• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.238-245
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• 2009

Pure culture experiments were conducted to assess the bacteriostatic and bactericidal effects of phlorotannins (PT) isolated from Ascophyllum nodosum (brown seaweed) on Escherichia coli O157:H7. In Exp. 1, one non-O157:H7 strain (25922) and three strains of E. coli O157:H7 (3081, EDL933 and E318N) were cultured in M9 medium with PT included at 0 (control), 25, 50 or $100{\mu}g/ml$ (n = 3). Bacterial growth was monitored by $OD_{600}$ at 0, 4, 6, 12 and 24 h, and by dilution plating at 0, 4, 6 and 24 h. All strains were inhibited (p<0.001) by PT to varying degrees. At 50 or $100{\mu}g/ml$, PT prevented growth of all four strains. At $25{\mu}g\;PT/ml$, growth of 25922, 3081, E318N and EDL933 was inhibited for 6, 12 and 24 h, respectively, but 25922 and 3081 resumed growth by 12 and 24 h. Direct plating confirmed bactericidal effects of PT on all four strains at $100{\mu}g/ml$, and on EDL933 and E318N at $50{\mu}g/ml$. In Exp. 2, strains 25922 and 3081 were incubated with no tannins or with $50{\mu}g/ml$ of PT, purified condensed tannins (CT) from Quebracho (Schinopsis balansaei), or purified tannic acid from Rhus semialata (Anacardiaceae) as hydrolysable tannins (HT). Strain 3081 was unaffected by HT or CT, but was completely inhibited (p<0.001) by PT at 4, 6 and 24 h. Strain 25922 was unaffected by HT, slightly inhibited by CT, and almost eradicated by PT at 4 and 6 h. Transmission electron microscopy revealed tannin-mediated alterations to bacterial cell walls. Phlorotannins from A. nodosum exhibit growth-inhibiting and bactericidal effects in vitro against the strains of E. coli O157:H7 investigated. Anti-E. coli efficacy of A. nodosum PT is superior to that of terrestrial tannins purified from Quebracho and from Rhus semialata.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.195-202
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• 2019

Rhus javanica L. is Anacardiaceae plant distributed in East Asia. We evaluated the antioxidant activity and antiinflammatory effect of leaf, branch, root of ethyl acetate fraction from R. javanica. To confirm effective each extraction, The antioxidant activity was evaluated using 1,1-Diphenyl-2-picryl-hydrazyl and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity assays, and the anti-inflammatory activity was evaluated based on inhibitory activities on the protein and mRNA expression of iNOS and COX-2 in LPS-induced RAW264.7 cells. The phenolic compounds content of each extract was analyzed with Folin reagents and HPLC/PDA method. The gallic acids were identified and quantified. The roots of R. javanica showed strong antioxidant activity. Its total phenolic compounds content were higher than the orders. In addition, anti-inflammatory activity inhibited the protein and mRNA expression of nitric oxide production factor, following the same pattern as contents of phenolic compounds included gallic acid and its antioxidant activity. In conclusion, R. javanica showed effective antioxidant and anti-inflammatory activity. Especially, the roots were evaluated to be highly valuable as a natural resource for reducing inflammation.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.855-863
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• 1999

To develop new natural antioxidants, antioxidative activity of ethanol (75%) extracts from 50 edible or medicinal plants were examined on lard and palm oil by Rancimat method ($120^{\circ}C$, 20 L/hr). The extracts from Rhus verviciflua STOKES showed comparatively strong antioxidative activity on test. Of the solvents used for extraction, chloroform extract exhibited the strongest antioxidant activity. AI (antioxidant index: induction period of oil containing extract/induction period of control oil) of chloroform extract was higher than that of commercial antioxidant, such as BHT, BHA and ${\delta}-tocopherol$. Free phenolic acid fraction (200 ppm) of the chloroform extract from 75% EtOH extract of Rhus verniciflua STOKES (RCF) showed stronger activity than that of BHT, BHA, and ${\delta}-tocopherol$ at the same concentration. RCF-11 and RCF-13 fractions separated by silicagel column chromatography from the RCF showed stronger activity than other fractions by the Rancimat method.

• Korean Journal of Medicinal Crop Science
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• v.12 no.1
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• pp.60-66
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• 2004

This study was carried out to confirm the phylogenetic relationships in Korean Rhus species. Sequences from internal transcribed spacers (ITS) of nuclear ribosomal DNA and rbcL gene of chloroplast DNA were determined. Cotinus coggygria was selected as outgroup because it is closest allied with Rhus in Anacardiaceae. Also, ingroup was limited as six Korean Rhus species. ITS 1 sequences in six species of Rhus and one species of Cotinus ranged from 246 to 253 bp and ITS 2 sequences from 234 to 244 bp. Concerning the G+C content of the studied taxa, ITS 1 sequences ranged from 58.0 to 68.13% and ITS 2 from 59.75 to 68.46%. On the other hand, rbcL sequences were same size in the all species examined by 1,428 bp. G+C contents of rbcL sequences were ranged from 43.56 to 43.77% which means there are nearly no different from interspecies each other. Phylogenetic tree strongly supports the colse relationships between R. succedanea and R. sylvestris. Rhus javanica and Cotinus coggygria were also closely allied with each other in ITS and rbcL trees. Therefore, R. javanica was regarded as most primitive species among the Korean Rhus species. ITS 1 region of nuclear ribosomal DNA was suggested as very useful taxonomical marker for genus Rhus.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1654-1660
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• 1999

The free phenolic acid fraction of the chloroform extract from 75% ethanol extract of Rhus verniciflua STOKES (RCF) showed stronger antioxidative activity than BHT, BHA and ${\delta}-tocopherol$ at the same concentration. RCF components were isolated and identified by silica gel column chromatography, thin layer chromatography, mass spectrometer and $^1H-NMR\;and\;^{13}C-NMR$. The antioxidative activity was confirmed by electron donating activity, Rancimat method and thiobarbituric acid test in liposome system. RCF-11 could be further separated into three fractions. The antioxidative active compounds were purified and identified as gallic acid, butin and butein. The RCF-13 was purified and identified as sulfuretin.