Effects of Epigallocatechin-3-Gallate on Matrix Metalloproteinases in Terms of Its Anticancer Activity.

Epidemiological studies have shown that the consumption of green tea has beneficial effects against cancer. Basic studies have provided evidence that epigallocatechin gallate (EGCG) is a major contributor to these effects. Matrix metalloproteinases (MMPs) are zinc-dependent metalloproteinases with the ability to degrade the extracellular matrix proteins and are involved in various diseases including cancer in which MMPs have a critical role in invasion and metastasis. In this review, we discuss the effects of EGCG on several types of MMPs in the context of its anticancer activity. In the promoter region, MMPs have binding sites for at least one transcription factor of AP-1, Sp1, and NF-κB, and EGCG can downregulate these transcription factors through signaling pathways mediated by reactive oxygen species. EGCG can also decrease nuclear ERK, p38, heat shock protein-27 (Hsp27), and ß-catenin levels, leading to suppression of MMPs' expression. Other mechanisms by which EGCG inhibits MMPs include direct binding to MMPs to prevent their activation and downregulation of NF-κB to suppress the production of inflammatory cytokines such as TNFα and IL-1ß. Findings from studies on EGCG presented here may be useful in the development of more effective anti-MMP agents, which would give beneficial effects on cancer and other diseases.

Effect of comprehensive cancer genomic profiling on therapeutic strategies and clinical outcomes in patients with advanced biliary tract cancer: A prospective multicenter study.

Characterization of the genomic landscape of biliary tract cancer (BTC) may lead to applying genotype-matched therapy for patients with this disease. Evidence that comprehensive cancer genomic profiling (CGP) guides genotype-matched therapy to improve clinical outcomes is building. However, the significance of CGP in patients with BTC remains unclarified in clinical practice. Therefore, the purposes of this study were to assess the utility of CGP and identify associations between clinical outcomes and genomic alterations in patients with BTC. In this prospective analysis, detection rates for actionable genomic alterations and access rates for genotype-matched therapy were analyzed in 72 patients with advanced BTC who had undergone commercial CGP. Cox regression analyses assessed relationships between overall survival and genomic alterations detected with CGP. The most common genomic alterations detected were TP53 (41, 56.9%), followed by CDKN2A/B (24, 33.3%/20, 27.8%), and KRAS (20, 27.8%). Actionable genomic alterations were identified in 58.3% (42/72) of patients. Detection rates for FGFR2 fusions, IDH1 mutations, and BRAF V600E were low in this cohort. Eight (11.1%) patients received genotype-matched therapy. For patients with intrahepatic cholangiocarcinoma (ICC), CDKN2A/B loss was associated with shorter overall survival. These real-world data demonstrate that CGP can identify therapeutic options in patients with advanced BTC. CDKN2A/B loss was identified as a poor prognostic factor in patients with ICC. Thus, this study provides a rationale for considering CGP in planning therapeutic strategies for advanced BTC.

Clinical significance of comprehensive genomic profiling tests covered by public insurance in patients with advanced solid cancers in Hokkaido, Japan.

BACKGROUND: Comprehensive cancer genomic profiling has been used recently for patients with advanced solid cancers. Two cancer genomic profiling tests for patients with no standard treatment are covered by Japanese public health insurance since June 2019. METHODS: We prospectively analyzed data of 189 patients with solid cancers who underwent either of the two-cancer genomic profiling tests at Hokkaido University Hospital and its liaison hospitals and whose results were discussed in molecular tumor board at Hokkaido University Hospital between August 2019 and July 2020. RESULTS: All 189 patients had appropriate results. Actionable gene alterations were identified in 93 patients (49%). Frequent mutations included PIK3CA (12%) mutation, BRCA1/2 alteration (7%), ERBB2 amplification (6%) and tumor mutation burden-High (4%). The median turnaround time from sample shipping to acquisition by the expert panel was 26 days. Although 115 patients (61%) were provided with information for genotype-matched therapies, only 21 (11%) received them. Notably, four of eight patients below the age of 20 years were provided information for genotype-matched therapies, and three received them. Their response rates and disease control rates were 29% and 67%, respectively. Most patients who did not undergo the genotype-matched therapies were provided information for only investigational drugs in phases I and II at distant clinical trial sites in central Japan. Twenty-six patients were informed of suspected germline findings, while 11 patients (42%) received genetic counseling. CONCLUSIONS: The publicly reimbursed cancer genomic profilings may lead to the modest but favorable therapeutic efficacy of genotype-matched therapy for solid cancer patients with no standard therapy. However, poor access to genotype-matched therapy needs to be resolved.

