title: Plumbagin-silver nanoparticle formulations enhance the cellular uptake of plumbagin and its antiproliferative activities.
abstract: Colloidal silver nanoparticles (AgNPs) have attracted much attention in recent years as diagnostics and new drug delivery system in cancer medicine. To study the effects of plumbagin (PLB), a relatively non-toxic napthaquinone isolated from the roots of Plumbago indica in human cervical cancer cell line and developed a formulation to enhance its cytotoxic activities. Silver nanoparticles were synthesised by chemical reduction method and complexed with PLB. Both the AgNPs and the complex PLB-AgNPs were characterised by dynamic light scattering, high-resolution scanning electron microscopy and transmission electron microscopy. The amount of PLB and PLB-AgNPs internalised was determined by ultra-violet-visible spectrophotometer. Cell inhibition was determined by sulphorhodamine B assay. Mitotic index was determined by Wright-Giemsa staining. Apoptosis induction was assessed by western blot using cleaved poly adenosine diphosphate-ribose polymerase antibody. The scanning electron microscope analysis indicated an average particle size of 32±8 nm in diameter. Enhanced internalisation of PLB into the HeLa cells was observed in PLB-AgNPs. PLB inhibited proliferation of cells with IC50 value of about 18±0.6 µM and blocked the cells at mitosis in a concentration-dependent manner. PLB also inhibited the post-drug exposure clonogenic survival of cells and induced apoptosis. The antiproliferative, antimitotic and apoptotic activities were also found to be increased when cells were treated with PLB-AgNPs. The authors results support the idea that AgNP could be a promising and effective drug delivery system for enhanced activity of PLB in cancer treatment.
authors.affiliation: School of Biotechnology, National Institute of Technology Calicut, Calicut, Kerala, India.
authors.forename: Prakash
authors.initials: P
authors.lastname: Appadurai
authors.affiliation: School of Biotechnology, National Institute of Technology Calicut, Calicut, Kerala, India. rathin@nitc.ac.in.
authors.forename: Krishnan
authors.initials: K
authors.lastname: Rathinasamy
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D009285:Naphthoquinones / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology*; D012834:Silver / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D009285:Naphthoquinones; D012834:Silver; C014758:plumbagin