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Zhao B, Zhang Q, Liang X, Xie J, Sun Q. Quercetin reduces inflammation in a rat model of diabetic peripheral neuropathy by regulating the TLR4/MyD88/NF-κB signalling pathway. Eur J Pharmacol 2021; 912:174607. [PMID: 34743981 DOI: 10.1016/j.ejphar.2021.174607] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/01/2021] [Accepted: 10/26/2021] [Indexed: 12/20/2022]
Abstract
Neuroinflammation contributes significantly to the pathogenesis of diabetic peripheral neuropathy (DPN). Quercetin reportedly exerts neuroprotective effects in DPN. Here, we aimed to evaluate the potential anti-inflammatory effects of quercetin in a DPN rat model. Eight weeks after streptozotocin administration, diabetic rats were treated with quercetin (30 and 60 mg/kg/day orally) for 6 weeks. We assessed the mechanical withdrawal threshold (MWT), nerve conduction velocity (NCV) and morphological changes in sciatic nerves. Additionally, we measured the levels of tumour necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6 by ELISA and the expression of TLR4, MyD88, and NF-κB in sciatic nerves by western blotting and immunohistochemical assays. Our results revealed that blood glucose levels and body weight were unaltered following quercetin treatment. However, quercetin improved MWT (p < 0.05), NCV (p < 0.05), and pathological changes in the sciatic nerves of DPN rats. Quercetin significantly alleviated the increased expression of TNF-α (p < 0.05) and IL-1β (p < 0.001). Furthermore, high-dose quercetin administration significantly downregulated the expression of TLR4 (p < 0.001), MyD88 (p < 0.001), and NF-κB (p < 0.001) in sciatic nerves of DPN rats. Our findings revealed that quercetin could reduce the levels of inflammatory factors in DPN rats, possibly mediated via the downregulation of the TLR4/MyD88/NF-κB signalling pathway. Collectively, these results suggest that although quercetin did not decreased blood glucose levels or reversed the reduced body weight, it showed anti-inflammatory and neuroprotective effects, which was beneficial for the treatment of DPN.
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Affiliation(s)
- Bingjia Zhao
- Department of Traditional Chinese Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, China
| | - Qian Zhang
- Department of Traditional Chinese Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, China
| | - Xiaochun Liang
- Department of Traditional Chinese Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, China.
| | - Jun Xie
- Department of Traditional Chinese Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, China
| | - Qing Sun
- Department of Traditional Chinese Medicine, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, China
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Hangping Z, Ling H, Lijin J, Wenting Z, Xiaoxia L, Qi Z, Xiaoming Z, Qingchun L, Yiming L, Qian X, Ji H, Bin L, Shuo Z. The Preventive Effect of IL-1beta Antagonist on Diabetic Peripheral Neuropathy. Endocr Metab Immune Disord Drug Targets 2020; 20:753-759. [PMID: 31642797 DOI: 10.2174/1871530319666191022114139] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/26/2019] [Accepted: 10/03/2019] [Indexed: 11/22/2022]
Abstract
Objective:
To investigate the relationship between Interleukin-1beta (IL-1beta) and diabetic
peripheral neuropathy (DPN) using animal models.
Materials:
The rat model of diabetic neuropathy was induced by intraperitoneal injection of a single
dose of streptozotocin (STZ) at 65mg/kg. Diabetic rats were randomly divided into two groups (10
each), one treated with 0.9% saline (DMS group) and the other with interleukin-1 receptor antagonist
(IL-1RA) at 50mg/kg (DMI group) twice a day for 5 weeks. Ten normal rats matched for weight, age
and sex served as normal controls (Con group) and were treated with saline. Morphologic studies of
sciatic nerves were achieved using light and transmission electron microscopy.
Results:
Transmission electron microscopy of the sciatic nerve showed the ultrastructure of myelin and
the axon in the IL-1RA group was highly protected compared to diabetic controls.
Conclusions:
High levels of circulating IL-1beta may be associated with the risk of DPN and anti-IL-1
treatment may provide a potential strategy for the prevention of diabetic neuropathy.
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Affiliation(s)
- Zheng Hangping
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
| | - Han Ling
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Soochow University 1055# Sanxiang Road, Suzhou, Jiangsu, China
| | - Ji Lijin
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
| | - Zhao Wenting
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
| | - Liu Xiaoxia
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
| | - Zhang Qi
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
| | - Zhu Xiaoming
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
| | - Li Qingchun
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
| | - Li Yiming
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
| | - Xiong Qian
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
| | - Hu Ji
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Soochow University 1055# Sanxiang Road, Suzhou, Jiangsu, China
| | - Lu Bin
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
| | - Zhang Shuo
- Department of Endocrinology and Metabolism, Huashan Hospital, Fudan University 12# Middle Wulumuqi Road, Shanghai, China
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