Dose-dependent effects of luteolin in combination with 2 IU of IFN-β upon PHA-dependent production of MMP-9 (3A) and TIMP-1 (3B) and MMP-9/TIMP-1 ratio (3C) in cell culture supernatant. PBMCs derived from MS patients were incubated in the presence of 0.2-50 μM luteolin and 0.2-10 μM luteolin in combination with 2IU IFN-β. Values of 3A and 3B expressed are a percentage of maximum response (% of control). Data is average mean ± SE of 14 MS patients. Values of MMP-9/TIMP-1 ratio were obtained by dividing each indicated concentration of MMP-9 with corresponding concentration of TIMP-1. Asterisks indicate significant differences between luteolin and luteolin in combination with 2IU of IFN-β, P < 0.05 is significant. Abbrev: Lu = luteolin.