Vonoprazan-based triple therapy is non-inferior to susceptibility-guided proton pump inhibitor-based triple therapy for Helicobacter pylori eradication.

BACKGROUND: All Helicobacter pylori-infected patients are recommended for eradication with an appropriate regimen in each geographic area. The choice of the therapy is somewhat dependent on the antimicrobial susceptibility. The rate of clarithromycin resistance has been increasing and is associated with failure; thus, susceptibility testing is recommended before triple therapy with clarithromycin. However, antimicrobial susceptibility testing is not yet clinically available and an alternative newly developed acid inhibitor vonoprazan is used for triple therapy in Japan. The aim of this study was to determine whether vonoprazan-based triple therapy is plausible treatment in H. pylori eradication. METHODS: A retrospective observational study of H. pylori eradication was conducted in a single institute. The patients who requested antimicrobial susceptibility testing were treated with susceptibility-guided proton pump inhibitor-based triple therapy in International University of Health and Welfare Hospital from 2013 to 2016. Other patients were treated with empirical treatment with a proton pump inhibitor. From 2015 to 2016, vonoprazan-based triple treatment (vonoprazan, 20 mg; amoxicillin, 750 mg; and clarithromycin, 200 or 400 mg, b.i.d.) was conducted, and its effectiveness was compared with susceptibility-guided proton pump inhibitor-based triple therapy. We also investigated the improvement in eradication rate when antimicrobial susceptibility testing was performed, and compared the outcomes of vonoprazan-based and proton pump inhibitor-based empirical therapy. RESULTS: A total of 1355 patients who received first-line eradication treatment were enrolled in the present study. The eradication rates of the empirical proton pump inhibitor-based therapy and the vonoprazan-based therapy group in a per-protocol analysis were 86.3% (95% CI 83.8-88.8) and 97.4% (95% CI 95.7-99.1), respectively. In 212 patients who received antimicrobial susceptibility testing, the rate of clarithromycin resistant was 23.5% and the eradication rate in susceptibility-guided treatment was 95.7% (95% CI 92.9-98.4). The difference between susceptibility-guided and vonoprazan-based therapy was - 1.7% (95% CI - 4.9 to 1.5%), and the non-inferiority of vonoprazan-based triple therapy was confirmed. CONCLUSIONS: Vonoprazan-based triple therapy was effective as susceptibility-guided triple therapy for H. pylori eradication. An empirical triple therapy with vonoprazan is preferable even in area with high rates of clarithromycin-resistance. Trial registration The study was retrospectively registered in University Hospital Medical Information Network (UMIN000032351).

Beneficial Effects of Green Tea Catechins on Neurodegenerative Diseases.

Tea is one of the most consumed beverages in the world. Green tea, black tea, and oolong tea are made from the same plant Camellia sinensis (L.) O. Kuntze. Among them, green tea has been the most extensively studied for beneficial effects on diseases including cancer, obesity, diabetes, and inflammatory and neurodegenerative diseases. Several human observational and intervention studies have found beneficial effects of tea consumption on neurodegenerative impairment, such as cognitive dysfunction and memory loss. These studies supported the basis of tea's preventive effects of Parkinson's disease, but few studies have revealed such effects on Alzheimer's disease. In contrast, several human studies have not reported these favorable effects with regard to tea. This discrepancy may be due to incomplete adjustment of confounding factors, including the method of quantifying consumption, beverage temperature, cigarette smoking, alcohol consumption, and differences in genetic and environmental factors, such as race, sex, age, and lifestyle. Thus, more rigorous human studies are required to understand the neuroprotective effect of tea. A number of laboratory experiments demonstrated the benefits of green tea and green tea catechins (GTCs), such as epigallocatechin gallate (EGCG), and proposed action mechanisms. The targets of GTCs include the abnormal accumulation of fibrous proteins, such as Aß and α-synuclein, inflammation, elevated expression of pro-apoptotic proteins, and oxidative stress, which are associated with neuronal cell dysfunction and death in the cerebral cortex. Computational molecular docking analysis revealed how EGCG can prevent the accumulation of fibrous proteins. These findings suggest that GTCs have the potential to be used in the prevention and treatment of neurodegenerative diseases and could be useful for the development of new drugs.

