Mulberry fruit (Morus alba L.) contains abundant bioactive compounds, including anthocyanins and flavonols, and has been reported to possess potent beneficial properties including anticancer, antidiabetic, and anti-oxidant effects. High hydrostatic pressure (HHP) processing, a nonthermal food processing technology, is suitable for the extraction of bioactive compounds from plants. Nevertheless, the anti-inflammatory effects of HHP extract of mulberry fruit (HM) in RAW264.7 cells remain unclear. The present study aimed to investigate the anti-inflammatory effects of HM on lipopolysaccharide (LPS)-induced inflammation in vitro. RAW264.7 cells were treated with various concentrations (0.1-1 μg/mL) of HM in the presence or absence of LPS. HM inhibited the inflammatory mediator, nitric oxide (NO) release, and mRNA expression of nitric oxide synthase 2 (NOS2) in LPS-induced RAW264.7 cells. In addition, HM suppressed both mRNA and protein expressions of prostaglandin-endoperoxide synthase 2 (PTGS2). Moreover, it reduced the LPS-induced secretion of proinflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α. These results revealed that HM exerts anti-inflammatory effects by inhibiting several mediators and cytokines involved in the inflammatory process.
Keywords: high hydrostatic pressure; inflammation; macrophage; mulberry fruit.