Green Tea Extract Reduced Lipopolysaccharide-Induced Inflammation in L2 Cells as Acute Respiratory Distress Syndrome Model Through Genes and Cytokine Pro-Inflammatory

Background: Acute Respiratory Distress Syndrome (ARDS) is a severe lung inflammatory condition that has the capacity to impair gas exchange and lead to hypoxemia. This condition is found to have been one of the most prevalent in patients of COVID-19 with a more serious condition. Green tea (Camellia sinensis L.) contains polyphenols that possess many health benefits. The purpose of this study was to assess the anti-inflammatory activities of green tea extract in Lipopolysaccharide (LPS)-induced lung cells as ARDS cells model. Methods: In this study, rat lung cells (L2) were induced by LPS to mimic the inflammation observed in ARDS and later treated with green tea extract. Pro-inflammatory cytokines such as Interleukin (IL)-12, C-Reactive Protein (CRP) as well as Tumor Necrosis Factor-α (TNF-α) were investigated using the ELISA method. Gene expression of NOD-Like Receptor Protein 3 (NLRP-3), Receptor for Advanced Glycation End-product (RAGE), Toll-like Receptor-4 (TLR-4), and Nuclear Factor-kappa B (NF-κB) were evaluated by qRTPCR. Apoptotic cells were measured using flow cytometry. Results: The results showed that green tea extract treatment can reduce inflammation by suppressing gene expressions of NF-κB, NLRP-3, TLR-4, and RAGE, as well as pro-inflammatory cytokines such as IL-12, TNF-α, and CRP, an acute phase protein. Apoptosis levels of inflamed cells also found to be lowered when green tea extract was administered; thus, also increasing live cells compared to non-treated cells. Conclusion: These findings could lead to the future development of supplements from green tea to help alleviate ARDS symptoms, especially during critical moments such as the current pandemic.