• Journal of Microbiology and Biotechnology
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• v.31 no.9
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• pp.1241-1255
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• 2021

This study was carried out to explore a non-chemical strategy for enhancing productivity by employing some antagonistic rhizobacteria. One hundred eighteen bacterial isolates were obtained from the rhizospheric zone of various crop fields of Gangwon-do, Korea, and screened for antifungal activity against Fusarium wilt (Fusarium oxysporum f. sp. lactucae) in lettuce crop under in vitro and in vivo conditions. In broth-based dual culture assay, fourteen bacterial isolates showed significant inhibition of mycelial growth of F. oxysporium f. sp. lactucae. All of the antagonistic isolates were further characterized for the antagonistic traits under in vitro conditions. The isolates were identified on the basis of biochemical characteristics and confirmed at their species level by 16S rRNA gene sequencing analysis. Arthrobacter sulfonivorans, Bacillus siamensis, Bacillus amyloliquefaciens, Pseudomonas proteolytica, four Paenibacillus peoriae strains, and Bacillus subtilis were identified from the biochemical characterization and 16S rRNA gene sequencing analysis. The isolates EN21 and EN23 showed significant decrease in disease severity on lettuce compared to infected control and other bacterial treatments under greenhouse conditions. Two bacterial isolates, EN4 and EN21, were evaluated to assess their disease reduction and growth promotion in lettuce in field conditions. The consortium of EN4 and EN21 showed significant enhancement of growth on lettuce by suppressing disease caused by F. oxysporum f. sp. lactucae respectively. This study clearly indicates that the promising isolates, EN4 (P. proteolytica) and EN21 (Bacillus siamensis), can be commercialized and used as biofertilizer and/or biopesticide for sustainable crop production.

• Nutrition Research and Practice
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• v.15 no.5
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• pp.591-603
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• 2021

BACKGROUND/OBJECTIVES: Unregulated inflammatory responses caused by hyperglycemia may induce diabetes complications. Hesperetin, a bioflavonoid, is a glycoside in citrus fruits and is known to have antioxidant and anticarcinogenic properties. However, the effect of inflammation on the diabetic environment has not been reported to date. In this study, we investigated the effect of hesperetin on proinflammatory cytokine secretion and its underlying mechanistic regulation in THP-1 macrophages with co-treatment LPS and hyperglycemic conditions. MATERIALS/METHODS: THP-1 cells differentiated by PMA (1 µM) were cultured for 48 h in the presence or absence of hesperetin under normoglycemic (5.5 mM/L glucose) or hyperglycemic (25 mM/L glucose) conditions and then treated with LPS (100 ng/mL) for 6 h before harvesting. Inflammation-related proteins and mRNA levels were evaluated by enzyme-linked immunosorbent assay, western blot, and quantitative polymerase chain reaction analyses. RESULTS: Hesperetin (0-100 µM, 48 h) treatment did not affect cell viability. The tumor necrosis factor-α and interleukin-6 levels increased in cells co-treated with LPS under hyperglycemic conditions compared to normoglycemic conditions, and these increases were decreased by hesperetin treatment. The TLR2/4 and MyD88 activity levels increased in cells co-treated with LPS under hyperglycemic conditions compared to normoglycemic conditions; however, hesperetin treatment inhibited the TLR2/4 and MyD88 activity increases. In addition, nuclear factor-κB (NF-κB) and Acetyl-NF-κB levels increased in response to treatment with LPS under hyperglycemic conditions compared to normoglycemic conditions, but those levels were decreased when treated with hesperetin. SIRT3 and SIRT6 expressions were increased by hesperetin treatment. CONCLUSIONS: Our results suggest that hesperetin may be a potential agent for suppressing inflammation in diabetes.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.160-164
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• 2021

This study investigated various physiological activities to examine the applicability of the functional materials of Allium tuberosum root extract. The A. tuberosum root extract showed a low cytotoxicity against murine melanoma B16F10 cells. It also showed high DPPH radical scavenging activity (ID50, 6.2 ㎍/mL), inhibited tyrosinase activity (ID50, 115.4 ㎍/mL), and decreased melanin content (ID50, 31.5 ㎍/mL). Treatment of B16F10 cells with A. tuberosum root extract suppressed the protein expression of tyrosinase in a dose-dependent manner. These findings suggest that A. tuberosum root extract inhibits melanin synthesis by suppressing intracellular tyrosinase expression. Additionally, A. tuberosum root extract inhibited elastase with an ID50 value of 145.1 ㎍/mL and contained isoquercitrin. These results indicate that A. tuberosum root extract is an appropriate natural material.

