Resveratrol Inhibits Particulate Matter-Induced Inflammatory Responses in Human Keratinocytes.

Particulate matter (PM), a major air pollutant, is a complex mixture of solid and liquid particles of various sizes. PM has been demonstrated to cause intracellular inflammation in human keratinocytes, and is associated with various skin disorders, including atopic dermatitis, eczema, and skin aging. Resveratrol is a natural polyphenol with strong antioxidant properties, and its beneficial effects against skin changes due to PM remain elusive. Therefore, in the present study, we investigated the effect of resveratrol on PM-induced skin inflammation and attempted to deduce the molecular mechanisms underlying resveratrol's effects. We found that resveratrol inhibited PM-induced aryl hydrocarbon receptor activation and reactive oxygen species formation in keratinocytes. It also suppressed the subsequent cellular inflammatory response by inhibiting mitogen-activated protein kinase activation. Consequentially, resveratrol reduced PM-induced cyclooxygenase-2/prostaglandin E2 and proinflammatory cytokine expression, including that of matrix metalloproteinase (MMP)-1, MMP-9, and interleukin-8, all of which are known to be central mediators of various inflammatory conditions and aging. In conclusion, resveratrol inhibits the PM-induced inflammatory response in human keratinocytes, and we suggest that resveratrol may have potential for preventing air pollution-related skin problems.

Stimulatory effects of platycodin D on osteoblast differentiation.

Previous studies have suggested that platycodin D is implicated in bone biology and ameliorates osteoporosis development. Platycodin D repressed the osteoclast activity and enhanced bone mineral density in the mouse model. However, the effects of platycodin D on osteoblast differentiation have not been elucidated yet. In C3H10T1/2 cells, platycodin D upregulated osteogenic markers including alkaline phosphatase (ALP), bone sialoprotein, and collagen type 1 alpha 1, and transcription factors, such as Runx2 and osterix, subsequently enhancing the bone mineralization. In a molecular mechanism study, platycodin D induced ß-catenin nuclear accumulation by upregulating GSK3ß phosphorylation. Furthermore, platycodin D upregulated the ALP activity and enhanced the mineralization process in osteoblast cells via the sirtuin 1/ß-catenin pathways. Taken together, these results suggested that platycodin D could be an effective therapeutic compound against osteoporosis because of its regulatory effects during the osteoblast differentiation.

Platycodin D Inhibits Osteoclastogenesis by Repressing the NFATc1 and MAPK Signaling Pathway.

Platycodon grandiflorum root-derived saponins (Changkil saponins, CKS) are reported to have many pharmacological activities. In our latest research, CKS was proven to have a significant osteogenic effect. However, the detail molecular mechanism of CKS on osteoclastic differentiation has not been fully investigated. Administration of CKS considerably reduced OVX-induced bone loss, and ameliorated the reduction in plasma levels of alkaline phosphatase, calcium, and phosphorus observed in OVX mice. CKS also repressed the deterioration of bone trabecular microarchitecture. Interestingly, platycodin D, the most abundant and major pharmacological constituent of triterpenoid CKS, inhibited receptor activator of NF-κB ligand (RANKL)-induced activation of NF-κB, and ERK and p38 MAPK, ultimately repressing osteoclast differentiation. OVX-induced bone turnover was attenuated by CKS, possibly via repression of osteoclast differentiation by platycodin D, the active component of CKS. Platycodin D can be regarded as an antiosteoporotic candidate for treatment of osteoporosis diseases. J. Cell. Biochem. 118: 860-868, 2017. © 2016 Wiley Periodicals, Inc.

Tripterygium regelii decreases the biosynthesis of triacylglycerol and cholesterol in HepG2 cells.

In the course of screening to find a plant material decreasing the activity of triacylglycerol and cholesterol, we identified Tripterygium regelii (TR). The methanol extract of TR leaves (TR-LM) was shown to reduce the intracellular lipid contents consisting of triacylglycerol (TG) and cholesterol in HepG2 cells. TR-LM also downregulated the mRNA and protein expression of the lipogenic genes such as SREBP-1 and its target enzymes. Consequently, TR-LM reduced the TG biosynthesis in HepG2 cells. In addition, TR-LM decreased SREBP2 and its target enzyme HMG-CoA reductase, which is involved in cholesterol synthesis. In this study, we evaluated that TR-LM attenuated cellular lipid contents through the suppression of de novo TG and cholesterol biosynthesis in HepG2 cells. All these taken together, TR-LM could be beneficial in regulating lipid metabolism and useful preventing the hyperlipidemia and its complications, in that liver is a crucial tissue for the secretion of serum lipids.

