Shahrekord University of Medical Sciences Journal of Herbmed Pharmacology 2345-5004 13 1 2024 01 01 Magnolia kobus DC leaf ethanol extract alleviated lipopolysaccharide-induced acute lung inflammation by suppressing NF-κB and Nrf2 signaling 90 100 10.34172/jhp.2024.48116 EN Yeyoung Kim https://orcid.org/0000-0001-6597-3602 Soyoung Lee https://orcid.org/0000-0002-9949-6477 Young-Ae Choi https://orcid.org/0000-0001-6359-5492 Jae-Min Chung https://orcid.org/0000-0002-2942-6641 Eun-Nam Kim https://orcid.org/0000-0001-7473-1453 Byungheon Lee https://orcid.org/0000-0003-4561-1027 Sang-Yong Kim https://orcid.org/0000-0002-1819-5913 Gil-Saeng Jeong https://orcid.org/0000-0002-1882-0256 Sang-Hyun Kim https://orcid.org/0000-0002-6160-7354 Journal Article 10.34172/jhp.2024.48116 2023 05 26 2023 07 25 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.