Ju Sun Kim

Antibacterial coumarins fromAngelica gigas roots

Systematic fractionation ofAngelica gigas roots led to the isolation of linear furano(pyrano)coumarins such as bergapten (1), decursinol angelate (2), decursin (3), nodakenetin (4) and nodakenin (5). The antibacterial activities of those compounds against pathogenic bacteria were investigated. Among the compounds tested, decursinol angelate (2) and decursin (3) exhibited significant antibacterial activity againstBacillus subtilis with the minimum inhibitory concentrations (MICs) of 50 and 12.5 μg/mL, respectively.

Anti-inflammatory and anti-arthritic activity of total flavonoids of the roots of Sophora flavescens

ETHNOPHARMACOLOGICAL RELEVANCE The roots of Sophora flavescens have long been used in Chinese medicine for the treatment of fever, inflammatory disorders, ulcers and skin burns. Sophora flavescens contains flavonoids and alkaloids. AIM OF THE STUDY This study was conducted to develop a plant-based anti-inflammatory agent focused on chronic inflammatory disorders. To accomplish this, the alkaloid-free prenylated flavonoid-enriched fraction (PFS) of rhizomes of Sophora flavescens was prepared and its in vitro and in vivo anti-inflammatory activities were then evaluated for the first time. MATERIALS AND METHODS The inhibitory activity of PFS on PGE(2), NO, IL-6 and TNF-alpha production of lipopolysaccharide (LPS)-treated RAW 264.7 cells was measured. Additionally, adjuvant-induced arthritis in rats was used as an animal model of chronic inflammation to establish the in vivo anti-inflammatory effects of PFS. RESULT PFS inhibited cyclooxygenase-2 (COX-2)-catalyzed PGE(2) and inducible nitric oxide synthase (iNOS)-catalyzed NO production by lipopolysaccharide (LPS)-treated RAW 264.7 cells at 10-50 microg/ml, and these effects primarily occurred via COX-2 inhibition and iNOS down-regulation, respectively. PFS also inhibited IL-6 and TNF-alpha production. When tested against adjuvant-induced arthritis in rats (chronic inflammation), PFS strongly inhibited arthritic inflammation when administered orally at doses of 10-100mg/kg/day. In addition, PFS administered orally potently inhibited acetic acid-induced writhing in mice. CONCLUSIONS Our results suggest that PFS inhibits chronic inflammatory response and the inhibition of proinflammatory molecules such as COX-2, iNOS and IL-6 may contribute, at least in part, to the anti-inflammatory activity in vivo. Overall, these results indicate that PFS from Sophora flavescens may have the potential for treatment of chronic inflammatory disorders such as rheumatoid arthritis.

Effects of sophoraflavanone G, a prenylated flavonoid from Sophora flavescens, on cyclooxygenase-2 and in vivo inflammatory response.

Previously, several prenylated flavonoids having a C-8 lavandulyl moiety were found to inhibit cyclooxygenase-1 (COX-1) as well as 5-lipoxygenase (5-LOX), and sophoraflavanone G was the most potent inhibitor against these eicosanoid generating enzymes among 19 prenylated flavonoids tested. In this investigation, effects of sophoraflavanone G on COX-2 induction from RAW 264.7 cells andin vivo inflammatory response were studied. Sophoraflavanone G inhibited prostaglandin E2 (PGE2) production from lipopolysaccharide (LPS)-treated RAW cells by COX-2 down-regulation at 1-50 uM. Other prenylated flavonoids including kuraridin and sanggenon D also down-regulated COX-2 induction at 10-25 uM, while kurarinone and echinoisoflavanone did not. In addition, sophoraflavanone G showedin vivo anti-inflammatory activity against mouse croton oil-induced ear edema and rat carrageenan paw edema via oral (2-250 mg/kg) or topical administration (10-250 ug/ear). Although the potencies of inhibition were far less than that of a reference drug, prednisolone, this compound showed higher antiinflammatory activity when applied topically, suggesting a potential use for several eicosanoidrelated skin inflammation such as atopic dermatitis.

Hyperoside prevents oxidative damage induced by hydrogen peroxide in lung fibroblast cells via an antioxidant effect.

