To determine the mechanism of action of the effects of phytoalexins in soybeans, we analyzed
-glucosidase inhibition kinetics using Michaelis-Menten plots and Lineweaver-Burk plots. The results ...showed that the type of inhibition with glyceollin was competitive, that of genistein was noncompetitive, that of daidzein was uncompetitive, and luteolin showed a mixed mode of action. The
values were determined using a Dixon plot as glyceollin, 18.99 μM; genistein, 15.42 μM; luteolin, 16.81 μM; and daidzein, 9.99 μM. Furthermore, potential synergistic effects between glyceollin and the three polyphenols were investigated. A combination of glyceollin and luteolin at a ratio of 3:7 exhibited synergistic effects on
-glucosidase inhibition, having a combination index (CI) of 0.64244, according to the CI-isobologram equation. Collectively, these results showed that a combination of glyceollin and luteolin has the potential to inhibit
-glucosidase activity via a synergistic mode of inhibition.
A new small molecule probe for in vivo lipid imaging, LipidGreen (compound 5), was developed. LipidGreen stained lipid droplets in 3T3L1 cell lines and fat deposits in zebrafish without apparent ...toxicity up to 100 μM. The utility of LipidGreen as a drug screening platform for fat regulation was also demonstrated in live zebrafish.
Increasing evidence that decreased bone density and increased rates of bone fracture are associated with abnormal metabolic states such as hyperglycemia and insulin resistance indicates that diabetes ...is a risk factor for osteoporosis. In this study, we observed that TallyHo/JngJ (TH) mice, a polygenic model of type II diabetes, spontaneously developed bone deformities with osteoporotic features. Female and male TH mice significantly gained more body weight than control C57BL/6 mice upon aging. Interestingly, bone density was considerably decreased in male TH mice, which displayed hyperglycemia. The osteoblast-specific bone forming markers osteocalcin and osteoprotegerin were decreased in TH mice, whereas osteoclast-driven bone resorption markers such as IL-6 and RANKL were significantly elevated in the bone marrow and blood of TH mice. In addition, RANKL expression was prominently increased in CD4+ T cells of TH mice upon T cell receptor stimulation, which was in accordance with enhanced IL-17 production. IL-17 production in CD4+ T cells was directly promoted by treatment with leptin while IFN-γ production was not. Moreover, blockade of IFN-γ further increased RANKL expression and IL-17 production in TH-CD4+ T cells. In addition, the osteoporotic phenotype of TH mice was improved by treatment with alendronate. These results strongly indicate that increased leptin in TH mice may act in conjunction with IL-6 to preferentially stimulate IL-17 production in CD4+ T cells and induce RANKL-mediated osteoclastogenesis. Accordingly, we propose that TH mice could constitute a beneficial model for osteoporosis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Serotonin (5-hydroxytryptophan) is a hormone that regulates emotions in the central nervous system. However, serotonin in the peripheral system is associated with obesity and fatty liver disease. ...Because serotonin cannot cross the blood-brain barrier (BBB), we focused on identifying new tryptophan hydroxylase type I (TPH1) inhibitors that act only in peripheral tissues for treating obesity and fatty liver disease without affecting the central nervous system. Structural optimization inspired by
-chlorophenylalanine (pCPA) resulted in the identification of a series of oxyphenylalanine and heterocyclic phenylalanine derivatives as TPH1 inhibitors. Among these compounds, compound
with an
value of 37 nM was the most active in vitro. Additionally, compound
showed good liver microsomal stability and did not significantly inhibit CYP and Herg. Furthermore, this TPH1 inhibitor was able to actively interact with the peripheral system without penetrating the BBB. Compound
and its prodrug reduced body weight gain in mammals and decreased in vivo fat accumulation.
