Effect of luteolin on oxidative stress and inflammation in the human osteoblast cell line hFOB1.19 in an inflammatory microenvironment.

Background: Periapical lesions are characterized by periapical inflammation and damage to periapical tissues and eventually lead to bone resorption and even tooth loss. H₂O₂ is widely used in root canal therapy for patients with periapical inflammation. Luteolin possesses high anti-inflammatory, antioxidant, and anticancer potential. However, the underlying mechanism of the efficacy of H₂O₂ and luteolin on oxidative stress and inflammatory tissue has not been previously addressed. We aimed to investigate the anti-inflammatory and antioxidative effects of luteolin on H₂O₂-induced cellular oxidative inflammation.

Methods: After human osteoblasts (hFOB1.19) were treated with lipopolysaccharide (LPS), luteolin, or H₂O₂, cell proliferation was analysed by using a cell counting kit-8 (CCK-8), cell apoptosis was measured by using flow cytometry, the production of reactive oxygen species (ROS) was evaluated by using an oxidation-sensitive probe DCFH-DA ROS assay kit, and the expression of genes and proteins was detected by using reverse transcription quantitative polymerase chain reaction (RT‒qPCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA).

Results: We demonstrated that inflammation is closely related to oxidative stress and that the oxidative stress level in the inflammatory environment is increased. Luteolin inhibited the H₂O₂-induced increase in the expression of interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor α (TNF-α) and significantly repressed the H₂O₂-induced increase in ROS, as well as markedly strengthened superoxide dismutase (SOD) activity in hFOB1.19 cells. Moreover, we detected that luteolin may inhibit H₂O₂-induced hFOB1.19 cell injury by suppressing the NF-κB pathway.

Conclusion: We elucidated that luteolin protected human osteoblasts (hFOB1.19) from H₂O₂-induced cell injury and inhibited the production of proinflammatory cytokines by suppressing the NF-κB signalling pathway. Our findings provide a potential drug for treating H₂O₂-induced periodontitis and cell injury.