scholarly journals Theoretical Exploring of a Molecular Mechanism for Melanin Inhibitory Activity of Calycosin in Zebrafish

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6998
Author(s):  
Nilupaier Tayier ◽  
Ning-Yi Qin ◽  
Li-Nan Zhao ◽  
Yi Zeng ◽  
Yu Wang ◽  
...  
Keyword(s):  
Free Energy ◽  
Molecular Docking ◽  
Energy Analysis ◽  
Kojic Acid ◽  
Inhibitory Effect ◽  
In Vivo Model ◽  
In Vitro Test ◽  
Free Energy Analysis

Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin in the human body. Overproduction of melanin can lead to a variety of skin disorders. Calycosin is an isoflavone from Astragali Radix, which is a traditional Chinese medicine that exhibits several pharmacological activities including skin whitening. In our study, the inhibitory effect of calycosin on melanin production is confirmed in a zebrafish in vivo model by comparing with hydroquinone, kojic acid, and arbutin, known as tyrosinase inhibitors. Moreover, the inhibitory kinetics of calycosin on tyrosinase and their binding mechanisms are determined using molecular docking techniques, molecular dynamic simulations, and free energy analysis. The results indicate that calycosin has an obvious inhibitory effect on zebrafish pigmentation at the concentration of 7.5 μM, 15 μM, and 30 μM. The IC50 of calycosin is 30.35 μM, which is lower than hydroquinone (37.35 μM), kojic acid (6.51 × 103 μM), and arbutin (3.67 × 104 μM). Furthermore, all the results of molecular docking, molecular dynamics simulations, and free energy analysis suggest that calycosin can directly bind to the active site of tyrosinase with very good binding affinity. The study indicates that the combination of computer molecular modeling and zebrafish in vivo assay would be feasible in confirming the result of the in vitro test and illustrating the target-binding information.

scholarly journals Gilteritinib overcomes lorlatinib resistance in ALK-rearranged cancer

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hayato Mizuta ◽  
Koutaroh Okada ◽  
Mitsugu Araki ◽  
Jun Adachi ◽  
Ai Takemoto ◽  
...  
Keyword(s):  
Gene Rearrangement ◽  
Kinase Inhibitors ◽  
Inhibitory Effect ◽  
In Vivo Model ◽  
Resistance Mutations ◽  
Lung Cancer Patients ◽  
Short Period ◽  
Tki Resistance

AbstractALK gene rearrangement was observed in 3%–5% of non-small cell lung cancer patients, and multiple ALK-tyrosine kinase inhibitors (TKIs) have been sequentially used. Multiple ALK-TKI resistance mutations have been identified from the patients, and several compound mutations, such as I1171N + F1174I or I1171N + L1198H are resistant to all the approved ALK-TKIs. In this study, we found that gilteritinib has an inhibitory effect on ALK-TKI–resistant single mutants and I1171N compound mutants in vitro and in vivo. Surprisingly, EML4-ALK I1171N + F1174I compound mutant-expressing tumors were not completely shrunk but regrew within a short period of time after alectinib or lorlatinib treatment. However, the relapsed tumor was markedly shrunk after switching to the gilteritinib in vivo model. In addition, gilteritinib was effective against NTRK-rearranged cancers including entrectinib-resistant NTRK1 G667C-mutant and ROS1 fusion-positive cancer.

scholarly journals An Analysis Based on Molecular Docking and Molecular Dynamics Simulation Study of Bromelain as Anti-SARS-CoV-2 Variants

2021 ◽  
Vol 12 ◽  
Author(s):  
Trina Ekawati Tallei ◽  
Fatimawali ◽  
Afriza Yelnetty ◽  
Rinaldi Idroes ◽  
Diah Kusumawaty ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Docking ◽  
Molecular Dynamics Simulation ◽  
Three Dimensional ◽  
Md Simulations ◽  
Inhibitory Effect ◽  
Dynamics Simulation ◽  
Novel Coronavirus

