Lacidipine,thiamine pyrophosphate and their combination on the ocular ischemic syndrome induced by bilateral common carotid artery ligation

AIM:To investigate the effect of lacidipine,thiamine pyrophosphate(TPP)and the combination of lacidipine and TPP against oxidative and inflammatory eye damage induced by bilateral common carotid artery ligation in rats.METHODS:Male albino Wistar rats were categorized as those who underwent sham surgery(SG),right and left common carotid cross-clamping and unclamping procedure(CCU),lacidipine+CCU(LCCU),TPP+CCU(TCCU),and combination of lacidipine and TPP(LTC)+CCU(LTCCU).One hour before anesthesia,the LCCU(n=6)received lacidipine(4 mg/kg,orally)and the TCCU(n=6)received TPP(20 mg/kg,intraperitoneally).The SG(n=6)and CCU(n=6)received the same volume of distilled water from the same route.After anesthesia(60 mg/kg ketamine,intraperitoneally),the necks of the rats were opened in the midline.Ischemia was created for 10min by placing clips on the right and left common carotid arteries.Rats in the SG only underwent subcutaneous incision.After 10min,the clips were removed and reperfusion was achieved for six days.Then,the animals were euthanized(120 mg/kg ketamine,intraperitoneally)and the levels of oxidant,antioxidant and proinflammatory cytokines in the eye tissues were determined.The retinal tissue of the eye was also examined histopathologically.RESULTS:Lacidipine,TPP,and LTC significantly prevent the increase in malondialdehyde,tumor necrosis factoralpha,interleukin-1β(IL-1β),and IL-6 levels,decrease in total glutathione levels,superoxide dismutase and catalase activities and histopathological retinal damage in eye tissue induced by bilateral common carotid artery ligation in rats.The impact of these drugs on protection is determined to be LTC>lacidipine>TPP.CONCLUSION:As a result of the study,it is concluded that LTC may be more effective than lacidipine and TPP alone in treating ocular ischemic syndrome.

Protective effects of Rutin against methanol induced acute toxic optic neuropathy：an experimental study

AIM：To determine the effects of Rutin on methanol induced optic neuropathy and compare the results with the effects of ethanol.METHODS：Totally 30 rats were divided into 5 groups,with 6 rats in each group as follows：healthy controls（C）,methotrexate（MTX）,methotrexate＋methanol（MTM）,methotrexate＋methanol＋ethanol（MTME） and methotrexate＋ methanol＋Rutin（MTMR）.In all rabbits except those of the control group,MTX,diluted in sterile serum physiologic,0.3 mg/kg per oral was applied for 7 d by the aid of a tube.After this procedure to the rats of MTM,MTME and MTMR groups,20% methanol with a dose of 3 g/kg per oral was given by the aid of a tube.In MTME group,4 h after the application of methanol,20% ethanol was applied by the same way with a dose of 0.5 g/kg.On the other hand,in MTMR group 4 h after the application of methanol,Rutin,which was dissolved in distilled water,was applied by the same way with a dose of 50 mg/kg.RESULTS：There were statistically significant differences in tissue 8-hydroxy-2 deoxyguanine（8-OHdG）,interleukin-1β（IL-1β）,tumor necrosis factor-alpha（TNF-α）,malondialdehyde（MDA）,myeloperoxidase（MPO）.glutathione peroxidase（t GSH） and superoxide dismutase（SOD） levels between groups（P〈0.001）.In MTMR group tissue 8-OHdG,IL-1β,MDA,and MPO levels were similar with the healthy controls but significantly different than the other groups.In histopathological evaluations,in MTX group there was moderate focal destruction,hemorrhage and decrease innumber of astrocytes and oligodendrocytes;in MTM group there was severe destruction and edema with decrease in number of astrocytes and oligodendrocytes;in MTME group there was mild hemorrhage,mild edema,mildly dilated blood vessels with congestion while in MTMR group,optic nerve tissue was resembling the healthy controls.CONCLUSION：Rutin may prevent methanol-induced optic neuropathy via anti-inflammatory effects and decreasing the oxidative stress.New treatment options are warranted in this disease to avoid loss of vision in patients.

Gene expression and histopathological evaluation of thiamine pyrophosphate on optic neuropathy induced with ethambutol in rats

AIM： To compare the effects of thiamine pyrophosphate（TPP） and thiamine（TM） in oxidative optic neuropathy in rats induced by ethambutol.METHODS： The animals were divided into four groups：a control group（CG）,an ethambutol control（ETC） group,TM plus ethambutol group（TMG）,and TPP plus ethambutol group（TPPG）.One hour after intraperitoneal administration of TM 20 mg/kg to the TMG group and TPP 20 mg/kg to TPPG group,30 mg/kg ethambutol was given via gavage to all the groups but the CG.This procedure was repeated once daily for 90 d.After that period,all rats were exposed to high levels of anaesthesia in order to investigate the gene expression of malondialdehyde and glutathione in removed optic nerve tissue and histopathologically to examine these tissues. RESULTS： Malondialdehyde gene expression significantly increased,whereas glutathione gene expression significantly decreased in the ETC group compared to the CG.TM could not prevent the increase of malondialdehyde gene expression and the decrease of glutathione,while TPP significantly could suppress.Histopathologically,significant vacuolization in the opticnerve,single-cell necrosis in the glial cells,and a decrease in oligodendrocytes were observed in the ETC group.Vacuolization in the optic nerve,a decrease in oligodendrocytes and single-cell necrosis were found in the TMG group,while no pathological finding was observed in the TPPG group except for mild vacuolization.CONCLUSION： TPP protects the optic nerve against the ethambutol-induced toxicity but TM does not.TPP can be beneficial in prophilaxis of optic neuropathy in ethambutol therapy.