Enhanced neuronal activity by suffruticosol A extracted from Paeonia lactiflora via partly BDNF signaling in scopolamine-induced memory-impaired mice.

Neurodegenerative diseases are explained by progressive defects of cognitive function and memory. These defects of cognition and memory dysfunction can be induced by the loss of brain-derived neurotrophic factors (BDNF) signaling. Paeonia lactiflora is a traditionally used medicinal herb in Asian countries and some beneficial effects have been reported, including anti-oxidative, anti-inflammatory, anti-cancer activity, and potential neuroprotective effects recently. In this study, we found that suffruticosol A is a major compound in seeds of Paeonia lactiflora. When treated in a SH-SY5 cell line for measuring cell viability and cell survival, suffruticosol A increased cell viability (at 20 µM) and recovered scopolamine-induced neurodegenerative characteristics in the cells. To further confirm its neural amelioration effects in the animals, suffruticosol A (4 or 15 ng, twice a week) was administered into the third ventricle beside the brain of C57BL/6 mice for one month then the scopolamine was intraperitoneally injected into these mice to induce impairments of cognition and memory before conducting behavioral experiments. Central administration of suffruticosol A into the brain restored the memory and cognition behaviors in mice that received the scopolamine. Consistently, the central treatments of suffruticosol A showed rescued cholinergic deficits and BDNF signaling in the hippocampus of mice. Finally, we measured the long-term potentiation (LTP) in the hippocampal CA3-CA1 synapse to figure out the restoration of the synaptic mechanism of learning and memory. Bath application of suffruticosol A (40 µM) improved LTP impairment induced by scopolamine in hippocampal slices. In conclusion, the central administration of suffruticosol A ameliorated neuronal effects partly through elevated BDNF signaling.

Asterias pectinifera-Derived Collagen Peptides Mixed with Halocynthia roretzi Extracts Exhibit Anti-Photoaging Activities during Exposure to UV Irradiation, and Antibacterial Properties.

Asterias pectinifera, a species of starfish and cause of concern in the aquaculture industry, was recently identified as a source of non-toxic and highly water-soluble collagen peptides. In this study, we investigated the antioxidant and anti-photoaging functions of compounds formulated using collagen peptides from extracts of Asterias pectinifera and Halocynthia roretzi (AH). Our results showed that AH compounds have various skin protective functions, including antioxidant effects, determined by measuring the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl radicals, as well as anti-melanogenic effects, determined by measuring tyrosinase inhibition activity. To determine whether ethosome-encapsulated AH compounds (E(AH)) exert ultraviolet (UV)-protective effects, human dermal fibroblasts or keratinocytes were incubated with E(AH) before and after exposure to UVA or UVB. E(AH) treatment led to inhibition of photoaging-induced secretion of matrix metalloproteinase-1 and interleukin-6 and -8, which are associated with inflammatory responses during UV irradiation. Finally, the antibacterial effects of AH and E(AH) were confirmed against both gram-negative and gram-positive bacteria. Our results indicate that E(AH) has the potential for use in the development of cosmetics with a range of skin protective functions.

Astrocytes Render Memory Flexible by Releasing D-Serine and Regulating NMDA Receptor Tone in the Hippocampus.

