Scrophularia buergeriana Extract (Brainon) Attenuates Neuroinflammation in BV-2 Microglia Cells and Promotes Neuroprotection in SH-SY5Y Neuroblastoma Cells.

Microglia-induced neuroinflammation is one of the causative factors in cognitive dysfunction and neurodegenerative disorders. Our previous studies have revealed several benefits of Scrophularia buergeriana extract (Brainon®) in the central nervous system, but the underlying mechanism of action has not been elucidated. This study is purposed to investigate the anti-inflammatory and neuroprotective mechanisms of Brainon in the BV-2 condition SH-SY5Y model. Lipopolysaccharide (LPS)-induced BV-2 conditioned media (CM) were used to treat SH-SY5Y cells to investigate neuroprotective effects of the extract against microglial cytotoxicity. Results demonstrated that pretreated Brainon decreased nitric oxide release, the inducible nitric oxide synthase expression level, and expression of cytokines like interleukin-6, interleukin-1ß, and tumor necrosis factor-α by blocking expression of TLR4/MyD88 and NLRP3 and suppressing nuclear factor κB/AP-1 and p38/JNK signaling pathways in LPS-induced BV-2 cells. In addition, when SH-SY5Y cells were treated with CM, pretreatment with Brainon increased neuronal viability by upregulating expression of antioxidant proteins like as SODs and Gpx-1. Increased autophagy and mitophagy-associated proteins also provide important clues for SH-SY5Y to prevent apoptosis by Brainon. Brainon also modulated mTOR/AMPK signaling to clear misfolded proteins or damaged mitochondria via auto/mitophagy to protect SH-SY5Y cells from CM. Taken together, these results indicate that Brainon could reduce inflammatory mediators secreted from BV-2 cells and prevent apoptosis by increasing antioxidant and auto/mitophagy mechanisms by regulating mTOR/AMPK signaling in SH-SY5Y cells. Therefore, Brainon has the potential to be developed as a natural product in a brain health functional food to inhibit cognitive decline and neuronal death.

Preventive Effect of Citrus aurantium Peel Extract on High-Fat Diet-Induced Non-alcoholic Fatty Liver in Mice.

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic lipid accumulation, which is the most common form of chronic liver disease. Multiple clinical studies using natural compounds such as flavonoids have been conducted to treat NAFLD. In the present study, the pharmacological effect of Citrus aurantium L. (Rutaceae) peel extract (CAE), which contains over 27% of polymethoxyflavone nobiletin, on NAFLD was evaluated using a high-fat diet (HFD) animal model susceptible to developing NAFLD. C57BL/6 mice were fed an HFD (60% kcal of energy derived from fat) for 8 weeks to induce obesity. Obese mice were randomly allocated to four groups of eight mice each (HFD alone, HFD with silymarin, HFD with 50 mg/kg CAE, and HFD with 100 mg/kg CAE). After 8 weeks of treatment, all mice were euthanized, and plasma and liver tissues were analyzed biochemically and histopathologically. The results indicate that CAE treatment significantly reduced HFD-induced NAFLD, as shown by decreased serum lipid index and prevented liver histopathology. The expression of genes involved in lipid synthesis including free fatty acid (FFA), peroxisome-proliferator-activated receptor γ (PPAR-γ), sterol receptor element binding protein 1c (SREBP-1c), and fatty acid synthesis enzyme was suppressed by CAE treatment. Moreover, compared to untreated mice, CAE-treated HFD mice showed decreased pro-inflammatory cytokine expression. These results demonstrated that CAE prevented HFD-induced NAFLD by reducing plasma levels of triglyceride and cholesterol and de novo lipid synthesis.

Improvement in Oil Production by Increasing Malonyl-CoA and Glycerol-3-Phosphate Pools in Scenedesmus quadricauda.

