RESUMO
OBJECTIVE: To examine the neuroprotective effect of extract from Naomaitong following focal cerebral ischemia reperfusion induced by occlusion of middle cerebral artery (MCA), and to determine the biochemical alterations in urine using proton nuclear magnetic resonance spectroscopy and principal component analysis. METHODS: Wistar rats were randomly assigned to three groups: sham-operated group, MCA focal cerebral ischemia reperfusion model group, and active extract of Naomaitong treatment group. The model was established by an improved MCA occlusion (MCAO) method. Sham-operated rats received the same surgical procedure, but without occlusion. The Naomaitong treatment group were treated with active extract from Naomaitong at a dose of 3.0 gkg-1d-1. Brain tissues and urine samples were collected from all groups for histopathological assessment and proton nuclear magnetic resonance spectroscopy-based metabonomics, respectively. RESULTS: Hematoxylin-eosin and triphenyl tetrazolium chloride staining of brain tissues showed a significant decrease in cerebral infarction area in the Naomaitong group. In model rats, metabonomic analyses showed increased urinary levels of glutamate, taurine, trimetlylamine oxide, betaine, and glycine, and reduced levels of creatinine and creatine. Naomaitong regulated the metabolic changes by acting on multiple metabolic pathways, including glycine metabolism, glutaminolysis, transmethylation metabolism and creatinine metabolism. CONCLUSION: These data demonstrate that extract from Naomaitong is neuroprotective against focal cerebral ischemia induced by MCAO, and can alleviate biochemical changes in urinary metabolism. Metabonomics may be a useful approach for assessing the biochemical mechanisms underlying the neuroprotective actions of extract from Naomaitong.
RESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: The ischemia cerebrovascular disease is one of leading causes of death and long-term disability in modern society. Rhubarb is one of the common traditional Chinese medicine with many effects, and the main pharmacodynamic ingredients are aloe-emodin, rhein, emodin, chrysophanol and physcion. The five components are also known as rhubarb aglycone. Rhubarb aglycone has been confirmed to play a remarkable curative effect on cerebral ischemia, but the mechanism is not clear. In this study, (1)H NMR-based metabonomics approach has been used to investigate the protective effect of the optimized rhubarb aglycone on rats of cerebral ischemia-reperfusion. MATERIALS AND METHODS: Male Wistar rats were divided into four groups: sham operation group, model group, Nimodipine group and the optimized rhubarb aglycone group. Based on (1)H-NMR spectra of plasma and urine, principal component analyses were performed to identify different metabolic markers and explore the changes of associated biochemical pathways. Behavior research and brain histopathology examinations were also performed. RESULTS: It was showed that the optimized rhubarb aglycone treatment improved neurological deficits, cerebral infarction and neuronal apoptosis. Principal component analysis scores plots demonstrated that the cluster of model rats was separated from those of sham operation group; rats of the optimized rhubarb aglycone group were classified from model group, but the optimized rhubarb aglycone group closed to the sham operation group. Optimized rhubarb aglycone regulated the associated amino acid, energy and lipid metabolisms disturbed in model rats. CONCLUSION: Our results suggested that the optimized rhubarb aglycone had protective effect on rats of cerebral ischemia-reperfusion and explored the metabolic regulation mechanism. This work showed that the NMR-based metabonomics approach might be a promising approach to study mechanisms of traditional Chinese medicines.