Taste intensity modulates effective connectivity from the insular cortex to the thalamus in humans.

Evaluation of taste intensity is one of the most important perceptual abilities in our daily life. In contrast with extensive research findings regarding the spatial representation of taste in the insula and thalamus, little is known about how the thalamus and insula communicate and reciprocally influence their activities for processing taste intensity. To examine this neurophysiological relationship, we investigated the modulatory effect of intensity of saltiness on connections in the network processing taste signals in the human brain. These "effective connectivity" relationships refer to the neurophysiological influence (including direction and strength of influence) of one brain region on another. Healthy adults (N=34), including 17 males and 17 females (mean age=21.3years, SD=2.4; mean body mass index (BMI)=20.2kg/m(2), SD=2.1) underwent functional magnetic resonance imaging as they tasted three concentrations of sodium chloride solutions. By effective connectivity analysis with dynamic causal modeling, we show that taste intensity enhances top-down signal transmission from the insular cortex to the thalamus. These results are the first to demonstrate the modulatory effect of taste intensity on the taste network in the human brain.

Atranorin and lecanoric acid antagonize TCDD-induced xenobiotic response element-driven activity, but not xenobiotic response element-independent activity.

Lichens are symbiotic organisms that consist of fungi and photosynthetic symbionts (algae and/or cyanobacteria). Previous studies of their constituents suggested lichens produce many kinds of aromatic secondary metabolites, such as depsides, quinones, and dibenzofurans. In this study, we evaluated the aryl hydrocarbon receptor (AhR) antagonistic activity of 17 lichen substances and demonstrated that atranorin (1) and lecanoric acid (2), isolated from Parmotrema tinctorum Hale, showed an inhibitory effect on luciferase activity increased by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), using an XRE-driven pX4TK-Luc reporter gene assay. In addition, CYP1A1 mRNA and protein levels increased by TCDD were also suppressed by 1 and 2. Conversely, neither 1 nor 2 antagonized the suppressive effect of TCDD on interleukin (IL)-1ß-induced acute-phase response (APR) gene expression. Thus, we concluded that 1 and 2 were selective AhR modulators that antagonize XRE-dependent activity, but not XRE-independent activity. However, 1 has different characteristics to 2 in that 1 alone showed a suppressive effect on IL-1ß-induced APR gene expression in a similar fashion to TCDD.

Heterogeneous Nuclear Ribonucleoprotein A1 Improves the Intestinal Injury by Regulating Apoptosis Through Trefoil Factor 2 in Mice with Anti-CD3-induced Enteritis.

BACKGROUND: The role of hnRNP A1 in the onset of intestinal inflammation remains unclear. This study investigated the function of hnRNP A1 in mice enteritis models. METHODS: C57Bl6/J mice were intraperitoneally injected with anti-CD3 antibodies to develop enteritis. In the DSS-induced colitis group, the mice were allowed free access to 3% DSS solution in their drinking water for 5 days. 3H-mannitol flux and complementary DNA array tests were used to assess the intestinal barrier function and messenger RNA (mRNA) expression, respectively. Real-time PCR was performed after immunoprecipitation with anti-hnRNP antibodies to determine the specific mRNA binding of hnRNP A1. RESULTS: The hnRNP A1 expression was increased in the intestine of the mouse at 24 hours after treatment with anti-CD3 antibodies and 5 days after starting DSS administration. Small interfering RNA (siRNA) against hnRNP A1 exacerbated the intestinal injuries in both models. According to the microarray analysis, trefoil factor 2 (TFF2) was identified as a candidate molecule targeted by hnRNP A1 in the anti-CD3 antibody-induced enteritis group. Moreover, the binding between hnRNP A1 and TFF2 mRNA significantly increased in the enteritis mice, and the administration of siRNA against either hnRNP A1 or TFF2 exacerbated the degree of intestinal injury. In the DSS-induced colitis group, treatment with the siRNA of hnRNP A1 worsened the intestinal injury, while the expression of TFF3 did not change. CONCLUSIONS: hnRNP A1 improves intestinal injury in anti-CD3 antibody-induced enteritis mice through the upregulation of TFF2, which regulates apoptosis and enhances epithelial restoration, whereas this molecule ameliorates DSS-induced colitis through a different pathway.

