Gypenoside attenuates white matter lesions induced by chronic cerebral hypoperfusion in rats.
ABSTRACT Cerebral white matter lesions (WMLs) are frequently observed in vascular dementia and Alzheimer's disease and are believed to be responsible for cognitive dysfunction. The cerebral WMLs are most likely caused by chronic cerebral hypoperfusion and can be experimentally induced by permanent bilateral common carotid artery occlusion (BCCAO) in rats. Previous studies found the involvement of oxidative stress and astrocytic activation in the cerebral WMLs of BCCAO rats. Gypenoside (GP), a pure component extracted from the Gyrostemma pentaphyllum Makino, a widely reputed medicinal plants in China, has been reported to have some neuroprotective effects via anti-oxidative stress and anti-inflammatory mechanisms. In the present study, we investigated the protective effect of GP against cerebral WMLs and the underlying mechanisms for its inhibition of cognitive decline in BCCAO rats. Adult male Sprague-Dawley rats were orally administered daily doses of 200 and 400mg/kg GP for 33 days after BCCAO, and spatial learning and memory were assessed using the Morris water maze. Following behavioral testing, oxygen free radical levels and antioxidative capability were measured biochemically. The levels of lipid peroxidation and oxidative DNA damage were also assessed by immunohistochemical staining for 4-hydroxynonenal and 8-hydroxy-2'-deoxyguanosine, respectively. Activated astrocytes were also assessed by immunohistochemical staining and Western blotting with GFAP antibodies. The morphological changes were stained with Klüver-Barrera. Rats receiving 400mg/kg GP per day performed significantly better in tests for spatial learning and memory than saline-treated rats. GP 400mg/kg per day were found to markedly scavenge oxygen free radicals, enhance antioxidant abilities, decrease lipid peroxide production and oxidative DNA damage, and inhibit the astrocytic activation in corpus callosum and optic tract in BCCAO rats. However, GP 200mg/kg per day had no significant effects. GP may have therapeutic potential for treating dementia induced by chronic cerebral hypoperfusion and further evaluation is warranted.
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ABSTRACT: Neurodegenerative disorders affect a significant portion of the world's population leading to either disability or death for almost 30 million individuals worldwide. One novel therapeutic target that may offer promise for multiple disease entities that involve Alzheimer's disease, Parkinson's disease, epilepsy, trauma, stroke, and tumors of the nervous system is the mammalian target of rapamycin (mTOR). mTOR signaling is dependent upon the mTORC1 and mTORC2 complexes that are composed of mTOR and several regulatory proteins including the tuberous sclerosis complex (TSC1, hamartin/TSC2, tuberin). Through a number of integrated cell signaling pathways that involve those of mTORC1 and mTORC2 as well as more novel signaling tied to cytokines, Wnt, and forkhead, mTOR can foster stem cellular proliferation, tissue repair and longevity, and synaptic growth by modulating mechanisms that foster both apoptosis and autophagy. Yet, mTOR through its proliferative capacity may sometimes be detrimental to central nervous system recovery and even promote tumorigenesis. Further knowledge of mTOR and the critical pathways governed by this serine/threonine protein kinase can bring new light for neurodegeneration and other related diseases that currently require new and robust treatments.Progress in Neurobiology 08/2012; 99(2):128-48. · 9.04 Impact Factor
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ABSTRACT: Gynostemma pentaphyllum is a traditional Chinese medicine that has previously been used for the treatment of chronic inflammation, hyperlipidemia and liver disease. Gypenoside (GP), the predominant component of Gynostemma pentaphyllum, exhibits a therapeutic effect on chronic hepatic injury, fibrosis and fatty liver disease via its anti-inflammatory and anti-oxidant activity. However, the effect of GP on ischemia/reperfusion (I/R)-induced hepatic injury has, to the best of our knowledge, not previously been investigated. In the present study, a hepatic I/R-injury model was successfully established using C57BL/6 mice. In the treatment group, 50 mg/kg GP was administered orally 1 h prior to ischemia. Following hepatic I/R, the levels of hepatic lipid peroxidation and serum alanine aminotransferase increased, while the ratio of hepatic glutathione (GSH):oxidized GSH was reduced, which was effectively attenuated by pretreatment with GP. Furthermore, an increased protein expression of heme oxygenase-1 in the liver tissues of the I/R mice was attenuated by the administration of GP. In addition, the present study indicated that treatment with GP suppressed the I/R-induced increase in the pro-apoptotic protein levels of Bax and cytochrome c and the activity of caspase-3/8, as well as the I/R-induced decrease in the levels of anti-apoptotic protein Bcl-2. In conclusion, the present study indicated that GP effectively protected against I/R-induced hepatic injury via its anti-oxidative and anti-apoptotic bioactivity.Experimental and therapeutic medicine 05/2014; 7(5):1388-1392. · 0.34 Impact Factor
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ABSTRACT: Scutellarin had protective effects against neuronal injury, however, there is few study on the protective effect of scutellarein, which is the main metabolite of scutellarin in vivo. This study investigated whether the neural injury by ischemia/reperfusion would be influenced by different doses of scutellarin and scutellarein. Male Wistar rats were orally administered with scutellarin and scutellarein at the doses of 0.09, 0.17, 0.35, 0.70, 1.40mmol/kg, respectively; then after six consecutive days, they were subjected to global ischemia by occlusion of the bilateral common carotid arteries (BCCAO). After reperfusion for about 21h, neurological and histological examinations were performed. The present results showed that scutellarein attenuated neuronal cell damage, reduced cerebral water content, regulated the expression of glutamic acid (Glu), aspartic acid (Asp), glycine (Gly), γ-aminobutyric acid (GABA) and taurine (Tau), and improved the Ca(2+)-ATPase and Na(+),K(+)-ATPase activity. Meanwhile, significant difference was found among various doses of scutellarin and scutellarein. Our studies indicated that scutellarin and scutellarein could improve neuronal injury, and scutellarein had better protective effect than scutellarin in rat cerebral ischemia.Pharmacology Biochemistry and Behavior 01/2014; · 2.82 Impact Factor