In recent years, microalgae have attracted considerable interest as a biofuel resource owing to their rapid growth, tolerance to harsh conditions, and ability to accumulate a large amount of triacylglycerols (TAGs). However, the economic effectiveness of algal biofuel is still low. In this study, we attempted to increase oil production of the microalga Scenedesmus quadricauda by elevating intracellular malonyl-CoA and glycerol-3-phosphate (G3P) pools. To increase intracellular oil content, yeast-derived genes encoding acetyl-CoA carboxylase (ACC1), glycerol kinase (GPD1), and glycerol-3-phosphate dehydrogenase (GUT1) were overexpressed under the control of CaMV 35S and NOS promoters with SV40 large T antigen components. Fatty acid profiling, G3P content, and the number of cells with high oil content were analyzed by gas chromatography-mass spectrometry, G3P assay kit, and flow cytometry, respectively. Overexpression of ACC1 increased the total fatty acid content by 1.6-fold. Overexpression of GPD1 and GUT1 increased intracellular G3P content by 1.6- and 1.9-fold, respectively. Multi-gene expression of ACC1, GPD1, and GUT1 increased the number of cells with high oil content by 1.45-fold compared with that observed with the wild-type. This study is the first to report increased oil production by overexpression of the key genes (ACC1, GPD1, and GUT1) for TAG biosynthesis in microalgae.

Glutathione S-transferase pi (GST-pi) inhibition and anti-inflammation activity of the ethyl acetate extract of Streptomyces sp. strain MJM 8637.

To investigate the anti-cancer properties of soil-borne actinobacteria, MJM 8637, the glutathione S-transferase pi (GST-pi) assay, anti-tumor necrosis factor (TNF)-α assay, the level of antioxidant potential by DPPH radical scavenging activity, NO scavenging activity, and ABTS radical scavenging activity in ethyl acetate extract were determined. The 16S rDNA sequencing analysis revealed that Streptomyces sp. strain MJM 8637, which was isolated from Hambak Mountain, Korea, has 99.5% similarity to Streptomyces atratus strain NBRC 3897. The physiological and the morphological characteristics of the strain MJM 8637 were also identified. The ethyl acetate extract of MJM 8637 inhibited TNF-α production approximately 61.8% at concentration 100 µg/ml. The IC50 value of the strain MJM 8637 extract on GST-pi was identified to be 120.2 ± 1.6 µg/ml. In DPPH, NO, and ABTS radical scavenging assays, the IC50 values of the strain MJM 8637 extract were found to be 977.2 µg/ml, 1143.7 µg/ml, and 454.4 µg/ml, respectively. The ethyl acetate extract of the strain MJM 8637 showed 97.2 ± 1.3% of cell viability at 100 µg/ml in RAW 264.7 cell viability assay. The results obtained from this study suggest that the ethyl acetate extract of Streptomyces sp. strain MJM 8637 could be considered as a potential source of drug for the cancers that have multidrug resistance with its GST-pi inhibition and anti-inflammation activities, and low cytotoxicity.

An ABC transporter complex containing S-adenosylmethionine (SAM)-induced ATP-binding protein is involved in antibiotics production and SAM signaling in Streptomyces coelicolor M145.

A sco3956-deletion mutant (ΔSCO3956) of Streptomyces coelicolor was generated to characterize the S-adenosylmethionine (SAM)-induced, ATP-binding cassette transporter (ABC transporter) ATP-binding protein, SCO3956. It produced actinorhodin (ACT) and undecylprodigiosin (RED) decreased by approx. 82 and 64 %, respectively. In addition, the effect of exogenous SAM was lost in the ΔSCO3956. Plasmid-based complementation of sco3956 in ΔSCO3956 restored ACT and RED levels of ΔSCO3956 to wild-type levels (ACT: 20 ± 1.4 mg g(-1) DCW and RED: 5.3 ± 0.6 mg g(-1) DCW) and the exogenous effect significantly increased ACT and RED by approx. 129 and 135 %, respectively, when compared to the exogenous SAM non-treated sco3956 complementation strain. Thus, the ABC transporter ATP-binding protein, SCO3956, plays a critical role in ACT and RED production serving as a transducer of SAM signaling.

Phosphoprotein affinity purification identifies proteins involved in S-adenosyl-L-methionine-induced enhancement of antibiotic production in Streptomyces coelicolor.

Streptomycetes are the major natural source of clinical antibiotics. The enhanced secondary metabolite production of many streptomycetes by S-adenosylmethionine (SAM) in previous studies suggested the existence of a common SAM regulatory effect. We screened nine proteins using the phosphoprotein purification column from Streptomyces coelicolor. Among them, genes (SCO5477, SCO5113, SCO4647, SCO4885 and SCO1793) for five proteins were disrupted by insertion mutation. The undecylprodigiosin and actinorhodin productions were changed in all mutations. The SAM-induced enhancement of actinorhodin production was abolished by all mutations except SCO4885 mutation, which reduced the production of actinorhodin and undecylprodigiosin with SAM treatment. This study demonstrates that phosphoprotein affinity purification can be used as a screening method to identify the proteins involved SAM signaling.

