Doyerea emetocathartica: espécie vegetal da Caatinga rica em Saponinas apresentou forte atividade analgésica e anti-inflamatória.

Abstract

Doyerea emetocathartica is a plant from the Cucurbitaceae family used by communities in northeastern Brazil to combat inflammation and pain. The study aimed to isolate and identify chemical compounds from the aqueous extract (DEAQ) and ethyl acetate phase (FAcoEt) of the stems of D. emetocathartica, as well as evaluating the acute oral toxicity, mutagenicity and in vivo analgesic and anti-inflammatory properties of DEAQ. Chromatographic techniques were used to fractionate DEAQ and FAcOEt and Nuclear Magnetic Resonance (NMR) to identify the compounds. In addition, mass spectrometry was used to determine the chemical profile of DEAQ. Acute oral toxicity was assessed for 14 days after administration of DEAQ at a dose of 2000 mg/kg. In addition, the micronucleus test on erythrocytes in peripheral blood of mice was carried out. The anti-inflammatory and analgesic activity of DEAQ was evaluated at doses of 25, 50 and 100 mg/kg. The analgesic activity was evaluated through the model of abdominal contortions induced by acetic acid and nociception induced by formalin while the anti-inflammatory evaluation was conducted in models of paw edema, peritonitis and air pocket induced by carrageenan. Using chromatographic and spectroscopic techniques, it was possible to isolate and identify the saponins from FAcOEt: cayaponoside C5B, cayaponoside B5, the 6,7 dehydrofevicordin A, cayaponoside A 5 and cayaponoside D2, while DEAQ cayaponoside D2. the in vivo tests results indicate no evidence of acute oral toxicity or mutagenicity. DEAQ promoted analgesia, with doses of 50 and 100 mg/kg, reducing writhing by 49,6 and 69,6%, respectively. The formalin test occurred predominantly during the inflammatory phase, reducing licking time at doses of 50 and 100 mg/kg to 59.7 and 83.6%, respectively. Treatment with DEAQ at doses of 25, 50 and 100 mg/kg reduced the paw oedema by 32,63, 52,93 and 64,43 % in 4 h, respectively. In the peritonitis assay DEAQ reduced the migration of leukocytes by (37,59 - 66,52%), neutrophils (36,76 - 66,91%), TNF-α (20,62 - 53,66%) and IL-1β (5,42 - 40,6%). Similarly, in the air pocket test, the same doses reduced leukocyte migration by 31.08,58.49 and 76.25%, respectively. The isolation of the 29-norcucurbitacins favors the development of new research aimed at evaluating the toxic and pharmacological profile of this class of molecules, as well as expanding the collection of chemotaxonomic information about the species. The results obtained from the in vivo tests indicate that DEAQ has potential analgesic and anti-inflammatory activity with the possible involvement of cayaponoside D2, with low acute toxicity for the dose and route used.