Anti-inflammatory properties of fermented pine (Pinus morrisonicola Hay.) needle on lipopolysaccharide-induced inflammation in RAW 264.7 macrophage cells

This study was aimed to explore the antioxidant and anti-inflammatory activity of various pine needle products (non-fermented, fermented, and commercial) extracted with different solvents (hexane, ethyl acetate, and water) in lipopolysaccharide (LPS) induced RAW 264.7 cells. The phenolic/flavonoid contents of ethyl acetate extract of fermented pine needle (EAE-FPN) is higher than other pine product extracts (hexane/water). The levels of antioxidant indices (TEAC, DPPH) as well as free radical scavenging activity (H2O2) were significantly improved in EAE-FPN than other pine needle product extracts. The levels of ROS and various inflammatory markers (NO, PGE2, TNF-α, and IL-1β/6) were considerably abolished by EAE-FPN in a dose-dependent manner (50–200 μg/ml). Moreover, the protein expressions of inducible NO synthase (iNOS), cyclooxygenase 2 (COX-2), and nuclear factor Kappa B (NF-κB) p65 subunit were also markedly downregulated by EAE-FPN. Collectively, EAE-FPN with phenolic/flavonoid content showed excellent antioxidant and anti-inflammatory properties via modulating NF-κB signaling pathway. Practical applications: Pine needle drink (Pinus morrisonicola Hay) has been used as a functional beverage for many years due to its various biological properties in Asia especially in Taiwan, China, and Korea. Many researchers hinted various biological activity of fermented pine needle product but none of them explored the in-depth mechanism underpinning its antioxidant and anti-inflammatory properties in LPS-induced RAW 264.7 cell model. Hence, the current cell line study was designed to assess the underlying mechanism behind the antioxidant and anti-inflammatory activity of Pine needles extract (both non-fermented and fermented) in LPS-induced RAW 264.7 cells (macrophage). The outcome of this study distinctly showed that EAE-FPN displayed potent antioxidant and anti-inflammatory activities by regulating NF-κB signaling pathway. Therefore, pine needle could be developed into functional drink to abolish the progression of inflammatory responses in various disease condition.