Luteolin Is a Potential Immunomodulating Natural Compound against Pulpal Inflammation

Figure 4

Luteolin induces superior inhibition of TNF-α expression with less suppression of cell viability compared with C-16 and 2-AP. (a–c) The effect of protein kinase R (PKR) inhibitors (C16 and 2-AP) and luteolin on cell proliferation of DP-1 cells was validated using WST-8 assay. Control indicates both: no stimulation (Ctrl) and treatment with guaiacol-parachlorophenol (0.1 vol %). Dimethyl sulfoxide (DMSO) for C16 and luteolin or 0.5% acetic acids for 2-AP were used as mock solvent control (Mock). Proliferation activity was expressed as the absorbance at 450 nm minus the absorbance at 650 nm. (d–f) Comparison of immune-modulating effects between PKR inhibitors (C16 and 2-AP) and luteolin. After pretreatment with C16, 2-AP, and luteolin for 24 h, dental pulp (DP-1)-supernatant-induced TNF-α production in dTHP-1 cells was quantified using enzyme-linked immune sorbent assay (ELISA) (). , . . Error bars represent . Data were analyzed using independent unpaired two-tailed Student’s -tests.

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