Anti-Inflammatory Effects and Mechanisms of Dandelion in RAW264.7 Macrophages and Zebrafish Larvae

Wenju Li; Fulong Luo; Xiaohui Wu; Bei Fan; Mingran Yang; Wu Zhong; Dongyan Guan; Fengzhong Wang; Qiong Wang

doi:10.3389/fphar.2022.906927

Anti-Inflammatory Effects and Mechanisms of Dandelion in RAW264.7 Macrophages and Zebrafish Larvae

Front Pharmacol. 2022 Aug 25:13:906927. doi: 10.3389/fphar.2022.906927. eCollection 2022.

Authors

Wenju Li^{1

2}, Fulong Luo^{1

2}, Xiaohui Wu³, Bei Fan¹, Mingran Yang¹, Wu Zhong^{2

4}, Dongyan Guan¹, Fengzhong Wang¹, Qiong Wang^{1

5}

Affiliations

¹ Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China.
² Department of Emergency Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China.
³ Department of Neurology, The First Affiliated Hospital, Chongqing Medical University, Chongqing, China.
⁴ Sichuan Provincial Rehabilitation Hospital, Chengdu, China.
⁵ Sino-Portugal TCM International Cooperation Center, The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, China.

Abstract

Dandelions (Taraxacum spp.) play an important role in the treatment of inflammatory diseases. In this study, we investigated the anti-inflammatory effects of Dandelion Extract (DE) in LPS-induced RAW264.7 macrophages and copper sulfate (CuSO₄)-induced zebrafish larvae. DE was not toxic to RAW264.7 cells at 75 μg/ml as measured by cell viability, and DE inhibited LPS-induced cell morphological changes as measured by inverted microscopy. In survival experiments, DE at 25 μg/ml had no toxicity to zebrafish larvae. By using an enzymatic standard assay, DE reduced the production of nitric oxide (NO) in LPS-induced RAW264.7 cells. Fluorescence microscopy results show that DE reduced LPS-induced ROS production and apoptosis in RAW264.7 cells. DE also inhibited CuSO4-induced ROS production and neutrophil aggregation in zebrafish larvae. The results of flow cytometry show that DE alleviated the LPS-induced cell cycle arrest. In LPS-induced RAW264.7 cells, RT-PCR revealed that DE decreased the expression of M1 phenotypic genes iNOS, IL-6, and IL-1β while increasing the expression of M2 phenotypic genes IL-10 and CD206. Furthermore, in CuSO4-induced zebrafish larvae, DE reduced the expression of iNOS, TNF-α, IL-6, and IL-10. The findings suggest that DE reduces the LPS-induced inflammatory response in RAW264.7 cells by regulating polarization and apoptosis. DE also reduces the CuSO4-induced inflammatory response in zebrafish larvae.

Keywords: M1/M2 subtype; RAW264.7 cells; apoptosis; dandelion extract (DE); inflammation; zebrafish larvae.