Association of UVRAG polymorphisms with susceptibility to non-segmental vitiligo in a Korean sample.

Autoimmune, self-destructive, oxidative stress and genetic theories have been proposed for the pathogenesis of vitiligo. Autophagy is essential for cellular homeostasis and is implicated in many pathophysiological conditions such as cancer, response to oxidative stress and autoimmunity. The ultraviolet (UV) radiation resistance-associated gene (UVRAG) activates the Beclin1-PI(3)KC3 complex, promoting autophagy. To evaluate whether UVRAG polymorphisms are associated with non-segmental vitiligo (NSV) patients in a Korean sample, we conducted a case-control association study of 225 NSV patients and 439 matched healthy controls. A total of five single nucleotide polymorphisms (SNPs) of UVRAG were selected for analysis. Among these, two SNPs (rs1458836, rs7933235) showed significant genotypic differences between the NSV patient group and the control group. These two SNPs were located within a strong linkage disequilibrium (LD) block. In addition, the haplotype of the UVRAG polymorphism was associated with NSV. This study suggests a possible association between UVRAG and NSV susceptibility.

Effects of Machilus thunbergii Sieb et Zucc on UV-induced photoaging in hairless mice.

Chronic ultraviolet (UV) exposure induces photoaging and oxidative stress in the skin. We investigated whether Machilus thunbergii Sieb et Zucc (M. thunbergii) could reduce UV-induced photoaging and oxidative stress in hairless mice. The dorsal skin of hairless mice was treated topically with M. thunbergii for 2 h prior to UV irradiation. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were then measured in skin and/or serum samples. Histological changes in the skin were assessed by hematoxylin-eosin (HE) staining. In addition, proteomes from the skin of hairless mice in each group were analyzed. The thickness of the dorsal skin and epidermis was significantly decreased by M. thunbergii treatment. We also found that MDA levels decreased after M. thunbergii treatment and the SOD levels were increased by M. thunbergii compared with those in the UV-only treated group. Proteomic analysis revealed 17 proteins associated with photoaging. These data indicate that M. thunbergii might have antiphotoaging effects.

Association of glutathione S-transferase gene polymorphisms (GSTM1 and GSTT1) of vitiligo in Korean population.

Vitiligo is an acquired pigmentary disorder of the skin involving melanocyte dysfunction. It has been reported that melanocyte impairment could be related to increased oxidative stress. The glutathione S-transferases (GSTs) are group of polymorphic enzymes that are important in protection against oxidative stress. To find the relationship between GSTM1 and GSTT1 polymorphisms with vitiligo susceptibility, GSTM1 and GSTT1 (homozygous deletion vs. non-deleted) polymorphisms between vitiligo patients (n=310) and healthy controls (n=549) were analyzed. We observed significant association in null alleles of the GSTM1 (P<0.001, OR=2.048, 95% CI=1.529-2.743). GSTM1 null type was also statistically different between two vitiligo subtypes and controls (Focal P<0.001, OR=2.224, 95% CI=1.499-3.298; Generalized P=0.001, OR=1.974, 95% CI=1.342-2.904). However, no significant association in GSTT1 (P=0.869, OR=1.024, 95% CI=0.775-1.353) was observed with vitiligo. In combined analysis of GSTM1 and GSTT1, both null type and GSTM1/GSTT1 (null/present) group showed significant differences between controls and vitiligo patients. These results suggest that GSTM1 null type might be associated with vitiligo susceptibility in Korean population.

Ganoderma lucidum extract stimulates glucose uptake in L6 rat skeletal muscle cells.

The effect of Ganoderma lucidum extract on glucose uptake was studied in L6 rat skeletal muscle cells. G. lucidum extract increased glucose uptake about 2-fold compared to control. The extract stimulated the activity of phosphatidylinositol (PI) 3-kinase which is a major regulatory molecule in the glucose uptake pathway. About 7-fold increased activity of a PI 3-kinase was observed after treatment with G. lucidum extract, whereas PI 3-kinase inhibitor, LY294002, blocked the G. lucidum extract-stimulated PI 3-kinase activity in L6 skeletal muscle cells. Protein kinase B, a downstream mediator of PI 3-kinase, was also activated by G. lucidum extract. We then assessed the activity of AMP-activated protein kinase (AMPK), another regulatory molecule in the glucose uptake pathway. G. lucidum extract increased the phosphorylation level of both AMPK alpha1 and alpha2. Activity of p38 MAPK, a downstream mediator of AMPK, was also increased by G. lucidum extract. Taken together, these results suggest that G. lucidum extract may stimulate glucose uptake, through both PI 3-kinase and AMPK in L6 skeletal muscle cells thereby contributing to glucose homeostasis.