Identification of a naturally occurring retinoid X receptor agonist from Brazilian green propolis.

BACKGROUND: Brazilian green propolis (BGP), a resinous substance produced from Baccharis dracunculifolia by Africanized honey bees (Apis mellifera), is used as a folk medicine. Our present study explores the retinoid X receptor (RXR) agonistic activity of BGP and the identification of an RXR agonist in its extract. METHODS: RXRα agonistic activity was evaluated using a luciferase reporter gene assay. Isolation of the RXRα agonist from the ethanolic extract of BGP was performed using successive silica gel and a reversed phase column chromatography. The interaction between the isolated RXRα agonist and RXRα protein was predicted by a receptor-ligand docking simulation. The nuclear receptor (NR) cofactor assay was used to estimate whether the isolated RXRα agonist bound to various NRs, including RXRs and peroxisome proliferator-activated receptors (PPARs). We further examined its effect on adipogenesis in 3T3-L1 fibroblasts. RESULTS: We identified drupanin as an RXRα agonist with an EC50 value of 4.8 ± 1.0 µM. Drupanin activated three RXR subtypes by a similar amount and activated PPARγ moderately. Additionally, drupanin induced adipogenesis and elevated aP2 mRNA levels in 3T3-L1 fibroblasts. CONCLUSIONS: Drupanin, a component of BGP, is a novel RXR agonist with slight PPARγ agonistic activity. GENERAL SIGNIFICANCE: This study revealed for the first time that BGP activates RXR and drupanin is an RXR agonist in its extract.

Retinoic acid receptor agonist activity of naturally occurring diterpenes.

Recent accumulating evidence indicates that all-trans retinoic acid (ATRA) may be useful for preventing or treating inflammation, allergy, and autoimmune diseases, despite its severe side effects. In this study, screening of 99 crude drugs for retinoic acid receptor (RAR) ligands by luciferase reporter assay demonstrated that the methanol extract of Aralia cordata Rhizoma most effectively activates the transcriptional activity of RARα. Pimaradienoic acid (ent-pimara-8(14),15-dien-19-oic acid) was subsequently isolated as the constituent capable of activating RAR. Pimaric acid and abietic acid, which have similar structures to pimaradienoic acid, were also found to be novel RAR agonists, although abietic acid only slightly activated peroxisome proliferator-activated receptor gamma. These three natural RAR agonists with diterpene structures, while structurally different from ATRA, were able to increase the mRNA levels of the constitutive androstane receptor in HepG2 cells, induce F9 cell differentiation followed by Cyp26a1 mRNA expression, and differentiate HL-60 cells via RAR activation in a different manner from ATRA. These results demonstrate that some diterpenes exist as naturally occurring RAR agonists and that the differences in chemical structure between ATRA and these diterpenes may induce distinct gene activation and a specific cellular response.

A naturally occurring rexinoid, honokiol, can serve as a regulator of various retinoid x receptor heterodimers.

We investigated the properties of honokiol, a natural rexinoid, as a regulator of retinoid X receptor (RXR) heterodimers with various partner nuclear receptors (NRs), in comparison with those of the synthetic rexinoid bexarotene. Honokiol alone was hardly capable of activating peroxisome proliferator-activated receptor (PPAR) γ/RXR, RXR/liver X receptor (LXR), and RXR/vitamin D receptor (VDR) heterodimers, whereas it effectively potentiated their activation by agonists for the partner NRs of the RXR heterodimers. These findings were further supported by increased mRNA and protein levels for the respective NR target genes. Bexarotene alone activated PPARγ/RXR and RXR/LXR heterodimers, but not RXR/VDR heterodimers, and facilitated the activation of all three RXR heterodimers by the respective PPARγ, LXR, and VDR agonists. When the potencies of honokiol and bexarotene were compared, honokiol was able to serve as a subsidiary agonist in the activation of RXR heterodimers in a similar manner to bexarotene. However, it seemed to potentiate the activation of PPARγ/RXR heterodimers by the PPARγ agonist rosiglitazone more efficiently than bexarotene, and was a less potent RXR agonist than bexarotene. In conclusion, we have demonstrated that honokiol is a rexinoid that possesses distinct properties from bexarotene, and mainly has subsidiary roles in the activation of RXR heterodimers by potentiating the activation of RXR heterodimers by agonists for the partner NRs.