BACKGROUND: NMDA receptor (NMDAR) hypofunction has been implicated in several psychiatric disorders with impairment of cognitive flexibility. However, the molecular mechanism of how NMDAR hypofunction with decreased NMDAR tone causes the impairment of cognitive flexibility has been minimally understood. Furthermore, it has been unclear whether hippocampal astrocytes regulate NMDAR tone and cognitive flexibility. METHODS: We employed cell type-specific genetic manipulations, ex vivo electrophysiological recordings, sniffer patch recordings, cutting-edge biosensor for norepinephrine, and behavioral assays to investigate whether astrocytes can regulate NMDAR tone by releasing D-serine and glutamate. Subsequently, we further investigated the role of NMDAR tone in heterosynaptic long-term depression, metaplasticity, and cognitive flexibility. RESULTS: We found that hippocampal astrocytes regulate NMDAR tone via BEST1-mediated corelease of D-serine and glutamate. Best1 knockout mice exhibited reduced NMDAR tone and impairments of homosynaptic and α1 adrenergic receptor-dependent heterosynaptic long-term depression, which leads to defects in metaplasticity and cognitive flexibility. These impairments in Best1 knockout mice can be rescued by hippocampal astrocyte-specific BEST1 expression or enhanced NMDAR tone through D-serine supplement. D-serine injection in Best1 knockout mice during initial learning rescues subsequent reversal learning. CONCLUSIONS: These findings indicate that NMDAR tone during initial learning is important for subsequent learning, and hippocampal NMDAR tone regulated by astrocytic BEST1 is critical for heterosynaptic long-term depression, metaplasticity, and cognitive flexibility.

Generation of expandable human pluripotent stem cell-derived hepatocyte-like liver organoids.

BACKGROUND & AIMS: The development of hepatic models capable of long-term expansion with competent liver functionality is technically challenging in a personalized setting. Stem cell-based organoid technologies can provide an alternative source of patient-derived primary hepatocytes. However, self-renewing and functionally competent human pluripotent stem cell (PSC)-derived hepatic organoids have not been developed. METHODS: We developed a novel method to efficiently and reproducibly generate functionally mature human hepatic organoids derived from PSCs, including human embryonic stem cells and induced PSCs. The maturity of the organoids was validated by a detailed transcriptome analysis and functional performance assays. The organoids were applied to screening platforms for the prediction of toxicity and the evaluation of drugs that target hepatic steatosis through real-time monitoring of cellular bioenergetics and high-content analyses. RESULTS: Our organoids were morphologically indistinguishable from adult liver tissue-derived epithelial organoids and exhibited self-renewal. With further maturation, their molecular features approximated those of liver tissue, although these features were lacking in 2D differentiated hepatocytes. Our organoids preserved mature liver properties, including serum protein production, drug metabolism and detoxifying functions, active mitochondrial bioenergetics, and regenerative and inflammatory responses. The organoids exhibited significant toxic responses to clinically relevant concentrations of drugs that had been withdrawn from the market due to hepatotoxicity and recapitulated human disease phenotypes such as hepatic steatosis. CONCLUSIONS: Our organoids exhibit self-renewal (expandable and further able to differentiate) while maintaining their mature hepatic characteristics over long-term culture. These organoids may provide a versatile and valuable platform for physiologically and pathologically relevant hepatic models in the context of personalized medicine. LAY SUMMARY: A functionally mature, human cell-based liver model exhibiting human responses in toxicity prediction and drug evaluation is urgently needed for pre-clinical drug development. Here, we develop a novel human pluripotent stem cell-derived hepatocyte-like liver organoid that is critically advanced in terms of its generation method, functional performance, and application technologies. Our organoids can contribute to the better understanding of liver development and regeneration, and provide insights for metabolic studies and disease modeling, as well as toxicity assessments and drug screening for personalized medicine.

Repositioning of the antipsychotic trifluoperazine: Synthesis, biological evaluation and in silico study of trifluoperazine analogs as anti-glioblastoma agents.

Repositioning of the antipsychotic drug trifluoperazine for treatment of glioblastoma, an aggressive brain tumor, has been previously suggested. However, trifluoperazine did not increase the survival time in mice models of glioblastoma. In attempt to identify an effective trifluoperazine analog, fourteen compounds have been synthesized and biologically in vitro and in vivo assessed. Using MTT assay, compounds 3dc and 3dd elicited 4-5 times more potent inhibitory activity than trifluoperazine with IC50 = 2.3 and 2.2 µM against U87MG glioblastoma cells, as well as, IC50 = 2.2 and 2.1 µM against GBL28 human glioblastoma patient derived primary cells, respectively. Furthermore, they have shown a reasonable selectivity for glioblastoma cells over NSC normal neural cell. In vivo evaluation of analog 3dc confirmed its advantageous effect on reduction of tumor size and increasing the survival time in brain xenograft mouse model of glioblastoma. Molecular modeling simulation provided a reasonable explanation for the observed variation in the capability of the synthesized analogs to increase the intracellular Ca2+ levels. In summary, this study presents compound 3dc as a proposed new tool for the adjuvant chemotherapy of glioblastoma.

