Parishin from Gastrodia elata Extends the Lifespan of Yeast via Regulation of Sir2/Uth1/TOR Signaling Pathway

Figure 2

Effects of parishin on the gene expression of SIR2 (a) in normal condition and growth of BY4741 yeast under oxidative stress conditions (b, c, and d). The change on SIR2 gene expression in yeast after treatment with parishin at doses of 0, 3, 10, and 30 μM (a). Amount of SIR2 mRNA was normalized to that of TUB1. The effects of parishin on yeast growth under oxidative stress induced by H₂O₂ (b). BY4741 yeast was incubated for 48 h after it was treated with 0, 3, 10, and 30 μM parishin or 10 μM resveratrol; then about 5 μL of the same concentration of yeast was dropped onto glucose medium agar plates containing 9 mM H₂O₂. The yeast was incubated for 3 d at 28°C and photographed. The micrographs (c) and survival rate (d) of yeast under oxidative stress condition. BY4741 yeast was incubated for 24 h after it was treated with 0, 3, 10, and 30 μM parishin or 10 μM resveratrol; then it was treated by H₂O₂ at doses of 0 or 180 mM for 3 h. Approximately 0.1 OD of yeast in each group was washed with cold PBS for three times and treated in 15% ethanol for 20 min. The treated yeast cells were incubated with propidium iodide at 10 μg/mL for 20 min after washing with PBS. Fluorescence microscope was used to observe the change of yeast cells under oxidative stress condition using an excitation wavelength of 535 nm and an emission wavelength of 615 nm. Approximately 100 cells were used to calculate the survival rate. Each experiment was performed at least three times. PC represents positive control treated with 180 mM H₂O₂ for 3 h. , , and indicate significant difference relative to the corresponding control (, , and , resp.).   represents significant difference relative to the positive control ().

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