title: Chemical and biological activity of leaf extracts of Chromolaena leivensis.
abstract: The flavonoids 3,5-dihydroxy-7-methoxy-flavanone, 3,5-dihydroxy-7-methoxyflavone and 3,5,7-trihydroxy-6-methoxyflavone were isolated from the leaves of C. leivensis. Preliminary observations in K562 cells (human erythroleukemia) using the trypan blue test, showed a 90% viability at a concentration of 100 microg/mL; however, further testing of the flavonoids at concentrations of 25, 50 and 100 microg/mL showed toxicity affecting the morphology of human erythroleukemia cells (K562) and human melanoma cells (A375). Induction of apoptosis was produced by 3,5-dihydroxy-7-methoxyflavone at 72 hours after treatment with arrest in the G2 / M phase of the cell cycle. The A375 cells treated with 50 microg/mL of 3,5-dihydroxy-7-methoxy-flavanone for 24, 48 and 72 hours, display effects on the behavior of the cell cycle. The flavonoid 3,5-dihydroxy-7-methoxyflavone has activity on the mitochondrial membrane at concentrations of 25, 50 and 100 microg/mL, at time intervals of 8 to 12 hours. The flavonoids 3,5-dihydroxy-7-methoxy-flavanone and 3,5-dihydroxy-7-methoxyflavone at a concentration of 25 microg/mL increased the expression of costimulatory molecules corresponding to the phenotype presented by mature dendritic cells with differentiation markers CD40, CD83, CD86 and HLA-DR. The two flavonoids at concentrations between 0.39 and 100 microg/mL slightly increased the proliferation of peripheral blood mononuclear cells in the presence and in the absence of phytohemagglutinin. These flavonoids at concentrations of 50 and 100 microg/mL slightly increased the proliferation of fibroblasts.
authors.affiliation: Facultad de Ciencias y Tecnología, Universidad de Ciencias Aplicadadas y Ambientales U.D.C.A, Bogota, Colombia. ruben.torrenegra@hotmail.com
authors.forename: Ruben D
authors.initials: RD
authors.lastname: Torrenegra
authors.forename: Oscar E
authors.initials: OE
authors.lastname: Rodríguez
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D036604:Chromolaena / Q000737:chemistry*; D003105:Colombia; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D005434:Flow Cytometry; D006801:Humans; D020014:K562 Cells; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D047309:Flavones; D010936:Plant Extracts