Análise antinociceptiva, antiartrítica e de toxicidade de extratos das folhas de Doliocarpus dentatus (Aubl.) Standl

Abstract

Several experimental models have been developed to study the inflammatory process and the associated pain, hence, these models are important for the discovery of new drugs. Medicinal plants are useful sources for developing new pharmacological therapies since conventional medicines could cause many side effects. Doliocarpus dentatus (Dilleniaceae) is used in folk medicine to relieve pain related to the inflammatory process and the literature reports few evidences of analgesic and anti-inflammatory effects. Thus, the objective of the study was to assess the antinociceptive and antiarthritic and determine the toxic potential of the aqueous (EADd) and ethanolic (EEDd) extracts from leaves of D. dentatus in in vivo experimental models. Compounds were identified in EADd by UHPLC-HRMS (Ultra high-performance liquid chromatography coupled to high resolution mass spectrometry). Male and female Swiss mice and C57BL/6 male mice were used for the tests. The oral dose of 17 mg/kg EADd, calculated according to ethnopharmacological uses and doses of 30, 100 and 300 mg/kg were used to test in formalin and acetic acid-induced models of pain and behavior. EADd (100, 1000 e 2000 mg/kg) was assayed in mice by comet, micronucleus and phagocytosis tests. Doses of 30, 100 and 300 mg/kg of EEDd was tested in formalin and acetic acid-induced models of pain. EEDd (100 and 300 mg/kg) was also tested in the assays of chronic inflammation with complete Freund's adjuvant (CFA) and joint inflammation induced by zymosan. Betulinic acid of 0.3, 3 e 30 mg/kg and EEDd 100 e 300 mg/kg were used in the zimosan-induced peritonitis model. In the cell viability test (MTT), EEDd was tested at 3, 10, 30 and 90 μg/mL. In the acute toxicity test, 500, 1000 and 2000 mg/kg EEDd were administered in a single dose. Doses of 75, 150 and 300 mg/kg EEDd were administered for subacute toxicity for 28 days and behavioral parameters were analyzed. Oral treatments with EADd and EEDd significantly inhibited nociceptive sensitivity in neurogenic and inflammatory phase and decreased formalin-induced cold hypersensitivity and also prevented nociceptive behavior in the model of acetic acid-induced abdominal contortions. In the CFA model, the treatment for 21 days with EEDd significantly inhibited mechanical hyperalgesia, edema and cold response. In the same way, EEDd prevented joint inflammation (mechanical hyperalgesia, knee edema and leukocyte migration) induced by zymosan. In the peritonitis model, betulinic acid (compound present in 0.23% of the EEDd) and EEDd significantly inhibited zymosan-induced leukocyte infiltration, however, did not produce significant effects on the concentration of nitrite. In addition, in vitro treatment did not induce leukocyte cytotoxicity. In the acute toxicity test with EEDd, LD50 above 2000 mg/kg was observed. Oral treatment for 28 days with EDD did not changed in the main organs, hematological and biochemical parameters and also did not induce depression or anxiety. Genetic assays in mice treated with EADd revealed no significant differences in genotoxic cell damage and did not alter phagocytic activity or peripheral leukocyte count, indicating that EADd has no genotoxic potential. Analyzing the results, we can conclude that could act as an antinociceptive agent that does not present genotoxicity and that EEDd exhibited antiarthritic potential, with no signs of toxicity and symptoms of depression or anxiety in mice. The compounds identified at the species such as betulinic acid, trigonelline and isoquercetin may be related to the activities observed in the extracts. This study contributes to justify, in part, the popular use of D. dentatus in pain management, ensuring its safe use.