Suppressive effect of Punica granatum on the production of tumor necrosis factor (Tnf) in BV2 microglial cells.

While the anti-oxidant properties of Punica granatum methanol extract (PGMF) are well documented, little is known concerning the anti-inflammatory effect of Punica granatum. PGMF was pretreated in BV2 microglial cells and cells were stimulated to induce inflammation by lipopolysaccharide (LPS). The effect of PGME on the production and expression of tumor necrosis factor alpha (Tnf, previously known as Tnf alpha) was determined by enzyme-linked immunosorbent assay (ELISA), western blotting, and reverse transcription-polymerase chain reaction (RT-PCR). In addition, the expression of nuclear factor kappa b (Nfkappab) was measured using an electrophoretic mobility shift assay (EMSA). By ELISA, PGME at the concentrations of 1, 5, 10, and 50 microg/ml inhibited Tnf production in LPS-stimulated cells by 30.2, 42.3, 57.6, and 88.4%, respectively, compared to LPS-stimulated cells. The LPS-stimulated Tnf production was reduced with a dose-dependent manner. Immuno blot and RT-PCR analyses revealed that PGME of 5 and 50 microg/ml inhibited the expression of both protein and mRNA levels of Tnf compared to LPS-stimulated cells. EMSA revealed that PGME of 5 and 50 microg/ml blocked the LPS-stimulated activation of Nfkappab. These data suggest that PGME may suppress LPS-stimulated Tnf production through inhibition of Nfkappab in BV2 microglia cells.

Amygdalin inhibits genes related to cell cycle in SNU-C4 human colon cancer cells.

AIM: The genes were divided into seven categories according to biological function; apoptosis-related, immune response-related, signal transduction-related, cell cycle-related, cell growth-related, stress response-related and transcription-related genes. METHODS: We compared the gene expression profiles of SNU-C4 cells between amygdalin-treated (5 mg/mL, 24 h) and non-treated groups using cDNA microarray analysis. We selected genes downregulated in cDNA microarray and investigated mRNA levels of the genes by RT-PCR. RESULTS: Microarray showed that amygdalin downregulated especially genes belonging to cell cycle category: exonuclease 1 (EXO1), ATP-binding cassette, sub-family F, member 2 (ABCF2), MRE11 meiotic recombination 11 homolog A (MRE11A), topoisomerase (DNA) I (TOP1), and FK506 binding protein 12-rapamycin-associated protein 1 (FRAP1). RT-PCR analysis revealed that mRNA levels of these genes were also decreased by amygdalin treatment in SNU-C4 human colon cancer cells. CONCLUSION: These results suggest that amygdalin have an anticancer effect via downregulation of cell cycle-related genes in SNU-C4 human colon cancer cells, and might be used for therapeutic anticancer drug.

Association between CDK5RAP1 polymorphisms and susceptibility to vitiligo in the Korean population.

The neuronal theory of the pathogenesis of vitiligo is supported by clinical, ultrastructural and biochemical findings. Cyclin-dependent kinase 5 regulatory subunit associated protein 1 (CDK5RAP1) is expressed in neuronal tissues, and cyclin-dependent kinase 5 (CDK5) seems to be critically involved in the migration of neuroblasts during early post-natal development. To evaluate whether CDK5RAP1 polymorphisms are associated with vitiligo patients in the Korean population, we conducted a case-control association study of 296 vitiligo patients and 426 healthy controls. A total of two single nucleotide polymorphisms (SNPs) of CDK5RAP1 were investigated. Genotypes were determined by polymerase chain reaction (PCR) and direct sequencing. A synonoymous SNP (rs291700, Thr54Thr) and intron SNP (rs158676) of CDK5RAP1 were associated with onset age of the vitiligo (rs291700, p=0.040 in co-dominant 1 and p=0.036 in overdominant; rs158676, p=0.034 in overdominant). Haplotype (AC) showed a difference between the vitiligo and control groups (p=0.036). These results suggest that CDK5RAP1 may be a risk factor of vitiligo in the Korean population.

