RESUMO
Cataract, a leading cause of blindness, is of special concern in diabetics as it occurs at earlier onset. Polyol accumulation and increased oxidative-nitrosative stress in cataractogenesis are associated with NFκB activation, iNOS expression, ATP depletion, loss of ATPase functions, calpain activation and proteolysis of soluble to insoluble proteins. Tocotrienol was previously shown to reduce lens oxidative stress and inhibit cataractogenesis in galactose-fed rats. In current study, we investigated anticataract effects of topical tocotrienol and possible mechanisms involved in streptozotocin-induced diabetic rats. Diabetes was induced in Sprague Dawley rats by intraperitoneal injection of streptozotocin. Diabetic rats were treated with vehicle (DV) or tocotrienol (DT). A third group consists of normal, non-diabetic rats were treated with vehicle (NV). All treatments were given topically, bilaterally, twice daily for 8 weeks with weekly slit lamp monitoring. Subsequently, rats were euthanized and lenses were subjected to estimation of polyol accumulation, oxidative-nitrosative stress, NFκB activation, iNOS expression, ATP levels, ATPase activities, calpain activity and total protein levels. Cataract progression was delayed from the fifth week onwards in DT with lower mean of cataract stages compared to DV group (p<0.01) despite persistent hyperglycemia. Reduced cataractogenesis in DT group was accompanied with lower aldose reductase activity and sorbitol level compared to DV group (p<0.01). DT group also showed reduced NFκB activation, lower iNOS expression and reduced oxidative-nitrosative stress compared to DV group. Lenticular ATP and ATPase and calpain 2 activities in DT group were restored to normal. Consequently, soluble to insoluble protein ratio in DT group was higher compared to DV (p<0.05). In conclusion, preventive effect of topical tocotrienol on development of cataract in STZ-induced diabetic rats could be attributed to reduced lens aldose reductase activity, polyol levels and oxidative-nitrosative stress. These effects of tocotrienol invlove reduced NFκB activation, lower iNOS expression, restoration of ATP level, ATPase activities, calpain activity and lens protein levels.
Assuntos
Catarata/prevenção & controle , Diabetes Mellitus Experimental/complicações , Cristalino/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Tocotrienóis/farmacologia , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Administração Tópica , Animais , Antioxidantes/administração & dosagem , Antioxidantes/farmacologia , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Calpaína , Catalase/metabolismo , Catarata/complicações , Diabetes Mellitus Experimental/sangue , Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Cristalino/metabolismo , Cristalino/patologia , Masculino , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Nitrosação/efeitos dos fármacos , Projetos Piloto , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo , Fatores de Tempo , Tocotrienóis/administração & dosagemRESUMO
Extraintestinal Salmonella infection involving the thoracic spine is very rare. It commonly presents with non-specific chronic back pain and can occur with no gastrointestinal manifestation. Blood test results and imaging findings are often indistinguishable from more common chronic spine infections such as spine tuberculosis. Culture studies remain the key to establishing a definitive diagnosis and subsequently successful treatment. We report a case in which a patient presented with symptoms and signs suggestive of spine tuberculosis, yet the culture examination revealed otherwise.
