Biomedicine

Abstract

Introduction and Aim: Placental extracts due to the unique biological properties have been widely utilized in various fields of medicine. The objective of the study was to investigate the effect of horse placenta extract on human peripheral blood mononuclear cells (PBMCs).
Materials and Methods: The placenta extract was obtained from the mares. PBMCs were isolated from venous blood samples from healthy volunteers. To assess the toxic effect of the placenta extract (in final protein concentrations of 1500, 750, 375, 187.5, 93.75, 46.88 μg/ml) an MTT test was employed. As a control, cultures of PBMCs untreated with an extract were used. The cytotoxicity of the extract was examined by using propidium iodide (PI). A CFSE test was utilized to evaluate T-cell proliferation. The levels of reactive oxygen species (ROS) were also evaluated. An enzyme-linked immune-sorbent assay was used to determine the level of interleukin secretion.
Results: According to the results of MTT assay, the placenta extract cytotoxicity was observed at a concentration of 1500 μg/ml and 750 μg/ml. PI test showed that the placenta extract solution had no toxic effect on PBMCs after 72 h (concentration range from 1500 to 46.9 μg/ml). However, toxic effect was observed after 72 hours of exposure to extract at a concentration of 1500 to 3250 μg/ml, where cytotoxicity was 4.6 and 12.0%, respectively (p ≤ 0.05). The 2-hour incubation of cells with placenta extract at concentrations of 1500 μg/ml and 375 μg/ml led to a significant decrease in ROS level (p ≤ 0.05). In addition, T-cell proliferation was considerably reduced at an extract's concentration of 1500 μg/ml and 375 μg/ml compared to the control (p ≤ 0.05). The detected increase in the production of human IL-4 PBMC (24-hour incubation) was dependent on the concentration of the placenta extract.
Conclusion: The results of the study indicate that the horse placenta extract does not possess cytotoxicity towards human PBMCs. Moreover, we observed the immune-modulating properties of placenta extract.