Alpha-lipoic acid enhances short-term spatial memory of mice in open-space forced swim-induced depression mouse model

Abstract
Depression affects over 264 million people of all ages globally. Major depressive disorder significantly and chronically reduced quality of life by its association with functional impairment both at home and in the workplace. Depressive patients consistently complain about cognitive disturbances, significantly exacerbating the burden of this illness. Several studies have shown that alpha-lipoic acid (ALA) possesses mitochondrial, antioxidant, anti-inflammatory and anti-diabetic properties, indicating a basis for evaluating the efficacy of ALA in depression. Hence, this research aimed to assess the possible anti-depressant effect of ALA in mice exposed to the open space forced swim test (OSFST) model of depression. Twenty-five (25) Swiss albino mice were grouped into five groups (n=5). Group 1: [Normal saline (NS)], Groups 2, 3 and 4 received graded doses of ALA 100, 200 and 400 mg/kg, respectively, Group 5 received fluoxetine 20 mg/kg orally. The animals were subjected to OSFST, novel object recognition test (NORT) and Y-maze test. Serotonin, brain-derived neurotrophic factor (BDNF), superoxide dismutase (SOD), malondialdehyde (MDA) and catalase levels of the mice were assessed. Treatment with ALA and fluoxetine significantly decreased immobility time compared to NS group in OSFST (p<0.05). Also, ALA at doses of 200 & 400 mg/kg and fluoxetine 20 mg/kg significantly increased spontaneous alternation ratio in the Y-maze test compared to the normal saline group (p<0.05), however, no significant difference was observed in novel object recognition using NORT between NS, ALA and fluoxetine treated groups. Similarly, the level of serotonin, SOD and catalase were not altered between the ALA and fluoxetine treated groups and NS group. In contrast, fluoxetine 20 mg/kg increased the brain BDNF level of the mice (p<0.05). Alpha-lipoic acid ameliorated depression in the OSFST murine model of depression and improved their cognition. Thus ALA can be a promising candidate in the development of novel anti-depressant medication.