• Title/Summary/Keyword: Drug-receptor binding assay

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Differential antiangiogenic and anticancer activities of the active metabolites of ginsenoside Rg3

  • Maryam Nakhjavani;Eric Smith;Kenny Yeo;Yoko Tomita;Timothy J. Price;Andrea Yool;Amanda R. Townsend;Jennifer E. Hardingham
    • Journal of Ginseng Research
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    • v.48 no.2
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    • pp.171-180
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    • 2024
  • Background: Epimers of ginsenoside Rg3 (Rg3) have a low bioavailability and are prone to deglycosylation, which produces epimers of ginsenoside Rh2 (S-Rh2 and R-Rh2) and protopanaxadiol (S-PPD and R-PPD). The aim of this study was to compare the efficacy and potency of these molecules as anti-cancer agents. Methods: Crystal violet staining was used to study the anti-proliferatory action of the molecules on a human epithelial breast cancer cell line, MDA-MB-231, and human umbilical vein endothelial cells (HUVEC) and compare their potency. Cell death and cell cycle were studied using flow cytometry and mode of cell death was studied using live cell imaging. Anti-angiogenic effects of the drug were studied using loop formation assay. Molecular docking showed the interaction of these molecules with vascular endothelial growth factor receptor-2 (VEGFR2) and aquaporin (AQP) water channels. VEGF bioassay was used to study the interaction of Rh2 with VEGFR2, in vitro. Results: HUVEC was the more sensitive cell line to the anti-proliferative effects of S-Rh2, S-PPD and R-PPD. The molecules induced necroptosis/necrosis in MDA-MB-231 and apoptosis in HUVEC. S-Rh2 was the most potent inhibitor of loop formation. In silico molecular docking predicted a good binding score between Rh2 or PPD and the ATP-binding pocket of VEGFR2. VEGF bioassay showed that Rh2 was an allosteric modulator of VEGFR2. In addition, SRh2 and PPD had good binding scores with AQP1 and AQP5, both of which play roles in cell migration and proliferation. Conclusion: The combination of these molecules might be responsible for the anti-cancer effects observed by Rg3.

Effects of Ginseng Total Saponin on [3H]DAGO Bindings of Opioid μ-Receptors

  • Oh, Ki-Wan;Lim, Hwa-Kyung;Park, Cheol-Beum;Shin, Im-Chul;Hong, Jin-Tae
    • Journal of Ginseng Research
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    • v.26 no.4
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    • pp.187-190
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    • 2002
  • Crude synaptic membrane fractions from the frontal cortex, striatum, brain stem and whole brain of rat were prepared to assay the effects of ginseng total saponin (GTS) on [$^3$H]DAGO bindings of the opioid $\mu$-receptors. Scatchard plots analysis binding data demonstrated that GTS (0.1 mg/ml) decreased the affinity of specific [$^3$H]DAGO bindings without changes in B$\_$max/ in the frontal cortex and striatum. On the other hand, GTS did not affect the [$^3$H]DAGO bindings iii the brain stem and whole brain. These results suggest that the regulation of [$^3$H]DAGO bindings by GTS may play roles in the change of the pharmacological responses of $\mu$-opioids.

Bleeding Time Prolongation Effect of Methanol Extract of Viscum album var. coloratum

  • Yang, Hyun-Ok;Park, Shin-Young;Hong, Kyung-Hee;Kang, Lin-Woo;Choe, Kwang-Hoon;Kim, Young-Kyoon
    • Natural Product Sciences
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    • v.8 no.4
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    • pp.152-154
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    • 2002
  • The methanol extract of Viscum album var. coloratum, Korean mistletoe, showed potent prolongation effects on the bleeding time in rats in vivo, and whole blood clotting time and plasma recalcification time in rats ex vivo. The prolongation effect on the bleeding time of Korean mistletoe is comparable to that of Viscum album L., European mistletoe, 185.6% and 176.5%, respectively. However, the water extracts of the both plants did not show any prolongation effects. Platelet activating factor (PAF) receptor binding assay was carried out to elucidate the action mechanisms of the extracts, and both of the methanol extracts did not show any inhibitory activity. The $LD_{50}$ of the methanol extracts of both mistletoes are more than 2 g/kg. These results suggest that the mehtanol extract of Korean mistletoe might be a potential candidate to develop new drug to improve microcirculation.

Anti-hyperlipidemic Effects of Scutellariae Radix, Aucklandiae Radix and Bupleuri Radix (SAB) extract in FL83B cells (지방간 유도 세포모델에서 황금(黃芩), 목향(木香), 시호(柴胡) 복합 추출물의 이상지질혈증에 대한 효과)

