scholarly journals Inhibitory Effect and Mechanism of Chitosan–Ag Complex Hydrogel on Fungal Disease in Grape

2021 ◽  
Author(s):  
Weizhong He ◽  
Yajuan Zhu ◽  
Yan Chen ◽  
Qi Shen ◽  
Zhenyu Hua ◽  
...  
Keyword(s):  
Room Temperature ◽  
Critical Role ◽  
Inhibitory Effect ◽  
Fungal Disease ◽  
Postharvest Diseases ◽  
Inhibitory Effects ◽  
Antibacterial Material ◽  
Antioxidant Effects

Hydrogel antibacterial agent is an ideal antibacterial material because of it could diffuses antibacterial molecules into the decayed area by providing a suitable microenvironment and the hydrogel acts as a protective barrier on the decay interface. The biocompatibility and biodegradation make the removal process easily which were widely used in medical fields. However, there have been few reports on its application for controlling postharvest diseases in fruit. In this study, the Chitosan-Ag (CS-Ag) complex hydrogels were prepared using the physical crosslinking method, which used for controlling postharvest diseases in grape. The prepared hydrogels were stable for a long period at room temperature. The structure and surface morphology of CS-Ag composite hydrogels were characterized by UV-Vis, FTIR, SEM, and XRD. The inhibitory effects of CS-Ag hydrogel on disease in grape caused by P. expansum, A. niger and B. cinerea were investigated both in vivo and in vitro. The remarkable antibacterial activity of CS-Ag hydrogels was mainly due to the synergistic antibacterial and antioxidant effects of CS and Ag. Preservation test showed that the CS-Ag hydrogel had positive fresh-keeping effect. This revealed CS-Ag hydrogels plays a critical role in controlling fungal disease in grape.

In vitro inhibitory effects of glucosamine, chondroitin and diacerein on human hepatic CYP2D6

2021 ◽  
Vol 36 (4) ◽  
pp. 259-270
Author(s):  
Boon Hooi Tan ◽  
Nafees Ahemad ◽  
Yan Pan ◽  
Uma Devi Palanisamy ◽  
Iekhsan Othman ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
High Performance ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
Time Curve ◽  
Clinical Drugs ◽  
Inhibition Potencies ◽  
P450 2D6

Abstract Objectives Glucosamine, chondroitin and diacerein are natural compounds commonly used in treating osteoarthritis. Their concomitant intake may trigger drug–natural product interactions. Cytochrome P450 (CYP) has been implicated in such interactions. Cytochrome P450 2D6 (CYP2D6) is a major hepatic CYP involved in metabolism of 25% of the clinical drugs. This study aimed to investigate the inhibitory effect of these antiarthritic compounds on CYP2D6. Methods CYP2D6 was heterologously expressed in Escherichia coli. CYP2D6–antiarthritic compound interactions were studied using in vitro enzyme kinetics assay and molecular docking. Results The high-performance liquid chromatography (HPLC)-based dextromethorphan O-demethylase assay was established as CYP2D6 marker. All glucosamines and chondroitins weakly inhibited CYP2D6 (IC50 values >300 µM). Diacerein exhibited moderate inhibition with IC50 and K i values of 34.99 and 38.27 µM, respectively. Its major metabolite, rhein displayed stronger inhibition potencies (IC50=26.22 μM and K i =32.27 μM). Both compounds exhibited mixed-mode of inhibition. In silico molecular dockings further supported data from the in vitro study. From in vitro–in vivo extrapolation, rhein presented an area under the plasma concentration-time curve (AUC) ratio of 1.5, indicating low potential to cause in vivo inhibition. Conclusions Glucosamine, chondroitin and diacerein unlikely cause clinical interaction with the drug substrates of CYP2D6. Rhein, exhibits only low potential to cause in vivo inhibition.