Inhibition of Cytochrome P450 by Propolis in Human Liver Microsomes.

Although propolis is one of the most popular functional foods for human health, there have been no comprehensive studies of herb-drug interactions through cytochrome P450 (CYP) inhibition. The purpose of this study was to determine the inhibitory effects of propolis on the activities of CYP1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1 and 3A4 using pooled human liver microsomes (HLMs). Propolis inhibited CYP1A2, CYP2E1 and CYP2C19 with an IC50 value of 6.9, 16.8, and 43.1 µg/mL, respectively, whereas CYP2A6, 2B6, 2C9, 2D6, and 3A4 were unaffected. Based on half-maximal inhibitory concentration shifts between microsomes incubated with and without nicotinamide adenine dinucleotide phosphate, propolis-induced CYP1A2, CYP2C19, and CYP2E1 inhibition was metabolism-independent. To evaluate the interaction potential between propolis and therapeutic drugs, the effects of propolis on metabolism of duloxetine, a serotonin-norepinephrine reuptake inhibitor, were determined in HLMs. CYP1A2 and CYP2D6 are involved in hydroxylation of duloxetine to 4-hydroxy duloxetine, the major metabolite, which was decreased following propolis addition in HLMs. These results raise the possibility of interactions between propolis and therapeutic drugs metabolized by CYP1A2.

HepG2 cells as an in vitro model for evaluation of cytochrome P450 induction by xenobiotics.

Although various in vitro assays have been developed to evaluate the cytochrome P450 (CYP)-inducing potential of drug candidates, there is a continuing need for the development of a reliable model in drug discovery. The objective of the present study was to compare CYP induction by chemicals in HepG2 cells with Huh7, NKNT-3, and reverted NKNT-3 cells. HepG2 cells showed more similarity to human liver than the other cell lines in comparisons of the expression of cellular proteins. In evaluation of basal CYP activity, Huh7 cells exhibited the highest CYP1A2 and CYP3A4 activity, and HepG2 cells showed the highest CYP2B6 activity. The inducibility of CYP1A2, CYP2B6, and CYP3A4 by prototypical inducers was determined using enzyme assay, immunoblot analysis, and real-time PCR. Among the cells tested, HepG2 cells were highly responsive to CYP inducers, such as 3-methylcholanthrene for CYP1A2 and phenobarbital for CYP2B6 and CYP3A4. Moreover, HepG2 cells were responsive to various CYP1A2, CYP2B6, and CYP3A4 inducers as determined using fluorogenic and LC-MS/MS substrates. Thus, HepG2 cells may be comparable to human hepatocytes for the evaluation of CYP induction or slightly less sensitive. These results suggest HepG2 cells as a cell-based model in screening for CYP inducers in drug discovery.

Inhibitory effects of Hwang-Ryun-Hae-Dok-Tang on cytochrome P450 in human liver microsomes.