Pharmacokinetic comparison of ginsenoside metabolite IH-901 from fermented and non-fermented ginseng in healthy Korean volunteers.

ETHNOPHARMACOLOGICAL RELEVANCE: IH-901 (20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol) is a novel ginseng saponin metabolite formed by human intestinal bacteria and is known to have antitumor and antimetastatic effects. However, there has been no pharmacokinetic study of IH-901 in human beings. AIM OF THE STUDY: The aim of this study was to investigate the pharmacokinetic differences of IH-901 from fermented and non-fermented ginseng. MATERIALS AND METHODS: To investigate whether the pharmacokinetics of IH-901 differ between fermented and non-fermented ginseng, an open label, randomized, single dose, fasting, two-period, cross-over, pharmacokinetic study was conducted. A total of 24 healthy Korean male volunteers participated in this study. All subjects were allocated into two equal groups and administered 3g of fermented or non-fermented Panax ginseng. Serial blood samples for pharmacokinetic analysis were collected in the 24 h after dosing. Plasma IH-901 concentration was measured by a validated high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Pharmacokinetic parameters including AUC(t), C(max), and T(max) were calculated by noncompartmental models in the BA-CALC program (KFDA, 2008, 1.0.0, Korea). RESULTS: After oral administration of fermented ginseng, 5 subjects experienced diarrhea. The means of AUC(t) and C(max) were significantly different between the two groups. In the fermented ginseng group, AUC(t) was 2083.09±91.97 ng h/mL, a 15.5-fold increase over that of IH-901 from the non-fermented group (134.50±63.10 ng h/mL), and the mean C(max) was 325.00±91.97 ng/mL in the fermented ginseng group, a 27-fold higher value than that in the non-fermented group (13.88±7.24 ng/mL). T(max) was 3.29±1.00 and 12.04±4.96 h in the fermented and non-fermented group, respectively. CONCLUSIONS: The results of this study showed that the pharmacokinetic parameters of IH-901 from fermented Panax ginseng are different from those of non-fermented ginseng, from which IH-901 is formed by intestinal fermentation.

Promoter polymorphisms of the HLA-G gene, but not the HLA-E and HLA-F genes, is associated with non-segmental vitiligo patients in the Korean population.

The aim of this study was to determine whether or not promoter polymorphisms of the class I major histocompatibility complex (HLA-E, HLA-F, and HLA-G) are associated with susceptibility to vitiligo. To identify a possible association with vitiligo, 241 patients with non-segmental vitiligo (NSV) and 395 healthy controls were recruited in this study. Three promoter single nucleotide polymorphisms (SNPs; rs1264459 of HLA-E, rs9258170 of HLA-F, and rs1736936 of HLA-G) were analyzed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique and direct sequencing. Multiple logistic regression models (co-dominant 1, co-dominant 2, dominant, recessive, and log-additive models) were applied for odds ratios (ORs), 95% confidence intervals (CIs), and P values. To obtain the defined results, P values were recalculated by a Bonferroni correction. After the Bonferroni correction, the genotype of the SNP (rs1736936) of HLA-G was shown to have significant association with NSV (P = 0.045 in the recessive model). The genotype frequencies of the HLA-G SNP (rs1736936) had a significant correlation with the age of onset of NSV (P = 0.016 in the co-dominant 1 model and P = 0.027 in the dominant model). Our results suggest that HLA-G, but not HLA-E and HLA-F, may be associated with susceptibility to NSV in the Korean population.

The association of PBX1 polymorphisms with overweight/obesity and metabolic alterations in the Korean population.

