Fig 3. Induction of IL8 gene expression in human chondrocytes treated with P. semirufa bristle extract is time- and dose-dependent.

Human chondrocytes (1 × 10⁵ cells/well, four wells per biological replicate) were treated with PBS buffer, IL-1β, or bristle extract (60 μg/mL) for 1 (A), 6 (B) and 24 (C) hours. The cells were then collected, and total RNA was extracted using TRIzol. Relative mRNA quantification was performed using RT-qPCR. All experiments were conducted in biological triplicates and technical duplicates, with values presented as the mean ± SEM normalized to GAPDH and RPL13A as endogenous controls. Data were analyzed using an unpaired t-test, with significance levels indicated as (**) p < 0.01, and (***) p < 0.001.