• Biomolecules & Therapeutics
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• v.27 no.1
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• pp.92-100
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• 2019

Ginger, one of worldwide consumed dietary spice, is not only famous as food supplements, but also believed to exert a variety of remarkable pharmacological activity as herbal remedies. In this study, a ginger constituent, 12-dehydrogingerdione (DHGD) was proven that has comparable anti-inflammatory activity with positive control 6-shogaol in inhibiting LPS-induced interleukin (IL)-6, tumor necrosis factor $(TNF)-{\alpha}$, prostaglandin (PG) $E_2$, nitric oxide (NO), inducible NO synthase (iNOS) and cyclooxygenase (COX)-2, without interfering with COX-1 in cultured microglial cells. Subsequent mechanistic studies indicate that 12-DHGD may inhibit neuro-inflammation through suppressing the LPS-activated $Akt/IKK/NF-{\kappa}B$ pathway. Furthermore, 12-DHGD markedly promoted the activation of NF-E2-related factor (Nrf)-2 and heme oxygenase (HO)-1, and we demonstrated that the involvement of HO-1 on the production of pro-inflammatory mediators such as NO and $TNF-{\alpha}$ by using a HO-1 inhibitor, Zinc protoporphyrin (Znpp). These results indicate that 12-DHGD may protect against neuro-inflammation by inhibiting $Akt/IKK/I{\kappa}B/NF-{\kappa}B$ pathway and promoting Nrf-2/HO-1 pathway.

• BMB Reports
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• v.52 no.7
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• pp.439-444
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• 2019

Although hypoxic/ischemic injury is thought to contribute to the incidence of Alzheimer's disease (AD), the molecular mechanism that determines the relationship between hypoxia-induced ${\beta}$-amyloid ($A{\beta}$) generation and development of AD is not yet known. We have now investigated the protective effects of N,4,5-trimethylthiazol-2-amine hydrochloride (KHG26702), a novel thiazole derivative, on oxygen-glucose deprivation (OGD)-reoxygenation (OGD-R)-induced $A{\beta}$ production in SH-SY5Y human neuroblastoma cells. Pretreatment of these cells with KHG26702 significantly attenuated OGD-R-induced production of reactive oxygen species and elevation of levels of malondialdehyde, prostaglandin $E_2$, interleukin 6 and glutathione, as well as superoxide dismutase activity. KHG26702 also reduced OGD-R-induced expression of the apoptotic protein caspase-3, the apoptosis regulator Bcl-2, and the autophagy protein becn-1. Finally, KHG26702 reduced OGD-R-induced $A{\beta}$ production and cleavage of amyloid precursor protein, by inhibiting secretase activity and suppressing the autophagic pathway. Although supporting data from in vivo studies are required, our results indicate that KHG26702 may prevent neuronal cell damage from OGD-R-induced toxicity.

• Journal of Microbiology and Biotechnology
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• v.28 no.12
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• pp.2079-2094
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• 2018

Sunflower trypsin inhibitor (SFTI) is a 14-amino-acid bicyclic peptide that contains a single internal disulfide bond. We initially constructed chimeras of SFTI with N-terminal secretion signals from the Escherichia coli OmpA and Pseudomonas aeruginosa ToxA, but only detected small amounts of protease inhibition resulting from these constructs. A substantially higher degree of protease inhibition was detected from a C-terminal SFTI fusion with E. coli YebF, which radiated more than a centimeter from an individual colony of E. coli using a culture-based inhibitor assay. Inhibitory activity was further improved in YebF-SFTI fusions by the addition of a trypsin cleavage signal immediately upstream of SFTI, and resulted in production of a 14-amino-acid, disulfide-bonded SFTI free in the culture supernatant. To assess the potential of the secreted SFTI to protect the ability of a cytotoxic protein to kill tumor cells, we utilized a tumor-selective form of the Pseudomonas ToxA (OTG-PE38K) alone and expressed as a polycistronic construct with YebF-SFTI in the tumor-targeted Salmonella VNP20009. When we assessed the ability of toxin-containing culture supernatants to kill MDA-MB-468 breast cancer cells, the untreated OTG-PE38K was able to eliminate all detectable tumor cells, while pretreatment with trypsin resulted in the complete loss of anticancer cytotoxicity. However, when OTG-PE38K was co-expressed with YebF-SFTI, cytotoxicity was completely retained in the presence of trypsin. These data demonstrate SFTI chimeras are secreted in a functional form and that co-expression of protease inhibitors with therapeutic proteins by tumor-targeted bacteria has the potential to enhance the activity of therapeutic proteins by suppressing their degradation within a proteolytic environment.