The rapid spread of a novel coronavirus known as SARS-CoV-2 has compelled the entire world to seek ways to weaken this virus, prevent its spread and also eliminate it. However, no drug has been approved to treat COVID-19. Furthermore, the receptor-binding domain (RBD) on this viral spike protein, as well as several other important parts of this virus, have recently undergone mutations, resulting in new virus variants. While no treatment is currently available, a naturally derived molecule with known antiviral properties could be used as a potential treatment. Bromelain is an enzyme found in the fruit and stem of pineapples. This substance has been shown to have a broad antiviral activity. In this article, we analyse the ability of bromelain to counteract various variants of the SARS-CoV-2 by targeting bromelain binding on the side of this viral interaction with human angiotensin-converting enzyme 2 (hACE2) using molecular docking and molecular dynamics simulation approaches. We have succeeded in making three-dimensional configurations of various RBD variants using protein modelling. Bromelain exhibited good binding affinity toward various variants of RBDs and binds right at the binding site between RBDs and hACE2. This result is also presented in the modelling between Bromelain, RBD, and hACE2. The molecular dynamics (MD) simulations study revealed significant stability of the bromelain and RBD proteins separately up to 100 ns with an RMSD value of 2 Å. Furthermore, despite increases in RMSD and changes in Rog values of complexes, which are likely due to some destabilized interactions between bromelain and RBD proteins, two proteins in each complex remained bonded, and the site where the two proteins bind remained unchanged. This finding indicated that bromelain could have an inhibitory effect on different SARS-CoV-2 variants, paving the way for a new SARS-CoV-2 inhibitor drug. However, more in vitro and in vivo research on this potential mechanism of action is required.

scholarly journals Use of 5-fluorouracil to analyze the effect of macrophage inflammatory protein-1 alpha on long-term reconstituting stem cells in vivo

Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1497-1504 ◽  
Author(s):  
VF Quesniaux ◽  
GJ Graham ◽  
I Pragnell ◽  
D Donaldson ◽  
SD Wolpe ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Inhibitory Effect ◽  
In Vivo Model ◽  
Hematopoietic Progenitors ◽  
Inflammatory Protein ◽  
Macrophage Inflammatory Protein

Abstract A macrophage-derived inhibitor of early hematopoietic progenitors (colony-forming unit-spleen, CFU-A) called stem cell inhibitor was found to be identical to macrophage inflammatory protein-1 alpha (MIP-1 alpha). We investigated the effect of MIP-1 alpha on the earliest stem cells that sustain long-term hematopoiesis in vivo in a competitive bone marrow repopulation assay. Because long-term reconstituting (LTR) stem cells are normally quiescent, an in vivo model was first developed in which they are triggered to cycle. A first 5-fluorouracil (5-FU) injection was used to eliminate later progenitors, causing the LTR stem cells, which are normally resistant to 5-FU, to enter the cell cycle and become sensitive to a second 5-FU injection administered 5 days later. Human MIP-1 alpha administered from day 0 to 7 was unable to prevent the depletion of the LTR stem cells by the second 5-FU treatment, as observed on day 7 in this model, suggesting that the LTR stem cells were not prevented from being triggered into cycle despite the MIP-1 alpha treatment. However, the MIP-1 alpha protocol used here did substantially decrease the number of more mature hematopoietic progenitors (granulocyte-macrophage colony-forming cells [CFC], burst- forming unit-erythroid, CFCmulti, and preCFCmulti) recovered in the bone marrow shortly after a single 5-FU injection. In vitro, MIP-1 alpha had no inhibitory effect on the ability of these progenitors to form colonies. This study confirms the in vivo inhibitory effect of MIP- 1 alpha on subpopulations of hematopoietic progenitors that are activated in myelodepressed animals. However, MIP-1 alpha had no effect on the long-term reconstituting stem cells in vivo under conditions in which it effectively reduced all later progenitors.

scholarly journals Evaluation of cannabidiol’s inhibitory effect on alpha-glucosidase and its stability in simulated gastric and intestinal fluids

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Hang Ma ◽  
Huifang Li ◽  
Chang Liu ◽  
Navindra P. Seeram
Keyword(s):  
Molecular Docking ◽  
High Performance ◽  
Inhibitory Effect ◽  
In Vitro Assays ◽  
Inhibitory Effects ◽  
In Vivo Models ◽  
Glucosidase Activity ◽  
Intestinal Fluids

Abstract Objective Cannabidiol (CBD) has been reported to have anti-diabetic effects in pre-clinical and clinical studies but its inhibitory effects on α-glucosidase, a carbohydrate hydrolyzing enzyme, remain unknown. Herein, we evaluated CBD’s inhibitory effects on α-glucosidase using in vitro assays and computational studies. Methods CBD’s inhibitory effect on α-glucosidase activity was evaluated in a yeast enzymatic assay and by molecular docking. The stability of CBD in simulated gastric and intestinal fluids was evaluated by high-performance liquid chromatography analyses. Results CBD, at 10, 19, 38, 76, 152, 304, 608, and 1216 μM, inhibited α-glucosidase activity with inhibition of 17.1, 20.4, 48.1, 56.6, 59.1, 63.7, 74.1, and 95.4%, respectively. Acarbose, the positive control, showed a comparable inhibitory activity (with 85.1% inhibition at 608 μM). CBD’s inhibitory effect on α-glucosidase was supported by molecular docking showing binding energy (-6.39 kcal/mol) and interactions between CBD and the α-glucosidase protein. CBD was stable in simulated gastric and intestinal fluids for two hours (maintained ≥ 90.0%). Conclusions CBD showed moderate inhibitory effect against yeast α-glucosidase activity and was stable in gastric and intestinal fluids. However, further studies on CBD’s anti-α-glucosidase effects using cellular and in vivo models are warranted to support its potential application for the management of type II diabetes mellitus.

