Antioxidant and Inhibitory Activities of Filipendula glaberrima Leaf Constituents against HMG-CoA Reductase and Macrophage Foam Cell Formation.

In our search for bioactive components, various chromatographic separations of the organic fractions from Filipendula glaberrima leaves led to the isolation of a new ellagitannin and a triterpenoid, along with 26 known compounds. The structures of the isolates were determined based on their spectroscopic properties and chemical evidence, which were then evaluated for their antioxidant activities, inhibitory activities on 3-hydroxy-3-methylglutaryl-coenzyme A reductase, and foam cell formation in THP-1 cells to prevent atherosclerosis. Rugosin B methyl ester (1) showed the best HMG-CoA reductase inhibition and significantly reduced ox-low-density lipoprotein-induced THP-1 macrophage-derived foam cell formation at 25 µM. In addition, no cytotoxicity was observed in THP-1 cells at 50 µg/mL of all extracts in the macrophage foam cell formation assay. Therefore, F. glaberrima extract containing 1 is promising in the development of dietary supplements due to its potential behavior as a novel source of nutrients for preventing and treating atherosclerosis.

Chemical Constituents from Leaves of Hydrangea serrata and Their Anti-photoaging Effects on UVB-Irradiated Human Fibroblasts.

Hydrangea serrata (THUNB.) SER. (Hydrangeaceae) leaves have been used as herbal teas in Korea and Japan. The objective of this study was to identify anti-photoaging compounds in aqueous EtOH extract prepared from leaves of H. serrata and their effects on UVB-irradiated Hs68 human foreskin fibroblasts. Phytochemical study on H. serrata leaves led to the isolation and characterization of ten compounds: hydrangenol, thunberginol A, thunberginol C, hydrangenoside A, hydrangenoside C, cudrabibenzyl A, 2,3,4'-trihydroxystilbene, thunberginol F, quercetin 3-O-ß-D-xylopyranosyl (1-2)-ß-D-galactopyranoside, quercetin 3-O-ß-D-xylopyranosyl (1-2)-ß-D-glucopyranoside. Cudrabibenzyl A, 2,3,4'-trihydroxystilbene, quercetin 3-O-ß-D-xylopyranosyl (1-2)-ß-D-galactopyranoside, quercetin 3-O-ß-D-xylopyranosyl (1-2)-ß-D-glucopyranoside were firstly isolated from H. serrata. We estimated the effects of 10 compounds on cell viability and production of pro-collagen Type I, matrix metalloproteinase (MMP)-1, and hyaluronic acid (HA) after UVB irradiation. Of these compounds, hydrangenol showed potent preventive activities against reduced cell viability and degradation of pro-collagen Type I in UVB-irradiated Hs68 fibroblasts. Hydrangenol had outstanding inductive activities on HA production. It suppressed mRNA expression levels of MMP-1, MMP-3, hyaluronidase (HYAL)-1, HYAL-2, cyclooxygenase-2 (COX-2), interleukin (IL)-6, IL-8, and IL-1ß in UVB-irradiated Hs68 fibroblasts. When Hs68 fibroblasts were exposed to hydrangenol after UVB irradiation, UVB-induced reactive oxygen species (ROS) production was suppressed. Hydrangenol also inhibited the activation of activator protein-1 (AP-1) and signal transduction and activation of transcription 1 (STAT-1) by downregulating phosphorylation of p38 and extracellular signal-regulated kinase (ERK). Our data indicate that hydrangenol isolated from H. serrata leaves has potential protective effects on UVB-induced skin photoaging.

3,4-Dihydroquinazoline derivatives inhibit the activities of cholinesterase enzymes.

A series of 3,4-dihydroquinazoline derivatives consisting of the selected compounds from our chemical library on the diversity basis and the new synthetic compounds were in vitro tested for their inhibitory activities for both acetylcholinesterase (AChE, from electric eel) and butyrylcholinesterase (BChE, from equine serum) enzymes. It was discovered that most of the compounds displayed weak AChE and strong BuChE inhibitory activities. In particular, compound 8b and 8d were the most active compounds in the series against BChE with IC50 values of 45nM and 62nM, as well as 146- and 161-fold higher affinity to BChE, respectively. To understand the excellent activity of these compounds, molecular docking simulations were performed to get better insights into the mechanism of binding of 3,4-dihydroquinazoline derivatives. As expected, compound 8b and 8d bind to both catalytic anionic site (CAS) and peripheral site (PS) of BChE with better interaction energy values than AChE, in agreement with our experimental data. Furthermore, the non-competitive/mixed-type inhibitions of both compounds further confirmed their dual binding nature in kinetic studies.

