• Plant Resources
• /
• v.8 no.3
• /
• pp.209-216
• /
• 2005

Persicaria thunbergii has been utilized for the treatment of cancer as a folk medicine. We examined the effect of isorhamnetin, a flavonoid isolated from Persicaria thunbergii, on angiogenesis in vitro and in vivo. Basic fibroblast growth factor (bFGF) is a potent angiogenic factor found in various tumors. In this study, we found that the isorhamnetin decreased bFGF-induced human umbilical vein endothelial cells (HUVECs) proliferation and migration in a concentration-dependent manner (5, 10 and $20\;{\mu}M$) whereas, it did not inhibit bFGF-induced capillary-like formation of HUVECs. The chicken chorioallantoic membrane assay revealed that addition of isorhamnetin (10, 20 and $40\;{\mu}M$) displayed an antiangiogenic effect in vivo. These results suggest that the isorhamnetin inhibits the proliferation and migration of endothelial cells induced by bFGF, which may explain its anti-angiogenic properties.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.3
• /
• pp.596-602
• /
• 2016

Staphylococcus aureus, like other gram-positive pathogens, has evolved a large repertoire of virulence factors as a powerful weapon to subvert the host immune system, among which alpha-hemolysin (Hla), a secreted pore-forming cytotoxin, plays a preeminent role. We observed a concentration-dependent reduction in Hla production by S. aureus in the presence of sub-inhibitory concentrations of isorhamnetin, a flavonoid from the fruits of Hippophae rhamnoides L., which has little antibacterial activity. We further evaluate the effect of isorhamnetin on the transcription of the Hla-encoding gene hla and RNAIII, an effector molecule in the agr system. Isorhamnetin significantly down-regulated RNAIII expression and subsequently inhibited hla transcription. In a co-culture of S. aureus and lung cells, topical isorhamnetin treatment protected against S. aureus-induced cell injury. Isorhamnetin may represent a leading compound for the development of anti-virulence drugs against S. aureus infections.

• Food Science and Biotechnology
• /
• v.16 no.3
• /
• pp.439-443
• /
• 2007

The effects of the methanol extract of the leaves of Brassica juncea and isorhamnetin $3-O-{\beta}-D-glucopyranoside$, major compound isolated from the ethyl acetate fraction of this plant on hepatic lipid peroxidation and drug-metabolizing enzymes, were evaluated in rats treated with bromobenzene. The extract and isorhamnetin $3-O-{\beta}-D-glucopyranoside$ of oral administration did not show any significant effects on activities of aminopyrine N-demethylase and aniline hydroxylase, enzymes forming toxic epoxide by bromobenzene as well as on glutathione content. However, both methanol extract and isorhamnetin $3-O-{\beta}-D-glucopyranoside$ significantly recovered the decreased activities of glutathione s-transferase and epoxide hydrolase, and also reduced the lipid peroxide level in rats treated with bromobenzene. From the results, the protections of this plant against bromobenzene-induced hepatotoxicity are thought to be via enhancing the activities of epoxide hydrolase and glutathione s-transferase, enzymes removing toxic epoxide, and reducing the lipid peroxide level.

• Natural Product Sciences
• /
• v.21 no.3
• /
• pp.170-175
• /
• 2015

The present study aims to detect the rare flavonoids isolated from the leaves of Persicaria glabra. The known flavonoids: quercetin (1), isorhamnetin (2), avicularin (3) and new one isorhamnetin-3-O-α-L-(6''-E-p-coumaroyl)-rhamnoside (4) were identified by HPLC, UV, IR and NMR. P. glabra has used traditionally for its analgesic, anti-inflammatory and anti-rheumatic properties. To find out the ingredients responsible for the efficiency of this plant, we have used to study the anti-microbial and anti-inflammatory activities of different extracts.

