Melanin Inhibitory Effect of Tuber himalayense Isolated in Incheon, Korea.

There has been a growing interest in skin beauty and antimelanogenic products. Melanogenesis is the process of melanin synthesis whereby melanocytes are activated by UV light or hormone stimulation to produce melanin. Melanogenesis is mediated by several enzymes, such as tyrosinase (TYR), microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1 (TRP-1), and TRP-2. In this study, we investigated the effect of Tuber himalayense extract on melanin synthesis in α-melanocyte-stimulating hormone (α-MSH)-treated B16F10 melanoma cells. We confirmed that T. himalayense extract was not toxic to α-MSH-treated B16F10 melanoma cells and exhibited a significant inhibitory effect on melanin synthesis at concentrations of 25, 50, and 100 µg/ml. Additionally, the T. himalayense extract inhibited melanin, TRP-1, TRP-2, tyrosinase, and MITF, which are enzymes involved in melanin synthesis, in a concentration-dependent manner. Furthermore, T. himalayense extract inhibited the mitogen-activated protein kinase (MAPK) pathways, such as extracellular signal-regulated kinase-1/2 (ERK), c-Jun N-terminal kinase (JNK), and p38. Therefore, we hypothesized that various components of T. himalayense extract affect multiple factors involved in melanogenesis in B16F10 cells. Our results indicate that T. himalayense extract could potentially be used as a new material for preparing whitening cosmetics.

Facile Detection of Light-Controlled Radical Scavengers from Natural Products Using In Situ UV-LED NMR Spectroscopy.

With the recent development of chemical analysis technology, attention has been placed on natural light-sensitive compounds that exhibit photoreactivity to expand the structural diversity of natural product chemistry. Photochemical reactions that proceed via a free radical mechanism could be used to modulate the radical-scavenging ability of natural products as well as involve structural change. As the health benefits of radicals are also presented, there is a need for a controllable radical scavenging method for topical and selective application. In this study, we developed a novel acquisition and processing method to identify light-controlled radical scavengers in plant extracts and evaluate their antioxidant activity under light irradiation based on in situ UV-LED NMR spectroscopy. Using the developed method, licochalcones A and B, in which the trans and cis isomers undergo reversible photoisomerization, were selectively identified from licorice root extract, and their light-induced free radical scavenging activity was confirmed.

Tropolone-Bearing Sesquiterpenes from Juniperus chinensis: Structures, Photochemistry and Bioactivity.

The tropolone-bearing sesquiterpenes juniperone A (1) and norjuniperone A (2) were isolated from the folk medicinal plant Juniperus chinensis, and their structures were determined by a combination of spectroscopic and crystallographic methods. Photojuniperones A1 (3) and A2 (4), bearing bicyclo[3,2,0]heptadienones derived from tropolone, were photochemically produced and structurally identified by spectroscopic methods. Predicted by the machine learning-based assay, 1 significantly inhibited the action of tyrosinase. The new compounds also inhibited lipid accumulation and enhanced the extracellular glycerol excretion.

Natural photosensitizers from Tripterygium wilfordii and their antimicrobial photodynamic therapeutic effects in a Caenorhabditis elegans model.

Tripterygium wilfordii Hook. f. is a traditional medicinal plant and has long been used in East Asia to treat many diseases. However, the extract and active components have never been investigated as potential photosensitizers for photodynamic treatment to kill pathogenic microorganisms. Here, the antimicrobial photodynamic treatment (APDT) effects of the extract, fractions, and compounds of T. wilfordii were evaluated in vitro and in vivo. Ethanolic extract (TWE) and the photosensitizer-enriched fraction (TW-F5) were prepared from dried T. wilfordii. Six active compounds were isolated from TW-F5 by semipreparative high-performance liquid chromatography, and their chemical structures were characterized through spectroscopic and spectrometric analysis. The singlet oxygen from extracts, fractions, and compounds was measured by using the imidazole-N,N-dimethyl-4-nitrosoaniline method. These extracts, fractions, and compounds were used as photosensitizers for the inactivation of bacteria and fungi by red light at 660 nm. The in vitro APDT effects were also evaluated in the model animal Caenorhabditis elegans. APDT with TWE showed effective antimicrobial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans. TW-F5, consisting of six pheophorbide compounds, also showed strong APDT activity. The photosensitizers were taken up into the bacterial cells and induced intracellular ROS production by APDT. TWE and TW-F5 also induced a strong APDT effect in vitro against skin pathogens, including Staphylococcus epidermidis and Streptococcus pyogenes. We evaluated the APDT effects of TWE and TW-F5 in C. elegans infected with various pathogens and found that PDT effectively controlled pathogenic bacteria without strong side effects. APDT reversed the growth retardation of worms induced by pathogen infection and decreased the viable pathogenic bacterial numbers associated with C. elegans. Finally, APDT with TWE increased the survivability of C. elegans infected with S. pyogenes. In summary, TWE and TW-F5 were found to be effective antimicrobial photosensitizers in PDT.

