Estudo dos efeitos tóxicos da formulação comercial do herbicida glifosato sobre células-tronco derivadas de tecido adiposo humano

Abstract

Glyphosate is the most commercialized herbicide in the world, known commercially as Roundup®, and many studies were conducted to investigate its potential damage to human health. To carry out this work, we chose human adipose tissue-derived stem cells (hASCs) as an experimental model, which are able to differentiate into adipogenic and osteogenic lineages. These cells were derived from volunteers subjected to liposuction surgery approved by ethics committee. The main objective of this work was to investigate the toxic effects of Roundup® on hASCs in undifferentiated and differentiated state of these cells. These cells were exposed to a mixture containing Roundup® and DMEM (Penicilin-streptomycin-gentamicin and human plasma enriched) or Roundup® and osteogenic or adipogenic differentiation medium at a concentration of 36 g mL-1 (IC50 42, 98 ±0, 91 g mL-1), during short (24, 48, and 72 hours) and long (until 21 days) time of exposure. We used MTT assay (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) to assess the toxicity of glyphosate throughout the days of culture. Annexin V-Alexa Fluor 488 and Propidium Iodide staining using fluorescence microscopy suggested that hASCss exposure to Roundup® induced cells to apoptosis after 24h exposure. Morphological changes were observed by light microscopy during the hASCs differentiations period with Roundup®. Otherwise, the expressions of genes related to differentiation, such as leptin, alkaline phosphatase, and osteopontin, accessed by standart PCR, were similar compared to the control during toxic challenge. However, despite alkaline phosphatase (AK) expression, the NBT (nitro-blue tetrazolium chloride) and BCIP (5-bromo-4-chloro-3'-indolyphosphate p-toluidine salt) hydrolysis have shown that the AK enzymatic activity were less intense in treated group during osteogenic differentiation. In conclusion, evidences have shown that Roundup® causes toxic effects on adult stem cells derived from adipose tissue.