Inhibitory effect of moschamine isolated from Carthamus tinctorius on LPS-induced inflammatory mediators via AP-1 and STAT1/3 inactivation in RAW 264.7 macrophages.

Seeds of Carthamus tinctorius L. (Compositae) have been used in Korean traditional medicines for the treatment of cardiovascular and bone diseases. In this study, we investigated the anti-inflammatory effects of known serotonin derivatives (1-9) isolated from the ethyl acetate (EtOAc) soluble fraction from the seeds of C. tinctorius. Compound 2, identified as moschamine, most potently inhibited lipopolysaccharide (LPS)-induced production of prostaglandin E2 (PGE2) and nitric oxide (NO) in RAW 264.7 macrophages. Moschamine concentration-dependently inhibited LPS-induced PGE2 and NO production in RAW 264.7 macrophages. Consistent with these findings, moschamine suppressed the protein and mRNA levels of cyclooxygenase-2 (COX-2), microsomal prostaglandin E2 synthase (mPGES)-1, and inducible NO synthase (iNOS), interleukin (IL)-6, and IL-1ß. In addition, pretreatment of moschamine significantly inhibited LPS-stimulated the transcriptional activity of activator protein-1 (AP-1) and the phosphorylation of signal transducer and activator of transcription (STAT)1/3 in RAW 264.7 macrophages. Moreover, moschamine inhibited LPS-induced the phosphorylation of p38 mitogen-activated protein kinase (p38) and extracellular signal-regulated kinase (ERK), but it had no effect on c-Jun N-terminal kinase (JNK). These results suggest that the mechanism of anti-inflammatory activity of moschamine is associated with the downregulation of COX-2, mPGES-1, iNOS, IL-6, and IL-1ß expression through the suppression of AP-1 and STAT1/3 activation in LPS-induced RAW 264.7 macrophages.

Synthesis and biological evaluation of fluoro-substituted 3,4-dihydroquinazoline derivatives for cytotoxic and analgesic effects.

As a bioisosteric strategy to overcome the poor metabolic stability of lead compound KYS05090S, a series of new fluoro-substituted 3,4-dihydroquinazoline derivatives was prepared and evaluated for T-type calcium channel (Cav3.2) block, cytotoxic effects and liver microsomal stability. Among them, compound 8h (KCP10068F) containing 4-fluorobenzyl amide and 4-cyclohexylphenyl ring potently blocked Cav3.2 currents (>90% inhibition) at 10µM concentration and exhibited cytotoxic effect (IC50=5.9µM) in A549 non-small cell lung cancer cells that was comparable to KYS05090S. Furthermore, 8h showed approximately a 2-fold increase in liver metabolic stability in rat and human species compared to KYS05090S. Based on these overall results, 8h (KCP10068F) may therefore represent a good backup compound for KYS05090S for further biological investigations as novel cytotoxic agent. In addition, compound 8g (KCP10067F) was found to partially protect from inflammatory pain via a blockade of Cav3.2 channels.

6'-O-Caffeoyldihydrosyringin isolated from Aster glehni suppresses lipopolysaccharide-induced iNOS, COX-2, TNF-α, IL-1ß and IL-6 expression via NF-κB and AP-1 inactivation in RAW 264.7 macrophages.

Previously, we found that ethyl acetate extract fraction of Aster glehni exhibited anti-hyperuricemic effects in animal models and also five new caffeoylglucoside derivatives were isolated from this fraction. In this work, we evaluated the anti-inflammatory effects of these caffeoylglucoside derivatives and found that 6'-O-caffeoyldihydrosyringin (2, CDS) most potently inhibited the LPS-induced production of nitric oxide (NO) and prostaglandin E2 (PGE2) in RAW 264.7 macrophages. In addition, CDS was found to concentration-dependently reduce the production of NO, PGE2, and the pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß) induced by LPS in macrophages. Consistent with these observations, CDS concentration-dependently inhibited LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxidase-2 (COX-2) expression at the protein level and also iNOS, COX-2, TNF-α, and IL-6, IL-1ß expression at the mRNA level. Furthermore, CDS suppressed the LPS-induced transcriptional activities of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) as well as the phosphorylation of p65 and c-Fos. Taken together, these results suggest that the anti-inflammatory effect of CDS is associated with the downregulation of iNOS, COX-2, TNF-α, IL-1ß, and IL-6 expression via the negative regulation of NF-κB and AP-1 activation in LPS-induced RAW 264.7 macrophages.

