BackgroundEnhancement of tumor cell sensitivity may help facilitate a reduction in drug dosage using conventional chemotherapies. Consequently, it is worthwhile to search for adjuvants with the potential of increasing chemotherapeutic drug effectiveness and improving patient quality of life. Natural products are a very good source of such adjuvants.MethodsThe biological activity of a fraction enriched in hydrolysable polyphenols (P2Et) obtained from Caesalpinia spinosa was evaluated using the hematopoietic cell line K562. This fraction was tested alone or in combination with the conventional chemotherapeutic drugs doxorubicin, vincristine, etoposide, camptothecin and taxol. The parameters evaluated were mitochondrial depolarization, caspase 3 activation, chromatin condensation and clonogenic activity.ResultsWe found that the P2Et fraction induced mitochondrial depolarization, activated caspase 3, induced chromatin condensation and decreased the clonogenic capacity of the K562 cell line. When the P2Et fraction was used in combination with chemotherapeutic drugs at sub-lethal concentrations, a fourfold reduction in doxorubicin inhibitory concentration 50 (IC50) was seen in the K562 cell line. This finding suggested that P2Et fraction activity is specific for the molecular target of doxorubicin.ConclusionsOur results suggest that a natural fraction extracted from Caesalpinia spinosa in combination with conventional chemotherapy in combination with natural products on leukemia cells may increase therapeutic effectiveness in relation to leukemia.

Background: There is ethnopharmacological evidence that Petiveria alliacea can have antitumor activity; however, the mechanism of its cytotoxic activity is not well understood. We assessed multiple in vitro biological activities of an ethyl acetate soluble plant fraction over several tumor cell lines.

BackgroundSeveral treatment alternatives are available for primary breast cancer, although those for metastatic disease or inflammation associated with tumor progression are ineffective. Therefore, there is a great need for new therapeutic alternatives capable of generating an immune response against residual tumor cells, thus contributing to eradication of micrometastases and cancer stem cells. The use of complex natural products is an excellent therapeutic alternative widely used by Chinese, Hindu, Egyptian, and ancestral Latin-American Indian populations.MethodsThe present study evaluated cytotoxic, antitumor, and tumor progression activities of a gallotannin-rich fraction derived from Caesalpinia spinosa (P2Et). The parameters evaluated in vitro were mitochondrial membrane depolarization, phosphatidylserine externalization, caspase 3 activation, DNA fragmentation, and clonogenic activity. The parameters evaluated in vivo were tumor growth, leukocyte number, metastatic cell number, and cytokine production by flow cytometry.ResultsThe in vitro results showed that the P2Et fraction induced apoptosis with mitochondrial membrane potential loss, phosphatidylserine externalization, caspase 3 activation, DNA fragmentation, and decreased clonogenic capacity of 4T1 cells. In vivo, the P2Et fraction induced primary tumor reduction in terms of diameter and weight in BALB/c mice transplanted with 4T1 cells and decreased numbers of metastatic cells, mainly in the spleen. Furthermore, decreases in the number of peripheral blood leukocytes (leukemoid reaction) and interleukin 6 (IL-6) serum levels were found, which are events associated with a poor prognosis. The P2Et fraction exerts its activity on the primary tumor, reduces cell migration to distant organs, and decreases IL-6 serum levels, implying tumor microenvironment mechanisms.ConclusionsOverall, the P2Et fraction lessens risk factors associated with tumor progression and diminishes primary tumor size, showing good potential for use as an adjuvant in breast cancer ER(+) treatment.

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contributed equally to this work. AbstractObjective. To evaluate the biological activity of Petiveria alliacea extracts on tumoral cells in vitro. Materials and methods. P.alliacea fractions prepared by a bioguided purification protocol were characterized by their biological activities on two human tumoral cell lines. Morphological changes, cell viability, mitochondrial membrane depolarization, nuclear staining and activity on HSP70 were analyzed. Results. The present study demonstrates that P.alliacea fractions can induce apoptosis in a mitochondria-dependent pathway and down regulate HSP70 expression in vitro. The possible compounds present in P.alliacea responsible for the described biological activities were identified by dereplication methods. Conclusion. The present study provides new knowledge on the antitumoral properties of the plant species P. alliacea described in several ethnobotanical studies.Key words: apoptosis; cancer; heat shock proteins; Petiveria alliacea. ResumenUna fracción de Petiveria alliacea induce apoptosis dependiente de la mitocondria y regula la expresión de la proteína HSP70. Objetivo. Evaluar la actividad biológica in vitro de extractos de Petiveria alliacea utilizando líneas celulares tumorales. Materiales y métodos. Las fracciones de P.alliacea fueron preparadas mediante un protocolo de purificación biodirigido. La actividad biológica fue caracterizada utilizando dos líneas celulares tumorales de origen humano, donde se analizaron los cambios morfológicos, la viabilidad celular, la actividad sobre la membrana mitocondrial y la fragmentación nuclear. Asimismo se evaluó la actividad de las fracciones sobre la expresión de la proteína HSP70. Resultados. El presente estudio muestra que las fracciones de P.alliacea inducen muerte celular por apoptosis dependiente de la mitocondria y además regulan negativamente la expresión de la proteína HSP70. Los compuestos que posiblemente son responsables de la actividad biológica presente en las fracciones de P.alliacea fueron identificados por dereplicación. Conclusión. El presente estudio contribuye a explicar en parte las propiedades antitumorales de la planta P.alliacea descritas en diversos escritos etnobotánicos.