Nootkatone Mitigates LPS-Induced Acute Lung Injury via modulation of NF-κB and Nrf2 Pathway in mice

D D V HANUMAN¹Anil Kumar Banothu^1*Kala Kumar Bharani¹Ravikumar Yadala²Amit Khurana¹Ambica Gadige³Nagarjuna Gandam¹

• ¹Department of Veterinary Pharmacology and Toxicology, College of Veterinary Science, P.V. Narsimha Rao Telangana Veterinary University, Hyderabad, India
• ²Department of Veterinary Pathology, College of Veterinary Science, P.V. Narsimha Rao Telangana Veterinary University, Hyderabad, Andhra Pradesh, India
• ³Department of Veterinary Medicine, College of Veterinary Science, P.V. Narsimha Rao Telangana Veterinary University, Hyderabad, Andhra Pradesh, India

Acute lung injury is a serious acute injury which may threaten the life of the patient. Nootkatone is a promising phytochemical with antioxidant and anti-inflammatory properties. The current research aimed to explore the anti-inflammatory properties of nootkatone, both in vitro using Raw 264.7 macrophages, and in vivo through intraperitoneal administration at doses of 50 and 100 mg/kg for seven days. Animals were divided into five groups: normal control (NC), disease control (DC; LPS 10 µg/kg, oropharyngeal), Nootkatone low dose (NLD; 50 mg/kg, i.p. for 7 days + LPS), Nootkatone high dose (NHD; 100 mg/kg, i.p. for 7 days + LPS), and Nootkatone per se (NPS; 100 mg/kg Nootkatone alone). The study focused on assessing its efficacy against lipopolysaccharide (LPS)-induced lung damage in mice, where LPS was administered at a dose of 10 µg/kg through oropharyngeal route. Concentrations of nootkatone up to 50 µM were considered safe, with a modest decrease in cell viability. Various nootkatone doses were found to mitigate LPS-induced inflammation in Raw 264.7 macrophage cells, as indicated by changes in inflammatory cytokines such as IL-10 and TNF-α. We observed significant (p<0.05) alteration in absolute and relative lung weights, and haematological profile. The levels of cytokines (IL-6; TNF-α; IL-1β; IL-22; IL-17; IFN-γ; TGF-β1 and IL-10) were significantly modulated in the Nootkatone Low Dose (50 mg/kg) and Nootkatone High Dose (100 mg/kg) treatment groups . Further, the levels of malondialdehyde and nitrite were significantly lower in these groups compared to the Disease control groupsthe . The histological damage was reversed in the as compared to the disease control group. Interestingly, the immunohistochemical expression of Nrf-2, NF-κB, TNF-α and COX-2 demonstrated the potent anti-inflammatory effects of nootkatone. This study presents a comprehensive evaluation suggesting that nootkatone may serve as a potential candidate for further research in managing pulmonary inflammation.