Mesut Aksakal

Protective effects of vitamin E on carbon tetrachloride-induced liver damage in rats.

In this study we investigated whether the increase of hepatic vitamin E content by intraperitoneal administration, influences chronic liver damage induced by carbon tetrachloride (CCl4) in rats. Thirty adult male Wistar rats were divided into three groups. The first group was used as a control and the rats in the second group were administered CCl4 in olive oil subcutaneously. Rats in the third group were administered intraperitoneally vitamin E (dl‐α‐tocopherol acetate, 100 mg kg−1). This administration was performed three times per week for five weeks. Liver samples were used for the determination of vitamin E levels, glutathione peroxidase (GSHPx) activities and histological examination.

Blood plasma levels of lipoperoxides, glutathione peroxidase, beta carotene, vitamin A and E in women with habitual abortion.

The plasma levels of lipoperoxides, glutathione peroxidase (GSH‐Px), reduced glutathione (GSH), beta carotene, vitamin A, E, some plasma biochemical and blood haematological parameters were investigated in 40 women with habitual abortion (HA) and controls. The levels of GSH, vitamin A, E and beta carotene were significantly lower in women with HA than in controls. However, the plasma levels of lipid peroxidation, alkaline phosphatase (ALP), glucose and blood haemoglobin were significantly higher in HA than in controls. In addition, plasma levels of GSH‐Px, AST, ALT, total bilirubin, total protein, albumin, sodium, potassium, calcium and number of white blood cells, red blood cells, platelet and values of packet cell volume showed no significant differences between HA and controls. According to the results of this study, we observed that the levels of lipid peroxidation were increased and plasma levels of vitamin A, E and beta carotene were decreased in HA. The decrease of those antioxidants may play a significant role in women with habitual abortion. Copyright

Effects of testosterone and vitamin E on the antioxidant system in rabbit testis

Summary.  The aim of the study was to investigate the effects of testosterone propionate and vitamin E on the antioxidant system in the testis. Thirty‐two male New Zealand White rabbits were randomly divided into four groups. The first group was used as control. The second group was injected with testosterone propionate, the third group vitamin E and the fourth group vitamin E and testosterone propionate combination. All treatments were carried out during 6 weeks and oxidative parameters were evaluated in homogenized testicular tissue. The levels of vitamin E and the activity of glutathione peroxidase were lower (P < 0.05) in the testosterone group than in controls. However, vitamin C and malondialdehyde levels were higher (P < 0.05) in this group than in controls. The levels of reduced glutathione, β‐carotene, vitamin C and E increased, but malondialdehyde levels decreased in the vitamin E group, when compared with controls (P < 0.05). Vitamin E and β‐carotene levels were significantly higher (P < 0.05) in the combination group than in testosterone group. However, MDA levels were lower (P < 0.05) in combination group than in the testosterone group. In conclusion, administration of testosterone propionate led to a significant elevation of oxidative stress. Vitamin E is quite an effective antioxidant which protects rabbit testis against lipid peroxidation, and, testosterone‐induced lipid peroxidation could be improved by additional vitamin E treatment.

Effects of dietary vitamin E and selenium on antioxidative defense mechanisms in the liver of rats treated with high doses of glucocorticoid.

The aim of this work was to determine the effects of dietary intake vitamin E and selenium (Se) on lipid peroxidation as thiobarbituric acid reactive substances (TBARS) and on the antioxidative defense mechanisms in the liver of rats treated with high doses of prednisolone. Two hundred fifty adult male Wistar rats were randomly divided into five groups. The rats were fed a normal diet, but groups 3, 4, and 5 received a daily supplement in their drinking water of 20 mg vitamin E, 0.3 mg Se, and a combination of vitamin E and Se, respectively, for 30 d. For 3 d subsequently, the control group (group 1) was treated with a placebo, and the remaining four groups were injected intramuscularly with 100 mg/kg body weight (BW) prednisolone. After the last administration of prednisolone, 10 rats from each group were killed at 4, 8, 12, 24, and 48 h and the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) enzymes and the levels of glutathione (GSH) and TBARS in their livers were measured. GSH-Px, SOD, and CAT enzyme activities and GSH levels in prednisolone-treatment group (group 2) began to decrease gradually at 4 h, falling respectively to 38%, 55%, and 40% of the control levels by 24 h, and recovering to the control levels at 48 h. In contrast, prednisolone administration caused an increase in the hepatic TBARS, reaching up to four times the levels of the control at 24 h. However, supplementation with vitamin E and Se had a preventive effect on the elevation of the hepatic TBARS and improved the diminished activities of the antioxidative enzymes and the levels of GSH. Therefore, the present study demonstrates the effectiveness of vitamin E and Se in reducing hepatic damage in glucocorticoid-treated rats and suggests that reductions in increased TBARS as a result of prednisolone may be an important factor in the action of vitamin E and Se.