• Journal of Mycology and Infection
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• v.23 no.4
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• pp.91-98
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• 2018

Background: Malassezia, a lipophilic yeast, is a causative agent for dandruff and seborrheic dermatitis. Many biological agents have been studied for anti-Malassezia effect but further studies are needed for their clinical application. Objective: The study was conducted to evaluate the inhibitory effect of different natural essential oils and a fruit extract on Malassezia species in an in vitro study and a clinical trial. Methods: The antifungal effects of natural essential oils and a fruit extract on Malassezia species (M. furfur and M. sympodialis) were evaluated by measuring the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) and using the disc diffusion method. Natural essential oils of citron seed, lavender, and rosemary and citrus junos fruit extract were used for the in vitro study. The clinical trial was conducted with a shampoo containing four ingredients. A total of 22 subjects used the shampoo every day for 4 weeks and were evaluated using clinical photography, trichoscopy, and sebumeter at baseline, 2 weeks, and 4 weeks after treatment. Results: Antifungal activity of agents was relatively lower in lavender and rosemary essential oils at MIC and MFC. Disc diffusion method revealed same results. In the clinical trial, the amount of sebum decreased statistically significantly and erythema, dandruff, and lesion extent also improved. Conclusion: The natural essential oils and fruit extract are effective for suppressing Malassezia activity, therefore these might be used as an alternative for treatment of dandruff and seborrheic dermatitis.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.5
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• pp.395-401
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• 2021

Extended inflammation and cytokine production pathogenically contribute to a number of inflammatory disorders. Formosanin C (FC) is the major diosgenin saponin found in herb Paris formosana Hayata (Liliaceae), which has been shown to exert anti-cancer and immunomodulatory functions. In this study, we aimed to investigate anti-inflammatory activity of FC and the underlying molecular mechanism. RAW264.7 macrophages were stimulated with lipopolysaccharide (LPS) or pretreated with FC prior to being stimulated with LPS. Thereafter, the macrophages were subjected to analysis of the expression levels of pro-inflammatory mediators, including nitric oxide (NO), prostaglandin E₂ (PGE), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6, as well as two relevant enzymes, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). The analysis revealed that FC administration blunted LPS-induced production of NO and PGE in a dose-dependent manner, while the expression of iNOS and COX-2 at both mRNA and protein levels was inhibited in LPS-stimulated macrophages pre-treated with FC. Moreover, LPS stimulation upregulated mRNA expression and medium release of TNF-α, IL-1β, and IL-6, whereas this effect was blocked upon FC pre-administration. Mechanistic studies showed that inhibitory effects of FC on LPS-induced inflammation were associated with a downregulation of IκB kinase, IκB, and p65/NF-κB pathway. Taken together, these data suggest that FC possesses an inflammation-suppressing activity, thus being a potential agent for the treatment of inflammation-associated disorders.

• Journal of the Korean Applied Science and Technology
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• v.38 no.3
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• pp.883-890
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• 2021

In this study, we investigated the melanogenesis inhibitory effects of Rubus crataefifolius Leaf Extract (RCLE) in B16F10 melanoma cells. We examined the effects of RCLE on the melanin contents and tyrosinase activity, as well as the protein expression levels of the melanogenic enzymes TRP-1, TRP-2, and MITF in α-MSH -stimulated B16F10 melanoma cells. RCLE effectively inhibited tyrosinase activity and melanogenesis, suppressed the phosphorylation of PKA and CREB, and expression of MIT involved in the melanogenesis pathway, and down-regulated expression of melanogenesis related proteins. These result suggest that RCLE inhibited α-MSH-stimulated melanin synthesis by suppressing MITF expression. Therefore, our study suggests that RCLE has potential as a safe treatment for excessive pigmentation or as a natural ingredient in cosmetics.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.4
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• pp.177-183
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• 2020

The Hippo-YAP signaling pathway is critical for cell proliferation, survival, and self-renewal in both Drosophila and mammals. Disorder of Hippo-YAP pathway leads to tumor development, progression and poor prognosis in various cancers. YAP/TAZ are the key downstream effectors of the Hippo pathway and they can be inhibited through LATS1/2, core kinases in the Hippo pathway, mediated phosphorylation. In this study, we investigated the effect of Angelica gigas Nakai extract (AGNE) on Hippo-YAP/TAZ pathway. First, ANGE induced YAP/TAZ phosphorylation and dissociation of the YAP/TAZ-TEAD transcription complex. By qRT-PCR, we found that ANGE inhibits the expression of YAP/TAZ-TEAD target gene, CTGF and CYR61. In addition, the transcriptional activity of YAP/TAZ was not suppressed significantly in LATS1/2 double-knockout (DKO) cells by ANGE compared to LATS1/2 wild-type (WT) cells, which means AGNE inhibits YAP/TAZ signaling through direct action on LATS1/2. Further, it was confirmed that AGNE-induced activation of LATS1/2 inhibited the migration potential of the vector-expressing cells by suppressing YAP/TAZ activity. The reduced migration potential was restored in active YAP-TEAD expressing cells. Taken together, the results of this study indicate that ANGE downregulates YAP/TAZ signaling in cells through the activation of LATS1/2.