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.