• Korean Journal of Pharmacognosy
• /
• v.14 no.4
• /
• pp.137-139
• /
• 1983

From the leaves of Typha latifolia, L. (Thyphaceae) isorhamnetin-3-O-glucoside and isorhammetin-3-O-neohesperidoside were isolated and characterized by chemical and spectral analysis.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.4
• /
• pp.588-592
• /
• 1996

The flavonoids isolated from Oenanthe javanica were investigated on the antimutagenic effect againt aflatoxin $B_1(AEB_1).$ The 0.5 and 1.0mg/plate of isorhamnetin reduced the mutagenicity of $AFB_1about$ 33 and 59%, respectively. Persicarin showed the 40 and 47% inhibition rate at Previous concentration, respectively.

• Natural Product Sciences
• /
• v.12 no.4
• /
• pp.214-216
• /
• 2006

Isorhamnetin from the aerial parts of Persicaria thunbergii has been reported to have anti-tumor activity mediated by the inhibition of farnesyl protein transferase. In this study, we investigated the anti-proliferation effects of isorhamnetin on NIH3T3, K-RAS, H-RAS and SW620 cells, and it showed anti-proliferative effects in a dose-dependent manner with $IC_{50}$ value 4.1, 7.9, 20.2, and $22.4{\mu}g/ml$, repectively.

• Archives of Pharmacal Research
• /
• v.28 no.2
• /
• pp.169-171
• /
• 2005

The methanolic extract of the aerial parts of Persicaria thunbergii was found to show inhibitory activity on Farnesyl Protein Transferase (FPTase). Bioassay-guided fractionation of the methanolic extract resulted in the isolation of isorhamnetin, as an inhibitor on FPTase. This compound inhibited FPTase activity in a dose-dependent manner, and the $IC_{50}$ value of isorhamnetin was $37.5\;{\mu}M$.

• Natural Product Sciences
• /
• v.20 no.3
• /
• pp.211-215
• /
• 2014

Opuntia humifusa, also called as Cheonnyuncho, is a cactus widely cultivated in southern regions of Korea. It has been known to have diverse biological activities, but most of the studies were performed with the MeOH extracts or solvent-partitioned fractions. Furthermore, the efforts to identify the responsible compounds for the biological activities are very limited. In this study, we tested the inhibitory effect of extracts and solvent-partitioned fractions of O. humifusa against LPS-induced nitric oxide (NO) production in Raw264.7 cells. The butanol fractions of O. humifusa efficiently inhibited the production of NO in Raw264.7 cells, but it was not due to the reduction of cell viability. Bioassay-guided isolation of butanol fractions of O. humifusa allowed the isolation of three flavonoids isorhamnetin 3-O-${\beta}$-$\small{D}$-galactosyl-4'-O-${\beta}$-$\small{D}$-glucoside (1), isorhamnetin 3,4'-di-O-${\beta}$-$\small{D}$-glucoside (2) and isorhamnetin 3-O-${\beta}$-$\small{D}$-(6-O-${\alpha}$-$\small{L}$-rhamnosyl)glucoside (3), and one lignan syringaresinol O-${\beta}$-$\small{D}$-glucopyranoside (4). Among them, isorhamnetin 3-O-${\beta}$-$\small{D}$-galactosyl-4'-O-${\beta}$-$\small{D}$-glucoside (1) and isorhamnetin 3,4'-di-O-${\beta}$-$\small{D}$-glucoside (2) exhibited the moderate inhibitory effects against LPS-induced NO production. This is the first time to report anti-inflammatory effects of these compounds.

• Archives of Pharmacal Research
• /
• v.25 no.5
• /
• pp.625-627
• /
• 2002

From the leaves of Brassica juncea, an radical scavenging isorhamnetin 7-Ο-glucoside on peroxynitrite and 1,1-diphenyl-2-picrylhydrazyl (DPPH) was isolated and characterized based on the spectroscopic evidence. The compound showed the peroxynitrite and DPPH scavenging activities with $IC_{50}$ values of 2.07$\pm$0.17 and 13.3 $\mu$M, respectively. Penicillamine and L-ascorbic acid as positive control exhibited radical scavenging activities with $IC_{50}$ values of 3.17$\pm$0.39 and 12.78 $\mu$M, respectively.