A new diagnostic paradigm for laryngopharyngeal reflux disease: correlation of impedance-pH monitoring and digital reflux scintigraphy results.

PURPOSE: No gold-standard investigation exists for laryngopharyngeal reflux (LPR). Multichannel intraluminal impedance (MII)-pH testing has uncertain utility in LPR. Meanwhile, reflux scintigraphy allows immediate and delayed visualisation of tracer reflux in the esophagus, pharynx, and lungs. The present study aimed to correlate MII-pH and scintigraphic reflux results in patients with primary LPR. METHODS: Consecutive patients with LPR underwent MII-pH and scintigraphic reflux studies. Abnormal values for MII-pH results were defined from existing literature. MII-pH and scintigraphic data were correlated. RESULTS: 105 patients with LPR [31 males (29.5%), median age 60 years (range 20-87)] were studied. Immediate scintigraphic reflux was seen in the pharynx in 94 (90.4%), and in the proximal esophagus in 94 (90.4%). Delayed scintigraphic contamination of the pharynx was seen in 101 patients (96.2%) and in the lungs of 56 patients (53.3%). For MII-pH, abnormally frequent reflux was seen in the distal esophagus in 12.4%, proximal esophagus in 25.7%, and in the pharynx in 82.9%. Patients with poor scintigraphic clearance had higher Demeester scores (p = 0.043), more proximal reflux episodes (p = 0.046), more distal acid reflux episodes (p = 0.023), and more prolonged bolus clearance times (p = 0.002). CONCLUSION: Reflux scintigraphy has a high yield in LPR patients. Scintigraphic time-activity curves correlated with validated MII-pH results. A high rate of pulmonary microaspiration was found in LPR patients. This study demonstrated a high level of pharyngeal contamination by scintigraphy and MII-pH, which supports the use of digital reflux scintigraphy in diagnosing LPR.

Nardosinone-Type Sesquiterpenes from the Hexane Fraction of Nardostachys jatamansi Attenuate NF-κB and MAPK Signaling Pathways in Lipopolysaccharide-Stimulated BV2 Microglial Cells.

Four nardosinone-type sesquiterpenes, nardosinone, isonardosinone, kanshone E, and kanshone B, were isolated from the hexane fraction of Nardostachys jatamansi (Valerianaceae) methanol extract. The structures of these compounds were mainly established by analyzing the data obtained from nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). In this study, we investigated their anti-neuroinflammatory effects in lipopolysaccharide (LPS)-induced BV2 microglial cells. The results showed that nardosinone-type sesquiterpenes inhibited the production of pro-inflammatory mediators, such as nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-induced BV2 microglial cells. These inhibitory effects were correlated with the downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, these sesquiterpenes also attenuated the mRNA expression of pro-inflammatory cytokines including interleukin-1ß (IL-1ß), IL-6, and tumor necrosis factor-α (TNF-α) in LPS-induced BV2 microglial cells. During the evaluation of the signaling pathways involved in these anti-neuroinflammatory effects, western blot analysis and DNA-binding activity assay revealed that the suppression of inflammatory reaction by these sesquiterpenes was mediated by the inactivation of nuclear factor-kappa B (NF-κB) pathway. These sesquiterpenes also suppressed the phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) signaling pathways in LPS-stimulated BV2 microglial cells. Taken together, these four nardosinone-type sesquiterpenes inhibited NF-κB- and MAPK-mediated inflammatory pathways, demonstrating their potential role in the treatment of neuroinflammation conditions.

Interaction of transcriptional repressor ArgR with transcriptional regulator FarR at the argB promoter region in Corynebacterium glutamicum.

