ABSTRACT
<p><b>BACKGROUND</b>The mechanisms underlying diabetic encephalopathy are largely unknown, and no effective treatments are available. Catalpol has received much attention due to its numerous biological effects, especially in neuroprotective studies. The aim of this study was to investigate the effects of catalpol on cognitive functions in diabetic rats and the underlying mechanisms.</p><p><b>METHODS</b>A rat model of diabetes was established by streptozotocin injection, followed by intraperitoneal infusion of catalpol after 10 weeks. Two weeks later, the Morris water maze was used to test the spatial learning performance. Nissl staining was performed to evaluate the morphological changes in the hippocampus. Expression of protein kinase Cγ (PKCγ) and caveolin-1 (Cav-1) in the hippocampus were assessed by reverse transcription PCR and Western blotting. Activities of anti-oxidative enzymes such as glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) and levels of malonaldehyde (MDA) were measured using commercial kits.</p><p><b>RESULTS</b>Significant hippocampal neuronal injury was observed in rats with streptozotocin-induced diabetes. Moreover, cognitive dysfunction was associated with markedly increased oxidative stress in the brain. Catalpol treatment significantly attenuated cognitive deficits, neuronal damage, and oxidative stress in the brain of diabetic rats. Biochemical analyses showed that catalpol reversed the down-regulation of PKCγ and Cav-1 expression in the diabetic rats.</p><p><b>CONCLUSIONS</b>Spatial memory in diabetic rats is associated with the expression of PKCγ and Cav-1. Catalpol treatment markedly attenuated oxidative stress, reversed the alteration of PKCγ, Cav-1 and spatial memory deficits.</p>
Subject(s)
Animals , Male , Rats , Caveolin 1 , Metabolism , Diabetes Mellitus, Experimental , Drug Therapy , Metabolism , Hippocampus , Metabolism , Iridoid Glucosides , Therapeutic Uses , Neuroprotective Agents , Therapeutic Uses , Oxidative Stress , Protein Kinase C , Metabolism , Spatial Memory , PhysiologyABSTRACT
This study was designed to explone whether catalpol exerts a protective effects on kidney of diabetic rats and its possible mechanism.Insulin-like growth factor- I ( IGF- I ) and protein kinase B (PKB/Akt)mRNA and protein expression in kidney of diabetic rats were up-regulated as results of assessments by RT-PCR,immunohistochemistry and Western blot.Catalpol could partially reduce IGF- Ⅰ and Akt expressions in kidney of diabetic rats,and thus alleviate the damage of kidney.
ABSTRACT
Serum p-amyloid peptide(Aβ)40 and Ap42 levels in patients with type 2 diabetes mellitus (T2DM)and atherosclerosis(AS)were detected by ELISA.The results showed that serum Ap40 level in T2DM group was significantly higher than that in the control group[(274.70±159.51 vs 162.63±87.58)pg/ml,P<0.05],especially in the diabetic patients accompanied with AS[(616.95±195.13)pg/m],P<0.01].Serum Ap40 level in simple AS group was also higher than that in control group[(318.52± 188.65)pg/ml,P<0.05].These results suggest that Ap40 is a risk factor of T2DM complicated with AS.However,there was no difference in serum Ap42 levels among various groups.