The analgesic drug dipyrone is used to treat side effects (including pain and fever) of cancer chemotherapeutic agents. Dipyrone is metabolized to 4-aminoantipyrine (4-AA), a PGE2-dependent blocker and inhibitor of cyclooxygenase (COX). We evaluated the genotoxic, mutagenic, apoptotic, and immunomodulatory activities of 4-AA in vivo and the effects of its combination with the antineoplastic drugs doxorubicin, cisplatin, and cyclophosphamide. 4-AA did not cause genotoxic/mutagenic damage, splenic phagocytosis, or leukocyte alterations. However, when combined with the antineoplastic agents, 4-AA decreased their genotoxic, mutagenic, apoptotic, and phagocytic effects. These results suggest that 4-AA might interfere with DNA damage-mediated chemotherapy.

The increased incidence of cancer and its high treatment costs have encouraged the search for new compounds to be used in adjuvant therapies for this disease. This study discloses the synthesis of (Z)-4-((1,5-dimethyl-3-oxo-2-phenyl-2,3dihydro-1H-pyrazol-4-yl) amino)-4-oxobut-2-enoic acid (IR-01) and evaluates not only the action of this compound on genetic integrity, increase in splenic phagocytosis and induction of cell death but also its effects in combination with the commercial chemotherapeutic agents doxorubicin, cisplatin and cyclophosphamide. IR-01 was designed and synthesized based on two multifunctionalyzed structural fragments: 4-aminoantipyrine, an active dipyrone metabolite, described as an antioxidant and anti-inflammatory agent; and the pharmacophore fragment 1,4-dioxo-2-butenyl, a cytotoxic agent. The results indicated that IR-01 is an effective chemoprotector because it can prevent clastogenic and/or aneugenic damage, has good potential to prevent genomic damage, can increase splenic phagocytosis and lymphocyte frequency and induces cell death. However, its use as an adjuvant in combination with chemotherapy is discouraged since IR-01 interferes in the effectiveness of the tested chemotherapeutic agents. This is a pioneer study as it demonstrates the chemopreventive effects of IR-01, which may be associated with the higher antioxidant activity of the precursor structure of 4-aminoantipyrine over the effects of the 1,4-dioxo-2-butenyl fragment.

Despite rapid advances in both the early detection and treatment of cancer, the mortality from this disease remains high, which justifies the development of new products that are more selective and effective and have fewer side effects. Accordingly, a novel ester was synthesized that contains two pharmacophores with important biological activities: (I) 4-aminoantipyrine, which has anti-inflammatory and antioxidant effects, and (II) the pharmacophore 1,4-dioxo-butenyl, which has cytotoxic activity. When administered alone, this compound is non-genotoxic, and it does not cause an increasing in splenic phagocytosis. Nevertheless, it can induce cell death. When administered in combination with commercial chemotherapeutic agents, such as doxorubicin, cisplatin, and cyclophosphamide, the ester shows antigenotoxic activity and decreases phagocytosis and reduces the potential to cause cell death. These results indicate that the compound should not be used in combination with chemotherapeutic agents that exert their effect through DNA damage, an important feature of antitumor drugs.

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ABSTRACT. Phosphatidylcholine is the main phospholipid present in cell membranes and in lipoproteins, and can interfere with various biological processes. This lipid also has antioxidant activity, and protects against damage caused by free radicals under conditions of ischemia/reperfusion. Therefore, the present study was designed to evaluate toxicogenetic damage caused by twisting of the spermatic cord in ischemia/reperfusion, and whether phosphatidylcholine plays a role in conditions of ischemia/reperfusion in preclinical trials. The results indicate that spermatic cord torsion does not cause genotoxic damage or mutagenesis. A dose of 300 mg/kg of phosphatidylcholine is toxic and is thus not recommended. However, a dose of 150 mg/kg does not promote toxicogenetic damage, and though it does not statistically prevent tissue damage occurring from lack of oxygenation and nutrition of testicular cells, it has a tendency to reduce this damage. Therefore, this research suggests that further studies should be conducted to clarify this tendency and to provide a better explanation of the possible therapeutic effects of phosphatidylcholine in cytoprotection of germ cells affected by ischemia/reperfusion.

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Cancer incidence is increasing, and the drugs are not very selective. These drugs cause adverse effects, and the cells become resistant. Therefore, new drugs are needed. Here, we evaluated the effects of ZIM, a candidate for chemotherapy, and 4-AA alone and in association with commercial chemotherapeutic agents. Subsequently, the results of ZIM and 4-AA were compared. Male Swiss mice were treated with doses of 12, 24, or 48 mg/kg ZIM or 4-AA alone or in association with cisplatin (6 mg/kg), doxorubicin (16 mg/kg), and cyclophosphamide (100 mg/kg). Biometric parameters, DNA damage (comet and micronuclei), cell death, and splenic phagocytosis were evaluated. DNA docking was also performed to confirm the possible interactions of ZIM and 4-AA with DNA. 4-AA has been shown to have low genotoxic potential, increase the frequency of cell death, and activate phagocytosis. ZIM causes genomic and chromosomal damage in addition to causing cell death and activating phagocytosis. In association with chemotherapeutical agents, both 4-AA and ZIM have a chemopreventive effect and, therefore, reduce the frequency of DNA damage, cell death, and splenic phagocytosis. The association of 4-AA and ZIM with commercial chemotherapeutic agents increased the frequency of lymphocytes compared to chemotherapeutic agents alone. Molecular docking demonstrated that ZIM has more affinity for DNA than 4-AA and its precursors (1 and 2). This was confirmed by the lower interaction energy of the complex (−119.83 kcal/mol). ZIM can break the DNA molecule and, therefore, its chemotherapeutic effect can be related to DNA damage. It is considered that ZIM has chemotherapeutic potential. However, it should not be used in combination with cisplatin, doxorubicin, and cyclophosphamide as it reduces the effects of these drugs.