You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Induction of apoptosis in human ovarian cancer cells by new anticancer compounds, epothilone A and B. Epothilones are a new group of compounds with action mechanisms similar to taxanes. The aim of this study was to compare the effects of epothilone A (Epo A) and epothilone B (Epo B) on ovarian cancer cell line SKOV-3 with those of paclitaxel (PTX), a classic taxane. We evaluate glycoprotein P (P-gp) activity in the ovarian cancer cell line. Apoptotic and necrotic cell levels were measured by double staining with Hoechst 33258 and propidium iodide (PI) as well as Annexin V staining. The production of reactive oxygen species (ROS) and changes in mitochondrial membrane potential (ΔΨm) in cells exposed to Epo A, Epo B and PTX were studied using specific fluorescence probes, DCFH(2)-DA (2',7'-dichlorodihydrofluorescein diacetate) and JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine). The cytotoxic activity of the drugs was determined by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide) test. All probes were analyzed in both the presence and absence of the antioxidant N-acetylcysteine (NAC). The results obtained demonstrated that the antiproliferative capacity of Epo A and Epo B in SKOV-3 cell line (measured as IC(50) after 72 h continuous treatment) was six and five times greater than that of PTX's respectively. Epothilones induced timecourse-dependent apoptosis and necrosis. Apoptotic and necrotic events were partially blocked by NAC, indicating ROS played a substantial role in epothilone-induced apoptosis. Cell death was also associated with a decrease in mitochondrial membrane potential, which was more pronounced after treatment with epothilones as compared to paclitaxel.
{"Chemical": ["3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide", "taxanes", "epothilone A", "epothilones", "NAC", "JC-1", "taxane", "epothilone", "epothilone A and B", "epothilone B", "Epothilones", "N-acetylcysteine", "Hoechst 33258", "DCFH(2)-DA", "oxygen", "propidium iodide", "5,5\u0027,6,6\u0027-tetrachloro-1,1\u0027,3,3\u0027-tetraethylbenzimidazolcarbocyanine", "paclitaxel", "Epo B", "2\u0027,7\u0027-dichlorodihydrofluorescein diacetate", "Epo A", "PTX", "MTT"]}