers. Other examined immunological parameters were not different from those of the controls. There was no increased DNA damage in the workers compared to controls.

Antioxidant and antigenotoxic effects of lycopene in obstructive jaundice.

BACKGROUND: Obstructive jaundice, a frequently observed condition caused by obstruction of the common bile duct or its flow and seen in many clinical situations, may end up with serious complications like sepsis, immune depression, coagulopathy, wound breakdown, gastrointestinal hemorrhage, and hepatic and renal failures. Intrahepatic accumulation of reactive oxygen species is thought to be an important cause for the possible mechanisms of the pathogenesis of cholestatic tissue injury from jaundice. Carotenoids have been well described that are able to scavenge reactive oxygen species. Lycopene, a carotenoid present in tomatoes, tomato products, and several fruits and vegetables, have been suggested to have antioxidant activity, so may play a role in certain diseases related to the oxidative stress. The aim of the present study was to determine the effects of lycopene on oxidative stress and DNA damage induced by experimental biliary obstruction in Wistar albino rats. MATERIALS AND METHODS: Daily doses of 100 mg/kg lycopene were given to the bile duct-ligation (BDL) rats orally for 14 days. DNA damage was evaluated by an alkaline comet assay. The levels of aspartate transferase, amino alanine transferase, gamma glutamyl transferase, alkaline phosphatase, and direct bilirubin were analyzed in plasma for the determination of liver functions. The levels of malondialdehyde, reduced glutathione, nitric oxide, catalase, superoxide dismutase, and glutathione S transferase were determined in the liver and kidney tissues. Pro-inflammatory cytokine tumor necrosis factor-alpha level was determined in the liver tissues. Histologic examinations of the liver and kidney tissues were also performed. RESULTS: According to this study, lycopene significantly recovered the parameters of liver functions in plasma, reduced malondialdehyde and nitric oxide levels, enhanced reduced glutathione levels, as well as enhancing all antioxidant enzyme activity in all tissues obtained from the BDL group. Moreover, the parameters of DNA damage in the liver and kidney tissue cells, whole blood cells, and lymphocytes were significantly lower in the lycopene-treated BDL group, compared with the BDL group. CONCLUSIONS: Lycopene significantly reduced the DNA damage, and markedly recovered the liver and kidney tissue injuries seen in rats with obstructive jaundice.

Effects of low-dose doxycycline and bisphosphonate clodronate on alveolar bone loss and gingival levels of matrix metalloproteinase-9 and interleukin-1ß in rats with diabetes: a histomorphometric and immunohistochemical study.

BACKGROUND: Bisphosphonates (BPs) and low-dose doxycycline (LDD) have been shown to inhibit bone resorption and to improve the levels of proinflammatory mediators and destructive enzymes in gingival tissues, respectively. The purpose of this study is to evaluate the effect of mono and combined BP clodronate and LDD therapies in reducing gingival levels of matrix metalloproteinase-9 (MMP-9), interleukin-1ß (IL-1ß), and alveolar bone loss in rats with diabetes. METHODS: Fifty adult Wistar rats were divided into five study groups as follows: 1) group 1 = diabetes control; 2) group 2 = diabetes + periodontitis; 3) group 3 = diabetes + periodontitis + LDD; 4) group 4 = diabetes + periodontitis + clodronate; and 5) group 5 = diabetes + periodontitis + LDD + clodronate. LDD and clodronate were given as a single agent or as combination therapy during the 7 days of the post-experimental periodontitis period. On day 7, the rats were sacrificed, the mobility of the tooth was recorded, and block biopsies were removed. The gingival tissues were analyzed histologically and immunohistochemically for expression of MMP-9 and IL-1ß. Alveolar bone loss was evaluated morphometrically under a light microscope. Data analysis was performed statistically by Kruskal-Wallis and post hoc Tukey and Spearman correlation tests. RESULTS: Alveolar bone loss was significantly greater in groups 2 through 5 than group 1 (P <0.05) but was not significantly different among groups 2 through 5 (P >0.05). Animals with periodontitis (group 2) expressed significantly higher levels of MMP-9 and IL-1ß compared with those without periodontitis (group 1) (P <0.05). MMP-9 expression was significantly lower in group 3 than groups 1, 2, and 5 (P <0.05). IL-1ß expression was significantly lower in the groups 1, 3, 4, and 5 than 2 (P <0.01) but was not significantly different among groups 1, 3, 4, and 5. Positive correlations were found between alveolar bone loss and density of inflammation (ρ = 0.319, P = 0.021) and between MMP-9 and IL-1ß (ρ = 0.418, P = 0.002), respectively. CONCLUSION: Our findings suggest that ligature-induced periodontitis in animals with diabetes results in significantly higher levels of MMP-9 and IL-1ß expression in gingiva. The use of mono and combined clodronate and LDD administrations may significantly reduce levels of MMP-9 and IL-1ß expression. However, drug administration did not affect alveolar bone levels during the study period.

