Becline

n-Hexane, chloroform, ethyl acetate (EtOAc), n-butanol, ethanol, and methanol were obtained from OCI (SEL, KR). Folin–Ciocalteu reagent (for total phenolics), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), dimethyl sulfoxide-d6 (DMSO, exclusive solvent for NMR), mushroom tyrosinase (EC 1.14.18.1), and ascorbic acid were obtained from Sigma Aldrich (St. Louis, MO, USA). All reagents used were of analytical grade. Phospho-CREB (p-CREB), phospho-PKA (p-PKA), AMPK, p-AKT, AKT, p-mTOR, mTOR, Becline, and LC3B were purchased from Cell Signaling (Danvers, MA, USA). Antibodies against tyrosinase (TYR), TRP-1, TRP-2, microphthalmia-associated transcription factor (MITF), CREB, PKA, α-melanocyte-stimulating hormone (α-MSH), and β-actin were purchased from Santa Cruz Biotechnology (Dallas, TX, USA). Horseradish-peroxidase-conjugated anti-mouse, anti-goat, and anti-rabbit antibodies were purchased from Invitrogen (Carlsbad, CA, USA).

WB analysis was performed as described previously^{12 (link)}. The antibodies against PCNA(Cell Signaling, 13110), HMGB1(Cell Signaling, 6893), LC3B(Cell Signaling, 12741), p62(Cell Signaling, 5114), Becline(Cell Signaling, 3495), BAX(abcam, ab32503), BCL2(Proteintech, 12789-1-AP), Cas8(abcam, ab25901), PARP1(Proteintech, 13371-1-AP), AKT(Cell Signaling, 9272), p-AKT(ser473) (Cell Signaling, 4060), p-AKT(thr308) (Cell Signaling, 13038), p-PTEN(ser380)(Cell Signaling, 9551), p-GSK-3β(ser9) (Cell Signaling, 5558), p-c-Raf(ser259) (Cell Signaling, 9421), mTOR(Cell Signaling, 2983), p-mTOR(ser2448) (Cell Signaling, 5536), p27(abcam, ab32034), p-p27(s10)(abcam, ab62364), CDK2(abcam, ab32147), CDK4(Santa Cruz, sc-23896), CyclinB1(abcam, ab181593), CyclinD1(abcam, ab134175), Cyclin E(Santa Cruz, sc-377100), NEDD4 L(Santa Cruz, sc-514954), C/EBPα(Cell Signaling, 8178) and GAPDH(Cell Signaling, 5174) were diluted in TBS containing 5% milk and 0.1% Tween 20. Signals were detected using a chemiluminescence system (Millipore, Bedford, MA, USA).