1. The herb-drug interaction potential of Hwang-Ryun-Hae-Dok-Tang (HR) extracts mediated by cytochrome P450 (CYP) inhibition was determined using human liver microsomes. 2. HR strongly inhibited CYP1A2 and moderately inhibited CYP2C19, CYP2D6, and CYP3A4 (testosterone) but not CYP2A6, CYP2B6, CYP2C8, CYP2C9, and CYP3A4 (midazolam). 3. The enzyme kinetic results suggest that CYP1A2 inhibition is competitively reversible (Ki, 13.4±1.8 µg/ml), and CYP2D6 inhibition is quasi-irreversible (KI, 0.234±0.138 µg/ml; kinact, 0.067±0.006 min(-1)). 4. Fermentation using Lactobacillus acidophilus attenuated the HR-induced inhibition of CYP2D6, but not the other isoforms. 5. Neither CYP1A2 nor CYP3A4 was markedly inhibited by berberine, palmatine, and geniposide-major components in HR-and CYP2D6 was inhibited by berberine (IC50, 13.8 µg/ml) in a metabolism-dependent manner. 6. The results suggest the possibility of HR-drug interaction through inhibition of CYP-particularly CYP2D6-which may be attenuated by fermentation using L. acidophilus.

Zerumbone suppresses IL-1ß-induced cell migration and invasion by inhibiting IL-8 and MMP-3 expression in human triple-negative breast cancer cells.

Inflammation is a key regulatory process in cancer development. Prolonged exposure of breast tumor cells to inflammatory cytokines leads to epithelial-mesenchymal transition, which is the principal mechanism involved in metastasis and tumor invasion. Interleukin (IL)-1ß is a major inflammatory cytokine in a variety of tumors. To date, the regulatory mechanism of IL-1ß-induced cell migration and invasion has not been fully elucidated. Here, we investigated the effect of zerumbone (ZER) on IL-1ß-induced cell migration and invasion in breast cancer cells. The levels of IL-8 and matrix metalloproteinase (MMP)-3 mRNA were analyzed by real-time polymerase chain reaction. The levels of secreted IL-8 and MMP-3 protein were analyzed by enzyme-linked immunosorbent assay and western blot analysis, respectively. Cell invasion and migration was detected by Boyden chamber assay. The levels of IL-8 and MMP-3 expression were significantly increased by IL-1ß treatment in Hs578T and MDA-MB231 cells. On the other hand, IL-1ß-induced IL-8 and MMP-3 expression was decreased by ZER. Finally, IL-1ß-induced cell migration and invasion were decreased by ZER in Hs578T and MDA-MB231 cells. ZER suppresses IL-1ß-induced cell migration and invasion by inhibiting IL-8 expression and MMP-3 expression in TNBC cells. ZER could be a promising therapeutic drug for treatment of triple-negative breast cancer patients.

Pharmacokinetics and metabolism of 4-O-methylhonokiol in rats.

The purpose of this study was to characterize the pharmacokinetics and metabolism of 4-O-methylhonokiol in rats. The absorption and disposition of 4-O-methylhonokiol were investigated in male Sprague-Dawley rats following a single intravenous (2 mg/kg) or oral (10 mg/kg) dose. Its metabolism was studied in vitro using rat liver microsomes and cytosol. 4-O-Methylhonokiol exhibited a high systemic plasma clearance and a large volume of distribution. The oral dose gave a peak plasma concentration of 24.1±3.3 ng/mL at 2.9±1.9 h and a low estimated bioavailability. 4-O-Methylhonokiol was rapidly metabolized and converted at least in part to honokiol in a concentration-dependent manner by cytochrome P450 in rat liver microsomes, predicting a high systemic clearance consistent with the pharmacokinetic results. It was also shown to be metabolized by glucuronidation and sulfation in rat liver microsomes and cytosol, respectively. 4-O-Methylhonokiol showed a moderate permeability with no apparent vectorial transport across Caco-2 cells, suggesting that intestinal permeation process is not likely to limit its oral absorption. Taken together, these results suggest that the rapid hepatic metabolism of 4-O-methylhonokiol could be the major reason for its high systemic clearance and low oral bioavailability.

MONNA, a potent and selective blocker for transmembrane protein with unknown function 16/anoctamin-1.

