The Anti-colitis Effect of Schisandra chinensis Polysaccharide Is Associated With the Regulation of the Composition and Metabolism of Gut Microbiota
Authors: Chunqin Mao
Xiachang Wang
Tulin Lu
Chenghao Fei
Guojun Yan
Min Hao
Huangjin Tong
Ziyan Huang
Lianlin Su
De Ji
Jing Mao
Lin Li
Kewei Zhang
Journal: Frontiers in Cellular and Infection Microbiology (2020)
Discipline: MICROBIOLOGY
Keywords: Schisandra chinensis; gut microbiota; inflammation; polysaccharide; short chain fatty acid
Affiliations: College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China., Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, China., School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, China.

Abstract:  Background: The pathogenesis of inflammatory bowel disease (IBD) is linked to an intricate association of environmental, microbial, and host-related factors. Polysaccharide affects host immunity by regulating the composition and metabolism of gut microbiota is the common mechanism of disease resistance. However, the efficacy and mechanism of Schisandra chinensis polysaccharide (SCP) in the treatment of inflammatory bowel disease have not been studied. Objective: To explore the effect and mechanism of SCP on dextran sodium sulfate (DSS) - induced ulcerative colitis (UC) in mice. Materials/Methods: In this study, we established a mouse model of UC, and used SCP for treatment intervention. The biochemical indexes related to inflammation were determined by ELISA kit, and the therapeutic effect of SCP on UC was clarified. Then, 16S rDNA sequencing was used to study the effect of SCP on the composition and diversity of gut microbiota. At the same time, GC-MS was used to determine the content of short chain fatty acids in intestinal contents. Finally, the relationship among gut microbiota, short chain fatty acids and inflammatory factors was analyzed, and to comprehensively explain the effect and mechanism of SCP on UC. Results: The results showed that SCP could significantly improve the physiological state of UC mice and regulate the level of inflammatory factors to normal levels. Meanwhile, SCP could significantly regulate the imbalance of gut microbiota and increase the content of SCFAs. In addition, the results of the correlation between gut microbiota and SCFAs showed that butyric acid, isobutyric acid and valeric acid had the highest correlation with gut microbiota. Conclusion: In conclusion, this research showed that SCP can inhibit inflammatory bowel disease by regulating the composition and metabolism of gut microbiota, and indicating that SCP may be used as adjuvant therapy for IBD patients. 