  • Do, Hyun Ju;Kim, Kyungho;Oh, Tae Woo
    • The Korea Journal of Herbology
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    • v.35 no.5
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    • pp.23-31
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    • 2020
  • Objectives : This study was conducted to evaluate the anti-hyperlipidemia effect of Scutellariae Radix, Aucklandiae Radix and Bupleuri Radix(SAB). Methods : FL83B cells were mouse liver hepatocytes, and we used this cell line. FL83B cells were treated with 0.5 mM oleic acid(OA) for 24 h, SAB extract was treated. After OA treatment, intracellular triglyceride (TG) and free fatty acid contents were measured with AdiopoRed™ assay and Free Fatty Acid Quantitation assay kit, respectively. Further, we evaluated several lipogenesis and metabolic markers such as sterol regulatory element-binding transcription factor-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), 3-hydroxy3-methyl-glutaryl CoA reductase (HMGCR), hormone-sensitive lipase (HSL), carnitine palmitoyltransferase (CPT-1), peroxisome proliferator activated receptor alpha (PPARα), and cluster of differentiation (CD36) using RT-PCR and Western-blot analysis. Results : OA markedly increased intracellular TG and free fatty acid, which plays a key role in reducing hepatic lipid accumulation, in FL83B cells. These increases were alleviated by SAB extract. The mRNA and protein expression of Fatty acid(FA) oxidation factors (CPT-1, PPARα), lipolysis factor(HSL), FA transporter(CD36), cholesterol synthesis factors (HMGCoA) and Lipodenesis (SREBP-1c, FAS, and ACC-1) were significantly increased by treatment of SAB extract in the OA-induced fatty liver cell model. Conclusions : In summary, the treat of SAB extract showed a significant reduction of the influx of fatty acids into hepatocytes, promoted the oxidation of fatty acids, and regulated fat synthesis-related factors, thereby regulating the accumulation of TG and free fatty acids.

Protein Arginine Methyltransferase 5 (PRMT5) Regulates Adipogenesis of 3T3L-1 Cells (단백질 아르기닌 메틸전이효소 5(PRMT5)에 의한 3T3L-1 세포의 지방세포 분화 조절)

  • Jang, Min Jung;Yang, Ji Hye;Kim, Eun-Joo
    • Journal of Life Science
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    • v.28 no.7
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    • pp.765-771
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    • 2018
  • Peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) is a key transcription factor that regulates adipogenesis, and epigenetic control of $PPAR{\gamma}$ is of great interest in obesity-inhibition research. Our previous study showed that CACUL1 (CDK2-associated cullin domain 1) acts as a corepressor that inhibits $PPAR{\gamma}$ transcriptional activity and adipocyte differentiation. Here, we investigated the roles of protein arginine methyltransferase 5 (PRMT5), a novel binding partner of CACUL1, in regulating $PPAR{\gamma}$. The interaction between PRMT5 and CACUL1 was shown by immunoprecipitation assay in vivo and GST pulldown assay in vitro. As shown by luciferase reporter assay, PRMT5 and CACUL1 cooperated to inhibit the transcriptional activity of $PPAR{\gamma}$. The suppressive role of PRMT5 in adipogenesis was examined by Oil Red O staining using 3T3-L1 cells, which stably overexpress or deplete PRMT5. Overexpression of PRMT5 suppresses $PPAR{\gamma}$-mediated adipogenesis, whereas PRMT5 knockdown increases lipid accumulation in 3T3-L1 cells. Consistently, PRMT5 attenuates the expression of Lpl and aP2, the target genes of $PPAR{\gamma}$, as demonstrated by RT-qPCR analysis. Overall, these results suggest that PRMT5 interacts with CACUL1 to impair the transcriptional activity of $PPAR{\gamma}$, leading to the inhibition of adipocyte differentiation. Therefore, the regulation of PRMT5 enzymatic activity may provide a clue to develop an anti-obesity drug.

Establishment of a NanoBiT-Based Cytosolic Ca2+ Sensor by Optimizing Calmodulin-Binding Motif and Protein Expression Levels

  • Nguyen, Lan Phuong;Nguyen, Huong Thi;Yong, Hyo Jeong;Reyes-Alcaraz, Arfaxad;Lee, Yoo-Na;Park, Hee-Kyung;Na, Yun Hee;Lee, Cheol Soon;Ham, Byung-Joo;Seong, Jae Young;Hwang, Jong-Ik
    • Molecules and Cells
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    • v.43 no.11
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    • pp.909-920
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    • 2020
  • Cytosolic Ca2+ levels ([Ca2+]c) change dynamically in response to inducers, repressors, and physiological conditions, and aberrant [Ca2+]c concentration regulation is associated with cancer, heart failure, and diabetes. Therefore, [Ca2+]c is considered as a good indicator of physiological and pathological cellular responses, and is a crucial biomarker for drug discovery. A genetically encoded calcium indicator (GECI) was recently developed to measure [Ca2+]c in single cells and animal models. GECI have some advantages over chemically synthesized indicators, although they also have some drawbacks such as poor signal-to-noise ratio (SNR), low positive signal, delayed response, artifactual responses due to protein overexpression, and expensive detection equipment. Here, we developed an indicator based on interactions between Ca2+-loaded calmodulin and target proteins, and generated an innovative GECI sensor using split nano-luciferase (Nluc) fragments to detect changes in [Ca2+]c. Stimulation-dependent luciferase activities were optimized by combining large and small subunits of Nluc binary technology (NanoBiT, LgBiT:SmBiT) fusion proteins and regulating the receptor expression levels. We constructed the binary [Ca2+]c sensors using a multicistronic expression system in a single vector linked via the internal ribosome entry site (IRES), and examined the detection efficiencies. Promoter optimization studies indicated that promoter-dependent protein expression levels were crucial to optimize SNR and sensitivity. This novel [Ca2+]c assay has high SNR and sensitivity, is easy to use, suitable for high-throughput assays, and may be useful to detect [Ca2+]c in single cells and animal models.