Protective effect of Lycium Barbarum polysaccharides on dextromethorphan-induced mood impairment and neurogenesis suppression

Brain Res Bull. 2017 Sep:134:10-17. doi: 10.1016/j.brainresbull.2017.06.014. Epub 2017 Jun 21.

Abstract

Dextromethorphan (DXM) is one of the common drugs abused by adolescents. It is the active ingredient found in cough medicine which is used for suppressing cough. High dosage of DXM can induce euphoria, dissociative effects and even hallucinations. Chronic use of DXM may also lead to depressive-related symptoms. Lycium barbarum, commonly known as wolfberry, has been used as a traditional Chinese medicine for the treatment of ageing-related neurodegenerative diseases. A recent study has shown the potential beneficial effect of Lycium barbarum to reduce depression-like behavior. In the present study, we investigated the role of Lycium barbarum polysaccharide (LBP) to alleviate DXM-induced emotional distress. Sprague Dawley rats were divided into 4 groups (n=6 per group), including the normal control (vehicles only), DXM-treated group (40 mg/kg DXM), LBP-treated group (1 mg/kg LBP) and DXM+ LBP-treated group (40 mg/kg DXM and 1 mg/kg LBP). After two-week treatment, the DXM-treated group showed increased depression-like and social anxiety-like behaviors in the forced swim test and social interaction test respectively. On the other hand, the adverse behavioral effects induced by DXM were reduced by LBP treatment. Histological results showed that LBP treatment alone did not promote hippocampal neurogenesis when compared to the normal control, but LBP could lessen the suppression of hippocampal neurogenesis induced by DXM. The findings provide insights for the potential use of wolfberry as an adjunct treatment option for alleviating mood disturbances during rehabilitation of cough syrup abusers.

Keywords: Cough syrup abuse; Dextromethorphan; Lycium barbarum; Neurogenesis.

MeSH terms

  • Animals
  • Antitussive Agents / toxicity
  • Anxiety Disorders / chemically induced
  • Anxiety Disorders / drug therapy*
  • Anxiety Disorders / pathology
  • Anxiety Disorders / physiopathology
  • Depressive Disorder / chemically induced
  • Depressive Disorder / drug therapy*
  • Depressive Disorder / pathology
  • Depressive Disorder / physiopathology
  • Dextromethorphan / toxicity*
  • Disease Models, Animal
  • Drugs, Chinese Herbal / pharmacology*
  • Hippocampus / drug effects
  • Hippocampus / pathology
  • Hippocampus / physiopathology
  • Male
  • Neurogenesis / drug effects
  • Neurons / drug effects
  • Neurons / pathology
  • Neurons / physiology
  • Neuroprotective Agents / pharmacology*
  • Psychotropic Drugs / pharmacology
  • Random Allocation
  • Rats, Sprague-Dawley
  • Social Behavior
  • Substance-Related Disorders / drug therapy*
  • Substance-Related Disorders / pathology
  • Substance-Related Disorders / physiopathology

Substances

  • Antitussive Agents
  • Drugs, Chinese Herbal
  • Neuroprotective Agents
  • Psychotropic Drugs
  • lycium barbarum polysaccharide
  • Dextromethorphan