Induction of Erythrocyte Membrane Blebbing by Methotrexate-Induced Oxidative Stress

Methotrexate (MTX) is a common chemotherapeutical agent and folate antagonist with reported apoptotic activity in nucleated cells. The presented research work was planned to investigate the eryptotic effects of methotrexate after the exposure of erythrocytes to therapeutical doses (10–15 μM) of methotrexate. Eryptosis and the role of calcium in the stimulation of membrane blebbing were evaluated through the determination of mean cell volume. Oxidative stress induced by methotrexate (10–15 μM) was determined by antioxidative enzyme activities. Cytotoxic activity against human erythrocytes was examined through hemolysis assay. Exposure of erythrocytes to methotrexate results in significant reduction of superoxide dismutase, catalase, and superoxide dismutase activities at 10 and 15 μM in comparison to the untreated cells. Erythrocytes mean cell volume (MCV) was increased after 48 hours exposure of erythrocytes to methotrexate (10 μM). Significantly increased hemolysis percentage was observed at 10 μM after 48 hours incubation of erythrocytes with methotrexate. The results of the study suggested that the therapeutical doses (10–15 μM) of methotrexate may lead to increase in eryptotic and hemolytic activity of erythrocytes through free radical generation and subsequent calcium entry.

Stimulation of Erythrocyte Membrane Blebbing by Bifenthrin Induced Oxidative Stress

Background

Bifenthrin is an insecticide and anti-estrogenic compound primarily used to control residential pests by depolarizing sodium gated voltage channels in the nervous system. Eryptosis, the suicidal death of erythrocytes, featured by PS exposure, membrane blebbing and cell shrinkage. Anemia is an outcome of uncontrolled eryptosis.

Research Design

In this study, erythrocytes were treated with different concentrations (.5-1-1.5 μM) of bifenthrin over a period of 48 hours. In order to investigate the oxidative stress induced by bifenthrin, catalase, superoxide dismutase, and glutathione peroxidase activities were investigated.

Results

Obtained data indicated the decrease in the enzymes (superoxide dismutase, glutathione peroxidase, and catalase) activities in bifenthrin treated cells at 1 μM concentration. In addition, measurement of cell size and confirmation of the role of calcium in the stimulation of the eryptotic activity of bifenthrin were performed. A significant increase in mean cell volume was found in the presence of bifenthrin and a decrease in mean cell volume in the presence of calcium channel blocker was observed. Similarly, there was also a significant increase in the percentage of hemolysis indicating the necrotic activity of bifenthrin.

Conclusions

It is concluded that the indicated doses of bifenthrin triggered oxidative stress which may lead to early cell death by eryptosis and hemolysis.