Journal ArticleDOI
Cytotoxic Action of Juglone and Plumbagin: A Mechanistic Study Using HaCaT Keratinocytes
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TLDR
The findings indicate that topical preparations containing juglone and plumbagin should be used with care as their use may damage the skin, and it is probable that the antifungal, antiviral, and antibacterial properties of these quinones are the result of redox cycling.Abstract:
Juglone (5-hydroxy-1,4-naphthoquinone) and plumbagin (5-hydroxy-3-methyl-1,4-naphthoquinone) are yellow pigments found in black walnut (Juglans regia). Herbal preparations derived from black walnut have been used as hair dyes and skin colorants in addition to being applied topically for the treatment of acne, inflammatory diseases, ringworm, and fungal, bacterial, or viral infections. We have studied the cytotoxicity of these quinones to HaCaT keratinocytes. Exposure to juglone or plumbagin (1−20 μM) resulted in a concentration-dependent decrease in cell viability. The cytotoxicity of these quinones is due to two different mechanisms, namely, redox cycling and reaction with glutathione (GSH). Redox cycling results in the generation of the corresponding semiquinone radicals, which were detected by electron paramagnetic resonance. Incubation of keratinocytes with the quinones generated hydrogen peroxide (H2O2) and resulted in the oxidation of GSH to GSSG. Depletion of GSH by buthionine sulfoximine enhanced ...read more
Citations
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Iron-sulphur clusters and the problem with oxygen.
TL;DR: The history of Fe‐S clusters is an unusual one that has profoundly shaped contemporary microbial ecology, and aerobes remain vulnerable to iron restriction and oxidative stress, features that higher organisms exploit in defending themselves against bacterial pathogens.
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When quinones meet amino acids: chemical, physical and biological consequences.
TL;DR: Physical and physiological phenomena such as browning of foods, discoloration of plants during processing, alteration of solubility and digestibility, formation of humic substances, germicidal activity, cytotoxicity and more occur when quinones from disintegrating cells meet amino acids.
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Why do bacteria use so many enzymes to scavenge hydrogen peroxide
Surabhi Mishra,James A. Imlay +1 more
TL;DR: This review examines the genetic, genomic, regulatory, and biochemical evidence that each of these is a bonafide scavenger of H( 2)O(2) in the cell and considers possible reasons that bacteria might require multiple enzymes to catalyze this process, including differences in substrate specificity, compartmentalization, cofactor requirements, kinetic optima, and enzyme stability.
Journal ArticleDOI
Plumbagin (5-Hydroxy-2-methyl-1,4-naphthoquinone) Suppresses NF-κB Activation and NF-κB-regulated Gene Products Through Modulation of p65 and IκBα Kinase Activation, Leading to Potentiation of Apoptosis Induced by Cytokine and Chemotherapeutic Agents
TL;DR: It is found that plumbagin inhibited NF-κB activation induced by TNF, and other carcinogens and inflammatory stimuli (e.g. phorbol 12-myristate 13-acetate, H2O2, cigarette smoke condensate, interleukin-1β, lipopolysaccharide, and okadaic acid).
Journal ArticleDOI
Micromolar intracellular hydrogen peroxide disrupts metabolism by damaging iron-sulfur enzymes
Soojin Jang,James A. Imlay +1 more
TL;DR: In scavenger-deficient mutants, the H2O2 that was generated as an adventitious by-product of metabolism (<1 μm) was sufficient to damage these [4Fe-4S] enzymes, demonstrating that aerobic organisms must synthesize H 2O2 scavengers to avoid poisoning their own pathways.
References
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Journal ArticleDOI
Normal keratinization in a spontaneously immortalized aneuploid human keratinocyte cell line.
TL;DR: The characteristics of the HaCaT cell line clearly document that spontaneous transformation of human adult keratinocytes can occur in vitro and is associated with sequential chromosomal alterations, though not obligatorily linked to major defects in differentiation.
Journal ArticleDOI
Simulation of Multiple Isotropic Spin-Trap EPR Spectra
TL;DR: A computer program has been developed for fitting EPR data with multiple free radicals as formed in biochemical and chemical spin-trapping systems, which has proven successful in several applications.
Journal ArticleDOI
Spin trapping of superoxide and hydroxyl radical: Practical aspects
TL;DR: This work has described straightforward procedures to determine whether superoxide or hydroxyl radical trapping have occurred, and which can help verify the assignment of the radical adduct.
Journal ArticleDOI
Overview of enzyme systems involved in bio-reduction of drugs and in redox cycling.
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Hepatic low-level chemiluminescence during redox cycling of menadione and the menadione-glutathione conjugate: Relation to glutathione and NAD(P)H:quinone reductase (DT-diaphorase) activity
Heribert Wefers,Helmut Sies +1 more
TL;DR: Menadione-induced chemiluminescence of the perfused rat liver does not only arise from menadione itself but from the menADione-GSH conjugate as well, and the conjugation of the quinone with glutathione is not in itself of protective nature and does not abolish semiquinone formation.