Effects of Various Antioxidants on Rat Lung Tissue During Chemotherapy: Electron Microscopic Study

Abstract

Objectives: This study uses transmission electron microscopy technique to investigate the efficacy of different antioxidants (such as ascorbic acid, alpha-tocopherol and selenium) in repairing or reversing lung damage caused by the possible adverse effects of the chemotherapy (cyclophosphamide) application on the lung tissue of the subjects.

Materials and Methods: Thirty female Wistar rats were divided into five groups of six rats each: (I) control, (II) cyclophosphamide only (75 µg/kg), (III) cyclophosphamide (75 µg/kg) + ascorbic acid (200 µg/kg/day), (IV) cyclophosphamide (75 µg/kg) + α-tocopherol (150 µg/kg/day) and (V) cyclophosphamide (75 µg/kg) + selenium (40 ppm/kg/day). At the end of the experimental period the rats were sacrificed and the left lung of the subjects was removed and placed in a 2.5% glutaraldehyde solution in a 1/15 µ phosphate buffer (pH 7.4). The tissues were then stained with uranyl acetate and lead citrate to enhance the contrast, and examined and photographed with an electron microscope (Carl Zeiss 900 EM).

Results: Alveolar type II cells were found to have degenerated in the cyclophosphamide-treated lung tissues. Vacuolization and crystolisis of mitochondria, disruption of the lamellar order and indications of apoptosis were observed. In the α-tocopherol group, mitochondria were normal and fibrosis was reduced. In this group, damage to the cell membrane and defects of lamellar bodies were present. Other groups produced similar results to the cyclophosphamide group.

Conclusion: The results of our study showed that from all the antioxidants administered to rats during chemotherapy, only α-tocopherol was efficient in healing the tissue damage caused by cyclophosphamide.