In vitro synergistic anticancer activity of the combination of T-type calcium channel blocker and chemotherapeutic agent in A549 cells.

As a result of our continuous research, new 3,4-dihydroquinazoline derivative containing ureido group, KCP10043F was synthesized and evaluated for T-type Ca(2+) channel (Cav3.1) blockade, cytotoxicity, and cell cycle arrest against human non-small cell lung (A549) cells. KCP10043F showed both weaker T-type Ca(2+) channel blocking activity and less cytotoxicity against A549 cells than parent compound KYS05090S [4-(benzylcarbamoylmethyl)-3-(4-biphenylyl)-2-(N,N',N'-trimethyl-1,5-pentanediamino)-3,4-dihydroquinazoline 2 hydrochloride], but it exhibited more potent G1-phase arrest than KYS05090S in A549 cells. This was found to be accompanied by the downregulations of cyclin-dependent kinase (CDK) 2, CDK4, CDK6, cyclin D2, cyclin D3, and cyclin E at the protein levels. However, p27(KIP1) as a CDK inhibitor was gradually upregulated at the protein levels and increased recruitment to CDK2, CDK4 and CDK6 after KCP10043F treatment. Based on the strong G1-phase cell cycle arrest of KCP10043F in A549 cells, the combination of KCP10043F with etoposide (or cisplatin) resulted in a synergistic cell death (combination index=0.2-0.8) via the induction of apoptosis compared with either agent alone. Taken together with these overall results and the favorable in vitro ADME (absorption, distribution, metabolism, and excretion) profiles of KCP10043F, therefore, it could be used as a potential agent for the combination therapy on human lung cancer.

Synthesis, structure determination, and biological evaluation of phenylsulfonyl hydrazide derivatives as potential anti-inflammatory agents.

In our previous research, a novel series of phenylsulfonyl hydrazide derivatives were found to reduce LPS-induced PGE2 levels in RAW 264.7 macrophage cells via an inhibition of mPGES-1 enzyme. Recently, it was found that a regioisomeric mixture of phenylsulfonyl hydrazide was formed depending on the reaction conditions, which favor either of two regioisomers. One regioisomer corresponds to a kinetic product (7a-7c) and the other regioisomer corresponds to a thermodynamic product (8a-8c). Among them, the structure of kinetic product 7b was confirmed by measuring single X-ray crystallography. In vitro PGE2 assay studies showed that the kinetic product (7a and 7b; IC50=0.69 and 0.55µM against PGE2) is generally more potent than the thermodynamic product (8a and 8b; IC50=>10 and 0.79µM against PGE2). A molecular docking study also exhibited that the kinetic product (7a) has a higher MolDock Score (-147.4) than that of 8a (-142.4), which is consistent with the PGE2 assay results. A new potent phenylsulfonyl hydrazide (7d; IC50=0.06µM against PGE2) without affecting COX-1 and COX-2 enzyme activities was identified based on these overall results.

Synthesis of (2-amino)ethyl derivatives of quercetin 3-O-methyl ether and their antioxidant and neuroprotective effects.

Reactive oxygen species have been implicated in several diseases, particularly in ischemia-reperfusion injury. Quercetin 3-O-methyl ether has been reported to show potent antioxidant and neuroprotective activity against neuronal damage induced by reactive oxygen species. Several aminoethyl-substituted derivatives of quercetin 3-O-methyl ether have been synthesized to increase water solubility while retaining antioxidant and neuroprotective activity. Among such derivatives, compound 3a shows potent and well-balanced antioxidant activity in three types of cell-free assay systems and has in vivo neuroprotective effects on transient focal ischemic injury induced by the occlusion of the middle cerebral artery in rats.

Aster glehni Extract, Including Caffeoylquinic Acids as the Main Constituents, Induces PPAR ß/δ-Dependent Muscle-Type Change and Myogenesis in Apolipoprotein E Knockout Mice.

