Propolis protects human spermatozoa from DNA damage caused by benzo[a]pyrene and exogenous reactive oxygen species.

Many environmental, physiological and genetic factors have been implicated in defective sperm function, the most common cause of infertility. In addition, sperm preparation techniques such as centrifugation, used prior to in vitro fertilization, are associated with the generation of reactive oxygen species (ROS) and an increase in the level of DNA damage. Factors that can offer spermatozoa protection are, therefore, of great importance. This study was designed to examine in vitro the effect of a Chilean propolis ethanolic extract on human spermatozoa treated with benzo[a]pyrene and exogenous reactive oxygen species. Our experimental evidence demonstrated that the natural drug under investigation is able to protect genomic DNA by damage induced by benzo[a]pyrene, hydrogen peroxide (H2O2) and hydrogen peroxide in combination with adenosine 5'-diphosphate (ADP) and ferrous sulfate (FeSO4), determining a significant reduction of the intracellular oxidants. An increase in membrane damage, measured by monitoring the formation of thiobarbituric acid-reactive substances (TBARS) and lactic dehydrogenase (LDH) release, was observed only in sperm treated with H2O2, ADP and FeSO4. The propolis extract was shown to possess the capacity to protect sperm membrane from the deleterious action of oxidative attack, reducing TBARS formation and LDH release. In summary, our results evidence that the protective effect exhibited by this natural compound in human spermatozoa is correlated, at least in part, to the antioxidant capacity of its active components, and suggest that propolis may have a role in protection against male infertility.

Fast high performance liquid chromatography and ultraviolet-visible quantification of principal phenolic antioxidants in fresh rosemary.

An improved HPLC method is reported for the determination of rosemary's principal phenolic antioxidants, rosmarinic and carnosic acids, providing a fast and simultaneous determination for both of them by using a solid phase column. The analysis was performed with fresh methanolic extractions of Rosmarinus officinalis. To quantify the amount of antioxidants in a fast and reproducible way by means of UV-vis absorption measurements, a spectrophotometric multi-wavelength calibration curve was constructed based on the antioxidant contents obtained with the recently developed HPLC method. This UV-vis methodology can be extended to the determination of other compounds and herbs if the restrictions mentioned in the text are respected.

Chilean propolis: antioxidant activity and antiproliferative action in human tumor cell lines.

Propolis, a natural product derived from plant resins collected by honeybees, has been used for thousands of years in traditional medicine all over the world. The composition of the propolis depends upon the vegetation of the area from where it was collected and on the bee species. In this study, we investigated the antioxidant activity of a propolis sample, provided by NATURANDES-CHILE, collected in a temperate region of central Chile. In addition, this natural compound was tested for its antiproliferative capacity on KB (human mouth epidermoid carcinoma cells), Caco-2 (colon adenocarcinoma cells) and DU-145 (androgen-insensitive prostate cancer cells) human tumor cell lines. Results showed that this Chilean propolis sample exhibits interesting biological properties, correlated with its chemical composition and expressed by its capacity to scavenge free radicals and to inhibit tumor cell growth.

Métodos de medición de la flexibilidad de isquiotibiales: análisis crítico / Methods of messuring flexibility in hamstrings muscles: a critical analysis

Propósito: La flexibilidad como cualidad física debe ser considerada por su influencia en la motricidad humana. Su complejidad se hace evidente desde su definición debido a las variables involucradas en ella, por tal motivo, se trata de definir el alcance conceptual de su significado, los isquiotibiales por sus características anatómicas y biomecánicas se utilizan frecuentemente para el estudio de esta cualidad física. El propósito de este trabajo, es realizar un análisis comparativo entre diferentes métodos de medición de flexibilidad en isquiotibiales. Resultados: Se revisaron 10 test de evaluación de flexibilidad de isquiotibiales clasificándolos en dos modalidades: test de sentarse y alcanzar y test en posición supina, presentando confiabilidad similar y mayor validez los test en posición supina. En la bateria de test de sentarse y alcanzar, la modificación para protección de columna (MBS) reúne el mayor número de ventajas comparativas. Conclusiones: En base al material recopilado, no se logró un acuerdo en la definición de flexibilidad. Las propiedades pasivas del grupo muscular isquiotibial son un buen traductor en el estudio de la flexibilidad. Hay aspectos metodológicos y técnicos que requieren mayor desarrollo y profundización en lo que se refiere a los test goniométricos.