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

Dextromethorphan (DXM), a common ingredient in cough medicine, is abused by adolescents and can cause euphoria, dissociation, hallucinations, and depressive symptoms with chronic use. Lycium barbarum (wolfberry), a traditional Chinese medicine for neurodegenerative diseases, may reduce depression-like behavior. In a rat study, DXM-treated animals showed increased depression-like and social anxiety-like behaviors after two weeks. Co-treatment with Lycium barbarum polysaccharide (LBP) reduced these adverse effects. Histological analysis revealed that LBP did not promote hippocampal neurogenesis alone but lessened the suppression of neurogenesis caused by DXM. These findings suggest wolfberry could be an adjunct treatment for mood disturbances during cough syrup abuse rehabilitation.

Study at a glance

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.