Recently the herbal medicine was widely used to treat the neurodegenerative diseases. Neuroinflammation is a characteristic of pathologically affected tissue in several neurodegenerative disorders. These changes are particularly observed in affected brain areas of Alzheimer's disease (AD) and neuronal injury. In the central nervous system, ischemic insult-induced neuronal injury is believed to result from glutamate toxicity and glucose deprivation. Rhubarb– the root of Rheum officinale is one of the famous Chinese herbs as astringent bitters in gastric constipation and in diarrhea. It is used to treat blood stasis and cathartic by traditional medicine. Rhubarb has a very broad spectrum of biological activities and pharmacological functions, such as laxative, antiphlogistic, and homeostatic in the treatment of constipation, diarrhea, jaundice, and gastro-intestinal hemorrhage, etc. In this study, five natural anthraquionones of R. officinale were investigated the neuroprotective effects against glutamate/NMDA (Glu/NMDA) stimulation in primary cultured rat brain cortical neurons. Cell death was accessed by lactate dehydrogenase (LDH) release assay for necrosis, and mitochondrial activity was accessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction activity assay. Among the five anthraquionones tested, it was found aloin, emodin and aloe-emodin decreased MTT reduction activity, whereas sennoside A and B significantly reduced Glu/NMDA-increased LDH release in cultured neurons. These results suggest that Rhubarb extract contain both neuroprotective and neurotoxic anthraquionones
