Fig. 5.

The effects of C. fistula flower extract on MMP-2 activity were determined using gelatin zymography. Fibroblast cells were cultured in DMEM serum-free medium for 24 h and the culture supernatant was subjected to 10% polyacrylamide gels containing 0.1% w/v of gelatin under non-reducing conditions. The gels were incubated with or without various concentrations of red rice extract (0–200 μg/mL) and were then stained with Coomassie Brillant Blue R. The digestion bands were quantitated by the Image J program. All assays have been performed in triplicate and the mean ± standard deviations are shown as *p < 0.05, ***p < 0.001 and ****p < 0.0001 versus the non-treated culture supernatant