Fig. 6.

The effects of C. fistula flower extract on HA synthesis were determined using an ELISA kit. Fibroblast cells were pre-treated in serum free medium for 6 h and were further treated with or without various concentrations of the flower extract (0–200 μg/mL) for 48 h. The cultured medium was collected for ELISA and the absorbance was measured at 450 and 570 nm using a microplate reader. All assays have been performed in triplicate and the mean ± standard deviations are shown as **p < 0.01, ***p < 0.001 and ****p < 0.0001 versus the non-treated cells