Water-Soluble Ginseng Oligosaccharides Prevent Scopolamine-Induced Cholinergic Dysfunction and Inflammatory Cytokine Overexpression.

Abstract

Cholinergic deficiency and neuroinflammation are the two main factors of Alzheimer's disease. Recent studies have shown that water-soluble ginseng oligosaccharides (WGOS) derived from Panax ginseng roots can protect against scopolamine-induced impairments in learning and memory. However, the fundamental mechanisms remain unclear for the most part. The purpose of this study was to examine the effect of WGOS on cholinergic function and protein levels of proinflammatory cytokines in the hippocampus of mice. Mice were first pretreated with WGOS or saline, and then treated with scopolamine to establish an Alzheimer's disease model. The cognition memory of the mice was assessed through the behavioral test. The effect of WGOS on the cholinergic system was evaluated by measuring acetylcholine (ACh) neurotransmitter concentration and acetylcholinesterase (AChE) activity in the hippocampus. Using ELISA, the inflammatory cytokines IL-1β and TNF-α in the hippocampus were identified. This study found that WGOS treatment prevented the scopolamine-induced impairment of mice's recognition memory, as seen by their enhanced object recognition. In addition, WGOS prevented the scopolamine-induced decrease in ACh concentration and increase in AChE activity. Moreover, WGOS treatment inhibited scopolamine-induced upregulation of the inflammatory proteins IL-1β and TNF-α. These findings suggest that the amelioration of scopolamine-induced cognitive impairment in mice by WGOS was a consequence of the control of cholinergic function and inflammatory response in the hippocampus. Our findings suggest that WGOS should be investigated as a dietary supplement or medication for the treatment of learning and memory disorders in humans.