Synthesis and calculated properties of some 1,4-bis(amino)anthracene-9,10-diones

Design, synthesis and evaluation of an anthraquinone derivative conjugated to myelin basic protein immunodominant (MBP85-99) epitope: Towards selective immunosuppression

Anthraquinone type compounds, especially di-substituted amino alkylamino anthraquinones have been widely studied as immunosuppressants. The anthraquinone ring is part of mitoxandrone that has been used for the treatment of multiple sclerosis (MS) and several types of tumors. A desired approach for the treatment of MS would be the immunosuppression and elimination of specific T cells that are responsible for the induction of the disease. Herein, the development of a peptide compound bearing an anthraquinone derivative with the potential to specifically destroy the encephalitogenic T cells responsible for the onset of MS is described. The compound consists of the myelin basic protein (MBP) 85-99 immunodominant epitope (MBP_85-99) coupled to an anthraquinone type molecule (AQ) via a disulfide (S-S) and 6 amino hexanoic acid (Ahx) residues (AQ-S-S-(Ahx)₆MBP_85-99). AQ-S-S-(Ahx)₆MBP_85-99 could bind to HLA II DRB1*-1501 antigen with reasonable affinity (IC₅₀ of 56 nM) The compound was localized to the nucleus of Jurkat cells (an immortalized line of human T lymphocytes) 10 min after its addition to the medium and resulted in lowered Bcl-2 levels (apoptosis). Entrance of the compound was abolished when cells were pre-treated with cisplatin, an inhibitor of thioredoxin reductase. Accordingly, levels of free thiols were elevated in the culture supernatants of Jurkat cells exposed to N-succinimidyl 3-(2-pyridyldithio) propionate coupled to (Ahx)₆MBP_85-99 via a disulphide (SPDP-S-S-(Ahx)₆MBP_85-99) but returned to normal after exposure to cisplatin. These results raise the possibility of AQ-S-S-(Ahx)₆MBP_85-99 being used as an eliminator of encephalitogenic T cells via implication of the thioredoxin system for the generation of the toxic, thiol-containing moiety (AQ-SH). Future experiments would ideally determine whether SPDP-S-S-(Ahx)₆MBP_85-99 could incorporate into HLA II DRB1*-1501 tetramers and neutralize encephalitogenic T cell lines sensitized to MBP_85-99.

Mitoxantrone, More than Just Another Topoisomerase II Poison

Mitoxantrone is a synthetic anthracenedione originally developed to improve the therapeutic profile of the anthracyclines and is commonly applied in the treatment of breast and prostate cancers, lymphomas, and leukemias. A comprehensive overview of the drug's molecular, biochemical, and cellular pharmacology is presented here, beginning with the cardiotoxic nature of its predecessor doxorubicin and how these properties shaped the pharmacology of mitoxantrone itself. Although mitoxantrone is firmly established as a DNA topoisomerase II poison within mammalian cells, it is now clear that the drug interacts with a much broader range of biological macromolecules both covalently and noncovalently. Here, we consider each of these interactions in the context of their wider biological relevance to cancer therapy and highlight how they may be exploited to further enhance the therapeutic value of mitoxantrone. In doing so, it is now clear that mitoxantrone is more than just another topoisomerase II poison.

Anthraquinone derivative O,O'-bis-(3'-iodopropyl)-1,4-dihydroxyanthraquinone modulates immune response and improves experimental autoimmune encephalomyelitis

The present study investigated the effects of the anthraquinone derivative (O,O'-bis-(3'-iodopropyl)-1,4-dihidroxyanthraquinone - DIPDHAQ), mitoxantrone analog, in an experimental autoimmune encephalomyelitis (EAE) model. The results showed that DIPDHAQ treatment improved the clinical signs of the disease (n=10; vehicle: 3.8 ± 0.3; DIPDHAQ: 1.4 ± 0.9). The improvement was associated with a decrease of inflammatory cells, demyelination, IL-17, IFN-γ, IL-12p40, IL-6, TGF-β, CCL5 and CCL20 levels in the spinal cord. DIPDHAQ presented a low cytotoxicity when in vitro assays were performed. Therefore, the findings suggest a major role for DIPDHAQ in multiple sclerosis, disease characterized as an autoimmune inflammatory disorder against myelin proteins of the brain and spinal cord. The attenuation of inflammation and consequently improvement of clinical signs, involving a decrease of pro-inflammatory cytokines and the low cytotoxicity of DIPDHAQ, suggest that this compound could be used as an alternative treatment for autoimmune diseases in the central nervous system.