Anti-inflammatory Activity of Methanolic Extract and an Alkaloid from Palicourea crocea (Sw.) Roem and Schult

Palicourea crocea (Sw.) Roem. and Schult., “douradinha,” are used by treat inflammation (edema). Croceaine A (PC-1) was isolated from P. crocea (MEPC) leaves and studied for its antioxidant and anti-inflammatory activity, as well as concentrations of constituents and acute toxicity. The phenols and polyphenolics compounds and HPLC/DAD were determined. The antioxidant activity were evaluated for DPPH, ABTS, and MDA. MEPC (300, 100, and 300 mg/kg) and PC-1 (10 and 30 mg/kg) were tested for anti-inflammatory effects in paw edema, pleurisy, cold sensitivity, and mechanical hyperalgesia. Acute toxicity is also described. MEPC contained high concentrations of phenolic and flavonoid compounds (≤ 800.35 mg/g), as well as caffeic acid, ferulic acid, rutin, and quercetin, revealed by HPLC-DAD analysis. MEPC displayed antioxidant activity against ABTS radicals (IC₅₀ = 68.5 μg/mL) and MDA (74%). MEPC and alkaloid PC-1 demonstrated an anti-edematogenic effect in Cg-induced paw edema in 2 and 4 h, and also significantly reduced mechanical hyperalgesia, cold response to acetone in mice, at 3 and 4 h after injection, as well as leukocyte migrationin the pleurisy model. No toxicity was detected by MEPC. For the first time, P. crocea was evaluated for its antioxidant, systemic anti-inflammatory, and anti-hyperalgesic activities.