To probe the functions of Aster glehni (AG) extract containing various caffeoylquinic acids on dyslipidemia, obesity, and skeletal muscle-related diseases focused on the roles of skeletal muscle, we measured the levels of biomarkers involved in oxidative phosphorylation and type change of skeletal muscle in C2C12 cells and skeletal muscle tissues from apolipoprotein E knockout (ApoE KO) mice. After AG extract treatment in cell and animal experiments, western blotting, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA) were used to estimate the levels of proteins that participated in skeletal muscle type change and oxidative phosphorylation. AG extract elevated protein expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), phosphorylated 5'-AMP-activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor beta/delta (PPARß/δ), myoblast determination protein 1 (MyoD), and myoglobin in skeletal muscle tissues. Furthermore, it elevated the ATP concentration. However, protein expression of myostatin was decreased by AG treatment. In C2C12 cells, increments of MyoD, myoglobin, myosin, ATP-producing pathway, and differentiation degree by AG were dependent on PPARß/δ and caffeoylquinic acids. AG extract can contribute to the amelioration of skeletal muscle inactivity and sarcopenia through myogenesis in skeletal muscle tissues from ApoE KO mice, and function of AG extract may be dependent on PPARß/δ, and the main functional constituents of AG are trans-5-O-caffeoylquinic acid and 3,5-O-dicaffeoylquinic acid. In addition, in skeletal muscle, AG has potent efficacies against dyslipidemia and obesity through the increase of the type 1 muscle fiber content to produce more ATP by oxidative phosphorylation in skeletal muscle tissues from ApoE KO mice.

Hydrangenol, an active constituent of Hydrangea serrata (Thunb.) Ser., ameliorates colitis through suppression of macrophage-mediated inflammation in dextran sulfate sodium-treated mice.

Ulcerative colitis (UC) is a chronic disease of the colon characterized by mucosal damage and relapsing gastrointestinal inflammation. Hydrangea serrata (Thunb.) Ser. and its bioactive compound, hydrangenol, are reported to have anti-inflammatory effects, but few studies have investigated the effects of hydrangenol in colitis. In the present study, we evaluated for the first time the anti-colitic effects and molecular mechanisms of hydrangenol in a dextran sodium sulfate (DSS)-induced mouse colitis model. To investigate the anti-colitic effects of hydrangenol, DSS-induced colitis mice, HT-29 colonic epithelial cells treated with supernatant from LPS-inflamed THP-1 macrophages, and LPS-induced RAW264.7 macrophages were used. In addition, to clarify the molecular mechanisms of this study, quantitative real time-PCR, western blot analysis, TUNEL assay, and annexin V-FITC/PI double staining analysis were conducted. Oral administration of hydrangenol (15 or 30 mg kg-1) significantly alleviated DSS-induced colitis by preventing DAI scores, shortening colon length, and colonic structural damage. F4/80+ macrophage numbers in mesenteric lymph nodes and macrophage infiltration in colonic tissues were significantly suppressed following hydrangenol treatment in DSS-exposed mice. Hydrangenol significantly attenuated DSS-induced destruction of the colonic epithelial cell layer through regulation of pro-caspase-3, occludin, and claudin-1 protein expression. Moreover, hydrangenol ameliorated abnormal tight junction protein expression and apoptosis in HT-29 colonic epithelial cells treated with supernatant from LPS-inflamed THP-1 macrophages. Hydrangenol suppressed the expression of pro-inflammatory mediators, such as iNOS, COX-2, TNF-α, IL-6, and IL-1ß through NF-κB, AP-1, and STAT1/3 inactivation in DSS-induced colon tissue and LPS-induced RAW264.7 macrophages. Taken together, our findings suggest that hydrangenol recovers the tight junction proteins and down-regulates the expression of the pro-inflammatory mediators by interfering with the macrophage infiltration in DSS-induced colitis. Our study provides compelling evidence that hydrangenol may be a candidate for inflammatory bowel disease therapy.

Synthesis of cinnamoyl ketoamides as hybrid structures of antioxidants and calpain inhibitors.

The excessive calpain activation causes serious cellular damage or even cell death in neurological disorders such as stroke and Alzheimer's disease. Oxidative stress has also been implicated in the initiation or progression of neurodegenerative diseases. In the present studies, a series of cinnamoyl ketoamides 4a-4j were synthesized as hybrid structures of antioxidants and calpain inhibitors. Cinnamoyl ketoamides, possessing an alkyl chain at the α-position, showed potent µ-calpain inhibitory activities indicating that the cinnamoyl skeleton can be regarded as an acyclic variant of calpain inhibitory chromone carboxamide 2. Among synthesized, compound 4e was the most potent inhibitor of µ-calpain (IC(50)=0.13 µM) and also exhibited strong antioxidant activities in DPPH and superoxide anion radical scavenging and lipid peroxidation inhibition assay systems.

Aster glehni F. Schmidt Extract Modulates the Activities of HMG-CoA Reductase and Fatty Acid Synthase.

