Exposure of calcium carbide induces apoptosis in mammalian fibroblast L929 cells

Abstract

Inspite of various health warnings from Government and health organizations, Calcium carbide (CaC₂) is still the most commonly and widely used artificial fruit ripener, probably due to its easy availability, low cost and convenience of usage. Assessment of the hazardous effects of the CaC₂ applications for fruit ripening has been a matter of interest since long. Several <i>in vivo</i> studies have reported the toxicological outcomes such as histopathological changes in lungs and kidneys, haematological and immunological responses, upon exposure with CaC₂. However, a well-controlled study investigating the effects of CaC₂ under <i>in-vitro</i> setup was lacking. Hence, this study has been conducted to explore the toxicity associated cellular events in L929 cells exposed with varying concentrations of CaC₂ (0.00312-0.2 μg/μl) for 24 h exposure time. A 23.14% reduction in cell viability was observed at the highest dose of CaC₂. A similar trend in cellular stress levels at 0.2 μg/μl dose was observed in terms of rounded cellular morphology and decreased adherence as compared to the control. Furthermore, Annexin V FITC/PI staining and subsequent confocal imaging revealed a similar trend of CaC₂ induced apoptosis in a dose dependent manner. A gradual elevation of intracellular ROS has also been observed up to 0.025 μg/μl dose. Thus, the study concludes that short term CaC₂ exposure may increase the cellular oxidative stress and disturb the redox balance of the cell which then undergoes apoptosis. The study concludes that the exposure of CaC₂ can be associated with severe diseases and suggests to stop the uses of CaC₂ as fruit ripening agent.