Dihydrokaempferol attenuates LPS-induced inflammation and apoptosis in WI-38 cells.

Background: Globally, pneumonia has been associated as a primary cause of mortality in children aged less than 5 years. Dihydrokaempferol (DHK) has been proposed for being correlated with the process of various diseases. Nevertheless, whether DHK has a role in the progression of infantile pneumonia remains unclear. This study aimed at exploring whether DHK was involved in the progression of infantile pneumonia.

Methods: Human fibroblast cells WI-38 were treated with lipopolysaccharide (LPS). The viability of WI-38 cells was measured via Cell counting kit-8. Reverse transcription-quantitative polymerase chain reaction was used to evaluate the levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α). Western blot analysis revealed the protein levels of IL-1β, IL-6, TNF-α, Bax, and cleaved-caspase 3. Flow cytometry was applied for exploring the apoptosis of WI-38 cells. The concentrations of IL-1β, IL-6, and TNF-α were assessed via enzyme-linked-immunosorbent serologic assay.

Results: DHK modulated the viability of WI-38 cells in infantile pneumonia. Furthermore, we identified that DHK treatment inversely changed LPS induction-mediated elevation on the levels of inflammation biomarkers. Besides, DHK counteracted LPS-induced production of (ROS) in WI-38 cells. DHK also decreased LPS-induced elevation of WI-38 cells apoptosis and mediated the levels of apoptosis-associated indexes. Moreover, modulating sirtuin-1 (SIRT1) protein level was lowered by the induction of LPS, and was reversed by DHK treatment. In addition, DHK counteracted LPS induction-mediated elevation of p-p65 and phosphorylated inhibitor of nuclear factor kappa-B kinase subunit alpha (p-IκBα) protein levels.

Conclusion: DHK alleviated LPS-induced WI-38 cells inflammation injury in infantile pneumonia through SIRT1/NF-κB pathway. The results shed light on the implications of DHK on the prevention and treatment of infantile pneumonia.