Cactus (Opuntia humifusa) water extract ameliorates loperamide-induced constipation in rats.

BACKGROUND: Korean cactus Cheonnyuncho (Opuntia humifusa) is rich in pectin, phenols, flavonoids, and minerals such as calcium and phosphorus. Some Koreans drink Cheonnyuncho juice prepared by grinding Cheonnyuncho with water. Cheonnyuncho is well known for its functional properties and antioxidant effects, but its effect on constipation has not been sufficiently studied. METHODS: Loperamide (2 mg/kg) was injected subcutaneously to induce constipation in rats. The animals were divided into four groups: a normal group (NOR), constipation control group (CON), and two constipation groups receiving the Cheonnyuncho extract (CE) at two different concentrations in drinking water, 3% (L-CE group) and 6% (H-CE group), for 25 days. RESULTS: The fecal pellet numbers of NOR and L-CE were significantly increased from 35.67 ± 2.09 (CON) to 50.60 ± 1.38 and 46.50 ± 2.91 after loperamide treatment, respectively (p < 0.05). The water content of fecal excretions was significantly enhanced in only the L-CE group (33.05 ± 0.49%) compared to control (23.38 ± 1.26%) (p < 0.05) after loperamide treatment. The oral intake of CE (L-CE and H-CE groups) significantly increased levels of the intestinal transit ratio (45.25 ± 1.86% and 41.05 ± 2.47%, respectively) compared to the CON group (32.15 ± 2.05%) (p < 0.05). Treatment with the low concentration of CE significantly increased fecal levels of acetic, propionic, butyric, and valeric acids, as well as the total short-chain fatty acid (SCFA) concentration. Histological analyses revealed that the thickness of the distal colon also increased in the CE-treated groups in a dose-dependent manner. CONCLUSIONS: Constipation decreased when CE was fed to the rats. In particular, the fecal pellet number and water content, as well as histological parameters such as distal colon thickness, improved. The CE treatment also increased the fecal SCFA content. These results show that the extract of Cheonnyuncho (O. humifusa) alleviated the symptoms of loperamide-induced constipation.

The Co-Expression Pattern of p63 and HDAC1: A Potential Way to Disclose Stem Cells in Interfollicular Epidermis.

Stem cell markers of interfollicular epidermis (IEF) have not been established thus far. The aim of this study is to suggest a new way to disclose IFE-stem cells by combining the expression of histone deacetylases (HDAC) 1 and p63. Immunohistochemical staining of HDAC1 and p63 was performed in six normal human samples. Moreover, a skin equivalent (SE) model was treated with suberoylanilohydroxamic acid (SAHA, an HDAC inhibitor) to elucidate the role of HDAC1. Finally, rapidly adhering (RA) keratinocytes to a type IV collagen, which have been identified to represent epidermal stem cells, were subjected to Western blot analysis with antibodies against HDAC1. In normal samples, there was a minor subpopulation comprised of p63-positive and HDAC1-negative cells in the basal layers. The proportion of this subpopulation was decreased with age. In the SE model, SAHA treatment increased the epidermal thickness and number of p63-positive cells in a dose dependent manner. After SAHA treatment, the expression of differentiation markers was decreased, while that of basement membrane markers was increased. In a Western blot analysis, HDAC1 was not expressed in RA cells. In conclusion, the combination of p63-positive and HDAC1-negative expressions can be a potential new way for distinguishing epidermal stem cells.

Hypoglycaemic effects of functional tri-peptides from silk in differentiated adipocytes and streptozotocin-induced diabetic mice.

