Meryem Akpolat

Effects of curcumin on apoptosis and oxidoinflammatory regulation in a rat model of acetic acid-induced colitis: the roles of c-Jun N-terminal kinase and p38 mitogen-activated protein kinase.

The present study evaluated the effects of curcumin on epithelial cell apoptosis, the immunoreactivity of the phospho-c-Jun N-terminal kinase (JNK) and phospho-p38 mitogen-activated protein kinases (MAPKs) in inflamed colon mucosa, and oxidative stress in a rat model of ulcerative colitis induced by acetic acid. Rats were randomly divided into three groups: control, acetic acid, and acetic acid+curcumin. Curcumin (100 mg/kg per day, intragastrically) was administered 10 days before the induction of colitis and was continued for two additional days. Acetic acid-induced colitis caused a significant increase in the macroscopic and microscopic tissue ranking scores as well as an elevation in colonic myeloperoxidase (MPO) activity, malondialdehyde (MDA) levels, and the number of apoptotic epithelial cells in colon tissue compared to controls. In the rat colon, immunoreactivity of phospho-p38 MAPK was increased, whereas the phospho-JNK activity was decreased following the induction of colitis. Curcumin treatment was associated with amelioration of macroscopic and microscopic colitis sores, decreased MPO activity, and decreased MDA levels in acetic acid-induced colitis. Furthermore, oral curcumin supplementation clearly prevented programmed cell death and restored immunreactivity of MAPKs in the colons of colitic rats. The results of this study suggest that oral curcumin treatment decreases colon injury and is associated with decreased inflammatory reactions, lipid peroxidation, apoptotic cell death, and modulating p38- and JNK-MAPK pathways.

Protective effect of sildenafil on liver injury induced by intestinal ischemia/reperfusion.

BACKGROUND This study evaluated the protective effect of sildenafil on liver injury induced by intestinal ischemia-reperfusion. METHODS Forty female Sprague Dawley rats were divided into 4 groups: sham-control (SC), ischemia (I), ischemia-reperfusion (IR), and ischemia-reperfusion+sildenafil (SIL; sildenafil gavaged at 50mg/kg before operating). A 2-h ischemia-reperfusion was performed by clamping the superior mesenteric artery. Liver function, plasma alanine (ALT) and aspartate (AST) aminotransferase, and intestinal and liver malondialdehyde (MDA) were measured at the end of the experiment. Intestinal and liver tissue damage was examined by histology. Liver samples were immunologically stained for endothelial nitric oxide synthase (eNOS) and proliferating cell nuclear antigen (PCNA). RESULTS The ALT and AST levels were highest in the IR group and were lower in the SIL group (p<0.05). Intestinal MDA levels were statistically higher in the IR group than in the SC, I and SIL groups. Liver MDA levels were significantly higher in the IR group than in the I and SC groups (p<0.05) and higher than in the SIL group (p>0.05). Intestinal damage based on Chiu scoring was more severe in the IR than in the SIL group (p<0.05). Sildenafil reduced damage and also increased eNOS and PCNA immunoreactivity in liver tissue. CONCLUSIONS Sildenafil shows a protective effect on intestinal ischemia-reperfusion-induced liver injury, possibly by decreasing vascular resistance through increased nitric oxide levels.

Protective Effect of flaxseed oil on renal injury in hyperlipidaemic rats: the effect of flaxseed oil on hyperlipidaemia

This study evaluated the possible effects of flaxseed oil on renal damage associated with hyperlipidaemic rats. Wistar albino male rats were divided into three groups. Group I was fed with a pellet chow. Group II was fed with a high cholesterol diet (HCD) consisting of 5% cholesterol and 0.35% cholic acid added to the pellet chow. Group III was fed with the same HCD, but were orally treated with a dose of 15 mg/kg body wt/day flaxseed oil. Flaxseed oil treatment started 1 week before and continued throughout the 22 weeks of the HCD. At the end of the experiment, renal tissue and blood samples were collected. The biochemical and histopathological findings confirmed renal damage in hypercholesterolaemia conditions. Flaxseed oil reduced the hypercholesterolaemia‐induced increase in the serum levels of total cholesterol, LDL and urea. Oil red O stain revealed that lowered serum lipid was accompanied by a decreased deposition of neutral lipid. Flaxseed oil effectively reversed these abnormalities, verifying the protective effects of flaxseed oil in ameliorating renal injuries associated with hypercholesterolaemia. Copyright

Protection by L-carnitine against radiation-induced ileal mucosal injury in the rat: Pattern of oxidative stress, apoptosis and cytokines

Abstract Purpose: In this study, we tested the effects of L-carnitine (LC) on radiation-induced ileal mucosal damage. Materials and methods: Thirty Wistar albino rats were divided into five groups. The control group received physiological saline intraperitoneally (i.p.). Radiation-1 and radiation-2 groups received whole-body X-irradiation of 8.3 Gy as a single dose. These groups were sacrificed at the 6th hour and 4th day after irradiation, respectively. The Radiation-1 + LC and the radiation-2 + LC groups received the same dose irradiation plus a daily dose of 200 mg/kg LC. LC was applied one day before and for four days after irradiation. Results: The levels of serum monocyte chemotactic protein-1 (MCP-1) and interferon gamma (IFN-γ) were significantly higher in the radiation groups when compared with the control. Treatment with LC decreased the serum MCP-1 and IFN-γ levels considerably. In the radiations groups, the Chiu score was significantly elevated compared with that of the control group. However, LC administered prior to the irradiation reduced the severity of mucosal damage. The number of apoptotic cells of the ileal crypt in the irradiated rats increased from the 6th hour after irradiation and then decreased at 4th day. Conclusions: Our data demonstrated that LC may be beneficial to radiation enteritis.