Transmembrane protein with unknown function 16/anoctamin-1 (ANO1) is a protein widely expressed in mammalian tissues, and it has the properties of the classic calcium-activated chloride channel (CaCC). This protein has been implicated in numerous major physiological functions. However, the lack of effective and selective blockers has hindered a detailed study of the physiological functions of this channel. In this study, we have developed a potent and selective blocker for endogenous ANO1 in Xenopus laevis oocytes (xANO1) using a drug screening method we previously established (Oh et al., 2008). We have synthesized a number of anthranilic acid derivatives and have determined the correlation between biological activity and the nature and position of substituents in these derived compounds. A structure-activity relationship revealed novel chemical classes of xANO1 blockers. The derivatives contain a --NO2 group on position 5 of a naphthyl group-substituted anthranilic acid, and they fully blocked xANO1 chloride currents with an IC50 < 10 µM. The most potent blocker, N-((4-methoxy)-2-naphthyl)-5-nitroanthranilic acid (MONNA), had an IC50 of 0.08 µM for xANO1. Selectivity tests revealed that other chloride channels such as bestrophin-1, chloride channel protein 2, and cystic fibrosis transmembrane conductance regulator were not appreciably blocked by 10∼30 µM MONNA. The potent and selective blockers for ANO1 identified here should permit pharmacological dissection of ANO1/CaCC function and serve as potential candidates for drug therapy of related diseases such as hypertension, cystic fibrosis, bronchitis, asthma, and hyperalgesia.

Cytochrome P450-mediated herb-drug interaction potential of Galgeun-tang.

We evaluated the herb-drug interaction potential of Galgeun-tang (GGT) extracts, mediated by cytochrome P450 (CYP) inhibition/induction. Further, the effects of fermentation on the CYP-mediated herb-drug interaction potential of GGT extracts were determined. As measured by LC-ESI/MS/MS, GGT extracts (0-300µg/mL) showed no inhibitory activity toward eight CYP isoforms (1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, and 3A4) in pooled human liver microsomes, suggesting that GGT may have low potential for herb-drug interactions mediated by CYP inhibition. Hepatic CYP expression and activity in rats treated with GGT extracts twice per day for 1week was examined. Among the tested CYP isoforms (1A1, 1A2, 1B1, 2B1, 2C11, 2E1, 3A1, 3A2, and 4A1), CYP1B1 and 4A1 were increased by GGT extracts. Hepatic activities of 7-ethoxyresorufin-O-deethylase, 7-pentoxyresorufin-O-depentylase, and chlorzoxazone 6-hydroxylase, but not midazolam hydroxylase were also elevated. These results raise the possibility that GGT extracts may increase the toxicity of environmental toxicants through the elevating CYP-dependent metabolic activation. Interestingly, the increases in CYP1B1 and CYP4A1 levels, and 7-ethoxyresorufin-O-deethylase, 7-pentoxyresorufin-O-depentylase, and chlorzoxazone 6-hydroxylase activities were attenuated by fermentation of GGT extract using Lactobacillus plantarum KFRI 402, but not 144. Further studies are needed to identify the CYP regulatory component(s) from GGT and determination its metabolism.

In vitro and in vivo assessment of cytochrome P450-mediated herb-drug interaction of Ssang-hwa-tang.

We have evaluated the herb-drug interaction potential of Ssang-hwa-tang (SHT) mediated by cytochrome P450 (CYP) inhibition/induction. Further, the effects of fermentation on the CYP-mediated herb-drug interaction potential were determined. SHT showed inhibitory activity toward CYP1A2, but not 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, and 3A4 in human liver microsomes. The results of the enzyme kinetic study suggested that the SHT-induced CYP1A2 inhibition is mixed reversible inhibition. The hepatic CYP expression and activity in rats treated with SHT were examined. The expression/activity of CYP2E1 increased as a result of SHT extract treatment (P<0.005 or P<0.001, respectively), which raises the possibility that SHT may increase the toxicity of environmental toxicants through the elevation of CYP2E1-mediated metabolic activation. SHT fermentation using Lactobacillus fermentum or Lactobacillus gasseri resulted in attenuation of the SHT-induced CYP1A2 inhibition, but not CYP2E1 induction, suggesting that changes in the chemical composition of SHT through fermentation can affect the inhibition of CYP1A2 activity.

