Chemical Properties
ORANGE CRYSTALLINE POWDER OR CRYSTALS
Uses
antibacterial, antifungal, tuberculostatic; antifeedant (worm)
Definition
ChEBI: A hydroxy-1,4-naphthoquinone that is 1,4-naphthoquinone in which the hydrogens at positions 2 and 5 are substituted by methyl and hydroxy groups, respectively.
Description
Plumbagin is a natural 1,4-naphthoquinone first isolated from plants of the genus
Plumbago. It has diverse effects in cells and animals. Plumbagin causes the generation of reactive oxygen species and induces apoptosis in cancer cells.
1,2 It activates signaling through Nrf2 and the antioxidant response element, inducing the expression of Nrf2 target genes, including NQO1 and heme oxygenase-1 in cultured neuronal cells.
1 Plumbagin also inhibits NADPH oxidase 4 in a time- and dose-
dependent manner.
3 It can be protective against peroxide stress or deprivation of glucose or oxygen.
1
General Description
Plumbagin is a bioactive naphthoquinone present majorly in Plumbago indica L. It is a quinoid and is also derived from the roots of Plumbago zeylanica?roots.
Biochem/physiol Actions
Plumbagin exhibits various pharmacological activities including antimicrobial, anticancer, anti-atherosclerotic, antidiabetic, anti-inflammatory, hypolipidemic, and neuroprotective activities. It inhibits the signal transducer and activator of transcription 3 (STAT3) signaling and halts the proliferation of esophageal squamous cell carcinoma (ESCC). Plumbagin elicits protective antioxidative functionality in 4-nitroquinoline-N-oxide (NQNO) induced stress in lymphoma. Plumbagin in a nanoemulsion formulation has antiproliferative effect towards prostate cancer.
in vitro
plumbagin exhibited effective cell growth inhibition via inducing cancer cells to undergo g2/m phase arrest and apoptosis. blockade of cell cycle was associated with increased levels of p21 and reduced amounts of cdc2, cdc25c and cyclinb1. plumbagin treatment also found to enhance the levels of inactivated phosphorylated cdc2 and cdc25c. blockade of p53 activity partially decreased plumbagin-induced apoptosis and g2/m arrest, indicating it might be operated by p53-dependent and independent pathway [1].
in vivo
to determine whether plumbagin inhibited the in vivo tumor growth, a549 cells were injected into nude mice. tumor growth inhibition was most evident in mice treated with plumbagin at 2 mg/kg/day, where around 80% reductions in tumor size were observed, in contrast with mice treated with the vehicle. no sign of toxicity was observed in plumbagin-treated mice as judged by monitoring body weight [1].
IC 50
11.69 μm for a549 cells
Purification Methods
It crystallises in yellow needles from aqueous EtOH. It is soluble in organic solvents, it is steam volatile and it sublimes on heating in a vacuum. [Fieser & Dunn J Am Chem Soc 58 572 1936, Beilstein 8 III 2576, 8 IV 2376.]
References
[1] hsu yl,cho cy,kuo pl,huang yt,lin cc. plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone) induces apoptosis and cell cycle arrest in a549 cells through p53 accumulation via c-jun nh2-terminal kinase-mediated phosphorylation at serine 15 in vitro and in vivo. j pharmacol exp ther.2006 aug;318(2):484-94.