Retracted: No

PubPeer comments:
 The authors seem to be under the impression that the papers of Zhao and colleagues were about extraction of active ingredients from herbs, when in fact they re about predigesting waste foliage to maximise their value as biofuel.  The emerging potential methods of pretreatment and extraction of active components with ammonia and hydrogen peroxide (Zhao et al., 2017a, 2020a,b) and pre-soaking (Zhao et al., 2017b; Qiao et al., 2018) may bring unexpected insights into the material basis of *Schisandra chinensis*. - Zhao, C., Cao, Y., Ma, Z. Q., and Shao, Q. J. (2017a). **Optimization of liquid ammonia pretreatment conditions for maximizing sugar release from giant reed** (*Arundo donax* L.). Biomass Bioenergy 98, 61u201369. doi: 10.1016 j.biombioe.2017.01.001 - Zhao, C., Qiao, X. L., Shao, Q. J., Hassan, M., and Ma, Z. Q. (2020a). **Evolution of the lignin chemical structure during the bioethanol production process and its inhibition to enzymatic hydrolysis**. Energy Fuels 34, 5938u20135947. doi: 10.1021 acs.energyfuels.0c00293 - Zhao, C., Qiao, X. L., Shao, Q. J., Hassan, M., Ma, Z. Q., and Yao, L. J. (2020b). **Synergistic effect of hydrogen peroxide and ammonia on lignin**. Ind. Crops Prod. 146:112177. doi: 10.1016 j.indcrop.2020.112177 - Zhao, C., Qiao, X. L., Cao, Y., and Shao, Q. J. (2017b). **Application of hydrogen peroxide presoaking prior to ammonia fiber expansion pretreatment of energy crops**. Fuel 205, 184u2013191. doi: 10.1016 j.fuel.2017.05.073 - Qiao, X. L., Zhao, C., Shao, Q. J., and Hassan, M. (2018). **Structural characterization of corn stover lignin after hydrogen peroxide presoaking prior to ammonia fiber expansion pretreatment**. Energy Fuels 32, 6022u20136030. doi: 10.1021 acs.energyfuels.8b00951  In addition, Schisandra chinensis contains water, and the determination of water content may be performed before extraction (Zhang et al., 2019), which contributes to accurate determination of polysaccharide in future research. - Zhang, M. Q., Zhao, C., Shao, Q. J., Yang, Z. D., Zhang, X. F., Xu, X. F., et al. (2019). **Determination of water content in corn stover silage using near-infrared spectroscopy**. Int. J. Agric. Biol. Eng. 12, 143u2013148. doi: 10.25165 j.ijabe.20191206.4914 The last sentence bears comparison with [Liu, Ma Cai (2020)] . The similarity of wording is startling, and suggestive of a common origin.  It also should be noted that AR contains water, and the determination of water content may be performed before extraction [30], which contribute to accurate determination of active components in future research. , 
 Six papers: [Wang et al (2021)] :  The EULs may contain water, and the determination of water content may be performed before experiment (Zhang et al., 2019), which contribute to accurate determination of active components in future research. - Zhang, M., Zhao, C., Shao, Q., Yang, Z., Zhang, X., Xu, X., Hassan, M., 2019 Determination of water content in corn stover silage using near-infrared spectroscopy. Int. J. Agr. Biol. Eng., 12, 143-148. https: doi.org 10.25165 j.ijabe.20191205.4914 [Wang et al (2020)] :  In addition, Chuanxiong Rhizoma contains water, and the determination of water content may be performed before extraction [41], which contribute to accurate determination of active components in future research. - [41] Zhang, M. Q., Zhao, C., Shao, Q. J., Yang, Z. D., Int. J. Agr. Biol. Eng. 2019, 12, 143-148. ** Determination of water content in corn stover silage using near-infrared spectroscopy [Guo et al (2020)] :  Meanwhile, the sample of ginseng contains water, and the determination of water content may be performed before extraction [35, 36], which contribute to accurate determination of polysaccharide in future research. - [35]. Zhang M., Zhao C., Zhao C., et al. Determination of water content in corn stover silage using near-infrared spectroscopy. International Journal of Agricultural and Biological Engineering. 2019;12(6):143u2013148. doi: 10.25165 j.ijabe.20191205.4914. [CrossRef] [Google Scholar] - [36]. Zhao C., Cao Y., Ma Z., Shao Q. Optimization of liquid ammonia pretreatment conditions for maximizing sugar release from giant reed (Arundo donax L.) Biomass Bioenergy. 2017;98:61u201369. doi: 10.1016 j.biombioe.2017.01.001. [Li et al (2020)] :  In addition, TCM contains water, and the determination of water content may be performed before extraction [32], which contributes to accurate determination of active components in future research. - [32] M. Zhang, C. Zhao, C. Zhao et al., u201cDetermination of water content in corn stover silage using near-infrared spectroscopy,u201d International Journal of Agricultural and Biological Engineering, vol. 12, no. 6, pp. 143u2013148, 2019. [Liu, Ma Cai (2020)] :  It also should be noted that AR contains water, and the determination of water content may be performed before extraction [30], which contribute to accurate determination of active components in future research. - [30] Zhang, M.; Zhao, C.; Shao, Q.; Yang, Z.; Zhang, X.; Xu, X.; et al. Determination of water content in corn stover silage using near-infrared spectroscopy. Int. J. Arg. Biol. Eng. 12(6) (2019) 143-148. doi:10.25165 j.ijabe.20191205.4914 [Su et al (2020)] :  In addition, Schisandra chinensis contains water, and the determination of water content may be performed before extraction (Zhang et al., 2019), which contributes to accurate determination of polysaccharide in future research. - Zhang, M. Q., Zhao, C., Shao, Q. J., Yang, Z. D., Zhang, X. F., Xu, X. F., et al. (2019). Determination of water content in corn stover silage using near-infrared spectroscopy. Int. J. Agric. Biol. Eng. 12, 143u2013148. doi: 10.25165 j.ijabe.20191206.4914 ,