Wogonin hydrate

Wogonin hydrate, Dynasan 118, and mannitol were obtained from Sigma-Aldrich (Steinheim, Switzerland). Stearic acid and GMS were purchased from Samchun Chemical Co., Ltd. (Pyungtaek, Korea). Lecithin and poloxamer 188 were obtained from Junsei (Tokyo, Japan) and BASF (Ludwigshafen, Germany), respectively. Dialysis membrane (Membra-Cel) was purchased from Viskase, Inc. (Chicago, IL, USA).

DMEM F12 (Dulbecco’s Modified Eagle’s Medium: Nutrient Mixture F-12, (BE)12-708), HBSS (Hank’s Balanced Salt Solution, BE10-547F), FBS (fetal bovine serum, BI Biological Industries, 04-007-1A), ultraglutamine 1 (Bio Whittaker, BE 17-605E/U1), and gentamicin sulfate were purchased from Lonza (17-518Z, Basel, Switzerland). Accutase™ Cell Detachment solution was obtained from BD Biosciences (BD 561527, Franklin Lakes, NewJersey, USA). Alexa Fluor^® 488 Annexin V/Dead Cell Apoptosis Kit was from Thermofisher (V 13245), TrypLE™ Express was from Gibco (cat. 12604054, Waltham, MA, USA), celastrol (>98% purity), was purchased from Cayman Chemical Company (Item No. 70950, AnnArbor, MI, USA). DMSO (D2650), melatonin (M5250), wogonin hydrate (W0769), irinotecan hydrochloride (1347609) and MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, M5655) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Isopropanol (117515002) was from Chempur (Poland).

In the present study, the compounds irinotecan, wogonin, Celastrol, and melatonin were examined. The following were purchased from Sigma-Aldrich (St. Louis, MO, USA): irinotecan hydrochloride, wogonin hydrate, and melatonin. Celastrol was purchased from Cayman Chemical Company (Ann Arbor, MI, USA). Wogonin, irinotecan, and Celastrol were dissolved in DMSO as a 10 mM stock solution and stored at −20 °C. Melatonin was dissolved in DMSO as a 2 M stock solution and stored at −20 °C. Further dilution was performed in cell culture media. Cells were treated with 2 mM of melatonin, 5 or 20 µM of irinotecan, 1.25 or 0.625 µM of Celastrol, and 25 or 50 µM of wogonin. The final DMSO concentration in the cell culture did not exceed 0.5% in the highest concentration of the compounds.