Precision-cut liver slices as a model for assess hepatic cellular response of chitosan-glutathione nanoparticles on cultures treated with zilpaterol and clenbuterol.

Zilpaterol and clenbuterol are two ß-adrenergic agonist drugs used in animal production. Both drugs have anabolic effects with advantages on carcass yield. Meanwhile, zilpaterol is approved for animal feed in authorized countries. Clenbuterol is a banned substance due to the risk of toxicity; however, it is still being used in unknown dose levels in many farm species. Therefore, the use and abuse of these substances should be closely monitored, considering the clenbuterol ability and the not proved yet of zilpaterol to produce reactive oxygen and nitrogen species. Regarding glutathione which is the main intracellular antioxidant plays detoxification functions on liver metabolism; in this work, it is our interest to know the capacity of chitosan-glutathione nanoparticles (CS/GSH-NP) as a complementary source of exogenous GSH to modify the oxide-reduction status on bovine precision-cut liver slice cultures (PCLS) exposed to clenbuterol and zilpaterol. A single drug assay was performed in first instance by adding clenbuterol, zilpaterol, chitosan nanoparticles (CS-NP), and CS/GSH-NP. Then combinate drug assay was carried out by testing clenbuterol and zilpaterol combined with CS-NP or CS/GSH-NP. The results showed that both ß-adrenergic agonists modify in a dose-dependent manner in oxide-reduction response through ROS generation. The activity or content of glutathione peroxidase activity, intracellular GSH, gamma glutamyl-transpeptidase, aspartate aminotrasnferase and alanine aminotrasnferase were modified. The exogenous GSH delivered by nanoparticles could be used to modulate these markers.

Modification of Proliferation and Apoptosis in Breast Cancer Cells by Exposure of Antioxidant Nanoparticles Due to Modulation of the Cellular Redox State Induced by Doxorubicin Exposure.

In this report, we investigated whether the use of chitosan-carrying-glutathione nanoparticles (CH-GSH NPs) can modify proliferation and apoptosis, and reduce cell damage induced by doxorubicin on breast cancer cells. Doxorubicin is a widely used antineoplasic agent for the treatment of various types of cancer. However, it is also a highly toxic drug because it induces oxidative stress. Thus, the use of antioxidant molecules has been considered to reduce the toxicity of doxorubicin. CH-GSH NPs were characterized in size, zeta potential, concentration, and shape. When breast cancer cells were treated with CH-GSH nanoparticles, they were localized in the cellular cytoplasm. Combined doxorubicin exposure with nanoparticles increased intracellular GSH levels. At the same time, decreasing levels of reactive oxygen species and malondialdehyde were observed and modified antioxidant enzyme activity. Levels of the Ki67 protein were evaluated as a marker of cell proliferation and the activity of the Casp-3 protein related to cell apoptosis was measured. Our data suggests that CH-GSH NPs can modify cell proliferation by decreasing Ki67 levels, induce apoptosis by increasing caspase-3 activity, and reduce the oxidative stress induced by doxorubicin in breast cancer cells by modulating molecules associated with the cellular redox state. CH-GSH NPs could be used to reduce the toxic effects of this antineoplastic. Considering these results, CH-GSH NPs represent a novel delivery system offering new opportunities in pharmacy, material science, and biomedicine.