Pectin and high-amylose maize starch increase caecal hydrogen production and relieve hepatic ischaemia-reperfusion injury in rats.

We investigated whether the feeding of high H2-generating dietary fibre and resistant starch (RS) could suppress hepatic ischaemia-reperfusion (IR) injury, which results from oxidative stress, in rats fed a pectin (Pec) or high-amylose maize starch (HAS) diet. Male Sprague-Dawley rats were fed a control (C) diet, with or without Pec (0-5 % Pec) or HAS (0-30 % HAS) supplementation for 7 d. Portal H2 concentration showed a significant dose-dependent increase with the amount of Pec or HAS supplementation. Plasma alanine and aspartate aminotransferase activities remarkably increased in the C rats (5 % cellulose) due to IR treatment, while it decreased significantly or showed tendencies to decrease in 5 % Pec and 20 % HAS diet-fed rats. The hepatic oxidised glutathione (GSSG):total glutathione ratio increased significantly in IR rats maintained on the C diet compared with sham-operated rats. On the other hand, reduced glutathione (GSH):total glutathione and GSH:GSSG ratios decreased significantly. The GSSG:total glutathione ratio that increased due to IR treatment decreased significantly on HAS and Pec intake, while GSH:total glutathione and GSH:GSSG ratios increased significantly. Hepatic sinusoids of IR rats fed the C diet were occluded, but those of IR rats fed the Pec diet were similar to those in the sham-operated rats. In conclusion, we found that Pec or HAS, which enhance H2 generation in the large intestine, alleviated hepatic IR injury. The present study demonstrates another physiological significance of dietary fibre and RS.

Effects of a catechin-free fraction derived from green tea on gene expression of gluconeogenic enzymes in rat hepatoma H4IIE cells and in the mouse liver.

Many biological activities of green tea have been attributed to a major constituent, (-)-epigallocatechin gallate (EGCG). We previously reported that EGCG and a catechin-rich green tea beverage modulated the gene expression of gluconeogenic enzymes, glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK), in the mouse liver. However, it remains to be examined whether or not a constituent other than EGCG contributes to the change in gene expression of these enzymes. In this study, we separated the hot water infusion of green tea leaves (GT) into an ethanol-soluble fraction (GT-E) and an EGCG-free water-soluble fraction (GT-W), and examined their effects using rat hepatoma H4IIE cells. The inclusion of GT, GT-E, and GT-W in the culture medium reduced the gene expression of G6Pase and PEPCK. GT-W caused a decrease in expression of the transcription factor HNF4α. Reduced levels of PEPCK and HNF4α proteins were demonstrated in the cells treated with GT-W. GT-W showed an activity similar to insulin, but different from EGCG. Administration of GT-W to mice for 4 weeks reduced the hepatic expression of G6Pase, PEPCK, and HNF4α. These results suggest that green tea contains some component(s) with insulin-like activity distinguishable from EGCG and that drinking green tea may help to prevent diabetes.

Differential gene expression in rat vascular smooth muscle cells following treatment with coptisine exerts a selective antiproliferative effect.

It is known that coptisine (1), an isoquinoline alkaloid, selectively inhibits proliferation of rat primary vascular smooth muscle cells (VSMCs). In the present study, the characteristics of its antiproliferative effect on several types of smooth muscle-like cells were investigated and compared to the effects of berberine (2) and palmatine (3). To clarify further the mechanism underlying the VSMC-selective antiproliferative effect of 1, the genes responsible were investigated by determining which mRNAs showed expression regulated by 1. Coptisine (1) showed a greater antiproliferative effect on smooth muscle cells derived from the aorta than on those derived from other organs. Analysis of the mRNA expression revealed that 1 upregulated two genes, growth arrest and DNA-damage-inducible alpha (Gadd45a) and response gene to complement32 (Rgc32). Both genes remained unchanged in 3Y1 fibroblasts and were not affected by 2 and 3. Coptisine (1) was found to induce the mRNA of the Gadd45a and Rgc32 genes, specifically in VSMC. Activation of these genes by 1 may mediate inhibition of cell-cycle progression. However, as these genes are commonly expressed in various cell types, a selective target for 1 activity is likely to exist upstream of these genes.

