Antimutagenic and antioxidant properties of plumbagin and other naphthoquinones.


The structure-function relationships of the naphthoquinone phytochemicals, plumbagin, juglone, and menadione, have been studied with regard to antimutagenic and antioxidant activities. Antimutagenicity of these compounds was assessed by the Ames test and RNA polymerase B (rpoB)-based rifampicin resistance assay. Antioxidant potential was evaluated by radical scavenging assays and reducing power measurement. Protection of cells and DNA against gamma radiation-induced oxidative damage was assayed by survival analysis and gel electrophoresis profiling, respectively. On the 1,4-naphthoquinone nucleus, plumbagin possesses 5-hydroxyl and 2-methyl functional groups, whereas juglone has only the 5-hydroxyl and menadione only the 2-methyl group. Plumbagin showed strong antimutagenic (against ultraviolet and ethyl methanesulfonate) and antioxidant activities, whereas juglone displayed only strong antimutagenic, and menadione only strong antioxidant activities. Thus, these two functional groups (5-OH/2-CH3) play important roles in the differential bioactivity of naphthoquinones. Escherichia coli, microarray analysis showed upregulation of the genes rep (replication/repair), ybaK (tRNA editing), speE (spermidine synthesis), and yjfC (glutathionyl spermidine synthesis) by plumbagin or juglone, and sodC (superoxide dismutase), xthA (oxidative repair), hycB (electron carrier between hydrogenase 3 and fumarate dehydrogenase), and ligA (formation of phosphodiester bond in DNA) by plumbagin or menadione. Studies with E. coli single-gene knockouts showed that ybaK and speE, reported to prevent mistranslation, are likely to be involved in the antimutagenicity displayed by juglone, and sodC to be involved in the antioxidant activity of menadione.


  • Publisher Full Text
  • Authors

    Kumar S

    Food Technology Division, Bhabha Atomic Research Centre, Mumbai, India.

    Gautam S

    Sharma A


    Mutation research 755:1 2013 Jul 4 pg 30-41


    Antifibrinolytic Agents
    Antimutagenic Agents
    Antineoplastic Agents
    Drug Resistance, Bacterial
    Escherichia coli
    Molecular Structure
    Nucleic Acid Synthesis Inhibitors
    Oxidative Stress
    Reactive Oxygen Species
    Salmonella typhimurium
    Structure-Activity Relationship
    Vitamin K 3

    Pub Type(s)

    Journal Article



    PubMed ID