Mehmet Güvenç
Fırat University
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Featured researches published by Mehmet Güvenç.
Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes | 2012
Ramazan Bal; Gaffari Türk; Mehmet Tuzcu; Ökkeş Yilmaz; Tuncay Kuloglu; Ramazan Gundogdu; Seyfettin Gür; Ali Agca; Mustafa Ulas; Zafer Çambay; Zeynep Tuzcu; Hasan Gencoglu; Mehmet Güvenç; Ayse Dilek Ozsahin; Nevin Kocaman; Abdullah Aslan; Ebru Etem
In the current study it was aimed to investigate the toxicity of low doses of imidacloprid (IMI) on the reproductive organ systems of adult male rats. The treatment groups received 0.5 (IMI-0.5), 2 (IMI-2) or 8 mg IMI/kg body weight by oral gavage (IMI-8) for three months. The deterioration in sperm motility in IMI-8 group and epidydimal sperm concentration in IMI-2 and IMI-8 groups and abnormality in sperm morphology in IMI-8 were significant. The levels of testosterone (T) and GSH decreased significantly in group IMI-8 compared to the control group. Upon treatment with IMI, apoptotic index increased significantly only in germ cells of the seminiferous tubules of IMI-8 group when compared to control. Fragmentation was striking in the seminal DNA from the IMI-8 group, but it was much less obvious in the IMI-2 one. IMI exposure resulted in elevation of all fatty acids analyzed, but the increases were significant only in stearic, oleic, linoleic and arachidonic acids. The ratios of 20:4/20:3 and 20:4/18:2 were decreased and 16:1n-9/16:0 ratio was increased. In conclusion, the present animal experiments revealed that the treatment with IMI at NOAEL dose-levels caused deterioration in sperm parameters, decreased T level, increased apoptosis of germ cells, seminal DNA fragmentation, the depletion of antioxidants and change in disturbance of fatty acid composition. All these changes indicate the suppression of testicular function.
Andrologia | 2014
Abdurrauf Yüce; Gaffari Türk; Songül Çeribaşı; Mehmet Güvenç; Mehmet Çiftçi; Mustafa Sönmez; Ş. Özer Kaya; Mehmet Çay; Mesut Aksakal
In this study, it was aimed to investigate the likelihood of detrimental effects of carbon tetrachloride (CCl4) on male reproductive system through oxidative stress mechanism and also protective effects of cinnamon bark oil (CBO). For this purpose, 28 healthy male Wistar rats were divided into four groups, seven rats in each. Group 1 received only olive oil daily; group 2 was treated with 100 mg kg−1 CBO daily; group 3 was treated with only 0.25 ml kg−1 CCl4 weekly; and group 4 received weekly CCl4 + daily CBO. All administrations were made by intragastric catheter and maintained for 10 weeks. Body and reproductive organ weights, sperm characteristics, testicular oxidative stress markers and testicular apoptosis were examined. CCl4 administration caused significant decreases in body and reproductive organ weights, testicular catalase (CAT) activity, sperm motility and concentration, and significant increases in lipid peroxidation (LPO) level, abnormal sperm rate and apoptotic index along with some histopathological damages compared with the control group. However, significant improvements were observed in absolute weights of testis and epididymis, all sperm quality parameters, LPO level, apoptotic index and testicular histopathological structure following the administration of CCl4 together with CBO when compared to group given CCl4 only. The findings of this study clearly suggest that CBO has protective effect against damages in male reproductive organs and cells induced by CCl4.