In Corynebacterium glutamicum, the ArgR protein, a transcriptional repressor, affects the expression level of the argB gene through binding to its promoter region. The argB promoter region (positions -77 to -25) has been found by in vitro electrophoretic mobility shift assay (EMSA) results and in silico analysis to be important for the DNA binding of ArgR. Proline supplementation prevented the DNA binding of ArgR to the argB promoter region and triggered an increase of the argB mRNA level. Additional mutational analyses of the argB promoter region found nucleotides critical for ArgR binding (G located at position -58, C at position -55, and A at position -41 of the argB promoter) in that region. Another transcriptional repressor, FarR, was also demonstrated to bind to the argB promoter region. This binding was delimited to positions -57 to -77 on the argB promoter. FarR has only one putative binding domain located at positions -57 to -77, but this region exactly overlapped with the binding region located from positions -55 to -77 for the binding of ArgR within the argB promoter; thus, if ArgR bound with the argB promoter first, the binding of FarR was not observed in this region. However, if FarR bound to the binding domain located at positions -57 to -77 first, ArgR could bind other binding sites located at positions -49 to -25 within the argB promoter. Finally, this study suggests that ArgR can affect FarR binding to the argB promoter region, as protein binding is dominated by the protein most able to do so.

Utilization of phenol and naphthalene affects synthesis of various amino acids in Corynebacterium glutamicum.

This article reports multiple metabolic pathways of amino acid production via phenol and naphthalene use by Corynebacterium glutamicum. Biodegradation of phenol and naphthalene by C. glutamicum occurred in a mineral salt medium containing 1% yeast extract without any additional carbon sources. Among the amino acids synthesized via the TCA-cycle, glutamate synthesis increased in C. glutamicum supplemented with 8.5 mM phenol or with 4.2 mM naphthalene. Aspartate synthesis significantly increased when cultured with 4.2 mM naphthalene, and increased synthesis of threonine and histidine was observed only with the addition of phenol. In addition, synthesis of valine and leucine decreased considerably under both conditions. Moreover, the bioconversion of glutamate from phenol and naphthalene is regulated by a transcriptional regulator, FarR, at the transcription level of the gltBD and gdh genes. In this study, we found that the utilization of phenol and naphthalene enhances biosynthesis of several amino acids and that this mechanism is controlled by a transcriptional regulator.

Proline reduces the binding of transcriptional regulator ArgR to upstream of argB in Corynebacterium glutamicum.

In this study, the ArgR-binding sites on the arg operon Corynbebacterium glutamicum were characterized by in vivo chromatin immunoprecipitation (ChIP). In addition, the ArgR-binding affinity in the presence of glutamate, proline, or arginine was examined to get further information on expression control. The ChIP assay showed that the ArgR protein binds specifically to the upstream regions of argC, argB, argF, and argG. Upon proline supplementation, ArgR-binding affinity was significantly reduced upstream of argB, resulting in increased ornithine production. In contrast, there was no change in the binding affinity of ArgR to the upstream regions of argC, argF, argG, or argB following the addition of glutamate and arginine. These results suggest that the upstream region of argB on the arg operon plays an important role in interacting with ArgR under proline-supplemented conditions and that proline causes an increase in the endogenous level of ornithine by reducing the binding affinity of ArgR to the upstream region of argB.

Plastic changes in sensory inputs to rat substantia gelatinosa neurons following peripheral inflammation.

Although hyperalgesia elicited by inflammation has been shown to be partly due to central sensitization, the cellular mechanisms are not clear at the moment. The present study was designed to address this issue using the blind whole-cell patch-clamp technique; glutamatergic primary-afferent inputs to substantia gelatinosa (SG) neurons were compared between spinal cord slices of naive rats and rats inflamed by an intraplantar injection of complete Freund's adjuvant. In naive rats, a large number of SG neurons examined received monosynaptic A delta- (69% of 41 neurons innervated by A fibers) and/or polysynaptic C- (94% of 36 neurons innervated by C fibers) afferent inputs, and only a few neurons received monosynaptic A beta inputs (7%). In addition, when examined in neurons which have both of the A- and C-afferent inputs, A afferent-evoked excitatory postsynaptic currents (EPSCs) were larger in amplitude than C afferent-induced ones; a ratio (A/C ratio) of the former to latter amplitude was 1.8 +/- 0.1 (n = 36). In inflamed rats, a change in the synaptic responses was observed: (1) SG neurons receiving monosynaptic A delta-afferent inputs decreased in number (to 20% of 30 neurons tested, innervated by A fibers), whereas those having monosynaptic A beta-afferent inputs increased to 33%, and (2) the A/C ratio decreased to 0.7 +/- 0.1 (n = 33). These results suggest that after inflammation, a substantial number of A beta-afferents sprout into the SG from their original location (laminae III-V) and that sensory information that used to be conveyed directly to the SG through A delta afferents is transmitted there indirectly through interneurons. These reorganizations of sensory pathway may contribute, at least in part, to underlying mechanisms for the development of hyperalgesia due to inflammation.