Presynaptic inhibition of canine renal adrenergic nerves by acetylcholine in vivo

1979 ◽  
Vol 237 (3) ◽  
pp. H326-H331
Author(s):  
N. W. Robie
Keyword(s):  
Nerve Stimulation ◽  
Neurotransmitter Release ◽  
Intact Animal ◽  
Inhibitory Effect ◽  
Inhibitory Effects ◽  
Renal Vasculature ◽  
Anesthetized Dogs ◽  
Renal Sympathetic

Experiments were performed in anesthetized dogs to determine whether previously reported in vitro inhibition of sympathetic neurotransmitter release by acetylcholine could be demonstrated in the renal vasculature of the intact animal. Vasoconstrictor responses to renal sympathetic nerve stimulation at varying frequencies were compared to intra-arterial injections of norepinephrine before and during intra-arterial infusions of acetylcholine, 2.5--80 micrograms/min. The vasoconstrictor responses to nerve stimulation were inhibited to a greater extent than were responses to norepinephrine during infusions of acetylcholine. The inhibitory effects of acetylcholine on nerve stimulation were dose and frequency dependent. The inhibition was blocked by atropine but not altered by physostigmine. Changes in renal blood flow per se did not contribute to the inhibitory effect of acetylcholine, since another vasodilator agent, sodium acetate, did not affect the nerve stimulation-norepinephrine vasocontriction relationship. Thus, acetylcholine produced inhibition of in vivo renal sympathetic vasoconstrictor responses, and the receptor involved appears to be muscarinic.

scholarly journals A Ral GAP complex links PI 3-kinase/Akt signaling to RalA activation in insulin action

2011 ◽  
Vol 22 (1) ◽  
pp. 141-152 ◽  
Author(s):  
Xiao-Wei Chen ◽  
Dara Leto ◽  
Tingting Xiong ◽  
Genggeng Yu ◽  
Alan Cheng ◽  
...  
Keyword(s):  
Glucose Transporter ◽  
Critical Role ◽  
Inhibitory Effect ◽  
Small Gtpase ◽  
Regulatory Subunit ◽  
Hydrolysis Of ◽  
Identification And Characterization

Insulin stimulates glucose transport in muscle  and adipose tissue by translocation of glucose transporter 4 (GLUT4) to the plasma membrane. We previously reported that activation of the small GTPase RalA downstream of PI 3-kinase plays a critical role in this process by mobilizing the exocyst complex for GLUT4 vesicle targeting in adipocytes. Here we report the identification and characterization of a Ral GAP complex (RGC) that mediates the activation of RalA downstream of the PI 3-kinase/Akt pathway. The complex is composed of an RGC1 regulatory subunit and an RGC2 catalytic subunit (previously identified as AS250) that directly stimulates the guanosine triphosphate hydrolysis of RalA. Knockdown of RGC proteins leads to increased RalA activity and glucose uptake in adipocytes. Insulin inhibits the GAP complex through Akt2-catalyzed phosphorylation of RGC2 in vitro and in vivo, while activated Akt relieves the inhibitory effect of RGC proteins on RalA activity. The RGC complex thus connects PI 3-kinase/Akt activity to the transport machineries responsible for GLUT4 translocation.

Cancer-chemopreventive effects of natural sweeteners and related compounds

2002 ◽  
Vol 74 (7) ◽  
pp. 1309-1316 ◽  
Author(s):  
Takao Konoshima ◽  
Midori Takasaki
Keyword(s):  
Mouse Skin ◽  
Stevia Rebaudiana ◽  
Chemical Carcinogenesis ◽  
Inhibitory Effect ◽  
Skin Carcinogenesis ◽  
Inhibitory Effects ◽  
Chemopreventive Agents ◽  
Vitro Assay

To search for possible cancer-chemopreventive agents from natural resources, several natural sweeteners were screened by the in vitro assay indicated by the inhibitory effects of Epstein-Barr virus early antigen (EBV-EA) induction. Of active compounds that showed the remarkable inhibitory effects on the EBV-EA induction, stevioside, from the leaves of Stevia rebaudiana, and mogroside V, from the fruits of Momordica grosvenori, exhibited significant inhibitory effects on the two-stage mouse skin carcinogenesis in vivo induced by 7,12-dimethylbenz[a]anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA). The inhibitory effect of stevioside is stronger than that of glycyrrhizin, which had been known as an antitumor-promoter in chemical carcinogenesis. Furthermore, stevioside also inhibited mouse skin carcinogenesis initiated by peroxynitrite. These results suggest that stevioside and mogroside V might be valuable as chemopreventive agents for chemical carcinogenesis.

scholarly journals Silencing of AURKA augments the antitumor efficacy of the AURKA inhibitor MLN8237 on neuroblastoma cells

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yan Yang ◽  
Lili Ding ◽  
Qi Zhou ◽  
Li Fen ◽  
Yuhua Cao ◽  
...  
Keyword(s):  
Small Interfering Rna ◽  
Neuroblastoma Cell ◽  
Neuroblastoma Cells ◽  
Inhibitory Effect ◽  
Neuroblastoma Cell Line ◽  
Inhibitory Effects ◽  
Rna Transfection ◽  
Interfering Rna

