Exposure to low-dose bisphenol A induces spleen damage in a murine model: Potentially through oxidative stress?

Background: During early life, exposure to environmental toxicants, including endocrine disruptor bisphenol A (BPA), can be detrimental to the immune system. To our knowledge, a few researches have looked at the effects of developing BPA exposures on the spleen. Aim: The murine model was developed to investigate the underlying molecular mechanisms and mode of BPA actions on the spleen subsequent to prolonged early-life exposure to BPA. Methods: Immature (3-week-old) male and female Swiss Albino mice were intraperitoneally injected with 50 µg/kg BPA in corn oil or corn oil alone for 6 weeks. Mouse spleens were harvested and examined histologically at 10 weeks old (adulthood). Results: We observed neurobehavioral impairments and a significant increase in peripheral monocyte and lymphocyte counts in mice (males and females). Moreover, several spleen abnormalities in both male and female mice were observed in adulthood. BPA-treated mice's histopathological results revealed toxicity in the form of significantly active germinal centers of the white pulp and a few apoptotic cells. There was also a notable invasion of the red pulp by eosinophils and lymphocytes that were significantly higher than normal. Agarose gel electrophoresis provided further evidence of internucleosomal DNA fragmentation and apoptosis in the splenic tissues of BPA-treated mice compared to controls. In addition, there were increased levels of the lipid peroxidation malondialdehyde end-product, a marker of oxidative lipid damage, in the spleens of BPA-treated mice compared to controls. Conclusion: Our study provides evidence that oxidative stress injury induced by early-life exposures to BPA could contribute to a range of splenic tissue damages during adulthood.

Microscopic examination of the intestinal wall and selected organs of minipigs orally supplemented with humic acids.

Humic acids are used to prophylactically treat intestinal diseases in a wide number of species, yet the mechanism of action remains unknown. The general assumption has been that humic acids act locally; however studies using young piglets show orally supplemented humic acids can penetrate the intestinal wall, and thus potentially act systemically. The objective of this study was to determine if humic acids could also cross the intestinal barrier in adult pigs and be detected in other organs. Adult minipigs (>18 months old) orally received either 1g humic acids/kg body weight (verum, n=3) or placebo (control, n=3), for 2 weeks. At the end of the feeding period tissue samples were harvested from the intestine, various glands and organs. Unstained tissue samples were examined by light microscopy for the presence of humic acid particles. No humic acid particles were detected in any of the unstained tissues from verum or control pigs.