Serpil Kalkan

Chemoprotective effect of vitamin E in cyclophosphamide-induced hepatotoxicity in rats

Cyclophosphamide (CP) has a range of adverse effects on liver tissue in humans and animals. Administering an antioxidant with CP might reduce such side effects. Therefore, we examined the role of vitamin E in CP-induced liver toxicity in rats. Male Wistar albino rats were divided into four groups, each of seven rats: control, CP only, CP + vitamin E, and vitamin E only groups. The rats were administered treatments intraperitoneally for 7 days. Then the serum malondialdehyde (MDA), alanine aminotransferase (ALT), aspartate transaminase (AST), and lactate dehydrogenase (LDH) levels were determined while the livers were removed, tissue was prepared using routine histological procedures, sections were stained using hematoxylin and eosin, and the terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) method was applied. Histopathologically, CP caused hydropic degeneration, necrosis, pleomorphism, and mitotic activity. The number of TUNEL-positive cells and the MDA and ALT levels were significantly higher in the CP group. The antioxidant effects of vitamin E significantly decreased the number of TUNEL-positive cells and the ALT and MDA levels, and normalized the liver histopathology. CP induces apoptosis, has toxic effects on liver tissue, and changes the histological structure. The administration of vitamin E prevented the liver tissue damage caused by CP.

Evaluation of neuroprotection by melatonin against adverse effects of prenatal exposure to a nonsteroidal anti-inflammatory drug during peripheral nerve development

The potential ability of melatonin to protect against impairment of the fetal peripheral nerve system due to maternal consumption of diclofenac sodium (DS) was investigated. Eighty‐four pregnant rats were divided into seven groups: control (CONT), saline administered (PS), DS administered (DS), DS with low‐dose melatonin administered (DS + MLT10), DS with high‐dose melatonin administered (DS + MLT50), low‐dose melatonin administered (MLT10), and high‐dose melatonin administered (MLT50). After the pregnancy, six male newborn rats from each group were sacrificed at 4 and 20 weeks of age. Their right sciatic nerves were harvested, and nerve fibers were evaluated using stereological techniques. Mean numbers of myelinated axons, axon cross‐section areas and the mean thickness of the myelin sheet were estimated. Four‐week‐old prenatally DS‐exposed rats had significantly fewer axons, a smaller myelinated axonal area, and a thinner myelin sheath compared to CONT group (p < 0.05). Although melatonin at both doses significantly increased axon numbers, only a high dose of melatonin increased the diameter of those axons (p < 0.05). At 20‐weeks of age, myelinated axon number in the DS group was not only significantly lower than all other groups (p < 0.05) but also the cross‐sectional area of these axons was smaller than all other groups (p < 0.05). There were no differences between the groups regarding the mean thickness of the myelin sheet. The current study indicates that prenatal exposure to DS decreases the number and the diameter of sciatic nerve axons and that melatonin prophylaxis can prevent these effects.

The effects of CO2 pneumoperitoneum on the apoptotic index in the peritoneum.

During laparoscopic surgery, gases such as carbon dioxide (CO2), helium, or normal air are insufflated into the intra-abdominal cavity so the surgeon can obtain a clear surgical field; however, this insufflation technique may cause injury to the intra-abdominal organs. This study was undertaken to evaluate the effects of different pressures of CO2 on the apoptotic index in the peritoneum during laparoscopic surgery. A total of 30 Sprague-Dawley male rats were used in the study. CO2 was insufflated into the intra-abdominal cavity via an angiocatheter cannula by an insufflator at pressures of 10 and 20 mm Hg over 60 min. In the control group, the cannula was inserted into the intra-abdominal cavity, but no gas was insufflated. After 60 min, the rats were killed; peritoneum was harvested from the abdominal wall and was cultured in the cell culture laboratory. Apoptotic and living cells were detected immunohistochemically, and the apoptotic index was calculated and statistically analyzed. The data collected revealed that the apoptotic index increases in proportion to the level of CO2 pressure. CO2 pneumoperitoneum is a very useful technique. Gas pressure must be carefully set during the operation, however, or injured mesothelial cells may cause serious malfunction.

Effects of Nigella sativa L. seed oil on intima-media thickness and Bax and Caspase 3 expression in diabetic rat aorta.

Objective: Hyperglycaemia is an important risk factor for the development and progression of the macrovascular and microvascular complications that occur in diabetes. The expression of apoptotic markers in the aortic medial layer of diabetic rats and the effects of N. sativa L. seed oil on the expression of these markers were investigated in this study. Methods: Four-month-old adult female Wistar rats (n=21) were divided into 3 groups: Group 1, control; Group 2, diabetes and Group 3, diabetes+N. sativa L. seed oil. Group 3 received 0.2 mg/kg/day N. sativa L. seed (black cumin) oil intraperitoneally 6 days per week for 30 days. At the end of the experiment, abdominal and thoracic aortas of all animals were collected and fixed in 10% formalin solution. Then, 5-µm-thick sections were stained with Verhoeff–Van Gieson stain to evaluate Bax and Caspase 3 expression. Tunica intima–media thickness was measured using the stained sections. Results: There were no significant differences in abdominal or thoracic aortic intima–media thickness among the 3 groups. However, there were significant differences in Bax and Caspase 3 expression in the tunica media of the thoracic and abdominal aortas between Group 1 and Group 2 (p<0.05) and between Group 2 and Group 3 (p<0.05) evaluated with the Kruskal–Wallis and Mann–Whitney U tests. Conclusion: It is understood that N. sativa L. seed oil is effective against diabetes. N. sativa L. seed oil is a plant material and has value for further investigation to develop diabetes treatment strategies for preventing apoptosis in vascular structures.

P53 expression between 13–27 weeks old human male fetus gonads

P53 is a tumor suppressor gene and a critical component of cellular mechanisms that respond to genotoxic stresses. During normal fetal development, some of these cells lose their genomic stability because of intensive cell proliferation. They arrest cell cycle progression and repair genomic stability by p53 induction or die via apoptosis. If p53 is overexpressed, some structures may have different abnormalities. This study was conducted to investigate normal p53 expression in human male gonads during second trimester. Twenty one normal human male fetuses’ testes in 2nd trimester were processed and immunohistochemistry was applied. The spermatogonia with nuclear and perinuclear staining, were accepted as p53 (+). The number of p53 (+) spermatogonia was counted in randomly 10 different seminiferous tubules. The results suggest that p53 expression in gonads of human male fetuses significantly increases in the 20th week.