Jiuseng Zeng1, Yafei Ji2, Fei Luan3, Jingwen Hu4, Yixing Rui5, Yao Liu6, Zhili Rao7, Rong Liu8, Nan Zeng9. 1. State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; Department of Pharmacology, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China. Electronic address: 814169023@qq.com. 2. State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; Department of Pharmacology, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China. Electronic address: 861204247@qq.com. 3. State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; Department of Pharmacology, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China. Electronic address: luanfeifen@163.com. 4. Department of Pharmacology, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China. Electronic address: 893216006@qq.com. 5. Department of Pharmacology, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China. Electronic address: ruiyixin1166@163.com. 6. Department of Pharmacology, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China. Electronic address: liuyao20210304@163.com. 7. Department of Pharmacology, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China. Electronic address: 1083490347@qq.com. 8. Department of Pharmacology, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China. Electronic address: liurong_1116@126.com. 9. State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China; Department of Pharmacology, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China. Electronic address: 19932015@cdutcm.edu.cn.
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE: Xiaoyaosan (XYS), a representative and classic traditional Chinese medicine (TCM) prescription with function of dispersing stagnated liver and strengthening spleen, has been used for thousands of years to treat depression. XYS' anti-depression effect has been demonstrated both clinically and experimentally; however, the material basis for this effect has yet to be elucidated. AIM OF THE STUDY: This study aimed to evaluate the impact and underlying action mechanism of XYS' antidepressant active component (Xiaoyaosan ethyl acetate fraction, XYSEF) against chronic unpredictable mild stress (CUMS)-induced depression-like behavior in mice. MATERIALS AND METHODS: First, we established a behavioral despair depression mouse model to preliminarily determine the effective antidepressant dose of XYSEF. Then, we created a CUMS mouse model and used various classic behavioral tests, including SPT, ST, NFST, and TST, to assess XYSEF's antidepressant properties. IGF-1 levels in mouse serum and hippocampus were quantified using ELISA. The average optical density of Nissl bodies in the mouse hippocampal CA3 region was determined utilizing toluidine blue staining. Brdu and DCX expression in the hippocampal dentate gyrus (DG) was assayed using the immunofluorescence method. IGF-1Rβ, PI3K, p-PI3K, Akt, p-Akt, Caspase-3, and cleaved Caspase-3 protein levels in the hippocampus were determined with Western blot. RESULTS: The behavioral despair mouse model findings showed that 9.1 and 40 g/kg of XYSEF both significantly shortened the immobility time of mice, suggesting that the effective dose range was 9.1-40 g/kg. Compared to the CUMS mouse model, XYSEF at 20 and 40 g/kg markedly increased the sucrose preference percentage in the SPT and grooming time in the ST, shortened the immobility time in the TST and the feeding latency in the NSFT, and reversed the downregulated IGF-1 content in mouse serum and hippocampus. In addition, XYSEF amplified the average optical density of Nissl bodies in the hippocampal CA3 region, promoted Brdu and DCX expression in DG, and diminished IGF-1Rβ, p-PI3K/PI3K, p-Akt/Akt, and cleaved Caspase-3/Caspase-3 protein levels in the hippocampi of CUMS mice. CONCLUSION: XYSEF acted as an antidepressant in mice exhibiting CUMS-induced depression-like behaviors, possibly by promoting hippocampal neurogenesis, reducing neuronal apoptosis, and inhibiting the over-activation of the IGF-1Rβ/PI3K/Akt pathway.
ETHNOPHARMACOLOGICAL RELEVANCE: Xiaoyaosan (XYS), a representative and classic traditional Chinese medicine (TCM) prescription with function of dispersing stagnated liver and strengthening spleen, has been used for thousands of years to treat depression. XYS' anti-depression effect has been demonstrated both clinically and experimentally; however, the material basis for this effect has yet to be elucidated. AIM OF THE STUDY: This study aimed to evaluate the impact and underlying action mechanism of XYS' antidepressant active component (Xiaoyaosan ethyl acetate fraction, XYSEF) against chronic unpredictable mild stress (CUMS)-induced depression-like behavior in mice. MATERIALS AND METHODS: First, we established a behavioral despair depression mouse model to preliminarily determine the effective antidepressant dose of XYSEF. Then, we created a CUMS mouse model and used various classic behavioral tests, including SPT, ST, NFST, and TST, to assess XYSEF's antidepressant properties. IGF-1 levels in mouse serum and hippocampus were quantified using ELISA. The average optical density of Nissl bodies in the mouse hippocampal CA3 region was determined utilizing toluidine blue staining. Brdu and DCX expression in the hippocampal dentate gyrus (DG) was assayed using the immunofluorescence method. IGF-1Rβ, PI3K, p-PI3K, Akt, p-Akt, Caspase-3, and cleaved Caspase-3 protein levels in the hippocampus were determined with Western blot. RESULTS: The behavioral despair mouse model findings showed that 9.1 and 40 g/kg of XYSEF both significantly shortened the immobility time of mice, suggesting that the effective dose range was 9.1-40 g/kg. Compared to the CUMS mouse model, XYSEF at 20 and 40 g/kg markedly increased the sucrose preference percentage in the SPT and grooming time in the ST, shortened the immobility time in the TST and the feeding latency in the NSFT, and reversed the downregulated IGF-1 content in mouse serum and hippocampus. In addition, XYSEF amplified the average optical density of Nissl bodies in the hippocampal CA3 region, promoted Brdu and DCX expression in DG, and diminished IGF-1Rβ, p-PI3K/PI3K, p-Akt/Akt, and cleaved Caspase-3/Caspase-3 protein levels in the hippocampi of CUMS mice. CONCLUSION: XYSEF acted as an antidepressant in mice exhibiting CUMS-induced depression-like behaviors, possibly by promoting hippocampal neurogenesis, reducing neuronal apoptosis, and inhibiting the over-activation of the IGF-1Rβ/PI3K/Akt pathway.