Apigenin

Quercetin, fisetin, hesperetin, naringenin, and α-tocopherol were from Sigma-Aldrich, Darmstadt, Germany; daidzein and kaempferol from Biorbyt, Cambridge, UK; genistein and ascorbic acid from Carl Roth, Karlsruhe, Germany; luteolin from Cayman Chemicals, Ann Arbor, Michigan, US; apigenin from Selleck Chemicals, Munich, Germany; and trolox from Fluka via Sigma-Aldrich. ascorbic acid and trolox were dissolved in water, α-tocopherol in ethanol (Normapur®, VWR, Darmstadt, Germany), and the flavonoids in DMSO (Carl Roth) at 100 mmol/L for preparing stock solutions.

The following dietary compounds were purchased from Selleckchem: apigenin (Selleckchem, Cat#- S2262), baicalein (Selleckchem, Cat#- S2269), baicalin (Selleckchem, Cat#- S2268), berberine hydrochloride (Selleckchem, Cat#- S2271), Cat#- S2268), caffeic acid (Selleckchem, Cat#- S2277), dihydromyricetin (Selleckchem, Cat#- S2399), emodin (Selleckchem, Cat#- S2295), (−)-epigallacatechin gallate (Selleckchem, Cat#- 2250), gossypol acetate (Selleckchem, Cat#- S2303), hematoxylin (Selleckchem, Cat#- S2384), indirubin (Selleckchem, Cat#- S2386), kaempferol (Selleckchem, Cat#- S2314), luteolin (Selleckchem, Cat#- S2320), morin hydrate (Selleckchem, Cat#- S2325), myricetin (Selleckchem, Cat#- S2326), myricitrin (Selleckchem, Cat#- S2327), palmatine chloride (Selleckchem, Cat#- S2397) and quercetin dihydrate (Selleckchem, Cat#- S2347).

The IDECs used for cellular oxidative stress experiments were obtained from the Zhejiang Academy of Agricultural Sciences. Cell processing was performed based on our previous study [38 (link)]. Cells were pretreated with different concentrations of apigenin (0, 5, 10, 25, or 50 μM, Selleck, Houston, TX USA) for 6 h to determine the optimal treatment concentration. After pretreatment with apigenin, the cells were exposed for an additional 6 h to 400 μM H₂O₂ (Sigma, St. Louis, MO, USA) diluted in dimethyl sulfoxide (DMSO; Sigma, St. Louis, MO, USA). The concentrations of H₂O₂ were based on a previous study [38 (link)].

The human normal prostate epithelial cell line RWPE-1 and PCa cells LNCaP, C4-2, and 22Rv1 were cultured in Roswell Park Memorial Institute (RPMI) 1640 (Sigma Darmstadt, Germany) with 10% fetal bovine serum (FBS) (Gibco, Thermo Fisher Scientific, Waltham, MA, USA). All cell lines were cultured in a humid environment containing 5% CO₂ and 95% air at 37 °C. The EnzR LNCaP and C4-2 cell lines were treated with Enz at 10, 20, 30, and then 40 µM until 20 days. Then, 10 µM Enz was added to make the cells resistant to Enz. After cell culture, the cell lines were treated with apigenin, chrysin, and fisetin (SelleckChem, Houston, TX, USA). These small molecules were added to the culture medium of PCa and EnzR PCa cells according to the manufacturer's instructions.

YAP, TAZ, TEADs, GAPDH, β-Actin, CTGF, CYR61, rabbit mAb IgG control and anti-rabbit IgG (Light-Chain Specific) were purchased from Cell Signaling (Danvers, MA, United States); anti-mouse IgG and anti-rabbit IgG were purchased from Bio-Rad (Bio-Rad, Hercules, CA, United States); CD24-PE and CD44-FITC antibodies from BD Biosciences (Franklin Lakes, NJ, USA); EGF and b-FGF was purchased from PeproTech, Inc. (Rocky Hill, NJ, USA), B27 and puromycin was from Thermo Fisher Scientific, Inc. (Waltham, MA, USA). BMStbl3 competent cells were from Biomed (Beijing, China); insulin, cholera toxin, hydrocortisone, ampicillin sodium salt, sulforhodamine B (SRB), LB broth, and LB broth with agar were purchased from MilliporeSigma (Burlington, MA, USA). 8xGTIIC-luciferase was a gift from Stefano Piccolo (Addgene plasmid # 34615). Apigenin (S2262, purity >99%) was obtained from Selleckchem (Houston, USA) and dissolved in sterile-filtered dimethyl sulfoxide (DMSO; MP Biomedicals, Santa Ana, CA, USA). Final DMSO concentration was 0.1% in Apigenin- and vehicle-treated cells. All consumables and regular reagents for the experiments were purchased from VWR Life Science (Radnor, PA, USA).