Fish and Shellfish Immunology Reports (Dec 2021)

Characterization of a macrophagic-like cell line derived from rabbit fish (Siganus fuscescens): An illustration of anti-inflammatory responses of the herbal extract of Scutellaria baicalensis

  • Yi-Teng Xia,
  • Edwin Hok-Chi Cheng,
  • Ying-Jie Xia,
  • Qi-Yun Wu,
  • Lynn Hoi-Lam Zhang,
  • Sheng-Ying Lin,
  • Tina Ting-Xia Dong,
  • Qi-Wei Qin,
  • Wen-Xiong Wang,
  • Karl Wah-Keung Tsim

Journal volume & issue
Vol. 2
p. 100036

Abstract

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A new cell line was isolated and characterized from the head kidney of Siganus fuscescens (rabbit fish). The new macrophagic-like cell line was named as rabbit fish macrophage (RFM), and which could be sub-cultured for over 50 cycles since the development. RFM cell line was tested for growth in different temperatures and serum concentrations: the best growing condition was optimized at 20% serum under 28 °C. In cultured RFM cells, sequencing of 18S rRNA, as well as immunostaining of cytokeratin and CD 68, confirmed the identity as macrophagic cell of S. fuscescens. Cultured RFM cells were exposed to challenge of inflammation, as triggered by LPS, showing highly sensitive responses to inflammation, including release of nitric oxide, expression of cytokine, and activation of phagocytosis. The water extract of aerial part of Scutellaria baicalensis, named as SBA, has been shown anti-inflammatory property in S. fuscescens fish. In order to extend the application of SBA in aquaculture, the extract and its effective flavonoids, i.e. baicalin and scutellarin, were applied in LPS-treated RFM cells. Application of SBA extract, baicalin or scutellarin, inhibited the expressions of LPS-induced inflammatory cytokines, i.e. IL-1β, TNF-α, as well as the signaling of transcription factor NF-κB. The results support the established RFM cell line could be an ideal in vitro model in drug screening relating to inflammation. Additionally, the notion of SBA herbal extract in fish aquaculture is supported by its efficacy against inflammation.

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