Jesmin Mondal, Ashis Kumar Panigrahi, Anisur Rahman Khuda-Bukhsh

Whether PLGA-loaded nano-Boldine (NBol) induces apoptosis and cell cycle arrest to alleviate cisplatin-induced toxicity preferentially in normal liver calls (WRL-68) primarily via DNA-targeting has been addressed in this study. Nano-encapsulation of Boldine (Bol) was accomplished by solvent displacement method.   Effects of Bol and NBol were quantitatively assessed in WRL-68 and HepG2 cells in vitro in respect of cell cycle progression, reactive oxygen species (ROS) accumulation, depolarization of mitochondrial membrane potential (MMP) and apoptosis with the aid of FACS. Qualitative changes were demonstrated in respect of reactive oxygen species generation (ROS) and depolarization of MMP through fluorescence microscopy. DNA damage was assessed by DNA fragmentation assay and DAPI staining. Drug-DNA interaction was analyzed by circular dichroism (CD) spectroscopy. Both Bol and NBol reduced overall cytotoxic effects of cisplatin in normal cells, but had no or negligible effect on cancer cells. NBol protected normal liver cells from cisplatin-induced DNA damage, reduced ROS, re-polarized MMP, and reduced cisplatin’s DNA binding ability leading to increased number of S-phase cell population at a greater scale than Bol. Both drugs reduced cytotoxicity of normal liver cells by targeting DNA and protecting from the adverse effect of cisplatin by interacting with DNA, presumably competing with cisplatin molecules. 
Key words: PLGA- nano-encapsulation, boldine, cisplatin, DNA-targeting; cytoprotection, cell cycle, FACS.