Andrologia | 2014
Mustafa Sönmez; Gaffari Türk; Songül Çeribaşı; Mehmet Çiftçi; Abdurrauf Yüce; Mehmet Güvenç; Ş. Özer Kaya; Mehmet Çay; Mesut Aksakal
This study was conducted to investigate the effect of quercetin on carbon tetrachloride (CCl4)‐induced sperm damages, testicular apoptosis and oxidative stress in male rats. Group 1 served as control, group 2 was treated with only quercetin, group 3 was treated with only CCl4 and group 4 received CCl4 + quercetin. All administrations were performed by gavage and maintained for 10 weeks. CCl4 administration caused significant decreases in absolute and relative reproductive organ weights, sperm motility, concentration and testicular glutathione peroxidase (GSH‐Px) and catalase (CAT) activities, and significant increases in lipid peroxidation (LPO) level, abnormal sperm rate and testicular apoptotic cell index, along with some histopathological damages when compared to the control group. However, administration of CCl4 together with quercetin provided statistically significant improvements in LPO level, abnormal sperm rate, the degree of histopathological lesions and testicular apoptotic cell index when compared to only CCl4 group. In addition, improvements observed in absolute and relative weights of reproductive organs, sperm motility and concentration, and testicular GSH‐Px and CAT activities in group 4 were statistically insignificant when compared to only CCl4 group. In conclusion, quercetin has antiperoxidative effect, and its oral administration attenuates the CCl4‐induced some damages in male reproductive organs and cells by decreasing the LPO.
Andrologia | 2013
Abdurrauf Yüce; Gaffari Türk; Songül Çeribaşı; Mustafa Sönmez; Mehmet Çiftçi; Mehmet Güvenç
Cinnamon and its contents have multifactorial properties such as antioxidant, anti‐inflammatory and antidiabetic. Male infertility is one of the major health problems in life. The aim of this study was to investigate the effects of long‐term cinnamon bark oil (CBO) ingestion on testicular antioxidant values, apoptotic germ cell and sperm quality of adult rats. Twelve male healthy Wistar rats were divided into two groups, each group containing six rats. While olive oil was given to control group, 100 mg kg−1 CBO was administered to the other group by gavage daily for 10 weeks. Body and reproductive organ weights, sperm characteristics, testicular lipid peroxidation and antioxidant enzyme activities, and testicular apoptosis via terminal deoxynucleotidyl transferase–mediated dUTP nick end labelling (TUNEL) method were examined. A significant decrease in malondialdehyde level and marked increases in reduced glutathione level, glutathione peroxidase and catalase activities were observed in rats treated with CBO compared with the control group. CBO consumption provided a significant increase in weights of testes and epididymides, epididymal sperm concentration, sperm motility and diameter of seminiferous tubules when compared with the control group. However, CBO consumption tended to decrease the abnormal sperm rate and apoptotic germ cell count, but it did not reach statistical significance. It is concluded that CBO has improvement effect on testicular oxidant–antioxidant balance and sperm quality, and its consumption may be useful for asthenozoospermic men.
Toxicology and Industrial Health | 2016
Gaffari Türk; Songül Çeribaşı; Mustafa Sönmez; Mehmet Çiftçi; Abdurrauf Yüce; Mehmet Güvenç; Şeyma Özer Kaya; Mehmet Çay; Mesut Aksakal
The aim of this study was to investigate whether pomegranate juice (PJ) consumption has an ameliorating effect on carbon tetrachloride (CCl4)-induced sperm damages and testicular apoptosis associated with the oxidative stress in male rats. The study comprised of four groups (groups 1–4). Group 1 received olive oil + distilled water daily; group 2 was treated with 5 ml/kg PJ + olive oil daily; group 3 was treated with 0.25 ml/kg CCl4 dissolved in olive oil, weekly + distilled water daily; and group 4 received weekly CCl4 + daily PJ. All administrations were performed by gavage and maintained for 10 weeks. CCl4 administration caused significant decreases in body and reproductive organ weights, sperm motility, concentration and testicular catalase activity, significant increases in malondialdehyde (MDA) level, and abnormal sperm rate and apoptotic index along with some histopathological damages when compared with the control group. However, significant ameliorations were observed in absolute weights of testis and epididymis, all sperm quality parameters, MDA level, apoptotic index, and testicular histopathological structure following the administration of CCl4 together with PJ when compared with group given CCl4 only. In conclusion, PJ consumption ameliorates the CCl4-induced damages in male reproductive organs and cells by decreasing the lipid peroxidation.