Abstract Background Aurora kinase A (AURKA) has been implicated in the regulation of cell cycle progression, mitosis and a key number of oncogenic signaling pathways in various malignancies including neuroblastoma. Small molecule inhibitors of AURKA have shown potential, but still not as good as expected effects in clinical trials. Little is known about this underlying mechanism. Here, we evaluated the inhibitory effects of AURKA inhibitor MLN8237 on neuroblastoma cells to understand the potential mechanisms responsible for tumor therapy. Methods MLN8237 treatment on neuroblastoma cell line IMR32 was done and in vivo inhibitory effects were investigated using tumor xenograft model. Cellular senescence was evaluated by senescence-associated β-gal Staining assay. Flow cytometry was used to tested cell cycle arrest and cell apoptosis. Senescence-associated signal pathways were detected by western blot. CD133 microbeads and microsphere formation were used to separate and enrich CD133+ cells. AURKA small interfering RNA transfection was carried to downregulate AURKA level. Finally, the combination of MLN8237 treatment with AURKA small interfering RNA transfection were adopted to evaluate the inhibitory effect on neuroblastoma cells. Results We demonstrate that MLN8237, an inhibitor of AURKA, induces the neuroblastoma cell line IMR32 into cellular senescence and G2/M cell phase arrest. Inactivation of AURKA results in MYCN destabilization and inhibits cell growth in vitro and in a mouse model. Although MLN8237 inhibits AURKA kinase activity, it has almost no inhibitory effect on the AURKA protein level. By contrast, MLN8237 treatment leads to abnormal high expression of AURKA in vitro and in vivo. Knockdown of AURKA reduces cell survival. The combination of MLN8237 with AURKA small interfering RNA results in more profound inhibitory effects on neuroblastoma cell growth. Moreover, MLN8237 treatment followed by AURKA siRNA forces senescent cells into apoptosis via suppression of the Akt/Stat3 pathway. Conclusions The effect of AURKA-targeted inhibition of tumor growth plays roles in both the inactivation of AURKA activity and the decrease in the AURKA protein expression level.

Inhibitory effects of (-)-Epigallocatechin-3-gallate from green tea on the growth of Babesia parasites

Parasitology ◽  
2009 ◽  
Vol 137 (5) ◽  
pp. 785-791 ◽  
Author(s):  
M. ABOULAILA ◽  
N. YOKOYAMA ◽  
I. IGARASHI
Keyword(s):  
Body Weight ◽  
Green Tea ◽  
Inhibitory Effect ◽  
Post Inoculation ◽  
Chemotherapeutic Drug ◽  
Inhibitory Effects ◽  
Viability Test ◽  
Anti Cancer

SUMMARY(-)-Epigallocatechin-3-gallate (EGCG) is the major tea catechin and accounts for 50–80% of the total catechin in green tea. (-)-Epigallocatechin-3-gallate has antioxidant, anti-inflammatory, anti-microbial, anti-cancer, and anti-trypanocidal activities. This report describes the inhibitory effect of (-)-Epigallocatechin-3-gallate on the in vitro growth of bovine Babesia parasites and the in vivo growth of the mouse-adapted rodent babesia B. microti. The in vitro growth of the Babesia species was significantly (P<0·05) inhibited in the presence of micromolar concentrations of EGCG (IC50 values=18 and 25 μM for B. bovis, and B. bigemina, respectively). The parasites showed no re-growth at 25 μM for B. bovis and B. bigemina in the subsequent viability test. The drug significantly (P<0·05) inhibited the growth of B. microti at doses of 5 and 10 mg/kg body weight, and the parasites completely cleared on day 14 and 16 post-inoculation in the 5 and 10 mg/kg treated groups, respectively. These findings highlight the potentiality of (-)-Epigallocatechin-3-gallate as a chemotherapeutic drug for the treatment of babesiosis.