We elucidated the cytoprotective effects of hyperoside (quercetin-3-O-galactoside) against hydrogen peroxide (H2O2)-induced cell damage. We found that hyperoside scavenged the intracellular reactive oxygen species (ROS) detected by fluorescence spectrometry, flow cytometry, and confocal microscopy. In addition, we found that hyperoside scavenged the hydroxyl radicals generated by the Fenton reaction (FeSO4)+H2O2) in a cell-free system, which was detected by electron spin resonance (ESR) spectrometry. Hyperoside was found to inhibit H2O2-induced apoptosis in Chinese hamster lung fibroblast (V79-4) cells, as shown by decreased apoptotic nuclear fragmentation, decreased sub-G(1) cell population, and decreased DNA fragmentation. In addition, hyperoside pretreatment inhibited the H2O2-induced activation of caspase-3 measured in terms of levels of cleaved caspase-3. Hyperoside prevented H2O2-induced lipid peroxidation as well as protein carbonyl. In addition, hyperoside prevented the H2O2-induced cellular DNA damage, which was established by comet tail, and phospho histone H2A.X expression. Furthermore, hyperoside increased the catalase and glutathione peroxidase activities. Conversely, the catalase inhibitor abolished the cytoprotective effect of hyperoside from H2O2-induced cell damage. In conclusion, hyperoside was shown to possess cytoprotective properties against oxidative stress by scavenging intracellular ROS and enhancing antioxidant enzyme activity.

Chemical constituents of the root of Dystaenia takeshimana and their anti-inflammatory activity.

In our ongoing search for bioactive compounds originating from the endemic species in Korea, we found that the hexane and EtOAc fractions of the MeOH extract from the root ofDystaenia takeshimana (Nakai) Kitagawa (Umbelliferae) showed cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) dual inhibitory activity by assessing their effects on the production of prostaglandin D2 (PGD2) and leukotriene C4 (LTC4) in mouse bone marrow-derived mast cells. By activity-guided fractionation, five coumarins, viz. psoralen (2), xanthotoxin (3), scopoletin (4), umbelliferone (5), and (+)-marmesin (6), together with β-sitosterol (1), were isolated from the hexane fraction, and two phenethyl alcohol derivatives, viz. 2-methoxy-2-(4′-hydroxyphenyl)ethanol (7) and 2-hydroxy-2-(4′-hydroxyphenyl)ethanol (8), three flavonoids, viz. apigenin (9), luteolin (10), and cynaroside (11), as well as daucosterol (12) were isolated from the EtOAc fraction using silica gel column chromatography. In addition, D-mannitol (13) was isolated from the BuOH fraction by recrystallization. Two of the coumarins, scopoletin (4) and (+)-marmesin (6), the two phenethyl alcohol derivatives (7, 8) and the three flavonoids (9–11) were isolated for the first time from this plant. Among the compounds isolated from this plant, the five coumarins as well as the three flavonoids showed COX-2/5-LOX dual inhibitory activity. These results suggest that the anti-inflammatory activity ofD. takeshimana might in part occurvia the inhibition of the generation of eicosanoids.

Rutin from Lonicera japonica inhibits myocardial ischemia/reperfusion-induced apoptosis in vivo and protects H9c2 cells against hydrogen peroxide-mediated injury via ERK1/2 and PI3K/Akt signals in vitro

We investigated pharmacological effects of rutin isolated form Lonicera japonica on H2O2-induced cell death in H9c2 cells in vitro and rat myocardial ischemia-reperfusion injury model in vivo. Western blot analysis showed that H2O2 increased expression of cleaved form of caspase-3 and proapoptotic Bax protein, but decreased antiapoptotic Bcl-2 protein in H9c2 cell. However, treatment with rutin decreased expression of both cleaved from of caspase-3 and increased Bcl-2/Bax ratio in H9c2 cells. The protective effect of rutin was inhibited not by JNK inhibitor or p38 MAPK inhibitor but by PI3K inhibitor or ERK inhibitor. Rutin increased phosphorylation of ERK and Akt in H9c2 cells. These anti-apoptotic effects of rutin were confirmed both by annexin-V and TUNEL assay. Furthermore, rutin improved I/R-induced myocardial contractile function and reduced infarct size. Rutin administration also inhibited apoptosis in myocardial tissues in I/R rats by increasing Bcl-2/bax ratio and decreasing active caspase-3 expression. These results suggest that rutin reduced oxidative stress-mediated myocardial damage in vitro model and in vivo model, which might be useful in treatment of myocardial infarction.

