Sea Cucumber Phospholipids Improve Chronic Stress-induced Depression-like Behavior in Zebrafish by Regulating the TRP-KYN Pathway

ZHANG Jingjing; SHI Wenxuan; TANG Lin; LIU Xiaochun; SONG Cai; ZHAO Yuntao; ZHANG Yongping

doi:10.13982/j.mfst.1673-9078.2026.1.1587

Abstract：To investigate the effects of sea cucumber phospholipids on depression-like behaviors induced by chronic unpredictable mild stress(CUMS)in zebrafish and associated mechanisms,Zebrafish were randomly divided into a control group,a stress group,a stress+low-dose(50 mg/kg)sea cucumber phospholipids intervention group,and a stress+high-dose(100 mg/kg)sea cucumber phospholipid intervention group.After the stress period,the novel tank and light-dark box behavioral tests were performed,the contents of interleukin(IL)-10,IL-6,indoleamine-2,3-dioxygenase(IDO),Tryptophan(TRP)and Kynurenine(KYN)were determined by enzyme linked immunosorbent assay(ELISA),whilst the level of 5-hydroxytryptamine(5-HT)was detected by high performance liquid chromatography(HPLC).Compared with the stress group,the depression degree of zebrafish in the low(50 mg/kg)and high dose(100 mg/kg)sea cucumber phospholipid groups was effectively reduced as shown in the new tank and the light-dark box behavior tests.Their contents of IL-10 in the brain increased by 12.05%and 15.26%(P<0.05 and P<0.01),contents of IL-6 decreased by 12.23%and 14.87%(P<0.01 and P<0.000 1),activities of IDO decreased by 14.12%and 22.20%(P<0.01 and P<0.000 1),and contents of TRP increased by 4.07%and 4.33%(P<0.05),contents of KYN decreased by 6.83%and 8.67%(P<0.05),ratios of KYN/TRP decreased by 9.43%and 11.32%(P<0.05),and contents of 5-HT increased by 28.57%(P<0.05)respectively.Therefore,depression can be ameliorated by sea cucumber phospholipids.The mechanisms include the amelioration ofinflammation and reduction of 5-HT synthesis caused by the activation of TRP-KYN pathway by IDO.This study provides new ideas for the development of antidepressant products by using sea cucumber phospholipids.