Effectiveness of cinnamon (Cinnamomum zeylanicum) bark oil in the prevention of carbon tetrachloride-induced damages on the male reproductive system

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.

Influence of dietary selenium and vitamin E on the levels of fatty acids in brain and liver tissues of lambs

In this study, the effects of dietary vitamin E, selenium, and their combination on the levels of fatty acid composition of the brain and liver tissues were examined. In brain tissue, the amounts of most fatty acids increased in vitamin E, combination and selenium groups compared with control group values. While the proportions of myristic, pentadecanoic, palmitic, linoleic, and total saturated fatty acids were decreased in vitamin E, Se and combination groups, eicosapentaenoic, total unsaturated and MUFA were increased in the same groups. In addition, the proportions arachidonic, eicosapentaenoic, total unsaturated, ω6 and MUFA in the combination group were higher than in the control group. In liver tissue, the amounts of myristic, pentadecanoic, palmitic, eicosedienoic, eicosapentaenoic, docosahexaenoic, ω3 and PUFA were higher in the combination group than in the control group. Also the proportions of eicosapentaenoic, docosahexaenoic acids in supplemented groups were higher than those in the control group. We conclude that dietary vitamin E and selenium have an influence on the levels of fatty acids in the brain and liver. Copyright

Quercetin attenuates carbon tetrachloride‐induced testicular damage in rats

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.

Ameliorating effect of pomegranate juice consumption on carbon tetrachloride-induced sperm damages, lipid peroxidation, and testicular apoptosis

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.

The facilitating effect of cigarette smoke on the colonization of instilled bacteria into the tracheal lumen in rats and the improving influence of supplementary vitamin E on this process

Objective: The aim of the present study was to investigate the direct influence of cigarette smoke on the bacterial colonization of the lower respiratory tract and the effect of supplementary vitamin E on the colonization of instilled bacteria into the trachea of rats that do not have the chronic airway pathology associated with smoking.

Effects of additional Vitamin E and selenium supply on G6PDH activity in rats treated with high doses of glucocorticoid.

The aim of this work was to determine the effects of dietary intake Vitamin E and selenium (Se) on glucose-6-phosphate dehydrogenase (G6PDH) activity in rats treated with high doses of prednisolone. Two hundred and fifty adult male Wistar rats were randomly divided into five groups. The rats were fed a normal diet, but groups 3, 4, and 5 received a daily supplement in their drinking water of 20mg Vitamin E, 0.3mg Se, and a combination of Vitamin E and Se, respectively, for 30 days. For 3 days subsequently, the control group (group 1) was treated with a placebo, and the remaining four groups were injected intramuscularly with 100 mg/kg body weight prednisolone. After the last administration of prednisolone, 10 rats from each group were killed at 4, 8, 12, 24, and 48 h and the activities of G6PDH enzymes in their tissues were measured. Hepatic and spleen G6PDH activities in the prednisolone treatment group began to decrease gradually at 8 h, while enzyme activities did not change in the kidney and heart. However, the administration of Vitamin E alone did not affect G6PDH activity in any of the tissues. Se supplementation had a preventive effect on the decrease of G6PDH caused by prednisolone and improved the diminished activities of G6PDH. Therefore, the present study demonstrates that a high dose of prednisolone may alter the effects of normal dose glucocorticoids and that Se is effective in reducing damage in prednisolone-treated rats. Se may prevent the changes in G6PDH activity in various tissues caused by prednisolone in various tissues.