Reproductive toxicity parameters and biological monitoring in occupationally and environmentally boron-exposed persons in Bandirma, Turkey.

Boric acid and sodium borates have been considered as being "toxic to reproduction and development", following results of animal studies with high doses. Experimentally, a NOAEL (no observed adverse effect level) of 17.5 mg B/kg-bw/day has been identified for the (male) reproductive effects of boron in a multigeneration study of rats, and a NOAEL for the developmental effects in rats was identified at 9.6 mg B/kg-bw/day. These values are being taken as the basis of current EU safety assessments. The present study was conducted to investigate the reproductive effects of boron exposure in workers employed in boric acid production plant in Bandirma, Turkey. In order to characterize the external and internal boron exposures, boron was determined in biological samples (blood, urine, semen), in workplace air, in food, and in water sources. Unfavorable effects of boron exposure on the reproductive toxicity indicators (concentration, motility, morphology of the sperm cells and blood levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and total testosterone) were not observed. The mean calculated daily boron exposure (DBE) of the highly exposed group was 14.45 ± 6.57 (3.32-35.62) mg/day. These human exposures represent worst-case exposure conditions to boric acid/borates in Turkey. These exposure levels are considerably lower than exposures, which have previously led to reproductive effects in experimental animals. In conclusion, this means that dose levels of boron associated with developmental and reproductive toxic effects in animals are by far not reachable for humans under conditions of normal handling and use.

Role of SIRT1 in homologous recombination.

The class III histone deacetylase (HDAC) SIRT1 plays a role in the metabolism, aging, and carcinogenesis of organisms and regulates senescence and apoptosis in cells. Recent reports revealed that SIRT1 also deacetylates several DNA double-strand break (DSB) repair proteins. However, its exact functions in DNA repair remained elusive. Using nuclear foci analysis and fluorescence-based, chromosomal DSB repair reporter, we find that SIRT1 activity promotes homologous recombination (HR) in human cells. Importantly, this effect is unrelated to functions of poly(ADP-ribose) polymerase 1 (PARP1), another NAD(+)-catabolic protein, and does not correlate with cell cycle changes or apoptosis. Interestingly, we demonstrate that inactivation of Rad51 does not eliminate the effect of SIRT1 on HR. By epistasis-like analysis through knockdown and use of mutant cells of distinct SIRT1 target proteins, we show that the non-homologous end joining (NHEJ) factor Ku70 as well as the Nijmegen Breakage Syndrome protein (nibrin) are not needed for this SIRT1-mediated effect, even though a partial contribution of nibrin cannot be excluded. Strikingly however, the Werner helicase (WRN), which in its mutated form causes premature aging and cancer and which was linked to the Rad51-independent single-strand annealing (SSA) DSB repair pathway, is required for SIRT1-mediated HR. These results provide first evidence that links SIRT1's functions to HR with possible implications for genomic stability during aging and tumorigenesis.