Paeonol and Paeoniflorin, the Main Active Principles of Paeonia albiflora, Protect the Heart from Myocardial Ischemia/Reperfusion Injury in Rats

The aim of this study was to investigate the effects of paeoniflorin (PF) and paeonol (PN), the main active compounds of the Paeonia albiflora Pallas, on myocardial ischemia and reperfusion (I/R)-induced injury in Sprague-Dawley rats IN VIVO. Under anesthesia, the rats were subjected to 25 min of ischemia by ligation of the left anterior descending coronary artery (LAD) followed by 6 h (Western blot analysis) or 24 h (hemodynamics and infarct size) of reperfusion. When the infarct size was measured as the percentage of the area at risk, both PF (25.0 % +/- 7.0 %) and PN (24.1 % +/- 5.5 %) significantly (P < 0.05) reduced it compared to I/R control (54.8 % +/- 2.6 %). Administration of 10 mg/kg PF or PN 1 h prior to I/R injury also resulted in a significant improvement of the hemodynamic parameters. Furthermore, both PF and PN decreased the caspase-3 and Bax expressions but up-regulated Bcl-2 in the left ventricles. The results show that both PF and PN reduced myocardial damage in rat through protection from apoptosis, suggesting that Paeonia albiflora Pallas might be useful in treating myocardial infarction.

Flavonoids from the aerial parts ofLonicera japonica

Seven flavonoids were isolated from the aerial parts ofLinocera japonica. Their structures were characterized as hydnocarpin1, quercetin2, ochnaflavone3, ochnaflavone 4′-O-methylether4, astragalin5, isoquercitrin6, and rhoifolin7 by chemical and spectroscopic evidences.

Cholinesterase and BACE1 inhibitory diterpenoids from Aralia cordata.

Fourteen diterpenes were isolated from the n-hexane fraction of the roots of Aralia cordata (syn. = A. continentalis). Through spectroscopy, the chemical structures were determined as: ent-pimara-8(14),15-diene-19-oic acid (1); ent-kaur-16-en-19-oic-acid (2); 18-nor-ent-pimara-8(14),15-diene-4β-ol (3); 18-nor-ent-kaur-16-ene-4β-ol (4); ent-pimara-8(14),15-diene-19-ol (5); 7α-hydroxy-ent-pimara-8(14),15-diene-19-oic acid (6); 7β-hydroxy-ent-pimara-8(14),15-diene-19-oic acid (7); ent-pimar-15-en-8α,19-diol (8); 7-oxo-ent-pimara-8(14),15-diene-19-oic acid (9); 16α-hydroxy-17-isovaleroyloxy-ent-kauran-19-oic acid (10); 17-hydroxy-ent-kaur-15-en-19-oic acid (11); 15α,16α-epoxy-17-hydroxy-ent-kauran-19-oic acid (12); 16α,17-dihydroxy-ent-kauran-19-oic acid (13); and 16α-methoxy-17-hydroxy-ent-kauran-19-oic acid (14). Compounds 4, 5, 8, 12, and 14 were first isolated from this plant. The anti-Alzheimer and antioxidant effects of ent-pimarane-type diterpenes 1, 3, 5, 8, and 9, as well as ent-kaurane-type diterpenes 2, 4, and 10∼13, were evaluated via β-site amyloid precursor protein cleaving enzyme 1 (BACE1), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), peroxynitrite (ONOO−), and nitric oxide (NO·) assays. Of the compounds tested, 8 exerted the most effective BChE inhibition with an IC50 value of 7.58 µM, followed by 3, 13, 11, 2, and 10. Compounds 9∼11 exhibited good BACE1 inhibitory activities with IC50 values of 18.58∼24.10 µM. However, 11 showed marginal AChE inhibitory effect, and all compounds tested showed no scavenging activities on ONOO− and NO· at a concentration of 100 µM.

Constituents of the fruits and leaves ofEuodia daniellii

Four flavonoid glycosides, flavaprin (7), evodioside B (8), vitexin (11), and hesperidin (12), as well as the coumarins bergapten (1), xanthotoxin (2), and isopimpinellin (3), the lignan simplex-oside (10), the steroids β-sitosterol (4) and daucosterol (5), the limonoids isolimonexic acid (6) and limonin (9), and uracil (13) andmyo-inositol (14) have been isolated fromEuodia daniellii. The structures of these compounds were established from spectral data. Among the isolates, bergapten showed cyclooxygenase-2 inhibitory activity with an IC50 value of 6.2 μg/ml. Fla-vonoids isolated from this plant exhibited no cytotoxic activity against the human tumor cell lines, A549, SKOV-3, SKMEL-2, XF498, and HCT15.