BACKGROUND: In this study, the tri-peptides Gly-Glu-Tyr (GEY) and Gly-Tyr-Gly (GYG), identified previously as active compounds from the silk peptide E5K6, significantly stimulated basal and insulin-mediated glucose uptake by 3T3-L1 fibroblasts in a dose-dependent manner. RESULTS: Synthetic GEY and GYG peptides at a concentration of 500 µmol L(-1) significantly increased glucose transporter type 4 expression by 157% and 239%, respectively. Differentiation of 3T3-L1 cells into adipocytes leads to accumulation of intracellular fat droplets, and GEY and GYG at a concentration of 250 µmol L(-1) suppressed this effect by 72% and 75%, respectively. GYG improved glucose tolerance in steptozotocin (STZ)-induced diabetic mice in a dose-dependent manner. CONCLUSION: These results suggest that GYG isolated from E5K6 has anti-diabetic potential and silk waste products containing bioactive peptides could be used to the developments of treatments to lower blood glucose.

Priming Wharton's jelly-derived mesenchymal stromal/stem cells with ROCK inhibitor improves recovery in an intracerebral hemorrhage model.

Mesenchymal stromal/stem cells (MSCs) have the potential to differentiate into neuron-like cells under specific conditions and to secrete paracrine factors for neuroprotection and regeneration. Previously, Rho-kinase inhibitors have been reported to potentiate differentiation of rodent bone marrow MSCs into neuron-like cells induced by CoCl2 (HIF-1α activation-mimicking agent). Here, a strategy of priming MSCs with fasudil, a Rho-kinase inhibitor, was investigated using Wharton's jelly-derived MSCs (WJ-MSCs) to improve recovery in a rat model of intracranial hemorrhage (ICH). In vitro culture of WJ-MSCs by co-treatment with fasudil (30 µM) and CoCl2 provoked morphological changes of WJ-MSCs into neuron-like cells and increased the expression of neuronal markers. Assessment of the secretion profiles showed that fasudil (30 µM) specifically increased glial cell line-derived neurotrophic factor (GDNF) among the secreted proteins at the transcription and secretion levels. For in vivo experiments, WJ-MSCs primed with fasudil (10 µM, exposure for 6 h) were transplanted into ICH rats with HIF-1α upregulation 1 week after injury, and neurological function was assessed via rotarod and limb placement tests for 7 weeks after transplantation. The group with WJ-MSCs primed with fasudil showed improved functional performance compared with the non-primed group. Accordingly, the primed group showed stronger expression of GDNF and higher levels of microtubule-associated protein 2 and neurofilament-H positive-grafted cells in the ICH lesion 3 weeks after transplantation compared with the non-primed group. Therefore, this work suggests that priming WJ-MSCs with fasudil is a possible application for enhanced cell therapy in stroke, with additional beneficial effect of up-regulation of GDNF.

Oleanane-type triterpenoids of Aceriphyllum rossii and their diacylglycerol acyltransferase-inhibitory activity.

Six known triterpenoid compounds, 3-oxoolean-12-en-27-oic acid (1), gypsogenic acid (2), 3α-hydroxyolean-12-en-27-oic acid (3), 3ß-hydroxyolean-12-en-27-oic acid (4), aceriphyllic acid A (5), and oleanolic acid (6), were isolated from the roots of Aceriphyllum rossii. Their chemical structures were determined by comparison with available (1)H-NMR and (13)C-NMR data on known compounds. All the isolated compounds were evaluated for inhibitory activity against human diacylglycerol acyltransferases 1 and 2. Most of the isolates exhibited a better inhibitory activity against diacylglycerol acyltransferase 2 (IC50: 11.6-44.2 µM) than against diacylglycerol acyltransferase 1 (IC50: 22.7-119.5 µM). In particular, compounds 1 and 5 showed strong inhibition efficacy towards diacylglycerol acyltransferases 1 and 2, and appeared to act competitively against oleoyl-CoA in vitro. The results also indicated that both compounds reduced newly synthesized triacylglycerol in HuTu80 and HepG2 cells. Oral administration of compound 1 significantly reduced postprandial triacylglycerol in mice following an oral lipid challenge. In conclusion, the current study indicates that compound 1 suppresses both de novo triacylglycerol biosynthesis and resynthesis through the inhibition of diacylglycerol acyltransferase activity, and therefore may be a useful agent for treating diseases associated with a high triacylglycerol level.

Inhibition of diacylglycerol acyltransferase by prenylated flavonoids isolated from the stem bark of Maackia amurensis.