Aster glehni F. Schmidt (AG), is a natural product known to have anti-obesity effects, but the mechanism underlying these effects is not well documented. We hypothesized that AG may have inhibitory effects on enzymes related to lipid accumulation. Herein, AG fractions were tested against HMG-CoA reductase (HMGR) and fatty acid synthase (FAS), two important enzymes involved in cholesterol and fatty acid synthesis, respectively. We found that dicaffeoylquinic acid (DCQA) methyl esters present in AG are largely responsible for the inhibition of HMGR and FAS. Since free DCQA is a major form present in AG, we demonstrated that a simple methylation of the AG extract could increase the overall inhibitory effects against those enzymes. Through this simple process, we were able to increase the inhibitory effect by 150%. We believe that our processed AG effectively modulates the HMGR and FAS activities, providing promising therapeutic potential for cholesterol- and lipid-lowering effects.

Stilbene derivatives as human 5-HT(6) receptor antagonists from the root of Caragana sinica.

The 5-HT6 receptor (5-HT6R) is a member of the class of recently discovered 5-hydroxytryptamine (5-HT) receptors. Due to the lack of selective 5-HT6R ligands, the cellular signaling mechanisms of the 5-HT6R are poorly understood. We previously developed a cell-based high-throughput screening (HTS) method for the 5-HT6R and screened synthetic chemical compounds. In the present study, we expanded our screening into natural products to find novel 5-HT6R ligands. We found that the ethyl acetate fraction from the root of Caragana sinica (537-18BE) produced the most potent antagonistic activity. After further isolation of 537-18BE, we found that three stilbene derivatives, (+)-α-viniferin, miyabenol C and pallidol, are active constituents of 537-18BE inhibiting the 5-HT6R. Among them, (+)-α-viniferin showed the most potent inhibition, and miyabenol C also produced a considerable inhibition. When examined effects on other neurotransmitters for selectivity, 537-18BE and three stilbene derivatives did not produce any notable effects on 5-HT4, 5-HT7, or muscarinic acetylcholine M1 (M(1)) receptors. Furthermore, 5-HT6R antagonistic effects of (+)-α-viniferin, miyabenol C and pallidol were confirmed on extracellular signal-regulated kinase 1 and 2 (ERK1/2) which exerts effects in downstream pathways of 5-HT6R activation.

A new diarylheptanoid glycoside from the stem bark of Alnus hirsuta and protective effects of diarylheptanoid derivatives in human HepG2 cells.

To search for secondary metabolites of Alnus hirsuta (Betulaceae), various chromatographic separations of the ethyl acetate soluble fraction of the stem bark of A. hirsuta led to the isolation of a new diarylheptanoid glycoside, (3R)-1,7-bis-(4-dihydroxyphenyl)-3-heptanol 3-O-beta-D-glucopyranosyl(1-->3)-beta-D-xylopyranoside (13) and twelve diarylheptanoid derivatives, namely, oregonin (1), rubranoside A (2), hirsutanonol 5-O-beta-D-glucopyranoside (3), rubranoside B (4), rubranoside C (5), hirsutanonol (6), hirsutenone (7), (5S)-O-methylhirsutanonol (8), platyphylloside (9), platyphyllonol 5-O-beta-D-xylopyranoside (10), aceroside VII (11) and platyphyllenone (12). Isolates were assessed for their hepatoprotective effects against tert-butylhydroperoxide (t-BHP)-induced toxicity in HepG2 cells. Of these isolates, compounds 1-8 showed significant hepatoprotective effects on t-BHP-induced damage to HepG2 cells, with 8 exhibiting the greatest protective effect (50.7 + or - 3.7% at a concentration of 10 microM).

Synthesis of tyrosinase inhibitory (4-oxo-4H-pyran-2-yl)acrylic acid ester derivatives.

Melanogenesis is a physiological process that results in the production of melanin pigment. However, excessive accumulations of epidermal pigmentation can cause various hyperpigmentary disorders such as, melasma and age spots. Kojic acid and hydroxylated cinnamic acid derivatives are known to inhibit tyrosinase, a key component of melanin biosynthesis. Pyronyl-acrylic acid esters 3a-i, which share structural features of kojic acid and hydroxylated cinnamic acid, were prepared and their abilities to inhibit tyrosinase and melanin production were evaluated. Of the esters synthesized, 3e and 3h, which derived from diethylene glycol moieties were found to inhibit melanin production by ca. 20% at 20 microg/ml, whereas kojic acid at 200 microg/ml inhibited melanin production by 15.8%.

Glucose-containing flavones--their synthesis and antioxidant and neuroprotective activities.