scholarly journals Cannabis Constituents and Acetylcholinesterase Interaction: Molecular Docking, In Vitro Studies and Association with CNR1 rs806368 and ACHE rs17228602

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 758
Author(s):  
Tiyyaba Furqan ◽  
Sidra Batool ◽  
Rabia Habib ◽  
Mamoona Shah ◽  
Huba Kalasz ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Cannabinoid Receptor ◽  
Human Subjects ◽  
Inhibitory Effect ◽  
Ache Inhibitor ◽  
Binding Affinities ◽  
Cannabinoid Receptor 1 ◽  
Inhibitory Potential

The study documented here was aimed to find the molecular interactions of some of the cannabinoid constituents of cannabis with acetylcholinesterase (AChE). Molecular docking and LogP determination were performed to predict the AChE inhibitory effect and lipophilicity. AChE enzyme activity was measured in the blood of cannabis addicted human subjects. Further, genetic predisposition to cannabis addiction was investigated by association analysis of cannabinoid receptor 1 (CNR1) single nucleotide polymorphism (SNP) rs806368 and ACHE rs17228602 using restriction fragment length polymorphism (RFLP) method. All the understudied cannabis constituents showed promising binding affinities with AChE and are lipophilic in nature. The AChE activity was observed to be indifferent in cannabis addicted and non-addicted healthy controls. There was no significant association with CNR1 SNP rs806368 and ACHE rs17228602. The study concludes that in silico prediction for individual biomolecules of cannabis is different from in vivo physiological action in human subjects when all are present together. However, for a deeper mechanistic insight into these interactions and association, multi-population studies are suggested. Further studies to explore the inhibitory potential of different cannabis constituents for intended AChE inhibitor-based drug are warranted.

scholarly journals Use of 5-fluorouracil to analyze the effect of macrophage inflammatory protein-1 alpha on long-term reconstituting stem cells in vivo

Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1497-1504 ◽  
Author(s):  
VF Quesniaux ◽  
GJ Graham ◽  
I Pragnell ◽  
D Donaldson ◽  
SD Wolpe ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Inhibitory Effect ◽  
In Vivo Model ◽  
Hematopoietic Progenitors ◽  
Inflammatory Protein ◽  
Macrophage Inflammatory Protein

A macrophage-derived inhibitor of early hematopoietic progenitors (colony-forming unit-spleen, CFU-A) called stem cell inhibitor was found to be identical to macrophage inflammatory protein-1 alpha (MIP-1 alpha). We investigated the effect of MIP-1 alpha on the earliest stem cells that sustain long-term hematopoiesis in vivo in a competitive bone marrow repopulation assay. Because long-term reconstituting (LTR) stem cells are normally quiescent, an in vivo model was first developed in which they are triggered to cycle. A first 5-fluorouracil (5-FU) injection was used to eliminate later progenitors, causing the LTR stem cells, which are normally resistant to 5-FU, to enter the cell cycle and become sensitive to a second 5-FU injection administered 5 days later. Human MIP-1 alpha administered from day 0 to 7 was unable to prevent the depletion of the LTR stem cells by the second 5-FU treatment, as observed on day 7 in this model, suggesting that the LTR stem cells were not prevented from being triggered into cycle despite the MIP-1 alpha treatment. However, the MIP-1 alpha protocol used here did substantially decrease the number of more mature hematopoietic progenitors (granulocyte-macrophage colony-forming cells [CFC], burst- forming unit-erythroid, CFCmulti, and preCFCmulti) recovered in the bone marrow shortly after a single 5-FU injection. In vitro, MIP-1 alpha had no inhibitory effect on the ability of these progenitors to form colonies. This study confirms the in vivo inhibitory effect of MIP- 1 alpha on subpopulations of hematopoietic progenitors that are activated in myelodepressed animals. However, MIP-1 alpha had no effect on the long-term reconstituting stem cells in vivo under conditions in which it effectively reduced all later progenitors.

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