PLUMBAGIN

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. 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. Plumbagin also inhibits NADPH oxidase 4 in a time- and dose-dependent manner. It can be protective against peroxide stress or deprivation of glucose or oxygen.

Chemical Properties

ORANGE CRYSTALLINE POWDER OR CRYSTALS

Uses

antibacterial, antifungal, tuberculostatic; antifeedant (worm)

Uses

Plumbagin from Plumbago indica has been used:

• as a reactive oxygen species agent (ROS) to induce cytotoxicity in mouse embryonic fibroblasts
• as an oxidative stress inducer to generate superoxide anion in Saccharomyces cerevisiae
• as a reference standard in thin layer chromatography and in spectrophotometric analysis for quantification of plumbagin in Plumbago auriculate samples

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.

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.