A new prenylated flavanone, erythraddison Z (1), together with eight known flavonoids (2-9), was isolated from the stem bark of Maackia amurensis. Their structures were elucidated on the basis of spectroscopic methods, including 1D and 2D NMR (COSY, HMQC, and HMBC) techniques. All the isolates, with the exception of 3, 6 and 7, strongly inhibited diacylglycerol acyltransferase activity in an in vitro assay with IC50 values ranging from 96.5 ± 0.6 to 135.1 ± 1.4 µM.

Saponins from the roots of Platycodon grandiflorum suppresses TGFß1-induced epithelial-mesenchymal transition via repression of PI3K/Akt, ERK1/2 and Smad2/3 pathway in human lung carcinoma A549 cells.

Transforming growth factor ß (TGFß) is a multifunctional cytokine that induces growth arrest, tissue fibrosis, and epithelial-mesenchymal transition (EMT) through activation of Smad and non-Smad signaling pathways. EMT is the differentiation switch by which polarized epithelial cells differentiate into contractile and motile mesenchymal cells. Our previous studies have shown that saponins from the roots of Platycodon grandiflorum (CKS) have antiinflammatory, antioxidant, antimetastatic, and hepatoprotective effects. In this study, we investigated the inhibitory effect of CKS on TGFß1-induced alterations characteristic of EMT in human lung carcinoma A549 cells. We found that CKS-treated cells displayed inhibited TGFß1-mediated E-cadherin downregulation and Vimentin upregulation and also retained epithelial morphology. Furthermore, TGFß1-increased Snail expression, a repressor of E-cadherin and an inducer of the EMT, was reduced by CKS. CKS inhibited TGFß1-induced phosphorylation of Akt, ERK1/2, and glycogen synthase kinase-3ß (GSK-3ß). Inhibition of PI3K/Akt and ERK1/2 also blocked TGFß1-induced GSK-3ß phosphorylation and Snail activation. Furthermore, TGFß1-increased Snail expression was reduced by selective inhibitors of Akt and ERK1/2. Moreover, CKS treatment attenuated TGFß1-induced Smad2/3 phosphorylation and upregulated Smad7 expression. These results indicate that pretreatment with the CKS inhibits the TGFß1-induced EMT through PI3K/Akt, ERK1/2, GSK-3ß and Smad2/3 in human lung carcinoma cells.

Discovery of a novel class of diacylglycerol acyltransferase 2 inhibitors with a 1H-pyrrolo[2,3-b]pyridine core.

Diacylglycerol acyltransferase 2 (DGAT2), which catalyzes the final step in triacylglycerol (TG) synthesis, is a key enzyme associated with hepatic steatosis and insulin resistance. Here, using an in vitro screen of 20000 molecules, we identified a class of compounds with a substituted 1H-pyrrolo[2,3-b]pyridine core which proved to be potent and selective inhibitors of human DGAT2. Of these compounds, H2-003 and -005 exhibited a considerable reduction in TG biosynthesis in HepG2 hepatic cells and 3T3-L1 preadipose cells. These compounds exert DGAT2-specific-inhibitory activity, which was further confirmed in DGAT2- or DGAT1-overexpressing HEK293 cells. In addition, these compounds almost completely abolished lipid droplet formation in 3T3-L1 cells when co-treated with a DGAT1 inhibitor, which was not attained using either a DGAT2 or DGAT1 inhibitor alone. Collectively, we identified two DGAT2 inhibitors, H2-003 and -005. These compounds will aid in DGAT2-related lipid metabolism research as well as in therapeutic development for the treatment of metabolic diseases associated with excessive TG.

Rotundifuran Induces Ferroptotic Cell Death and Mitochondria Permeability Transition in Lung Cancer Cells.

Rotundifuran (RF), a potent anti-inflammatory and anti-cancer compound, is a natural compound predominantly present in Vitex Rotundifolia. Herein, we investigated the effects of RF on the growth of lung cancer cells. Our findings suggested that RF inhibits cell growth, highlighting its potential as a therapeutic agent for cancer treatment. Interestingly, we observed that cell growth inhibition was not due to apoptosis, as caspases were not activated and DNA fragmentation did not occur. Furthermore, we found that intracellular vacuoles and autophagy were induced, but RF-induced cell death was not affected when autophagy was inhibited. This prompted us to investigate other possible mechanisms underlying cell growth inhibition. Through a cDNA chip analysis, we confirmed changes in the expression of ferroptosis-related genes and observed lipid peroxidation. We further examined the effect of ferroptosis inhibitors and found that they alleviated cell growth inhibition induced by RF. We also observed the involvement of calcium signaling, ROS accumulation, and JNK signaling in the induction of ferroptosis. Our findings suggested that RF is a potent anti-cancer drug and further studies are needed to validate its clinal use.