Pre-B-cell leukemia transcription factor 1 (PBX1), which is located on chromosome 1q23, was recently reported to be associated with type 2 diabetes mellitus. We examined whether single nucleotide polymorphisms (SNPs) of the PBX1 gene are associated with overweight/obesity in a Korean population. We genotyped 66 SNPs in the PBX1 gene and investigated their association with clinical phenotypes found in 214 overweight/obese subjects and 160 control subjects using the Affymetrix Targeted Genotyping chip array. Seven SNPs (g.+75186C>T, g.+78350C>A, g.+80646C>T, g.+138004C>T, g.+185219G>A, g.+191272A>C, and g.+265317T>A) were associated with the risk of obesity in three models (codominant, dominant, and recessive) (P=0.007-0.05). Haplotype 1 (CAC) and 3 (TAC) of block 3 and haplotype 2 (GGAAT) of block 10 were also strongly associated with the risk of obesity. In the control group, subjects that had homozygote for the major allele for both g.+185219G>A and g.+191272A>C showed lower high density lipoprotein-cholesterol (HDL-C) level compared to those possessing the minor allele, suggesting that the association between the homozygote for the major allele for both g.+185219G>A and g.+191272A>C and HDL-C is attributable to the increased risk of obesity. This study suggests that the PBX1 gene is a possible risk factor in overweight/obese patients.

Preservative effect of electrolyzed reduced water on pancreatic beta-cell mass in diabetic db/db mice.

Oxidative stress is produced under diabetic conditions and involved in progression of pancreatic beta-cell dysfunction. Both an increase in reactive oxygen free radical species (ROS) and a decrease in the antioxidant defense mechanism lead to the increase in oxidative stress in diabetes. Electrolyzed reduced water (ERW) with ROS scavenging ability may have a potential effect on diabetic animals, a model for high oxidative stress. Therefore, the present study examined the possible anti-diabetic effect of ERW in genetically diabetic mouse strain C57BL/6J-db/db (db/db). ERW with ROS scavenging ability reduced the blood glucose concentration, increased blood insulin level, improved glucose tolerance and preserved beta-cell mass in db/db mice. The present data suggest that ERW may protects beta-cell damage and would be useful for antidiabetic agent.

The association between endothelin-1 gene polymorphisms and susceptibility to vitiligo in a Korean population.

BACKGROUND: Vitiligo is a skin disorder affected by genetic, environmental, local and endocrine factors. Endothelin-1, which is expressed by keratinocytes, has paracrine effects on melanocytes, influencing their homeostasis, proliferation and pigmentation. It is thought to play a role in the skin response to 311-nm, narrow-band ultraviolet irradiation. OBJECTIVE: To investigate the association of endothelin-1 gene (EDN1) polymorphisms with vitiligo in a Korean population. METHODS: To evaluate the expression of endothelin-1 in cultured human keratinocytes after irradiation with narrow-band ultraviolet B (NBUVB), we performed RT-PCR and ELISA. In addition, we genotyped 312 vitiligo patients and 313 matched-healthy controls, and compared the genotype, allele and haplotype frequencies of EDN1 polymorphisms (intron 4 G/A, rs2071942 and exon 5 G/T, rs5370) between the two groups, using PCR-restriction fragment length polymorphism. The effects of sex, onset age, the presence of autoimmune diseases, family history and clinical type were analysed statistically. RESULTS: NBUVB induced the expression of endothelin-1 in cultured human keratinocytes. The genotype distributions and allele frequencies of EDN1 polymorphisms did not differ significantly between vitiligo patients and healthy controls. Moreover, the results were not related to sex, onset age, the presence of autoimmune diseases or family history. Interestingly, the haplotype frequencies of EDN1 polymorphisms differed significantly between vitiligo patients and healthy controls. When analysed according to clinical type, the haplotype frequencies in the focal and segmental clinical types differed significantly from healthy controls. CONCLUSION: This study suggests that EDN1 is related to the development of vitiligo in the Korean population.

Association study between catalase gene polymorphisms and the susceptibility to vitiligo in Korean population.

Vitiligo is an acquired pigmentary disorder characterized by well-circumscribed depigmented patches. Autoimmune, self-destruction, neural, and genetic theories have been proposed for the pathogenesis of vitiligo. Reactive oxygen species play an important role in the physiology of cell damage, and catalase is known to regulate oxidative stress. Reduced catalase enzyme activity and accumulation of excessive hydrogen peroxide were observed in vitiligo. To examine whether catalase gene polymorphisms are associated with vitiligo patients in Korean population, we investigated two CAT gene polymorphisms including (T/C) BstX I (A/T) Hinf I in 118 vitiligo patients and 200 healthy volunteers. The CAT gene genotype distribution and allele frequency were not significantly different between vitiligo patients and healthy controls. But, the haplotype of two polymorphisms was associated with vitiligo. This study suggests possible association between the CAT gene and the vitiligo susceptibility.