The peroxisome proliferator-activated receptor agonist troglitazone (TRO) was used for treatment of nonâinsulin-dependent
diabetes until its removal from the market because of its severe ...hepatotoxicity. However, the mechanism for its hepatotoxicity
is still poorly understood. In this study, we investigated whether TRO caused cell death by altering signaling pathways associated
with cell damage and survival in human hepatoma cells. Our data reveal that TRO caused time- and concentration-dependent apoptosis
of HepG2 and Chang liver human hepatoma cells, as evidenced by DNA fragmentation and staining with Hoechst 33342. In contrast,
50 or 100 μM rosiglitazone, a structural analog of TRO, did not cause apoptosis in these hepatoma cells. TRO activated both
c-Jun N-terminal protein kinase (JNK) and p38 kinase about 5-fold between 0.5 and 8 h before they returned to control levels
at 16 h in HepG2 cells. In contrast, TRO failed to activate the extracellular signal-regulated kinase. Furthermore, TRO increased
the levels of proapoptotic proteins, Bad, Bax, release of cytochrome c , and cleavage of Bid in a time-dependent manner. The antiapoptotic Bcl-2 protein level decreased in hepatoma cells treated
with TRO. Pretreatment of hepatoma cells with a selective JNK inhibitor, anthra1,9- cd pyrazol-6(2H)-one (SP600125), significantly reduced the rate of TRO-induced cell death, whereas 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole
(SB203580), an inhibitor of p38 kinase, had little effect on apoptosis. Pretreatment with SP600125 also prevented JNK activation
and c-Jun phosphorylation. In addition, rosiglitazone, which is not as toxic to hepatoma cells as TRO, did not stimulate JNK
activity. Transfection of cDNA for the dominant-negative mutant JNK-KR (LysâArg) or SEK1-KR (LysâArg), an immediate upstream
kinase of JNK, significantly reduced TRO-induced JNK activation and cell death rate. Furthermore, SP600125 pretreatment effectively
prevented the TRO-mediated changes in Bad, Bax, Bid cleavage, and cytochrome c release. These data strongly suggest that hepatotoxic TRO causes apoptosis by activating the JNK-dependent cell death pathway
accompanied by increased Bid cleavage and elevation of proapoptotic proteins.
Epilepsy is one of the most common neurological disorders, and it is characterized by spontaneous seizures. In a previous study, we identified ...4-(2-chloro-4-fluorobenzyl)-3-(2-thienyl)-1,2,4-oxadiazol-5(4H)-one (GM-90432) as a novel anti-epileptic agent in chemically- or genetically-induced epileptic zebrafish and mouse models. In this study, we investigated the anti-epileptic effects of GM-90432 through neurochemical profiling-based approach to understand the neuroprotective mechanism in a pentylenetetrazole (PTZ)-induced epileptic seizure zebrafish model. GM-90432 effectively improved PTZ-induced epileptic behaviors via upregulation of 5-hydroxytryptamine, 17-β-estradiol, dihydrotestosterone, progesterone, 5α -dihydroprogesterone, and allopregnanolone levels, and downregulation of normetanephrine, gamma-aminobutyric acid, and cortisol levels in brain tissue. GM-90432 also had a protective effect against PTZ-induced oxidative stress and zebrafish death, suggesting that it exhibits biphasic neuroprotective effects via scavenging of reactive oxygen species and anti-epileptic activities in a zebrafish model. In conclusion, our results suggest that neurochemical profiling study could be used to better understand of anti-epileptic mechanism of GM-90432, potentially leading to new drug discovery and development of anti-seizure agents.
•In this study, we show that KDZ-001, a novel anti-melanogenic agent, strongly inhibits melanin synthesis in the developing melanophores of zebrafish, HMV-II cells, and reconstituted human skin with ...no toxicity. We also show that KDZ-001 directly inhibits TYR enzymatic activity. Thus, KDZ-001 is a potential candidate for a skin-whitening agent in the cosmetic industry.
The demand for anti-melanogenic agents is increasing due to the unwanted side effects of current treatments. To find an effective anti-melanogenic agent, we used zebrafish as a whole animal model for phenotype-based drug and cosmetic discovery screening.
The aim of this study was to identify and explore a small molecule that could be used for skin-whitening cosmetics.
Using zebrafish embryos, we examined the effects of 1000 compounds on zebrafish development and pigmentation. Pigmentation production was assessed by tyrosinase (TYR) enzymatic activity and melanin contents. Pigmentation marker expression in the human melanoma cell line HMV-II was analyzed by western blot. We also tested reconstituted human skin tissue and analyzed KDZ-001 with computational molecular modeling.