Saponins, especially platycodin D, from Platycodon grandiflorum modulate hepatic lipogenesis in high-fat diet-fed rats and high glucose-exposed HepG2 cells.

AMP-activated protein kinase (AMPK) plays a central role in controlling hepatic lipid metabolism through modulating the downstream acetyl CoA carboxylase (ACC) and sterol regulatory element-binding protein-1c (SREBP-1c) pathway. Saponins, particularly platycodin D, from the roots of Platycodon grandiflorum (Changkil saponins, CKS) have a variety of pharmacological properties, including antioxidant and hepatoprotective properties. The aim of this study was to investigate the effects of CKS on hepatic lipogenesis and on the expression of genes involved in lipogenesis, and the mechanisms involved. CKS attenuated fat accumulation and the induction of the lipogenic genes encoding SREBP-1c and fatty acid synthase in the livers of HFD-fed rats and in steatotic HepG2 cells. Blood biochemical analyses and histopathological examinations showed that CKS prevented liver injury. CKS and platycodin D each increased the phosphorylation of AMPK and acetyl-CoA carboxylase in HFD-fed rats and HepG2 cells. The use of specific inhibitors showed that platycodin D activated AMPK via SIRT1/CaMKKß in HepG2 cells. This study demonstrates that CKS or platycodin D alone can regulate hepatic lipogenesis via an AMPK-dependent signalling pathway.

Discovery of indolyl acrylamide derivatives as human diacylglycerol acyltransferase-2 selective inhibitors.

A series of indolyl acrylamide derivatives was synthesized as potential diacylglycerol acyltransferase (DGAT) inhibitors. Furfurylamine containing indolyl acrylamide derivative 5h exhibited the most potent DGAT inhibitory activity using microsomes prepared from rat liver. Further evaluation against human DGAT-1 and DGAT-2 identified indolyl acrylamide analogues as selective inhibitors against human DGAT-2. In addition, the most potent compound 5h inhibited triglyceride synthesis dose-dependently in HepG2 cell lines.

Plasma homocysteine level and hepatic sulfur amino acid metabolism in mice fed a high-fat diet.

PURPOSE: Obesity, a feature of metabolic syndrome, is a risk factor for cardiovascular disease, and elevated plasma homocysteine is associated with increased cardiovascular risk. However, little published information is available concerning the effect of obesity on homocysteine metabolism. METHODS: Hepatic homocysteine metabolism was determined in male C57BL/6 mice fed a high-fat diet for 12 weeks. RESULTS: High-fat diet increased plasma homocysteine but decreased hepatic homocysteine levels. Hepatic S-adenosylhomocysteine hydrolase levels were down-regulated in the obese mice, which was in part responsible for the decrease in hepatic S-adenosylmethionine/S-adenosylhomocysteine, which served as an index of transmethylation potential. Despite the decrease in hepatic cysteine, hepatic taurine synthesis was activated via up-regulation of cysteine dioxygenase. Hepatic levels of methionine adenosyltransferase I/III, methionine synthase, methylene tetrahydrofolate reductase, and gamma-glutamylcysteine ligase catalytic subunit were unchanged. Obese mice showed elevated betaine-homocysteine methyltransferase and decreased cystathionine beta-synthase activities, although the quantities of these enzymes were unchanged. CONCLUSION: This study suggests that plasma homocysteine level is increased in obesity-associated hepatic steatosis, possibly as a result of increased hepatic homocysteine efflux along with an altered sulfur amino acid metabolism.

Identification and validation of a selective small molecule inhibitor targeting the diacylglycerol acyltransferase 2 activity.

