Lycium barbarum Polysaccharides Prevent Memory and Neurogenesis Impairments in Scopolamine-Treated Rats

Abstract

Lycium barbarum is used both as a food additive and as a medicinal herb in many countries, and L. barbarum polysaccharides (LBPs), a major cell component, are reported to have a wide range of beneficial effects including neuroprotection, anti-aging and anticancer properties, and immune modulation. The effects of LBPs on neuronal function, neurogenesis, and drug-induced learning and memory deficits have not been assessed. We report the therapeutic effects of LBPs on learning and memory and neurogenesis in scopolamine (SCO)-treated rats. LBPs were administered via gastric perfusion for 2 weeks before the onset of subcutaneous SCO treatment for a further 4 weeks. As expected, SCO impaired performance in novel object and object location recognition tasks, and Morris water maze. However, dual SCO- and LBP-treated rats spent significantly more time exploring the novel object or location in the recognition tasks and had significant shorter escape latency in the water maze. SCO administration led to a decrease in Ki67- or DCX-immunoreactive cells in the dentate gyrus and damage of dendritic development of the new neurons; LBP prevented these SCO-induced reductions in cell proliferation and neuroblast differentiation. LBP also protected SCO-induced loss of neuronal processes in DCX-immunoreactive neurons. Biochemical investigation indicated that LBP decreased the SCO-induced oxidative stress in hippocampus and reversed the ratio Bax/Bcl-2 that exhibited increase after SCO treatment. However, decrease of BDNF and increase of AChE induced by SCO showed no response to LBP administration. These results suggest that LBPs can prevent SCO-induced cognitive and memory deficits and reductions in cell proliferation and neuroblast differentiation. Suppression of oxidative stress and apoptosis may be involved in the above effects of LBPs that may be a promising candidate to restore memory functions and neurogenesis.

Lycium barbarum L. (goji berry) fruits improve anxiety, depression-like behaviors, and learning performance: the moderating role of sex

“…This means that the methanol extract of L. barbarum is more beneficial to spatial learning than control conditions and females are better at spatial memory than males. The finding that the methanol extract of L. barbarum is beneficial to spatial learning is consistent with a recent finding (Chen et al, 2014) of some beneficial effects of LBPs on learning and memory in rats. In line with this finding, this research also demonstrated that the methanol extract of L. barbarum increases spatial learning memory, especially for females.…”

The Effects of Inhaled Pimpinella peregrina Essential Oil on Scopolamine-Induced Memory Impairment, Anxiety, and Depression in Laboratory Rats

“…Scopolamine is thought to exert various toxic properties on the nervous system. It exhibited toxicity on the population and dendritic development of the newborn neurons and immature granular cells in dentate gyrus, which directly results in injury of the hippocampal circuits that may predominantly be responsible for cognitive and memory deficits [22]. Inhibition of the muscarinic acetylcholine receptor by scopolamine also contributes to characteristic cognitive and memory deficits of AD [23], as well as the cholinergic receptor antagonists [24].…”

Anxiolytic and antidepressant‐like effects of Ferulago angulata essential oil in the scopolamine rat model of Alzheimer's disease

“…Scopolamine is used as a standard/reference drug for inducing cognitive deficits in healthy humans and animals . It is thought to exert various toxic properties on the nervous system and also, exhibited toxicity in the population and dendritic development of the newborn neurons and immature granular cells in dentate gyrus, which directly results in injury of the hippocampal circuits that may predominantly be responsible for cognitive and memory deficits . Inhibition of the muscarinic acetylcholine receptor by scopolamine also contributes to characteristic cognitive and memory deficits of AD, as well as the cholinergic receptor antagonists .…”