ATP modulates the growth of specific microbial strains.

The regulatory function of extracellular ATP (exATP) in bacteria is unknown, but recent studies have demonstrated exATP induced enhanced secondary metabolite production and morphological differentiation in Streptomyces coelicolor. The growth of Streptomyces coelicolor, however, was unaffected by exATP, although changes in growth are common phenotypes. To identify bacteria whose growth is altered by exATP, we measured exATP-induced population changes in fast-growing microbes and actinomycetes in compost. Compared with the water-treated control, the addition of 10 ml 100 µM ATP to 10 g of compost enhanced the actinomycetes population by 30% and decreased fast-growing microbial numbers by 20%. Eight microbes from each group were selected from the most populated colony, based on appearance. Of the eight isolated fast-growing microbes, the 16S rRNA sequences of three isolates were similar to the plant pathogens Serratia proteamaculans and Sphingomonas melonis, and one was close to a human pathogen, Elizabethkingia meningoseptica. The growth of all fast-growing microbes was inhibited by ATP, which was confirmed in Pseudomonas syringae DC3000, a pathogenic plant bacterium. The growth of six of eight isolated actinomycetes strains, all of which were identified as close to Streptomyces neyagawaensis, was enhanced by ATP treatment. This study suggests that exATP regulates bacterial physiology and that the exATP response system is a target for the control of bacterial ecology.

A DNA-binding factor, ArfA, interacts with the bldH promoter and affects undecylprodigiosin production in Streptomyces lividans.

The fact that adpA promoter activity is enhanced by S-adenosylmethionine without the involvement of the A-factor/ArpA regulatory cascade suggests the existence of additional transcriptional regulators for adpA expression in Streptomyces griseus. In this study, an additional adpA promoter regulatory protein, named ArfA, that is conserved among many bacteria was identified using DNA affinity purification from the cell extracts of Streptomyces lividans. The interactions of ArfA with the adpA promoter from S. griseus and with the bldH promoter from S. lividans were specific and both adpA and bldH promoters required ArfA for the wild-type level of their expressions in S. lividans. bldH of S. lividans is a homolog of adpA of S. lividans. ArfA-deletion mutant had only 70% of the normal undecylprodigiosin production. This result was confirmed by reduced redD promoter activity in the ArfA-deletion mutant. These results suggest that ArfA is a new type of DNA-binding regulator.

Antioxidant and antimelanogenic activities of polyamine conjugates from corn bran and related hydroxycinnamic acids.

The antioxidant activity of three major polyamine conjugates, N,N'-dicoumaroyl-putrescine (DCP), N-p-coumaroyl-N'-feruloylputrescine (CFP), and N,N'-diferuloyl-putrescine (DFP) isolated from corn bran, and their related hydroxycinnamic acids, p-coumaric acid and ferulic acid, were evaluated by three antioxidant in vitro assay systems, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and superoxide and hydroxyl radicals generated by enzymatic and nonenzymatic reactions. Additionally, five phenolic compounds were evaluated for melanogenesis inhibitory activity using mushroom tyrosinase and B16 melanoma cells. Most of the phenolic compounds significantly scavenged DPPH, superoxide, and hydroxyl radicals in a dose-dependent manner. Particularly, DFP showed potent DPPH (IC50 = 38.46 microM) and superoxide (IC50 = 291.62 microM) radical scavenging activities, while DCP exhibited the strongest hydroxyl radical scavenging activity (IC50 = 120.55 microM). CFP also exerted moderate DPPH, superoxide, and hydroxyl radical scavenging activities. Meanwhile, DCP (IC50 = 181.73 microM) showed potent tyrosinase inhibitory activity toward l-tyrosine as the substrate, whereas DFP (IC50 = 733.64 microM) significantly inhibited melanin synthesis in B16 melanoma cells. These current results indicate that these three polyamine conjugates from corn bran may be useful potential sources of natural antioxidants and skin-whitening agents.