Anti-Bacterial, Anti-Viral, and Anti-Inflammatory Properties of Kumazasa Extract: A Potential Strategy to Regulate Smoldering and Inflammation

<i>Background and Objectives</i>: Kumazasa extract (KZExt) is a food product obtained by steam extraction of <i>Kumazasa</i> (<i>Sasa senanensis</i> and <i>Sasa kurilensis</i>) leaves under high temperature and pressure. It contains abundant polyphenols, including <i>trans</i>-p-coumaric acid and ferulic acid, as well as xylooligosaccharides. In this study, we investigated the antibacterial, anti-viral, and anti-inflammatory effects of KZExt in vitro and in vivo. <i>Materials and Methods:</i> The anti-oxidant, antibacterial, and anti-viral effects of KZExt were assessed in vitro. Anti-oxidant activity was evaluated based on the scavenging of •OH, •O₂^- and ¹O₂. Antibacterial effects were assessed by determining the minimum inhibitory concentration (MIC) using a microdilution method. Anti-influenza activity was measured via plaque formation in MDCK cells. Anti-inflammatory effects were assessed by measuring interleukin (IL)-1β inhibition in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. In vivo, KZExt was administered once (30 min before) in a formalin-induced inflammation model to evaluate pain-related behavior. In the LPS-induced inflammation model, KZExt was administered for five days before LPS injection. Behavioral changes and cytokine levels were assessed 24 h later via the open field test and cytokine quantification. <i>Results</i>: In vitro, KZExt showed antibacterial, anti-influenza, and anti-oxidant effects, and suppressed LPS-induced IL-1β production. In vivo, it significantly reduced the second phase of formalin-induced pain behavior. In the LPS model, although behavioral changes were unaffected, KZExt suppressed IL-6 and interferon-γ production. <i>Conclusions</i>: The antibacterial, anti-viral, and anti-inflammatory effects of KZExt were confirmed in vitro and in vivo. Notably, the anti-inflammatory effect suggests potential immunomodulatory activity. These findings indicate that KZExt may help suppress smoldering inflammation and inflammation associated with various diseases through its combined antibacterial, anti-viral, and immunomodulatory actions.