Nutrition and Cancer | 2016
Serpil Sarıözkan; Gaffari Türk; Mehmet Güvenç; Abdurrauf Yüce; Saim Ozdamar; Fazile Cantürk; Arzu Yay
ABSTRACT The aim of this study was to investigate whether cinnamon bark oil (CBO) has protective effect on taxanes-induced adverse changes in sperm quality, testicular and epididymal oxidant/antioxidant balance, testicular apoptosis, and sperm DNA integrity. For this purpose, 88 adult male rats were equally divided into 8 groups: control, CBO, docetaxel (DTX), paclitaxel (PTX), DTX+PTX, DTX+CBO, PTX+CBO, and DTX+PTX+CBO. CBO was given by gavage daily for 10 weeks at the dose of 100 mg/kg. DTX and PTX were administered by intraperitoneal injection at the doses of 5 and 4 mg/kg/week, respectively, for 10 weeks. DTX+PTX and DTX+PTX+CBO groups were treated with DTX during first 5 weeks and PTX during next 5 weeks. DTX, PTX, and their mixed administrations caused significant decreases in absolute and relative weights of all reproductive organs, testosterone level, sperm motility, concentration, glutathione level, and catalase activity in testicular and epididymal tissues. They also significantly increased abnormal sperm rate, testicular and epididymal malondialdehyde level, apoptotic germ cell number, and sperm DNA fragmentation and significantly damaged the histological structure of testes. CBO consumption by DTX-, PTX-, and DTX+PTX-treated rats provided significant ameliorations in decreased relative weights of reproductive organs, decreased testosterone, decreased sperm quality, imbalanced oxidant/antioxidant system, increased apoptotic germ cell number, rate of sperm with fragmented DNA, and severity of testicular histopathological lesions induced by taxanes. In conclusion, taxanes cause impairments in sperm quality, testicular and epididymal oxidant/antioxidant balance, testicular histopathological structure, and sperm DNA integrity, and long-term CBO consumption protects male reproductive system of rats.
Animal Reproduction Science | 2016
Gaffari Türk; Ali Osman Çeribaşı; Ülkü Gülcihan Şimşek; Songül Çeribaşı; Mehmet Güvenç; Şeyma Özer Kaya; Mehmet Çiftçi; Mustafa Sönmez; Abdurrauf Yüce; Ali Bayrakdar; Mine Yaman; Fadime Tonbak
Supplementation of natural antioxidants to diets of male poultry has been reported to be effective in reducing or completely eliminating heat stress (HS)-induced reproductive failures. In this study, the aim is to investigate whether rosemary oil (RO) has a protective effect on HS-induced damage in spermatozoa production, testicular histologic structures, apoptosis, and androgenic receptor (AR) through lipid peroxidation mechanisms in growing Japanese quail. Male chicks (n=90) at 15-days of age were assigned to two groups. The first group (n=45) was kept in a thermo-neutral (TN) room at 22°C for 24h/d. The second group (n=45) was kept in a room with a greater ambient temperature of 34°C for 8h/d (from 9:00 AM to 5:00 PM) and 22°C for 16h/d. Animals in each of these two groups were randomly assigned to three subgroups (RO groups: 0, 125, 250ppm), consisting of 15 chicks (six treatment groups in 2×3 factorial design). Each of subgroups was replicated three times with each replicate including five chicks. The HS treatment significantly reduced the testicular spermatogenic cell counts, amount of testicular Bcl-2 (anti-apoptotic marker) and amount of AR. In addition, it significantly increased testicular lipid peroxidation, Bax (apoptotic marker) immunopositive staining, and the Bax/Bcl-2 ratio in conjunction with some histopathologic damage. Dietary supplementation of RO to diets of quail where the HS treatment was imposed alleviated HS-induced almost all negative changes such as increased testicular lipid peroxidation, decreased numbers of spermatogenic cells, and decreased amounts of Bcl-2 and AR, increased ratio of Bax/Bcl-2 and some testicular histopathologic lesion. In conclusion, dietary supplementation of RO for growing male Japanese quail reared in HS environmental conditions alleviates the HS-induced structural and functional damage by providing a decrease in lipid peroxidation.