We identified three compounds that affected the pigmentation of developing melanophores in zebrafish. Among them, we identified KDZ-001, a novel anti-melanogenic agent, which strongly inhibits melanin synthesis in the developing melanophores of zebrafish, HMV-II cells, and reconstituted human skin with no toxicity. We found that KDZ-001 directly inhibits TYR enzymatic activity. Notably, computational molecular modeling of KDZ-001 suggested that its interaction with copper ions in the active site of TYR is essential for melanin synthesis, further demonstrating that KDZ-001 mainly acts as a TYR inhibitor to synthesize melanin.
KDZ-001 inhibits melanin synthesis and has a potential for use in skin-whitening cosmetics.
This study aims to develop new potential therapeutic moracin M prodrugs acting on lung inflammatory disorders. Potential moracin M prodrugs (KW01-KW07) were chemically synthesized to obtain potent ...orally active derivatives, and their pharmacological activities against lung inflammation were, for the first time, examined
using lipopolysaccharide (LPS)-induced acute lung injury model. In addition, the metabolism of KW02 was also investigated using microsomal stability test and pharmacokinetic study in rats. When orally administered, some of these compounds (30 mg/kg) showed higher inhibitory action against LPSinduced lung inflammation in mice compared to moracin M. Of them, 2-(3,5-bis((dimethylcarbamoyl)oxy)phenyl)benzofuran-6-yl acetate (KW02) showed potent and dose-dependent inhibitory effect on the same animal model of lung inflammation at 1, 3, and 10 mg/kg. This compound at 10 mg/kg also significantly reduced IL-1β concentration in the bronchoalveolar lavage fluid of the inflamed-lungs. KW02 was rapidly metabolized to 5-(6-hydroxybenzofuran-2-yl)-1,3-phenylene bis(dimethylcarbamate) (KW06) and moracin M when it was incubated with rat serum and liver microsome as expected. When KW02 was administered to rats via intravenous or oral route, KW06 was detected in the serum as a metabolite. Thus, it is concluded that KW02 has potent inhibitory action against LPS-induced lung inflammation. It could behave as a potential prodrug of moracin M to effectively treat lung inflammatory disorders.
MicroRNA-122 (miRNA-122), also known as liver-specific miRNA, has recently been shown to be a potent biomarker in response to liver injury in mammals. The objective of this study was to examine its ...expression in response to toxicant treatment and acute liver damage, using the zebrafish system as an alternative model organism. For the hepatotoxicity assay, larval zebrafish were arrayed in 24-well plates. Adult zebrafish were also tested and arrayed in 200 mL cages. Animals were exposed to liver toxicants (tamoxifen or acetaminophen) at various doses, and miRNA-122 expression levels were analyzed using qRT-PCR in dissected liver, brain, heart, and intestine, separately. Our results showed no significant changes in miRNA-122 expression level in tamoxifen-treated larvae; however, miRNA-122 expression was highly induced in tamoxifen-treated adults in a tissue-specific manner. In addition, we observed a histological change in adult liver (0.5 μM) and cell death in larval liver (5 μM) at different doses of tamoxifen. These results indicated that miRNA-122 may be utilized as a liver-specific biomarker for acute liver toxicity in zebrafish.
The blood-brain-barrier (BBB) is made up of blood vessels whose permeability enables the passage of some compounds. A predictive model of BBB permeability is important in the early stages of drug ...development. The predicted BBB permeabilities of drugs have been confirmed using a variety of in vitro methods to reduce the quantities of drug candidates needed in preclinical and clinical trials. Most prior studies have relied on animal or cell-culture models, which do not fully recapitulate the human BBB. The development of microfluidic models of human-derived BBB cells could address this issue. We analyzed a model for predicting BBB permeability using the Emulate BBB-on-a-chip machine. Ten compounds were evaluated, and their permeabilities were estimated. Our study demonstrated that the permeability trends of ten compounds in our microfluidic-based system resembled those observed in previous animal and cell-based experiments. Furthermore, we established a general correlation between the partition coefficient (Kp) and the apparent permeability (Papp). In conclusion, we introduced a new paradigm for predicting BBB permeability using microfluidic-based systems.
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