Sulfoquinovosyl oleoyl palmitoyl glycerol (SQDG) and hexane extract of Sargassum plagyophylum prevent depression induced by dexamethasone or stress in mice

Introduction: M Glucocorticoids and stress are a leading cause of depression by dysregulation of hypothalamic hypophyseal adrenal axis. Sargassum plagyophylum hexane extract (HxE) has proven antidepressant-like effects in mice. We aimed at evaluating HxE and sulfoquinovosyl oleoyl palmitoyl glycerol (SQDG) isolated compound antidepressant effects following dexamethasone (Dex) or water avoidance stress (WAS) induced depression in mice. Methods: The HxE was prepared and fractionated by different chromatography methods to isolate active compounds. Depression was induced in male mice by Dex single dose or by four days of WAS. After the locomotor test, depression was assessed by measuring the immobility time during the forced swimming test (FST) and sucrose preference test.Results: 6-Deoxy-6-sulpho-α-D-glucopyranosyl-1,2-O-diacyl-glycerol was isolated and elucidated from the seaweed. The manipulations did not cause important changes in animals’ locomotor activity. During FST, immobility time increased dramatically by Dex (193 ± 13 s vs control 109 ± 7 s) or WAS (189 ± 13 s vs sham 86 ± 14 s), that indicated depression. HxE 40 mg/kg reduced the immobility time when it was administered with Dex (110 ± 28 s, P < 0.01 vs Dex alone) or together with WAS (86 ± 11 s, P < 0.001 vs WAS). SQDG 40 mg/kg reduced the immobility time when co-administered with Dex (22 ± 9 s, P < 0.001 vs Dex alone) and when it was administered along with WAS (68 ± 16 s, P < 0.001 vs WAS). The results of the sucrose preference test were in line with FST results as sucrose preference below 65% was considered for anhedonia. Conclusion: SQDG and probably the steroid content in S. plagyophylum HxE prevented depression in mice; thus, they should be considered for further clinical evaluations.