The therapeutic potential of ACS84 in PD treatment.was changed to non-serum medium and incubated for another 12 h before treatment with ACS84, L-Dopa or NaHS for 1? h.Cell Viability Assay Materials and MethodsThe experimental protocol was approved by the Institutional Animal Care and Use Committee (IACUC) of National University of Singapore. All animal works were carried out strictly in accordance with IACUC regulations. Cell viability was measured using the MTT PD-168393 site reduction assay as described previously [21]. At the end of each treatment, MTT was added to each well at a final concentration of 0.5 mg?mL21 and the cells were further incubated at 37uC for 4 h. The insoluble formazan was dissolved in dimethyl sulphoxide. Colorimetric determination of MTT reduction was measured at 570 nm with a reference wavelength of 630 nm.Chemicals and ReagentsAll chemicals, antibodies for detecting tyrosine hydroxylase and LDH assay kit were purchased from Sigma (Sigma, St. Louis, MO). Antibodies for detecting Nrf-2 were purchased from Santa Cruz Biotechnology (Santa Cruz, CA). The Glutathione Assay Kit, TBARS Assay Kit and Superoxide Dismutase Assay Kit were purchased from Cayman Chemical (Ann Arbor, Michigan). ACS84 was prepared as previously described [25].Lactate Dehydrogenase (LDH) Release AssayAt the end of treatment, cell culture medium was collected and briefly centrifuged. The supernatants were transferred into wells in 96-well plates. Equal amounts of lactate dehydrogenase assay substrate, enzyme and dye solution 
were mixed. A half BIBS39 site volume of the above mixture was added to one volume of medium supernatant. After incubation at room temperature for 30 min, the reaction was terminated by the addition of 1/10 volume of 1N HCl to each well. Spectrophotometrical absorbance was measured at a wavelength of 490 nm and reference wavelength of 690 nm.Cell Culture and TreatmentThe human neuroblastoma cell line, SH-SY5Y, was obtained from the American Type Culture Collection (Manassas, VA, USA). Cells were maintained in Dulbecco’s modified Eagle’s Medium (DMEM) supplemented with 10 foetal bovine serum (FBS) and 0.05 U?mL-1 penicillin and 0.05 mg/ml streptomycin at 37uC in a humidified atmosphere containing 5 CO2/95 air. Cells were plated onto 96-well plates for viability tests and ROS generation assay, or 35 mm dishes and incubated overnight. Regular medium was replaced with low-serum medium (0.5 FBS/DMEM) before treatment. For Nrf-2 translocation, mediumReactive Oxygen Species (ROS) MeasurementFormation of reactive oxygen species (ROS) was evaluated using non-fluorescent dye 29, 79- dichlorofluorescin diacetate (DCFHDA), which freely penetrates cells and yields the highly fluorescent product dichlorofluorescein (DCF) by ROS oxidation. Following ACS84, L-Dopa or NaHS treatment, cells were rinsed with PBS solution and incubated with Hank’s Buffered Salt Solution (HBSS) containing DCFH-DA dye (10 mM final concentration)Protective Effect of ACS84 a PD ModelFigure 2. Protective effect of ACS84 against cell injury induced by 6-OHDA in SH-SY5Y cells. (A ): Dose dependent effects of ACS84 on (A) cell viability and (B) LDH release in the 6-OHDA-treated (50 mM) SH-SY5Y cells. Cells were pretreated with ACS84 at different concentrations for 1 h before the addition of 6-OHDA. The results were obtained at 12 h (MTT assay) or 6 h (LDH release assay) after the treatment with 6-OHDA. (C ): Effect of ACS84, L-Dopa and NaHS at 10 mM on cell viability (C) and LDH release (D.The therapeutic potential of ACS84 in PD treatment.was changed to non-serum medium and incubated for another 12 h before treatment with ACS84, L-Dopa or NaHS for 1? h.Cell Viability Assay Materials and MethodsThe experimental protocol was approved by the Institutional Animal Care and Use Committee (IACUC) of National University of Singapore. All animal works were carried out strictly in accordance with IACUC regulations. Cell viability was measured using the MTT reduction assay as described previously [21]. At the end of each treatment, MTT was added to each well at a final concentration of 0.5 mg?mL21 and the cells were further incubated at 37uC for 4 h. The insoluble formazan was dissolved in dimethyl sulphoxide. Colorimetric determination of MTT reduction was measured at 570 nm with a reference wavelength of 630 nm.Chemicals and ReagentsAll chemicals, antibodies for detecting tyrosine hydroxylase and LDH assay kit were purchased from Sigma (Sigma, St. Louis, MO). Antibodies for detecting Nrf-2 were purchased from Santa Cruz Biotechnology (Santa Cruz, CA). The Glutathione Assay Kit, TBARS Assay Kit and Superoxide Dismutase Assay Kit were purchased from Cayman Chemical (Ann Arbor, Michigan). ACS84 was prepared as previously described [25].Lactate Dehydrogenase (LDH) Release AssayAt the end of treatment, cell culture medium was collected and briefly centrifuged. The supernatants were transferred into wells in 96-well plates. Equal amounts of lactate dehydrogenase assay substrate, enzyme and dye solution were mixed. A half volume of the above mixture was added to one volume of medium supernatant. After incubation at room temperature for 30 min, the reaction was terminated by the addition of 1/10 volume of 1N HCl to each well. Spectrophotometrical absorbance was measured at a wavelength of 
490 nm and reference wavelength of 690 nm.Cell Culture and TreatmentThe human neuroblastoma cell line, SH-SY5Y, was obtained from the American Type Culture Collection (Manassas, VA, USA). Cells were maintained in Dulbecco’s modified Eagle’s Medium (DMEM) supplemented with 10 foetal bovine serum (FBS) and 0.05 U?mL-1 penicillin and 0.05 mg/ml streptomycin at 37uC in a humidified atmosphere containing 5 CO2/95 air. Cells were plated onto 96-well plates for viability tests and ROS generation assay, or 35 mm dishes and incubated overnight. Regular medium was replaced with low-serum medium (0.5 FBS/DMEM) before treatment. For Nrf-2 translocation, mediumReactive Oxygen Species (ROS) MeasurementFormation of reactive oxygen species (ROS) was evaluated using non-fluorescent dye 29, 79- dichlorofluorescin diacetate (DCFHDA), which freely penetrates cells and yields the highly fluorescent product dichlorofluorescein (DCF) by ROS oxidation. Following ACS84, L-Dopa or NaHS treatment, cells were rinsed with PBS solution and incubated with Hank’s Buffered Salt Solution (HBSS) containing DCFH-DA dye (10 mM final concentration)Protective Effect of ACS84 a PD ModelFigure 2. Protective effect of ACS84 against cell injury induced by 6-OHDA in SH-SY5Y cells. (A ): Dose dependent effects of ACS84 on (A) cell viability and (B) LDH release in the 6-OHDA-treated (50 mM) SH-SY5Y cells. Cells were pretreated with ACS84 at different concentrations for 1 h before the addition of 6-OHDA. The results were obtained at 12 h (MTT assay) or 6 h (LDH release assay) after the treatment with 6-OHDA. (C ): Effect of ACS84, L-Dopa and NaHS at 10 mM on cell viability (C) and LDH release (D.