Due to high reactivity, reactive oxygen species can attack biological molecules leading to cell or tissue injury. In this study, glucose moiety was attached at the C-7 position of quercetin 3-O-methyl ether (1) and luteolin (2) through glycosidic bond or ether linkage. The glucose-containing compounds showed potent DPPH and superoxide anion radical scavenging and lipid peroxidation inhibition activities and nearly equivalent protective actions to the parent aglycons against the H2O2-induced oxidative neuronal damage in primary cultured rat cortical cells. Among the compounds tested, 3b and 3c were the most potent (IC50 values=7.33 and 5.34 microM, respectively), exhibiting nearly equivalent actions to the parent compounds 1 and 2 (IC50=3.50 and 3.75 microM, respectively).

Hydrangenol Isolated from the Leaves of Hydrangea serrata Attenuates Wrinkle Formation and Repairs Skin Moisture in UVB-Irradiated Hairless Mice.

Our previous study showed that hydrangenol isolated from Hydrangea serrata leaves exerts antiphotoaging activity in vitro. In this study, we determined its antiphotoaging effect in UVB-irradiated HR-1 hairless mice. We evaluated wrinkle formation, skin thickness, histological characteristics, and mRNA and protein expression using qRT-PCR and Western blot analysis in dorsal skins. Hydrangenol mitigated wrinkle formation, dorsal thickness, dehydration, and collagen degradation. Hydrangenol increased the expression of involucrin, filaggrin, and aquaporin-3 (AQP3) as well as hyaluronic acid (HA) production via hyaluronidase (HYAL)-1/-2 downregulation. Consistent with the recovery of collagen composition, the expression of Pro-COL1A1 was increased by hydrangenol. Matrix metalloproteinase (MMP)-1/-3, cyclooxygenase-2 (COX-2), and interleukin-6 (IL-6) expression was reduced by hydrangenol. Hydrangenol attenuated the phosphorylation of mitogen-activated protein kinases (MAPKs) including ERK and p38, activator protein 1 (AP-1) subunit, and signal transduction and activation of transcription 1 (STAT1). Hydrangenol upregulated the expression of nuclear factor-E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO-1), glutamate cysteine ligase modifier subunit (GCLM), and glutamate cysteine ligase catalysis subunit (GCLC). Taken together, our data suggest that hydrangenol can prevent wrinkle formation by reducing MMP and inflammatory cytokine levels and increasing the expression of moisturizing factors and antioxidant genes.

Corrigendum to "Caffeoylquinic Acid-Rich Extract of Aster glehni F. Schmidt Ameliorates Nonalcoholic Fatty Liver through the Regulation of PPARδ and Adiponectin in ApoE KO Mice".

[This corrects the article DOI: 10.1155/2017/3912567.].

Hydrangea serrata (Thunb.) Ser. Extract Attenuate UVB-Induced Photoaging through MAPK/AP-1 Inactivation in Human Skin Fibroblasts and Hairless Mice.

Skin photoaging is mainly caused by exposure to ultraviolet (UV) light, which increases expressions of matrix metalloproteinases (MMPs) and destroys collagen fibers, consequently inducing wrinkle formation. Nutritional factors have received scientific attention for use as agents for normal skin functions. The aim of this study was to investigate the effect of hot water extracts from the leaves of Hydrangea serrata (Thunb.) Ser. (WHS) against ultraviolet B (UVB)-induced skin photoaging and to elucidate the underlying molecular mechanisms in human foreskin fibroblasts (Hs68) and HR-1 hairless mice. WHS recovered UVB-reduced cell viability and ameliorated oxidative stress by inhibiting intracellular reactive oxygen species (ROS) generation in Hs68 cells. WHS rescued UVB-induced collagen degradation by suppressing MMP expression, and reduced the mRNA levels of inflammatory cytokines. These anti-photoaging activities of WHS were associated with inhibition of the activator protein 1 (AP-1), signal transduction and activation of transcription 1 (STAT1), and mitogen-activated protein kinase (MAPK) signaling pathways. Oral administration of WHS effectively alleviated dorsal skin from wrinkle formation, epidermal thickening, collagen degradation, and skin dehydration in HR-1 hairless mice exposed to UVB. Notably, WHS suppressed UVB activation of the AP-1 and MAPK signaling pathways in dorsal mouse skin tissues. Taken together, our data indicate that WHS prevents UVB-induced skin damage due to collagen degradation and MMP activation via inactivation of MAPK/AP-1 signaling pathway.