Fig. 3.

Effect of R. officinalis polyphenols on the expressions of Hsp90, Vcp, HYOU1, NDK mRNAs in PC12 cells. GAPDH was used as reference (housekeeping genes). The mRNA expression of all genes was normalized by GAPDH mRNA expression and expressed as ratio of Ctrl. PC12 cells were treated with 30 μM luteolin, 20 μM carnosic acid, 15 μM rosmarinic acid and 50 ng/mL NGF for 6 and 12 h. Each bar represents the mean ± SD of three independent experiments. *p < 0.05 treatment versus control (Student’s t-test)