Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Mitigation of chronic unpredictable stressâ€“induced cognitive deficits in mice by Lycium barbarum L (Solanaceae) polysaccharides

Min-Qiu Xue¹, Hong-Feng Quan¹, Rui Wang¹, Xun-Xia Zhao², Lin Yan², Ya-Fei Zhu¹, Jing Jing¹, Bing Hua¹, Xiao-Dong Peng¹

¹Department of Pharmacology, College of Pharmacy; ²Functional Experiment Center, School of Basic Medicine, Ningxia Medical University, No. 1160 Shengli Road, Yinchuan, Ningxia 750004, China.

For correspondence:- Xiao-Dong Peng Email: pengxd@nxmu.edu.cn Tel:+869516980192

Received: 17 April 2017 Accepted: 21 July 2017 Published: 31 August 2017

Citation: Xue M, Quan H, Wang R, Zhao X, Yan L, Zhu Y, et al. Mitigation of chronic unpredictable stressâ€“induced cognitive deficits in mice by Lycium barbarum L (Solanaceae) polysaccharides. Trop J Pharm Res 2017; 16(8):1893-1901 doi: 10.4314/tjpr.v16i8.20

© 2017 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..

Abstract

Purpose: To investigate the neuroprotective effects of Lycium barbarum polysaccharide (LBP) against concomitant cognitive dysfunction and changes in hippocampal CREB-BDNF signaling pathway in chronically unpredictable stressed mice.

Methods: The mice were subjected to different unpredictable stressors for a period of 4 weeks. Behavioral tests, including open field (OFT) and Morris water maze (MWMT) tests were used to evaluate pharmacological effects. Serum corticosterone levels, protein expression level of BDNF and pCREB/CREB in hippocampus were assessed by ELISA, Western blot and immunohistochemistry methods, respectively. Morphological changes in pyramidal neurons in the hippocampus were studied by Nissl staining.

Results: LBP improved mice performance in MWMT, indicating that it reversed chronic unpredictable stress (CUS)-induced cognitive deficits. LBP treatment reduced serum corticosterone levels and prevented neuron loss in the hippocampus. It maintained expression levels of BDNF and phosphorylation of CREB in hippocampus during CUS procedure.

Conclusion: Lycium barbarum polysaccharide protects CREB-BDNF signaling pathway in hippocampus and relieves CUS-induced cognitive deficits. These results suggest that Lycium barbarum polysaccharides is potentially an alternative neuro-protective agent against stress-induced psychopathological dysfunction.

Keywords: Lycium barbarum, Polysaccharide, Chronic unpredictable stress, Cognitive deficits, Brain-derived neurotrophic factor, Calcium/cyclic-AMP responsive bi