Showing papers by "Sun Yeou Kim published in 2011"
TL;DR: Results indicate that fucoidan induces apoptosis of A549 human lung cancer cells through down‐regulation of p38, PI3K/Akt, and the activation of the ERK1/2 MAPK pathway.
Abstract: Fucoidan, a sulfated polysaccharide, has various biological activities, such as anticancer, antiangiogenic and antiinflammatory effects; however, the mechanisms of action of fucoidan on anticancer activity have not been fully elucidated. The anticancer effects of fucoidan from Undaria pinnatifida on A549 human lung carcinoma cells were examined. Treatment of A549 cells with fucoidan resulted in potent antiproliferative activity. Also, some typical apoptotic characteristics, such as chromatin condensation and an increase in the population of sub-G1 hypodiploid cells, were observed. With respect to the mechanism underlying the induction of apoptosis, fucoidan reduced Bcl-2 expression, but the expression of Bax was increased in a dose-dependent manner compared with the controls. Furthermore, fucoidan induced caspase-9 activation, but decreased the level of procaspase-3. Cleavage of poly-ADP-ribose polymerase (PARP), a vital substrate of effector caspase, was found. The study further investigated the role of the MAPK and PI3K/Akt pathways with respect to the apoptotic effect of fucoidan, and showed that fucoidan activates ERK1/2 in A549 cells. Unlike ERK1/2, however, treatment with fucoidan resulted in the down-regulation of phospho-p38 expression. In addition, fucoidan resulted in the down-regulation of phospho-PI3K/Akt. Together, these results indicate that fucoidan induces apoptosis of A549 human lung cancer cells through down-regulation of p38, PI3K/Akt, and the activation of the ERK1/2 MAPK pathway.
99 citations
TL;DR: Results demonstrate that PRE has protective effects on dopaminergic neurons via its anti-oxidant and anti-apoptotic activity in models of Parkinson's disease.
70 citations
TL;DR: It is found that LJ improved cell viability, inhibited cytotoxicity and apoptosis, and attenuated elevations in ROS and nuclear condensation, and its potential to treat neurodegenerative diseases warrants further research.
68 citations
TL;DR: It is demonstrated that EUE possesses potent neuroprotective effects and that its beneficial effects are mediated, in part, by AChE inhibition, and therefore, might be a potential candidate in neurodegenerative diseases such as AD.
66 citations
TL;DR: The findings indicate that DG, a major sapogenin obtained from Dioscorea nipponica, reverses functional and ultrastructural changes and induces neural regeneration in a diabetic neuropathy model.
Abstract: Diabetic neuropathy is characterized by axonal degeneration, demyelination, and atrophy in association with failed axonal regeneration, remyelination, and synaptogenesis. Recent reports suggest that reduced levels of nerve growth factor (NGF) may play a significant role in the pathogenesis of diabetic polyneuropathy. In this study, we investigated the regulation of NGF by steroid diosgenin (DG) in a diabetic neuropathy rodent model. We found that DG, the primary spirostane-type steroid in several Dioscorea species, increased NGF levels in the sciatic nerve of diabetic rats. Additionally, DG increased neurite outgrowth in PC12 cells and enhanced nerve conduction velocities in the diabetic neuropathy mouse model. DG-treated diabetic mice showed reduced disarrangement of the myelin sheath and increased area of myelinated axons by electron microscope studies and exhibited improvement in the damaged axons. Our data further suggest that DG increased the nerve conduction velocity through induction of NGF. Thus, our findings indicate that DG, a major sapogenin obtained from Dioscorea nipponica, reverses functional and ultrastructural changes and induces neural regeneration in a diabetic neuropathy model.
63 citations
TL;DR: Results suggest that CHE is useful for improving memory function via its action in upregulating NGF, as demonstrated by passive avoidance test and novel object recognition test.
60 citations
TL;DR: The investigation of rhizomes of Acorus gramineus afforded five new lignans, named ligraminols A-E (1-5), together with seven known ones (6-12), which were determined by a combination of 1D and 2D NMR, HRMS, CD, and enzymatic hydrolysis.
Abstract: As a part of our ongoing search for bioactive constituents from natural Korean sources, the investigation of rhizomes of Acorus gramineus afforded five new lignans, named ligraminols A-E (1-5), together with seven known ones (6-12). The structures of 1-5 were determined by a combination of 1D and 2D NMR, HRMS, CD, and enzymatic hydrolysis. Compounds 1-12 were tested for their antiproliferative activities toward a panel of human-derived normal and cancer cell lines. Moreover, compounds 1-12 were evaluated for their inhibitory activities on nitric oxide production in an activated murine microglial cell line.
44 citations
TL;DR: Two new furostanol saponins, coreajaponins A and B, together with 10 known compounds were isolated from the rhizomes of D. japonica, a food and medicinal source known as 'San Yak' in Korea that can potentially improve neurodegenerative diseases and diabetic polyneuropathy.
39 citations
TL;DR: All the isolated compounds except for dilignans (19 and 20) significantly inhibited nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells.
36 citations
TL;DR: The NGF agonistic activity of DA- 9801 and DA-9801E was demonstrated, which may contribute to their neuroprotective effect against diabetic peripheral neuropathy (DPN).
