Antioxidant, anti-rheumatic and anti-inflammatory investigation of extract and dicentrinone from Duguetia furfuracea (A. St.-Hil.) Benth. & Hook. f.

Ethnopharmacological relevanceThe preparations of teas and syrups using Duguetia furfuracea have been used in folk medicine to treat rheumatism and back pain. Several rheumatic diseases are anti-inflammatory and are treated with several anti-inflammatories.Aim of the studyThe objective of this work were to evaluate the chemical investigation of methanolic extract obtained from leaves of D. furfuracea (MEDF) and test the MEDF, such as chloroform (CF), ethyl acetate (EAF) and hydromethanol (HMF) fractions and the alkaloid dicentrinone (DF-1) in vitro antioxidant effects and in vivo models of inflammation.Material and methodsMEDF and CF were analyzed by LC-PDA and the results revealed the presence of alkaloid aporphine and oxoaporphine. The concentrations of total phenols, flavonoids and flavonols were determined. Additionally, MEDF, fractions and dicentrinone were evaluated free radical scavenging activity 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and peroxidation β-carotene/linoleic acid and malondialdehyde (MDA) assays. The anti-inflammatory effects of MEDF, fractions and dicentrinone were studied in carrageenan-induced paw edema. The anti-rheumatic potential was studied in air pouch model and zymosan-induced arthritis.ResultsCF fractionation resulted in the isolation of the oxaporphine alkaloid dicentrinone (DF-1). The highest phenols (624.37 mg GAE/g extract), flavonoids (580.51 mg QE/g extract) and flavonols (254.44 mg QE/g extract), concentration was found in extract. In antioxidant tests, MEDF exhibited the highest scavenging activity and lipoperoxidation. The extract (30-300 mg/kg) and all tested fractions inhibited the edema induced by carrageenan. The oral administration of DF-1 inhibited both edema associated with carrageenan-induced inflammation in mice. In air pouch model of inflammation, MEDF (30-300 mg/kg) and DF-1 (100 mg/kg) inhibited leukocyte migration and plasmatic leakage induced by carrageenan in mice. Finally, MEDF (100 mg/kg) did not alter zymozan-induced arthritis in mice.ConclusionThe results showed that D. furfuracea exhibits antioxidant, anti-rheumatic potential and anti-inflammatory activity. The presence of the alkaloid dicentrinone in extract and CF fraction could be responsible, at least in part, for the observed effects.

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