Raw Chinese yam (Dioscorea opposita) promotes cecal fermentation and reduces plasma non-HDL cholesterol concentration in rats.

We examined the effects of raw Chinese yam (Dioscorea opposita), containing resistant starch (RS), on lipid metabolism and cecal fermentation in rats. Raw yam (RY) and boiled yam (BY) contained 33.9% and 6.9% RS, respectively. Male Sprague-Dawley rats were fed a cholesterol-free, control (C) diet supplemented with or without 15 and 30 g of RY or BY/100 g for 3 wk. Plasma total cholesterol concentrations in the tail vein of rats fed the 30% RY diet were significantly lower than in the C group throughout the feeding period. Compared with the C group, non-HDL concentrations in arterial plasma in the 30% RY group was significantly reduced. Liver cholesterol concentration in rats fed the 30% RY diet was significantly higher compared with those fed the C diet. Hepatic cholesterol 7α-hydroxylase mRNA and fecal bile acid excretion were significantly higher in the BY, but not the RY group, compared with the C group. Fecal cholesterol excretion in the 30% RY group was greater compared with the C group. Hepatic microsomal triacylglycerol transfer protein mRNA was significantly lower in the 30% RY group compared with the C group. Cecal pools of acetate, propionate and butyrate were 113-257%, 181-476% and 410-789% greater in the RY group compared with the C group. These results suggest raw yam is effective as a source of RS and facilitates production of short chain fatty acid (SCFA), especially butyrate, in the rat cecum. In addition, RY has a plasma-cholesterol lowering effect, possibly due to the inhibited release of VLDL.

Identification of a naturally occurring rexinoid, honokiol, that activates the retinoid X receptor.

Screening of a total of 86 crude drugs for retinoid X receptor (RXR) ligands demonstrated that the methanol extract of the bark of Magnolia obovata markedly activated the transcriptional activity of RXRalpha in luciferase reporter assays. Thereafter, honokiol (1) was isolated as a constituent able to activate RXR selectively as a natural rexinoid, but not RARalpha. The activity of 1 was more potent than those of phytanic acid and docosahexaenoic acid, both of which are known to be natural RXR agonists. Honokiol (1) is capable of activating a RXR/LXR heterodimer, resulting in the induction of ATP-binding cassette transporter A1 mRNA and protein expression in RAW264.7 cells, as well as an increase in [(3)H]cholesterol efflux from peritoneal macrophages. These effects of 1 were enhanced synergistically in the presence of an LXR agonist, 22(R)-hydroxycholesterol. The results obtained demonstrate that 1, a newly identified natural rexinoid, regulates the functions of RXR/LXR heterodimer and abrogates foam cell formation by the induction of ABCA1 via activation of the RXR/LXR heterodimer.

Effects of catechin-rich green tea on gene expression of gluconeogenic enzymes in rat hepatoma H4IIE cells.

Rat hepatoma H4IIE cells were stimulated with dexamethasone and dibutyryl cAMP to increase gene expressions of gluconeogenic enzymes, glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK). Inclusion of catechin-rich green tea beverage (GTB) in the culture medium reduced the up-regulation of these genes as well as that of hepatocyte nuclear factor 4 alpha (HNF4alpha) gene. GTB was fractionated into chloroform-soluble (Fraction I), ethyl acetatesoluble (Fraction II), methanol-soluble (Fraction III) and residual (Fraction IV) fractions. Fractions II and III containing catechins caused an attenuation of the up-regulated expression of these genes as well as the down-regulation of HNF4alpha gene expression. Fraction IV had a synergistic effect on the up-regulation by dexamethasone/dibutyryl cAMP of the PEPCK gene expression and upregulated HNF4alpha gene expression. These results suggest that GTB down-regulated the expression of the HNF4alpha gene to cause the down-regulated gene expression of gluconeogenic enzymes. One reason why GTB did not down-regulate hepatic PEPCK gene expression in previous animal experiments may be that the component(s) acting to up-regulate PEPCK gene expression was more effective in vivo than in cultured cells.

Hydroxy monounsaturated fatty acids as agonists for peroxisome proliferator-activated receptors.

