Anti-inflammatory effects of Morus alba Linne bark on the activation of toll-like receptors and imiquimod-induced ear edema in mice

Umeyama L., Hardianti B., Kasahara S., Dibwe D.F., Awale S., Yokoyama S., Hayakawa Y.

Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan; Sekolah Tinggi Ilmu Farmasi Makassar, Perintis Kemerdekaan Street Km 13.7, Makassar, 90242, Indonesia; Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Science, University of Toyama, 2630 Sugitani, Toyama, 930-0194, Japan


Background: Morus alba L. bark has been widely used in traditional medicine for treating several inflammatory diseases, such as hypertension, diabetes mellitus and coughing; however, the molecular mechanisms underlying its anti-inflammatory effects are not well understood. Methods: We examined the effects of an extract of Morus alba L. bark (MabE) on Toll-like receptor (TLR) ligand-induced activation of RAW264.7 macrophages using a luciferase reporter assay and immunoassays. For the in vivo experiment, we used an imiquimod-induced ear edema model to examine the anti-inflammatory effects of MabE. Results: MabE inhibited the TLR ligand-induced activation of NF-κB in RAW264.7 cells without affecting their viability. Consistent with the inhibition of NF-κB activation, MabE also inhibited the production of IL-6 and IL-1β from TLR ligand-treated RAW264.7 cells. In vivo MabE treatment inhibited the ear swelling of IMQ-treated mice, in addition to the mRNA expression of IL-17A, IL-1β and COX-2. The increases in splenic γδT cells in IMQ-treated mice and the production of IL-17A from splenocytes were significantly inhibited by MabE treatment. Conclusion: Our study suggests that the anti-inflammatory effects of MabE on the activation of the macrophage cell line RAW246.7 by TLRs and IMQ-induced ear edema are through the inhibition of NF-κB activation and IL-17A-producing γδT cells, respectively. © 2021, The Author(s).

Inflammation; Innate immunity; Morus alba L. bark; Psoriasis; Toll-like receptor


BMC Complementary Medicine and Therapies

Publisher: BioMed Central Ltd

Volume 21, Issue 1, Art No 115, Page – , Page Count

Journal Link:

doi: 10.1186/s12906-021-03291-5

Issn: 26627671

Type: All Open Access, Gold, Green


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