36 citations
TL;DR: Coprismycins A-B (1 and 2) and dipyridines (5 and 6) displayed comparable neuroprotective effects against MPP(+) (1-methyl-4-phenylpyrimidium)-induced neurotoxicity in neuroblastoma SH-SY5Y cells.
TL;DR: GCD improved AβO-induced memory impairment as well as reduced neuronal cell death, astrogliosis, and microgliosis in the hippocampus and prevented A βO-triggered synaptic disruption and cholinergic fiber loss, suggesting that GCD may be useful in the prevention and treatment of AD.
TL;DR: The n-hexane and CHCl3 soluble fractions of the MeOH extract of the aerial parts of Piper kadsura were found to potently inhibit nitric oxide production in LPS-activated BV-2 cells, a microglial cell line.
Abstract: The n-hexane and CHCl3 soluble fractions of the MeOH extract of the aerial parts of Piper kadsura were found to potently inhibit nitric oxide (NO) production in LPS-activated BV-2 cells, a microglial cell line From the active fractions, a new stereoisomer of guaiane sesquiterpene, 1α,5β-guai-4(15)-ene-6β,10β-diol, kadsuguain A (1) and a new cyclohexadienone, kadsuketanone A (2), together with twelve known compounds (3–14) were isolated The structures of these compounds were elucidated by extensive NMR spectral studies The absolute configuration of 2 was determined by circular dichroism (CD) spectra Compounds 2, 6, and 11–14 significantly inhibited both nitric oxide (NO) and prostaglandin E2 (PGE2) production in the LPS-activated microglia cells In addition, compounds 4, 6, and 11–14 exhibited cytotoxicity against the A549, SK-OV-3, SK-MEL-2, and HCT15 human tumour cells
TL;DR: A bioassay-guided fractionation and chemical investigation of the trunk of Berberis koreana resulted in the isolation and identification of a new sesquilignan, named berbikonol, along with fourteen known lignan derivatives and a new phenolic compound, named Berfussinol, together with five known ones.
TL;DR: Two new lignans and a new phenylethanoid glycoside, termed pharbiniloside, and 22 known compounds, were isolated from the ethanol extract of the seeds of Pharbitis nil, determining the structures of the new compounds on the basis of spectroscopic analyses.
Abstract: Two new lignans, termed pharsyringaresinol (1) and pharbilignoside (2), a new phenylethanoid glycoside, termed pharbiniloside (3), and 22 known compounds, were isolated from the ethanol extract of the seeds of Pharbitis nil. The structures of the new compounds (1-3) were determined on the basis of spectroscopic analyses, including 2D-NMR and circular dichroism (CD) spectroscopy studies. Among the isolates, compounds 2, 11, 12, and 24 exhibited significant cytotoxicity against human tumor cell lines (A549, SK-OV-3, SK-MEL-2, and HCT-15) with IC(50) values ranging from 8.07 to 28.30 µM. In addition, compounds 11, 12 and 24 potently inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells, a microglia cells with IC(50) values ranging from 14.7 to 19.9 µM.
TL;DR: It is suggested that arctigenin may confer a neuroprotective effect via the inhibition of neuroinflammation through the activation of extracellular signal-regulated kinase and p38.
Abstract: In this study, we found that Forsythiae fructus (FF) and one of its main compounds, arctigenin, significantly inhibited nitric oxide production in lipopolysaccharide (LPS)-stimulated BV-2 microglial cells. Arctigenin also suppressed the expression of inducible nitric oxide synthase and cyclooxygenase-2, and inhibited the activation of extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38. Moreover, it also reduced levels of proinflammatory cytokines, interleukin , tumor necrosis factor and prostaglandin E2, and inhibited neuronal death in LPS-treated organotypic hippocampal cultures. Therefore, we suggest that arctigenin may confer a neuroprotective effect via the inhibition of neuroinflammation.
Patent•
29 Dec 2011
TL;DR: In this paper, a pharmaceutical composition and a health functional food for the prevention and treatment of diabetic peripheral neuropathy, comprising an herb extract of a mixture of 3.5:1 Dioscorea rhizoma : Diocorea nipponica (w/w).
Abstract: Disclosed are a pharmaceutical composition and a health functional food for the prevention and treatment of diabetic peripheral neuropathy, comprising an herb extract of a mixture of 3.5:1 Dioscorea Rhizoma : Dioscorea nipponica (w/w). Having the ability to synergistically increase in vivo levels of nerve growth factor, compared to the extracts from the herbs alone or herb mixtures of other weight ratios, the mixed herb extract is effective for preventing the apoptosis of nerve cells and promoting nerve regeneration. Thus, it can be applied to pharmaceutical compositions and health functional foods preventive and curative of diabetic peripheral neuropathy.
TL;DR: The new lignans (I) and (II) are isolated together with several known other Lignans from leaves and twigs as discussed by the authors. But they are not known to be related to each other.
Abstract: The new lignans (I) and (II) are isolated together with several known other lignans from leaves and twigs.
TL;DR: A bioassay-guided fractionation of title plant parts results in isolation and identification of a new sesquilignan (I), named berbikonol, along with other known lignan derivatives.
Abstract: A bioassay-guided fractionation of title plant parts results in isolation and identification of a new sesquilignan (I), named berbikonol, along with other known lignan derivatives.