PMID- 37277081 OWN - NLM STAT- MEDLINE DCOM- 20230619 LR - 20230619 IS - 1872-7573 (Electronic) IS - 0378-8741 (Linking) VI - 316 DP - 2023 Nov 15 TI - Saikosaponin B2 ameliorates depression-induced microglia activation by inhibiting ferroptosis-mediated neuroinflammation and ER stress. PG - 116729 LID - S0378-8741(23)00597-4 [pii] LID - 10.1016/j.jep.2023.116729 [doi] AB - ETHNOPHARMACOLOGICAL RELEVANCE: Saikosaponins B2 (SSB2) is one of the main active components isolated from Radix Bupleuri (Bupleurum chinense DC.), a herb widely used of traditional Chinese medicine. It has been used for the treatment of depression for more than two thousand years. However, the molecular mechanisms remain to be determined. AIM OF THE STUDY: In this study, we evaluated the anti-inflammatory effect and elucidated underlying molecular mechanisms of SSB2 in LPS-induced primary microglia and CUMS-induced mice model of depression. METHOD: The effects of SSB2 treatment were investigated both in vitro and in vivo. The chronic unpredictable mild stimulation (CUMS) procedure was applied to establish the animal model of depression. Behavioural tests were used to evaluate the depressive-like behaviors in CUMS-exposed mice, including sucrose preference test, open field test, tail suspension test, and forced swimming test. The GPX4 gene of microglia was silenced using shRNA, and inflammatory cytokines were determined by Western Blot and immunofluorescence analysis. Endoplasmic reticulum stress and ferroptosis-related markers were detected by qPCR, flow cytometry and confocal microscopy. RESULT: SSB2 reversed depressive-like behaviours in CUMS-exposed mice and relieved central neuroinflammation and ameliorated hippocampal neural damage. SSB2 alleviated LPS-induced activation of microglia through the TLR4/NF-kappaB pathway. LPS-induced ferroptosis, with increased levels of ROS, intracellular Fe(2+), mitochondrial membrane potential, lipid peroxidation, GSH, SLC7A11, FTH, GPX4 and Nrf2, and decreased transcription levels of ACSL4 and TFR1, was attenuated with SSB2 treatment in primary microglia cells. GPX4 knockdown activated ferroptosis, induced endoplasmic reticulum (ER) stress, and abrogated the protective effects of SSB2. Further, SSB2 attenuated ER stress, balanced calcium homeostasis, reduced lipid peroxidation and intracellular Fe(2+) content by regulating the level of intracellular Ca(2+). CONCLUSIONS: Our study suggested that SSB2 treatment can inhibit ferroptosis, maintain calcium homeostasis, relieve endoplasmic reticulum stress and attenuate central neuroinflammation. SSB2 exhibited anti-ferroptosis and anti-neuroinflammatory effects through the TLR4/NF-kappaB pathway in a GPX4-dependent manner. CI - Copyright (c) 2023 Elsevier B.V. All rights reserved. FAU - Wang, Xinmei AU - Wang X AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. FAU - Li, Shanshan AU - Li S AD - School of Pharmacy, Bengbu Medical College, Bengbu, 233030, China; Anhui Province Engineering Technology Research Center of Biochemical Pharmaceutical, Bengbu, 233030, China. FAU - Yu, Jiayu AU - Yu J AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. FAU - Wang, Wenlin AU - Wang W AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. FAU - Du, Zhuoqi AU - Du Z AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. FAU - Gao, Shuchun AU - Gao S AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. FAU - Ma, Yin AU - Ma Y AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. FAU - Tang, Ruixin AU - Tang R AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. FAU - Liu, Ting AU - Liu T AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. FAU - Ma, Shiping AU - Ma S AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. FAU - Fu, Qiang AU - Fu Q AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. Electronic address: 744298001@qq.com. FAU - Deng, Xueyang AU - Deng X AD - Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, 210009, China. Electronic address: dxy@cpu.edu.cn. LA - eng PT - Journal Article DEP - 20230603 PL - Ireland TA - J Ethnopharmacol JT - Journal of ethnopharmacology JID - 7903310 RN - 0 (NF-kappa B) RN - UR635J3F00 (saikosaponin D) RN - 0 (Toll-Like Receptor 4) RN - 0 (Lipopolysaccharides) RN - SY7Q814VUP (Calcium) RN - Bupleurum falcatum SB - IM MH - Mice MH - Animals MH - *NF-kappa B/metabolism MH - *Depression/drug therapy MH - Signal Transduction MH - Neuroinflammatory Diseases MH - Microglia/metabolism MH - Toll-Like Receptor 4/metabolism MH - Lipopolysaccharides/pharmacology MH - Calcium/metabolism MH - Endoplasmic Reticulum Stress MH - Stress, Psychological/drug therapy MH - Hippocampus/metabolism MH - Disease Models, Animal OTO - NOTNLM OT - Endoplasmic reticulum stress OT - Ferroptosis OT - Neuroinflammation OT - aikosaponin B2 COIS- Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled. EDAT- 2023/06/06 01:11 MHDA- 2023/06/19 13:09 CRDT- 2023/06/05 19:24 PHST- 2023/03/11 00:00 [received] PHST- 2023/05/21 00:00 [revised] PHST- 2023/06/02 00:00 [accepted] PHST- 2023/06/19 13:09 [medline] PHST- 2023/06/06 01:11 [pubmed] PHST- 2023/06/05 19:24 [entrez] AID - S0378-8741(23)00597-4 [pii] AID - 10.1016/j.jep.2023.116729 [doi] PST - ppublish SO - J Ethnopharmacol. 2023 Nov 15;316:116729. doi: 10.1016/j.jep.2023.116729. Epub 2023 Jun 3.