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 The Tubulin Inhibitor VERU-111 in Combination With Vemurafenib Provides an Effective Treatment of Vemurafenib-Resistant A375 Melanoma

2021 ◽  
Vol 12 ◽  
Author(s):  
Hongmei Cui ◽  
Qinghui Wang ◽  
Duane D. Miller ◽  
Wei Li
Keyword(s):  
Critical Role ◽  
Single Agent ◽  
Braf Inhibitor ◽  
Inhibitory Effect ◽  
Braf V600e ◽  
Akt Pathway ◽  
Great Promise ◽  
Tubulin Inhibitor

Melanoma is one of the deadliest skin cancers having a five-year survival rate around 15–20%. An overactivated MAPK/AKT pathway is well-established in BRAF mutant melanoma. Vemurafenib (Vem) was the first FDA-approved BRAF inhibitor and gained great clinical success in treating late-stage melanoma. However, most patients develop acquired resistance to Vem within 6–9 months. Therefore, developing a new treatment strategy to overcome Vem-resistance is highly significant. Our previous study reported that the combination of a tubulin inhibitor ABI-274 with Vem showed a significant synergistic effect to sensitize Vem-resistant melanoma both in vitro and in vivo. In the present study, we unveiled that VERU-111, an orally bioavailable inhibitor of α and β tubulin that is under clinical development, is highly potent against Vem-resistant melanoma cells. The combination of Vem and VERU-111 resulted in a dramatically enhanced inhibitory effect on cancer cells in vitro and Vem-resistant melanoma tumor growth in vivo compared with single-agent treatment. Further molecular signaling analyses demonstrated that in addition to ERK/AKT pathway, Skp2 E3 ligase also plays a critical role in Vem-resistant mechanisms. Knockout of Skp2 diminished oncogene AKT expression and contributed to the synergistic inhibitory effect of Vem and VERU-111. Our results indicate a treatment combination of VERU-111 and Vem holds a great promise to overcome Vem-resistance for melanoma patients harboring BRAF (V600E) mutation.

Inhibitory effect of Zanthoxylum bungeanum essential oil (ZBEO) on Escherichia coli and intestinal dysfunction

2017 ◽  
Vol 8 (4) ◽  
pp. 1569-1576 ◽  
Author(s):  
Lei Hong ◽  
Wu Jing ◽  
Wang Qing ◽  
Su Anxiang ◽  
Xue Mei ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Essential Oil ◽  
Inhibitory Effect ◽  
Intestinal Health ◽  
Inhibitory Effects ◽  
E Coli ◽  
Zanthoxylum Bungeanum

The inhibitory effects of Zanthoxylum bungeanum essential oil (ZBEO) on Escherichia coli (E. coli) in vitro and in vivo were investigated, as well as its function of improvement of intestinal health.

In Vivo and In Vitro Studies of the Inhibitory Effect of Propofol on Human Platelet Aggregation 

1998 ◽  
Vol 88 (2) ◽  
pp. 362-370 ◽  
Author(s):  
Hiroshi Aoki ◽  
Toshiki Mizobe ◽  
Shinji Nozuchi ◽  
Noriko Hiramatsu
Keyword(s):  
Platelet Aggregation ◽  
Intracellular Calcium ◽  
Bleeding Time ◽  
Inhibitory Effect ◽  
Ion Concentration ◽  
Inhibitory Effects ◽  
Fat Emulsion ◽  
Intracellular Calcium Ion

Background The inhibitory effects of propofol on platelet aggregation are controversial because the fat emulsion used as the solvent for propofol may affect platelet function. The effects of propofol on platelet intracellular calcium ion concentration and on aggregation were investigated. Methods Platelet aggregation was measured in 10 patients who received an intravenous infusion of propofol. Intralipos, the propofol solvent, was infused in 10 healthy volunteers and platelet aggregation were measured. The in vitro effects of propofol and Intralipos on platelets were also investigated. The inhibitory effects of various concentrations of propofol were studied. The effects of propofol on the changes in intracellular calcium level using a fluorescent dye, fura-2, were also observed. Template bleeding time was measured to determine the effect of propofol in clinical use. Results Platelet aggregation was significantly inhibited by infusion of propofol, although bleeding time was not prolonged. Intralipos did not inhibit platelets either in vivo or in vitro. Propofol significantly inhibited platelet aggregation in vitro and at 5.81 +/- 2.73 microg/ml but not at 2.08 +/- 1.14 microg/ml. The increase of intracellular calcium concentration was inhibited both in influx and discharge of calcium. Conclusions Propofol inhibited platelet aggregation both in vivo and in vitro. Inhibition of platelet aggregation appeared to be caused by propofol itself and not by the fat emulsion. This inhibitory effect was also supported by the suppressed influx and discharge of calcium. No change in the bleeding time suggests that this inhibitory effect does not impair hemostasis clinically.

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