The physiological and pathological role of oxidized polyunsaturated fatty acids (PUFAs) has been extensively studied, whereas those of hydroxy monounsaturated fatty acids (MUFAs) are not well understood. This study demonstrated that 11-hydroxy-(9Z)-octadecenoic acid ((9Z)-11-HOE), which was isolated from adlay seeds (Coix lacryma-jobi L. var. ma-yuen STAF.), can activate peroxisome proliferator-activated receptor (PPAR)alpha, delta and gamma in luciferase reporter assays more efficiently than (9Z)-octadecenoic acid (oleic acid), and to the same degree as linoleic acid. (9Z)-11-HOE increased the mRNA levels of UCP2 and CD36 in C2C12 myotubes and THP- 1 cells, respectively, and these effects were blocked by the PPARdelta- and gamma-specific antagonists GSK0660 and T0070907, respectively. Evaluation of the structure.activity relationship between hydroxy MUFAs and PPAR activation revealed that (9E)-11-HOE, the geometrical isomer of (9Z)-11-HOE, activated PPARs more potently than (9Z)-11-HOE, and that PPAR activation by hydroxyl MUFAs was not markedly influenced by the position of the hydroxy group or the double bond, although PPARdelta seemed to possess ligand specificity different to that of PPARalpha or gamma . Additionally, the finding that 11-hydroxy octadecanoic acid, the hydrogenated product of (9E)-11- HOE, was also capable of activating PPARs to a similar extent as (9E)-11-HOE indicates that the double bond in hydroxy MUFAs is not essential for PPAR activation. In conclusion, (9Z)-11-HOE derived from alday seeds and hydroxy MUFAs with a chain length of 16 or 18 acted as PPAR agonists. Hydroxylation of MUFAs may change these compounds from silent PPAR ligands to active PPAR agonists.

Differentiation-associated alteration in sensitivity to apoptosis induced by (-)-epigallocatechin-3-O-gallate in HL-60 cells.

Green tea and its constituent (-)-epigallocatechin-3-O-gallate (EGCG) are known to have apoptosis-inducing activity on tumor cells including human leukemia HL-60 cells, providing an explanation for their anti-cancer effects. In the present study, we compared the sensitivity of undifferentiated cells and differentiated HL-60 cells with normal-like phenotypic characters. HL-60 cells treated with three differentiating agents were found to be resistant to EGCG-mediated apoptosis as compared with undifferentiated cells. Gene and protein expression of 67 kDa laminin receptor was down-regulated in differentiated HL-60 cells, suggesting its contribution to the difference in sensitivity in view of the fact that the receptor is a target of EGCG's action to induce apoptosis. The finding supports the view that EGCG induces apoptosis preferentially in cancer cells as compared with normal counterparts.

Peroxisome proliferator-activated receptor gamma ligands isolated from adlay seed (Coix lacryma-jobi L. var. ma-yuen STAPF.).

Through screening for natural ligands against peroxisome proliferator-activated receptor gamma (PPARgamma) using the PPARgamma luciferase reporter assay, 6 hydroxy unsaturated fatty acids were isolated from adlay seed (Coix lacryma-jobi L. var. ma-yuen STAPF.) extracts with acetone and 70% ethanol. The structures of these compounds were determined via spectral analysis as 13-hydroxy-(9E,11E)-octadecadienoic acid (13-E,E-HODE) (1), 9-hydroxy-(10E,12E)-octadecadienoic acid (9-E,E-HODE) (2), 9-hydroxy-(10E)-octadecenoic acid (3), 10-hydroxy-(8E)-octadecenoic acid (4), 8-hydroxy-(9E)-octadecenoic acid (5), 11-hydroxy-(9Z)-octadecenoic acid (6). 9-E,E-HODE (2) exhibited the most potent PPARgamma agonist activity of the isolated hydroxy unsaturated fatty acids. 9-E,E-HODE (2) and 13-E,E-HODE (1) are the respective geometrical isomers of 9-hydroxy-(10E,12Z)-octadecadienoic acid and 13-hydroxy-(9Z,11E)-octadecadienoic acid, both of which are likely to be natural PPARgamma agonists produced in various mammalian cells, suggesting that 9-E,E-HODE may also act as PPARgamma agonist.