CYTOTOXIC EFFECT OF JUGLONE ON HUMAN PERIPHERAL BLOOD LYMPHOCYTES

Juglone, a naturally occurring naphthaquinone is reported to have several medicinal properties. However, juglone is also reported to be toxic to some cell types. Human peripheral blood lymphocytes were treated with various concentrations of juglone for various time points to assess the toxic effects on the cells. Toxicity studies were performed by the Trypan Blue dye exclusion method and the MTT assay. Decrease in viability percentage was noticed with increasing concentration of juglone in the cell culture system. Cell morphology was then studied using Giemsa staining and fluorescence microscopy and a significant increase in the apoptotic features were noticed in the juglone treated cells. SDS-PAGE, and silver staining and Western blotting were performed to study the protein expression. DNA fragmentation was assessed by TUNEL assay. The apoptotic cells were then studied by morphological evaluation. It was observed that exposure to juglone (5-50 microM) resulted in a concentration and time dependent decrease in cell viability. From TUNEL assay, fragmentation of DNA was observed there by apoptotic cell death was confirmed. Keywords: Quinones, Apoptosis, cell membrane blebbing, Juglone.