Theriogenology | 2015
Gaffari Türk; Ülkü Gülcihan Şimşek; Ali Osman Çeribaşı; Songül Çeribaşı; Şeyma Özer Kaya; Mehmet Güvenç; Mehmet Çiftçi; Mustafa Sönmez; Abdurrauf Yüce; Ali Bayrakdar; Mine Yaman; Fadime Tonbak
The aim of this study was to investigate the effect of cinnamon bark oil (CBO) on heat stress (HS)-induced changes in sperm production, testicular lipid peroxidation, testicular apoptosis, and androgenic receptor (AR) density in developing Japanese quails. Fifteen-day-old 90 male chicks were assigned to two main groups. The first group (45 chicks) was kept in a thermoneutral room at 22 °C for 24 h/day. The second group (45 chicks) was kept in a room with high ambient temperature at 34 °C for 8 h/day (from 9 AM-5 PM) and at 22 °C for 16 h/day. Each of these two main groups was then divided into three subgroups (CBO groups 0, 250, 500 ppm) consisting of 15 chicks (six treatment groups in 2 × 3 factorial order). Each of subgroups was replicated for three times and each replicate included five chicks. Heat stress caused significant decreases in body weight, spermatid and testicular sperm numbers, the density of testicular Bcl-2 (antiapoptotic marker) and AR immunopositivity, and significant increases in testicular lipid peroxidation level, the density of testicular Bax (apoptotic marker) immunopositivity, and a Bax/Bcl-2 ratio along with some histopathologic damages. However, 250 and 500 ppm CBO supplementation provided significant improvements in HS-induced increased level of testicular lipid peroxidation, decreased number of spermatid and testicular sperm, decreased densities of Bcl-2 and AR immunopositivity, and some deteriorated testicular histopathologic lesions. In addition, although HS did not significantly affect the testicular glutathione level, addition of both 250 and 500 ppm CBO to diet of quails reared in both HS and thermoneutral conditions caused a significant increase when compared with quails without any consumption of CBO. In conclusion, HS-induced lipid peroxidation causes testicular damage in developing male Japanese quails and, consumption of CBO, which has antiperoxidative effect, protects their testes against HS.
Andrologia | 2016
Serpil Sarıözkan; Gaffari Türk; P. Çıkla-Süzgün; Mehmet Güvenç; Abdurrauf Yüce; Arzu Yay; Fazile Cantürk; Ş. G. Küçükgüzel
The aim of this study was to investigate the effect of etodolac hydrazone (EH), a new compound synthesised from etodolac, on spermatozoon quality, testicular lipid peroxidation, apoptosis and spermatozoon DNA integrity in rats. Group 1 (n = 8) received 1 ml dimethyl sulfoxide (DMSO) daily (Control); group 2 (n = 8) was treated with 5 mg kg−1 day−1 EH, dissolved in 1 ml DMSO (EH‐5); and group 3 (n = 8) was treated with 10 mg kg−1 day−1 EH, dissolved in 1 ml DMSO (EH‐10). All administrations were performed by gavage and maintained for 8 weeks. Both doses of EH administration caused significant decreases in absolute and relative weights of testis, whole epididymis, right cauda epididymis, and spermatozoon motility, spermatozoon count in comparison with the control group. Only 10 mg kg−1 day−1 EH administration caused significant decreases in absolute and relative weights of seminal vesicles and serum testosterone level, and significant increases in testicular lipid peroxidation level, and numbers of TUNEL+ apoptotic germ cells and spermatozoa with damaged DNA along with some histopathological damages when compared to the control group. However, body and ventral prostate weight, and testicular antioxidant markers (glutathione, glutathione‐peroxidase and catalase), were unaffected significantly by both doses of EH administration. In conclusion, two different doses of EH, in particular its high dose, damage to testicular spermatogenic cells and spermatozoon DNA and, it decreases spermatozoon motility, count and testosterone level in healthy rats.
Biological Trace Element Research | 2011
Kazim Sahin; Mehmet Tuzcu; Cemal Orhan; Can Ali Agca; Nurhan Sahin; Mehmet Güvenç; Zbigniew Krejpcio; Halina Staniek; A. Hayirli