O uso de plantas medicinais na prevenção do estresse oxidativo induzido por ciclofosfamida em camundongos

• Ano de defesa: 2018
• Autor(a) principal: Luiz, Tatiane Cordeiro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Mato Grosso; Brasil; Instituto de Ciências Naturais, Humanas e Sociais (ICNHS) – Sinop; UFMT CUS - Sinop; Programa de Pós-Graduação em Ciências Ambientais
• Palavras-chave em Português: Etnofarmacologia; Oxidação biomolecular; Toxicicidade; CNPQ::OUTROS::CIENCIAS; Ethnopharmacology; Biomolecular oxidation; Toxicity
• Link de acesso: http://ri.ufmt.br/handle/1/4129

Oxidative stress occurs when there is an imbalance between free radicals and antioxidant defense, generating cellular damage. Medicinal plants have been studied in order to prevent these damages. In this context, this work was carried out with two plants of different families, Carica papaya Linn (Caricaceae) and Cecropia distachya Huber (Urticaceae), known as papaya and embaúba, respectively. Both have been distinguished by their leaves presenting compounds with antioxidant potential. The objective of the present work was to investigate the chemoprotection of crude aqueous extract (CE) of C. papaya leaves and methanolic fractions of C. distachya leaves (F1 and F2) on oxidative stress in the induction model using cyclophosphamide (CP ), as well as the phytochemical characterization of these extracts by LCMS/MS. In the biological tests were evaluated the enzymatic and non-enzymatic antioxidants, oxidative damage marker, blood parameters, liver histology and antimutagenic activity. The animals received 15 days of treatment with extract (500 mg kg-1 ) or fractions (50 mg kg-1 ) and on the 15th day an intraperitoneal injection of CP (75 mg kg-1 ) or saline (0.9%) and sacrificed 24 h after the last treatment to obtain the samples. CE has shown benefits against oxidative events, inhibited lipoperoxidation and may still prevent DNA damage. Regarding the studies with F1 and F2, they presented relevant activities, stimulating the antioxidant defenses, protecting against oxidative lesions, showing hypoglycemic (F1) and antimutagenic (F2). No significant tissue changes were observed in hepatic tissue histology of all treated animals. In phytochemical analyzes by LC-MS/MS, flavonoids, quercetin-3β-D-glucoside and rutin were found in CE and F2; F1 exhibited the same flavonoids plus luteolin. CE and fractions sometimes showed toxicity, which may have occurred due to the presence of other unidentified compounds, or prolonged treatment resulted in subchronic intoxication. Therefore, the use of these plants is not advised until the causes of these events are fully elucidated. In conclusion, it can be seen that the plants have properties such as antioxidant protection, possible hypoglycemic action, antimutagenic activity, signs of erythropoietic stimulation and immunosuppression, so that future studies are necessary to identify its adequate therapeutic potential.