Diacylglycerol acyltransferase 2 (DGAT2) is one of two distinct DGAT enzymes that catalyze the last step in triacylglycerol (TG) synthesis. Findings from previous studies suggest that inhibition of DGAT2 is a promising strategy for the treatment of hepatic steatosis and insulin resistance. Here, we identified compound 122 as a potent and selective inhibitor of human DGAT2, which appeared to act competitively against oleoyl-CoA in vitro. The selective inhibition of DGAT2 was also confirmed by the reductions in enzymatic activity and de novo TG synthesis in DGAT2-overexpressing HEK293 cells and hepatic cells HepG2. Compound 122, as a newly identified inhibitor of DGAT2, will be useful for the research on DGAT2-related lipid metabolism as well as the development of therapeutic drug for several metabolic diseases.

Yeast hydrolysate protects cartilage via stimulation of type II collagen synthesis and suppression of MMP-13 production.

Type II collagen (COL II) is one of the primary components of hyaline cartilage and plays a key role in maintaining chondrocyte function. COL II is the principal target of destruction, and matrix metalloproteases (MMPs) have a major role in arthritis. In the present study, we investigated the chondroctye protection effects of specific fraction of yeast hydrolysate ((10-30 kDa molecular weight peptides). The mRNA expression of COL II was significantly increased in the YH-treated group compared to the control at concentrations above 50 µg/ml, respectively. The 200 µg/ml YH-treated group (3.43 ± 0.23 µg/ml) showed significantly reduced glycosaminoglycan (GAG) degradation relative to that in the interleukin-1ß (IL-1ß)-treated control group (4.72 ± 0.05 µg/ml). In the YH-treated group, MMP-13 level was significantly decreased in a dose-dependent manner compared to the IL-1ß-treated group without YH treatment. However, MMP-1 and MMP-3 level were not different from that of control. Under the same conditions, we also examined mRNA levels of COL II. The mRNA expression of COL II was significantly higher in the YH-treated group than in the IL-1ß-treated control group at concentrations above 100 µg/ml. In conclusion, YH stimulated COL II synthesis and significantly inhibited MMP-13 and GAG degradation caused by IL-1ß treatment.

Nutritional Status and Frailty Improvement through Senior-Friendly Diet among Community-Dwelling Older Adults in South Korea.

Considering that Korea's aging population is rapidly increasing, health serves as an indicator of older adults' quality of life, and dietary life directly affects their health. For health maintenance and improvement, preventive healthcare measures including safe food selection and nutritional supply are needed. This study aimed to evaluate the effect of senior-friendly diet on nutrition and health status improvement in older adults receiving community care. A total of 180 older adults were analyzed, with 154 and 26 in the senior-friendly diet intervention group and the general diet group, respectively. Surveys, blood tests, and frailty evaluations were conducted before and after the study. After 5 months of intervention, the blood status, nutrient intake, and frailty level were evaluated. The participants' mean age was 82.7 years, and 89.4% of them were living alone. In both groups, energy, protein, vitamin A, vitamin D, vitamin C, calcium, and magnesium intake were insufficient initially but generally improved after the intervention. Especially in the intervention group, energy, protein, vitamin D, vitamin C, and folic acid intake significantly increased. The frailty level also slightly improved, and the malnutrition rate was reduced. Even after the passage of time, the improvement effect size significantly differed between the groups. Therefore, resolving and supporting meals corresponding to the physiological needs of the older adults has a great impact on improving their quality of life, and such special consideration is a reasonable way to respond to a super-aged society.

Garcinia mangostana Suppresses Triacylglycerol Synthesis in Hepatocytes and Enterocytes.

Regulation of diacylglycerol acyltransferase (DGAT) and pancreatic lipase (PL) activities is important in the treatment of triacylglycerol (TG)-related metabolic diseases. Garcinia mangostana, also known as mangosteen, is a traditional medicine ingredient used in the treatment of inflammation in Southeast Asia. In this study, The ethanolic extract of G. mangostana peel inhibited human recombinant DGAT1 and DGAT2, and PL enzyme activities in vitro. The inhibitory activity of DGAT1 and DGAT2 enzymes of four representative bioactive substances in mangosteen was confirmed. In addition, G. mangostana was confirmed to suppress the serum TG levels in C57 mice by inhibiting the absorption and synthesis of TG in the gastrointestinal tract. Through this study, it was revealed that G. mangostana extract could be useful for the prevention and amelioration of TG-related metabolic diseases such as obesity and fatty liver.