title: Antioxidant and cytotoxic effects of crude extract, fractions and 4-nerolidylcathecol from aerial parts of Pothomorphe umbellata L. (Piperaceae).
abstract: The crude ethanolic extract from aerial parts of Pothomorphe umbellata L. (Piperaceae) and fractions obtained by partitions sequentially among water-methanol, methylene chloride, and ethyl acetate, as well as the major constituent, 4-nerolidylcatechol, were, respectively, evaluated and evidenced for antioxidant and cytotoxic effects through fluorometric microplate and microculture tetrazolium assays in HL-60 cells. The crude ethanolic extract demonstrated the preeminent antioxidant activity (IC50 = 1.2  μg/mL) against exogenous cytoplasmic reactive oxygen species, followed by the water-methanolic (IC50 = 4.5  μg/mL), methylene chloride (IC50 = 5.9  μg/mL), ethyl acetate (IC50 = 8.0  μg/mL), 4-nerolidylcatechol (IC50 = 8.6  μg/mL), and the sterol fractions (IC50 > 12.5  μg/mL). Vitamin C, the positive control used in this assay, presented IC50 value equivalent to 1.7  μg/mL. 4-Nerolidylcatechol (IC50 = 0.4  μg/mL) and methylene chloride fraction (IC50 = 2.3  μg/mL) presented considerable cytotoxicity probably because of the presence of an o-quinone, an auto-oxidation by product of the catechol. Polar compounds, present in the ethanol extract, appear to increase the solubility and stability of the major active constituent, acting synergistically with 4-nerolidylcatechol, improving its pharmacokinetic parameters and increasing significantly its antioxidant activity which, in turn, suggests that the aqueous-ethanolic extract, used in folklore medicine, is safe and effective.
authors.affiliation: Departamento de Ciências Exatas e da Terra, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, São Nicolau Street 210, 09972-270 Diadema, SP, Brazil.
authors.forename: Andrey P
authors.initials: AP
authors.lastname: Lopes
authors.forename: Bianca S
authors.initials: BS
authors.lastname: Bagatela
authors.forename: Paulo C P
authors.initials: PC
authors.lastname: Rosa
authors.forename: Dhammika N P
authors.initials: DN
authors.lastname: Nanayakkara
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Tavares Carvalho
authors.forename: Edson L
authors.initials: EL
authors.lastname: Maistro
authors.forename: Jairo K
authors.initials: JK
authors.lastname: Bastos
authors.forename: Fábio F
authors.initials: FF
authors.lastname: Perazzo
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000378:metabolism; D002396:Catechols / Q000032:analysis / Q000494:pharmacology*; D003593:Cytoplasm / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D009682:Magnetic Resonance Spectroscopy; D010100:Oxygen / Q000378:metabolism; D026321:Piperaceae / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry; D011809:Quinones / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: C110583:4-nerolidylcatechol; D000975:Antioxidants; D002396:Catechols; D010936:Plant Extracts; D011809:Quinones; D017382:Reactive Oxygen Species; D001205:Ascorbic Acid; D010100:Oxygen