Assessment of reactive metabolites in drug-induced liver injury.

The aim of the current review is to summarize present methods used for the determination of reactive metabolites, which can predict drug-induced liver injury (DILI) in drug discovery and development. DILI is one of the most frequent reasons for the withdrawal of an approved drug from the market, and it accounts for up to 50% of acute liver failure cases. This review is structured into three sections. The first section is a general overview of the relationship between drug metabolism and liver injury. The second section introduces in vitro methods for the assessment of reactive metabolites for drug discovery and development. In the third section, limitations and future directions for the development of methods for predicting DILI are described.

Development of selective blockers for Ca²(+)-activated Cl channel using Xenopus laevis oocytes with an improved drug screening strategy.

BACKGROUND: Ca²(+)-activated Cl⁻ channels (CaCCs) participate in many important physiological processes. However, the lack of effective and selective blockers has hindered the study of these channels, mostly due to the lack of good assay system. Here, we have developed a reliable drug screening method for better blockers of CaCCs, using the endogeneous CaCCs in Xenopus laevis oocytes and two-electrode voltage-clamp (TEVC) technique. RESULTS: Oocytes were prepared with a treatment of Ca²(+) ionophore, which was followed by a treatment of thapsigargin which depletes Ca²(+) stores to eliminate any contribution of Ca²(+) release. TEVC was performed with micropipette containing chelerythrine to prevent PKC dependent run-up or run-down. Under these conditions, Ca²(+)-activated Cl⁻ currents induced by bath application of Ca²(+) to oocytes showed stable peak amplitude when repetitively activated, allowing us to test several concentrations of a test compound from one oocyte. Inhibitory activities of commercially available blockers and synthesized anthranilic acid derivatives were tested using this method. As a result, newly synthesized N-(4-trifluoromethylphenyl)anthranilic acid with trifluoromethyl group (-CF3) at para position on the benzene ring showed the lowest IC50. CONCLUSION: Our results provide an optimal drug screening strategy suitable for high throughput screening, and propose N-(4-trifluoromethylphenyl)anthranilic acid as an improved CaCC blocker.

Potent protective effect of isoimperatorin against aflatoxin B1-inducible cytotoxicity in H4IIE cells: bifunctional effects on glutathione S-transferase and CYP1A.

Typically chemopreventive agents either induce phase II detoxifying enzymes or inhibit the cytochrome P450 enzymes (CYPs) that are required for the metabolism of carcinogens. In this study, we isolated a coumarin compound, isoimperatorin from Poncirus trifoliata Raf., and studied its protective effects against aflatoxin B1 (AFB1)-induced cytotoxicity in H4IIE cells. Isoimperatorin (>0.3 microM) significantly inhibited the cytotoxic effect of AFB1. CDNB [1-chloro-2,4-dinitrobenzene; glutathine S-transferase (GST) subtype-non-specific] and NBD (7-chloro-4-nitrobenzo-2-oxa-1,3-diazole; GSTalpha type-specific) assays revealed that isoimperatorin (0.3-3 microM) increased GST activity in a concentration-dependent manner. Western blot analyses using subtype-specific antibodies confirmed that GSTalpha protein, but not GSTmu or GSTpi, was induced in cells treated with isoimperatorin. Reporter gene analysis using an antioxidant response element (ARE) containing construct and subcellular fractionation assays revealed that GSTalpha induction by isoimperatorin is associated with Nrf2/ARE activation. Moreover, ethoxyresorufin-O-deethylase assays showed that isoimperatorin (2 microM) completely inhibited 3-methylchoranthrene-inducible CYP1A activity. These results indicate that isoimperatorin from Poncirus trifoliata Raf. possesses a potent hepatoprotective effect against AFB1, presumably through the induction of GSTalpha and the direct inhibition of CYP1A, and suggest that isoimperatorin should be considered a potential chemopreventive.