Characterization of coal fly ash nanoparticles and their induced in vitro cellular toxicity and oxidative DNA damage in different cell lines.

Coal combustion generates considerable amount of ultrafine particles and exposure to such particulate matter is a major health concern in the developing countries. In this study, we collected nano sized coal fly ash (CFA) and characterized them by scanning electron microscope-energy dispersive X-ray analysis (SEM-EDX), particle size analyzer (PSA) and transmission electron microscope (TEM), and investigated its toxicity in vitro using different cell lines. The imaging techniques showed that the coal fly ash nanoparticles (CFA-NPs) are predominately spherical shaped. The analyses have revealed that the CFA-NPs are 7-50 nm in diameter and contain several heavy metals associated with CFA particles. The studies showed significant amount of toxicity in all cell lines on treatment with CFA-NPs. The cytotoxicity and oxidative DNA damage caused by CFA-NPs were determined by inhibition of cellular metabolism (MTT), total intracellular glutathione (GSH), reactive oxygen species (ROS) and DNA fragmentation in cultured cell lines (Chang liver, HS294T and LL29). The cellular metabolism was inhibited in a dose-dependent manner in CFA-NPs treated cell lines. The CFA-NPs induced ROS and decreased the total intracellular glutathione with increased dose. Further, the CFA-NPs treated cells showed severe DNA laddering as a result of DNA fragmentation.

Ferulic Acid Reduces Cell Viability through Its Apoptotic Efficacy: An In vitro Approach.

Aim: Ferulic acid, a well known dietary phenolic antioxidant, possesses diverse pharmacological and biochemical effects, including anti-inflammatory, hepatoprotective, antidiabetic and anticancer properties. The present study explores the cytotoxic potential of ferulic acid using Hep-2 cell line by analyzing its effect on cell viability, reactive oxygen species generation, apoptotic induction, nuclear damage, DNA fragmentation and expression of apoptosis related proteins. Materials and Methods: The effect of ferulic acid (2.5, 5, 10, 20 and 40 μg/ml) on Hep-2 cells viability for 24 hr was determined by MTT assay. To substantiate the cytotoxic effect of ferulic acid, the intracellular ROS level was determined using DCFH-DA assay; apoptosis by dual staining; nuclear damage by DAPI staining; DNA fragmentation by using agarose gel electrophoresis; apoptosis related proteins by western blotting. Results: Ferulic acid significantly inhibited the Hep-2 cell growth in a dose dependent manner and ferulic acid treated Hep-2 cells exhibited features of apoptosis and increase in nuclear damage and DNA fragmentation. We also observed excess reactive oxygen species generation in ferulic acid treated Hep-2 cells. Apoptosis related proteins (p53, Bcl-2, Bax, Caspase 3 & Caspase 9) were significantly modulated in favour of programmed cell death in ferulic acid treated cells. Conclusion: We thus conclude that the cytotoxic potential of ferulic acid might be due to its role in apoptosis induction, excessive ROS generation and DNA fragmentation in Hep-2 cells.