Atividade antioxidante da folha de Smilax fluminensis e da casca do caule de Caesalpinia ferrea em camundongos Swiss

Abstract

Paracetamol (PCM) is an antipyretic and analgesic medication widely used by the population, which in acceptable and recommended doses can be safe, however, if administered in high doses it can cause liver damage, leading to hepatoxicity, due to the formation of the toxic metabolite, N-acetyl-p-benzoquinone imine (NAPQI). Smilax fluminensis is popularly known as “parsley-parrilla” or “japecanga” and its species are used in folk medicine to treat various diseases, and its studies have shown antioxidant potential due to the presence of some secondary metabolites. Caesalpinia ferrea, popularly known as “pau-ferro” or “jucá” has undergone a reclassification and is now known as Libidibia ferrea and is popularly used for anti-inflammatory and analgesic purposes. The present work investigated whether the crude extract (EB) and the F1 and F2 fractions of the leaves of Smilax fluminensis and the ethanolic extract of the stem bark of Caesalpinia ferrea promoted biochemical changes in a model of oxidative stress, through a high dose of PCM, in Swiss mice. After acclimatization, the mice were divided into groups and the treatment was administered via gavage. For S. fluminensis they were divided into CONTROL (filtered water); PCM (paracetamol 250 mg kg-1 + filtered water); EB (crude extract - 250 mg kg-1 ), F1 (fraction 1 - 250 mg kg-1 ), F2 (fraction 2 - 250 mg kg-1 ), PCM + EB, PCM + F1, PCM + F2. For the administration of the ethanolic extract of C. ferrea, the mice were divided into 4 groups: CONTROL (filtered water + 0.1% Tween 80), PCM (250 mg kg-1 of PCM in a single dose + 0.1% Tween 80), PCM + EXT (250 mg kg-1 of PCM in a single dose + 100 mg kg-1 of EXT) and EXT (filtered water + 100 mg kg-1 of EXT). Initially, the oxidative stress inducer (PCM) or filtered water or 0.1% tween 80 was administered and after three hours treatment with the fractions or extracts or 0.1% tween 80 or filtered water was started. After 24 hours of the last dose of treatments, the animals were anesthetized via i.p. (intraperitoneal), cardiac puncture was performed to remove blood, and then euthanized through cervical dislocation to remove organs (liver, brain and kidneys) and the samples were frozen at -85 ºC. The data were evaluated by Anova followed by the Tukey post hoc test (p <0.05). We checked for changes in biochemical parameters such as enzyme antioxidants catalase (CAT) and glutathione-S-transferase (GST), non-enzymatic antioxidants reduced glutathione (GSH) and vitamin C, protein carbonylation (CARBONYL) and lipid peroxidation (TBARS) in liver, brain and kidney tissues. In plasma, the transaminases aspartate aminotransferase (AST) and alanine aminotransferase (ALT), glucose, triglycerides and cholesterol were evaluated. The best antioxidant effect found in the leaves of S. fluminensis was found in fraction 1 of the plant where there was a decrease in the activity of plasma AST and ALT, an increase in the activity of the enzymes CAT and GST, of the antioxidant GSH, although it increased TBARS, added decreased renal and cerebral CARBONYL and showed hypoglycemic and hypocholesterolemic action. The C. ferrea extract was able to reverse the lipid and protein damage caused by the drug in the liver tissue, causing the same effect on the renal and brain tissues in CARBONYL, decreased hepatic GST activity and increased CAT and GST brain activity, in addition to lowering glucose and cholesterol. Thus, it is believed that the good antioxidant activity observed in the extract of S. fluminensis may be due to the presence of flavonoid compounds, in this specific case, quercetin and for the extract of C. ferrea, it is probably due to the presence of tannins. Further research is needed in order to further explore the biological potential of these plants to gain more insight into their possible benefits.