The Protective Effect of Curcumin on Ionizing Radiation-induced Cataractogenesis in Rats

OBJECTIVE The aim of the study was to determine the protective effect of curcumin against ionizing radiation-induced cataract in the lens of rats. MATERIAL AND METHODS Rats were divided into six groups. Group 1: Control, Group 2: Dimethyl sulfoxide (DMSO), Group 3: DMSO+curcumin, Group 4: Irradiation, Group 5: Irradiation+DMSO, Group 6: Irradiation+DMSO+curcumin. A 15 Gy total dose was given to 4, 5, 6 groups for radiation damage. Curcumin (100 mg/kg) was dissolved in DMSO and given by intragastric intubation for 28 days. At the end of the experiment, lenses were graded and enucleated. The lenticular activity of the antioxidant enzymes, total antioxidant and glutathione peroxidase (GSH-Px), and the malondialdehyde (MDA) were measured. RESULTS 100% Cataract was seen in the irradiation group. Cataract rate fell to 40% and was limited at grade 1 and 2 in the curcumin group. In the irradiation group, antioxidant enzyme levels were decreased, MDA levels were increased. There was an increase in antioxidant enzyme levels and a significant decrease in MDA in the group which was given curcumin. CONCLUSION Curcumin has antioxidant and radioprotective properties and is likely to be a valuable agent for protection against ionizing radiation. Hence, it may be used as an antioxidant and radioprotector against radiation-induced cataractogenesis.

Vitamin E modulates apoptosis and c-jun N-terminal kinase activation in ovarian torsion–detorsion injury

The aim of this study was to evaluate the role of vitamin E in follicular degeneration and to assess histopathological and biochemical changes following ischemia-reperfusion (IR) injury in rat ovaries. Twenty-eight Wistar albino rats were randomly divided into four groups: sham, 4h torsion, 24h detorsion, and a vitamin E group. Thirty minutes before detorsion, a single dose of 200mg/kg vitamin E was administered intraperitoneally. The ovarian histology score was determined, serum levels of malondialdehyde (MDA) and myeloperoxidase (MPO) were measured. The apoptosis of granulosa cells and the phospho-c-jun N-terminal kinase (p-JNK) and phospho-p38 (p-p38) immunoreactivities of these cells were determined. MDA and MPO levels were significantly increased in the torsion and detorsion groups. Hemorrhage, edema, and congestion were also apparent in these groups. In addition, the apoptotic index and the immunoreactivity of p-JNK were highest in the detorsion group, which also showed marked follicular degeneration. However, p-p38 activity was not affected by torsion-detorsion (TD) induction. Vitamin E ameliorated TD-induced histological alterations. It also decreased serum levels of MDA and MPO, reduced the activity of p-JNK in the ovaries, and reduced numbers of apoptotic follicular cells. In conclusion, these data indicate that vitamin E attenuated ovarian follicular degeneration by inhibiting the immunoreactivity of p-JNK and reducing the apoptosis of granulosa cells.

İyonize Radyasyona Maruz Kalmış Sıçan Ovaryumunda Gelişmekte Olan Foliküllerde Morfolojik Değişiklikler Üzerine L-karnitinin Koruyucu Etkisi

AMAC: Radyasyon hucrelerin cekirdek ve sitoplazmasinda bir takim degisikliklere sebebiyet verebilir, memeli germ hucreleri de iyonize radyasyona (IR) karsi oldukca duyarlidir. Iyonize radyasyon ovaryum follikullerindeki dejenerasyonu arttirir. Bu calismanin amaci tum vucudu iyonize radyasyona maruz kalan sicanlarin ovaryum follikullerinde L-karnitinin (LK) antiapoptotik ve radyoprotektif etkilerini arastirmaktir. MATERYAL-METOD: Calismamizda 30 adet Wistar albino disi sican 5 ayri gruba ayrildi. Radyasyon hasari icin kontrol haric tum sicanlara 8,3 Gy X isini uygulandi. LK gruplarina isinlamadan once gunluk 200mg/kg LK uygulandi. Isinlama sonrasi 6.saatte (Rad-1) ve 4. gunde (Rad-2) ovaryum dokulari toplandi. Ovaryum dokusundan her 5. kesit alinarak hematoksilen-eozin boyamasi yapilarak oosit cekirdeginin goruldugu her oosit sayildi. Follikuller primordiyal, primer, preantral ve antral olacak sekilde siniflandirildi. Serumdaki IL-1α (interlokin-1 alfa), IL-4 (interlokin-4) ve GM-CSF (granulosit monosit koloni situmulan faktor) degerleri flow sitometri ile analiz edildi. BULGULAR : Iyonize radyasyon uygulamasinin sonrasinda 6.saat ve 4. gun ovaryum dokulari alinan gruplarda atretik follikullerin oraninda artis gozlendi. Granuloza hucreleri yuvarlak sekilli ve apoptotik hucre gorunumunde izlendi. Iyonize radyasyona maruz kalan sicanlarin ovaryum dokulari incelendiginde 4.gun IR grubunda atretik follikullerin sayisi 6. saat IR grubuna gore belirgin bir sekilde artmisti. LK uygulanan gruplarda IR’nun yarattigi hasarda belirgin bir duzelme gozlendi. IR gruplarinda serumdaki IL-1α, IL-4 ve GM-CSF duzeyleri kontrol grubu ve tedavi grubuna gore artmis olarak izlendi. SONUC : Iyonize radyasyonun akut olarak primordiyal ve primer follikullerdeki dejenerasyonu arttirdigi sonucuna varilmistir. Ayrica, L-karnitinin iyonize radyasyona bagli gelisen follikuler atrezide koruyucu bir rolu oldugunu dusunmekteyiz.