title: In Vitro Antileukemic Activity of Xanthosoma sagittifolium (Taioba) Leaf Extract.
abstract: Xanthosoma sagittifolium Schott is a herb of the Araceae family, popularly known as taioba, which is consumed as food in some regions of Brazil, Africa, and Asia. This species has already been evaluated for the antifungal activities. However, based on its potential antitumor activity, the present study further aimed to examine the antitumor, as well as chelation, activity of X. sagittifolium leaf extract. Results showed that hydroethanolic extract of X. sagittifolium leaves (HEXs-L) exhibits cytotoxic effects against the immortalized line of human T-lymphocytic (Jurkat) and myelogenous (K562) leukemia cells, but not nontumor RAW 264.7 macrophages or NIH/3T3 fibroblasts. HEXs-L inhibited 50.3% of Jurkat cell proliferation, reducing by 20% cells in G2/M phase, but increasing cells in sub-G1 phase, thereby inducing apoptosis by 54%. In addition, HEXs-L inhibited NO production by 59%, as determined by Griess reaction, and chelated 93.8% of free Fe(II), as demonstrated by ferrozine assay. Phytochemical studies were carried out by ESI-MS, identifying apigenin di-C-glycosides as major compounds. Overall, this work revealed that leaf extract of Xanthosoma sagittifolium presented chelating activity and in vitro antitumor activity, arresting cell cycle and inducing apoptosis of leukemia cells, thus providing evidence that taioba leaves may have practical application in cancer therapy.
authors.affiliation: Departamento de Bioquímica, IBRAG, Centro Biomédico, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro (UERJ), Avenida Professor Manoel de Abreu 44, PAPC, 4° Andar, 20550-170 Rio de Janeiro, RJ, Brazil ; Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
authors.forename: Marina L C
authors.initials: ML
authors.lastname: Caxito
authors.affiliation: Departamento de Bioquímica, IBRAG, Centro Biomédico, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro (UERJ), Avenida Professor Manoel de Abreu 44, PAPC, 4° Andar, 20550-170 Rio de Janeiro, RJ, Brazil.
authors.forename: Rachell R
authors.initials: RR
authors.lastname: Correia
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
authors.forename: Anne Caroline C
authors.initials: AC
authors.lastname: Gomes
authors.affiliation: Departamento de Bioquímica, IBRAG, Centro Biomédico, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro (UERJ), Avenida Professor Manoel de Abreu 44, PAPC, 4° Andar, 20550-170 Rio de Janeiro, RJ, Brazil.
authors.forename: Graça
authors.initials: G
authors.lastname: Justo
authors.affiliation: Departamento de Bioquímica, IBRAG, Centro Biomédico, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro (UERJ), Avenida Professor Manoel de Abreu 44, PAPC, 4° Andar, 20550-170 Rio de Janeiro, RJ, Brazil.
authors.forename: Marsen G P
authors.initials: MG
authors.lastname: Coelho
authors.affiliation: Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
authors.forename: Cássia M
authors.initials: CM
authors.lastname: Sakuragui
authors.affiliation: Núcleo de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil.
authors.forename: Ricardo M
authors.initials: RM
authors.lastname: Kuster
authors.affiliation: Departamento de Bioquímica, IBRAG, Centro Biomédico, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro (UERJ), Avenida Professor Manoel de Abreu 44, PAPC, 4° Andar, 20550-170 Rio de Janeiro, RJ, Brazil.
authors.forename: Katia C C
authors.initials: KC
authors.lastname: Sabino