Atividade antioxidante, anti-inflamatoria e anti-hiperalgesica do extrato metanólico e do alcaloide indólico monoterpênico de Palicourea crocea (SW.) Schult

Abstract

Objectives: Palicourea crocea showed promising results in chemical investigations, which include the isolation of alkaloids; however, no biological analyses have been conducted so far to evaluate the antioxidant, anti-inflammatory and antinociceptive properties. Methods: The chemical composition of the methanolic extract from P. crocea leaves (MEPC) were investigated using high performance liquid chromatography (HPLC/PAD) method, and the concentrations of total phenolics, flavonoids, flavonols and condensed tannins also were determined, so is the isolation the principal alkaloid (PC-1) of this plant. The antioxidant activity of the MEPC and PC-1 were evaluated for free radical scavenging activity using the DPPH and ABTS; lipid peroxidation using malondialdehyde (MDA). MEPC (300, 100 and 50 mg/kg) and PC-1 (50 and 10 mg/kg) also were tested in anti-inflammatory effects in carrageenan-induced mice paw edema and anti-hyperalgesic for cold sensitivity and mechanical hyperalgesia. Key findings: MEPC showed highest concentrations of phenolic and flavonoids compounds (≤ 800.35 mg/g), revealed by HPLC-PDA analysis the caffeic acid, ferulic acid, rutin and quercetin. The MEPC displayed potent antioxidant activity for ABTS radical (IC50 = 68.5 µg/ mL) and MDA (74%). The oral administration of the MEPC (300, 100 and 50 mg/kg) and croceaine A alkaloid PC-1 (50 and 10 mg/kg) exhibited an anti-oedematogenic effect in Cg-induced paw oedema in 2 and 4h. Also reduced significantly the mechanical hyperalgesia and the cold response to acetone in mice, at 3 and 4 h after injection. Conclusions: For the first time, evaluating antioxidant and systemic anti-inflammatory and antihyperalgesic activities from P. crocea.