magnolia kobus dc leaf ethanol extract alleviated lipopolysaccharide-induced acute lung inflammation by suppressing nf-κb and nrf2 signaling

Introduction: magnolia kobus dc has been used as herbal medicine to treat coughs and is known to exert biological effects such as anti-inflammatory, antioxidant, and antibacterial properties. we aimed to define the pharmacological effects of m. kobus leaf ethanol extract (mlee) on acute lung inflammation and explore the underlying mechanisms of action. methods: for in vitro investigations, raw 264.7 cells were pretreated with mlee (1, 10, and 100 μg/ml) and stimulated with lipopolysaccharide (lps). for in vivo investigations, balb/c mice were intratracheally administered with lps for 24 hours after injection of mlee (0.3, 3, and 30 mg/kg). hematoxylin and eosin staining was used for histopathology analysis of lung tissue. the phytochemical constituents of mlee were analyzed using high-performance liquid chromatography. results: in raw 264.7 cells, mlee reduced the activation of the inflammatory mediators (inducible nitric oxide synthase and cyclooxygenase-2) and the nuclear translocation of nuclear factor (nf)-κb and nuclear factor erythroid-2-related factor 2 (nrf2). the intraperitoneal injection of mlee (30 mg/kg) attenuated interstitial edema and immune cell infiltration in lps-induced acute lung inflammation. mlee also inhibited the activation of cyclooxygenase-2, nf-κb, and nrf2 in the lung tissue. conclusion: taken together, mlee exerted an anti-inflammatory effect by inhibiting inflammatory and oxidative mediators on acute lung inflammation suggesting that it might be used as a natural drug for treating acute lung inflammatory diseases.