Estudo in vitro da interação entre herbicidas e espermatozoide humano utilizando a Espectroscopia de Espalhamento Raman

Abstract

The unlimited use of pesticides, besides contribute with to increase environmental pollution, is also influencing negatively the health of the living beings, including the people health. Many studies show the result these chemicals in the reproductive system of animals and even same at man, can cause infertility problem, which can originate, among other factors, the low sperm quality and quantity. This is study aimed at evaluating human sperm quality parameters and the chemical evaluation of the core of the sperm trough Raman Scaterring Spectroscopy, after in vitro exposure to different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and atrazine. The choice of the use of the these herbicides was because they are widely use throughout the world, especially in Brazil, highlighted the west Paulista region, used at cane sugar plantation, significant culture of the region. In this context, sperm samples were selected according to the normal testing parameters that evaluate sperm quality, such as liquefaction, viscosity, appearance, volume, pH, sperm, vitality, morphology and motility. Semen samples of 10 healthy donor were exposed to study herbicides varying the concentration and time. After the different exposures (0.05, 0.5, 1.0, 5.0 and 125 &#956;g/mL, 30 and 60 min), the analysis of motility and vitality were again evaluated. The Raman Scaterring spectra were obtained from samples control sperm and after exposure to the herbicide 2,4-D e atrazine at concentration of 125 &#956;g/mL and 60 min incubation. The progressive motility and total motility decreased from the concentration 0,5 &#956;g/mL at times 30 and 60 minutes while the percentage of sperm properties increased. The progressive motility and total motility decreased from the concentration 0.5 mg / mL at times 30 and 60 minutes while the percentage of sperm immotile increased. The vitality (viable sperm) decreased significantly (p <0.05) from the exposure concentration 0.5 &#956;g/mL to 2,4-D and from 1.0 &#956;g/mL atrazine, at times 30 and 60 minutes, showing that there is a functional change of trend of human sperm after exposure to these herbicides, and this change is intensified with the exposure time factor and concentration of herbicides. Through the Raman Scaterring technique allowed us to characterize normal human sperm and exposed to herbicides and verify the change in the molecular structure in the exposed sperm, evidenced by changes in relative intensities of the bands 785, 1095, 1255, 1336, 1374, 1486 and 1575 cm-1 treated with 2,4-D and a decrease at 1095 after exposure to atrazine. These results indicate the modification of nitrogenous bases and the phosphate group that make up DNA present in the nucleus of the sperm.