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Concept: Toxicodendron


Toxicodendron vernicifluum (Stokes) F.A. Barkley (Anacardiaceae) has traditionally been used as a food supplement and in traditional herbal medicine to treat inflammatory diseases and cancers for centuries in Korea. This study was designed to isolate the bioactive constituents from the ethanol extract of Toxicodendron vernicifluum bark and evaluate their cytotoxic and anti-inflammatory activities.

Concepts: Inflammation, Disease, Infectious disease, Anti-inflammatory, Herb, Tradition, Urushiol, Toxicodendron


Rhus verniciflua (Toxicodendron vernicifluum) is a medicinal tree popularly used in Asian countries such as China, Japan and Korea as a food additive or herbal medicine because of its beneficial effects. R. verniciflua extract (RVE) contains diverse phenolic compounds, such as flavonoids, as its major biological active constituents. In this study, the pharmacokinetic profiles of eight phenolic compounds were investigated following oral administration of RVE to rats. The eight phenolic compounds were 2,4-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, fisetin, fustin, butin, sulfuretin, taxifolin, and garbanzol. The plasma concentrations of the eight compounds were determined by using a liquid chromatography-triple quadrupole mass spectrometer before and after treatment with β-glucuronidase. When 1.5 g/kg RVE was administered, the eight compounds were all detected in plasma, mainly as conjugated forms. These pharmacokinetic data would be useful for understanding the pharmacological effects of RVE.

Concepts: Pharmacology, Medicine, Pharmacokinetics, Catechin, Phenols, Quadrupole mass analyzer, Urushiol, Toxicodendron


A method to visually detect minute amounts of urushiol, the toxic catechol from poison oak, poison ivy, and poison sumac, has been developed utilizing the reaction of a profluorescent nitroxide with the B-n-butylcatecholboronate ester formed in situ from urushiol and B-n-butylboronic acid. The resulting N-alkoxyamine is strongly fluorescent upon illumination with a fluorescent lamp, allowing the location of the toxic urushiol contamination to be visualized. This methodology constitutes the groundwork for the future development of a spray to detect urushiol to avoid contact dermatitis, as well as to detect catecholamines for biomedical applications.

Concepts: Contact dermatitis, Catechol, Anacardiaceae, Poison ivy, Urushiol-induced contact dermatitis, Urushiol, Toxicodendron, Poison sumac


Contact with poison ivy plants is widely dreaded because they produce a natural product called urushiol that is responsible for allergenic contact delayed-dermatitis symptoms lasting for weeks. For this reason, the catchphrase most associated with poison ivy is “leaves of three, let it be”, which serves the purpose of both identification and an appeal for avoidance. Ironically, despite this notoriety, there is a dearth of specific knowledge about nearly all other aspects of poison ivy physiology and ecology. As a means of gaining a more molecular-oriented understanding of poison ivy physiology and ecology, Next Generation DNA sequencing technology was used to develop poison ivy root and leaf RNA-seq transcriptome resources. De novo assembled transcriptomes were analyzed to generate a core set of high quality expressed transcripts present in poison ivy tissue. The predicted protein sequences were evaluated for similarity to SwissProt homologs and InterProScan domains, as well as assigned both GO terms and KEGG annotations. Over 23,000 simple sequence repeats were identified in the transcriptome, and corresponding oligo nucleotide primer pairs were designed. A pan-transcriptome analysis of existing Anacardiaceae transcriptomes revealed conserved and unique transcripts among these species.

Concepts: DNA, DNA sequencing, Ivy, Poison ivy, Urushiol-induced contact dermatitis, Urushiol, Toxicodendron, Poison sumac


Urushiols are the allergenic components of Toxicodendron radicans (poison ivy) as well as other Toxicodendron species. They are alk-(en)-yl catechol derivatives with a 15- or 17-carbon side chain having different degrees of unsaturation. Although several methods have been developed for analysis of urushiols in plant tissues, the in situ localization of the different urushiol congeners has not been reported. Here, we report on the first analysis of urushiols in poison ivy stems by matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI). Our results show that the urushiol congeners with 15-carbon side chains are mainly localized to the resin ducts, while those with 17-carbon side chains are widely distributed in cortex and vascular tissues. The presence of these urushiols in stem extracts of poison ivy seedlings was confirmed by GC-MS. These novel findings provide new insights into the spatial tissue distribution of urushiols that might be biosynthetically or functionally relevant.

Concepts: Tissue, Plant stem, Ivy, Poison ivy, Urushiol-induced contact dermatitis, Urushiol, Toxicodendron, Poison sumac


Homeopathic remedy Rhus toxicodendron (Rhus tox) is used for several symptoms including skin irritations, rheumatic pains, mucous membrane afflictions, and typhoid type fever. Previously, we reported that Rhus tox treatment increased the cyclooxygenase-2 (COX-2) mRNA expression in primary cultured mouse chondrocytes.

Concepts: Inflammation, Gene, Irritation, Sumac, Poison ivy, Urushiol-induced contact dermatitis, Urushiol, Toxicodendron


Here, we report the whole-genome sequences and annotation of 11 endophytic bacteria from poison ivy (Toxicodendron radicans) vine tissue. Five bacteria belong to the genus Pseudomonas, and six single members from other genera were found present in interior vine tissue of poison ivy.

Concepts: Series, Sequence, Poison ivy, Toxicodendron, Vine


Rhus verniciflua stokes (RVS) (Anacardiaceae) has been traditionally used as a folk remedy for gastritis, several cancers, and various metabolic diseases. The present study evaluated the anti-inflammatory effect of RVS extract standardized to fustin content using lipopolysaccharide (LPS)-stimulated rats. The rats were randomly divided into six groups and intragastrically administered 0, 100, 250, or 500 mg/kg body weight (bw) of RVS or 15 mg/kg bw of fustin for 14 days. LPS was intraperitoneally injected 18 h before sacrifice. The nitric oxide levels of RVS extract in either the serum or liver were significantly decreased compared to the LPS-treated rats (P<.05). The treatment with the RVS extract also blunted the rise of malondialdehyde levels in the liver (P<.05). The administration of RVS extract and fustin significantly prevented the elevation of interleukin 6 cytokine, iNOS, and COX-2 mRNA expression in the liver. Inflammatory cell infiltration was also significantly attenuated by the RVS extract or fustin supplementation. These results suggest that our standardized RVS extract has preventive effects on inflammatory reactions.

Concepts: Immune system, Inflammation, Cancer, Liver, Interleukin, Anti-inflammatory, Nitric oxide, Toxicodendron


Many different tribes of American Indians used jewelweed, Impatiens capensis Meerb, as a plant mash to reduce development of poison ivy dermatitis. Saponins are a natural soapy constituent found within plants. A 2012 study suggested that saponins may be present in jewelweed which could be responsible for its efficacy in preventing rash development following contact with Toxicodendron radicans (L.) Kuntze (poison ivy). This study validated this hypothesis and demonstrated additional biological activity of the jewelweed saponin containing extract.

Concepts: Annual plant, Impatiens, Poison ivy, Urushiol-induced contact dermatitis, Urushiol, Toxicodendron, Poison sumac, Impatiens capensis


I read with interest the article of Cho and Colleagues (2012) entitled: “Neuroprotective and anti-inflammatory activities of the methanolic extract of Rhus verniciflua Stokes” Food and Chemical Toxicology 50(6), 1940-1945. This article is quite interesting and the authors should be complimented for the great amount of work they have done. The purpose of this letter is to call attention to the need for some clarification on the name of the plant described in this article.

Concepts: Psychology, Attention, Urushiol, Toxicodendron, Poisonous plants