scholarly journals INHIBITORY ACTIVITY OF COBALT(II)–MORIN COMPLEX AGAINST THE REPLICATION OF DENGUE VIRUS TYPE 2

2017 ◽  
Vol 6 (6) ◽  
pp. 141
Author(s):  
Teguh Hari Sucipto ◽  
Siti Churrotin ◽  
Harsasi Setyawati Setyawati ◽  
Kris Cahyo Mulyatno ◽  
Ilham Harlan Amarullah ◽  
...  

Dengue virus (DENV) is a significant pathogen emerging worldwide as a cause of infectious disease. Antidengue treatments are urgently required to control the emergence of dengue. DENV is a mosquito-borne disease responsible for acute systemic diseases and serious health conditions. DENVs were distributed in the tropical and sub-tropical areas and transmitted to humans by Aedes agypty and Aedes albopictus. Dengue vaccine or antiviral has not yet been clinically approved for humans, even though there have been great efforts toward this end. Antiviral activity against DENV is an important alternative for the characterization and development of drugs. Metal–organic compounds were reported to exhibit fungicidal, bactericidal, and antiviral activities its inhibitory activity was not significant, at high concentration it was more toxic to replicating cells than to stationary cell monolayers of Vero cells. The aim of this study is to investigate the antiviral effects of Cobalt(II)–Morin complex. This compound was further investigated for its inhibitory effect on the replication of DENV-2 in Vero cells. The replication of DENV was measured by enzyme-linked immunosorbent assay and the value of selectivity index (SI). SI was determined as the ratio of the 50% cytotoxic concentration (CC50) to the 50% inhibitory concentration (IC50). The IC50 value of the Cobalt(II)–Morin complex for DENV-2 was 3.08 µg/ml, and the CC50 value of the complex for Vero cells was 3.36 µg/ml; thus, the SI value was 1.09. The results of this study demonstrate the antidengue serotype 2 inhibitory activity of Cobalt(II)–Morin complex and its high toxicity in Vero cells. Further studies are not required before Co(II)–Morin can be applied in the treatment of DENV-2 infections.

2020 ◽  
Vol 8 (3) ◽  
pp. 183
Author(s):  
Teguh Hari Sucipto ◽  
Aswandi Wibrianto ◽  
Fahimah Martak ◽  
Siti Churrotin ◽  
Ilham Harlan Amarullah ◽  
...  

Dengue virus (DENV) is a significant pathogen emerging worldwide as a cause of infectious disease. DENVs are transmitted to humans through female mosquitoes from Aedes aegypti and Aedes albopictus species. Indonesia is one of the largest countries in the world in dengue endemic regions worldwide. Dengue fever was occurred for the first time as an outbreak in Surabaya and Jakarta in 1968. Many efforts have been made to prevent and treat DENV infections, and clinical trials of a number of vaccines are currently underway. Antiviral testing of DENV is an important alternative for drug characterization and development. Complex compounds are formed as a result of metal and organic complex reactions. Complex compounds can be used as an anti-inflammatory, antimicrobial antifungal, antibacterial, antivirus. The Zn2+ ion can be used as an antiviral candidate. The purpose of this project was investigated Zinc(II)-2,4,5-triphenyl-1H-imidazole antiviral compound to be further tested for inhibitory effect on the replication of DENV-2 in cell culture. DENV replication was measured by antiviral activity assay and cytotoxicity assay. The inhibitory activity of Zinc(II)-2,4,5-triphenyl-1H-imidazole complex compound was determined by Viral ToxGloTM Assay. The cytotoxicity of Zinc(II)-2,4,5-triphenyl-1H-imidazole complex compound was determined by CellTiter96® AQuoeus assay. The inhibitory concentration (IC50) of Zinc(II)-2,4,5-triphenyl- 1H-imidazole against dengue virus type-2 was 34.42 μg/ml. The cytotoxic concentration (CC50) of compound against Vero cell was <100 μg/ml. The results of this study demonstrate the antidengue serotype 2 inhibitory activity of investigated Zinc(II)-2,4,5-triphenyl-1H-imidazole complex and its high toxicity in Vero cells. Further studies are not required before investigated Zinc(II)-2,4,5-triphenylimidazole can be applied in the treatment of DENV-2 infections


Author(s):  
Teguh H. Sucipto ◽  
Fahimah Martak

Dengue fever and dengue hemorrhagic fever are transmitted to humans by the Aedes aegypti and Aedes albopictus mosquitoes, with an observed 30-fold increase in global incidence the last 50 years. Despite the tremendous efforts invested anti-dengue virus research, no clinically approved vaccine or antiviral chemotherapeutics are available for humans, and disease treatment is limited to supportive care. Over the years there has been a continuous interest in the chemistry of metal complexes with biological activity, including platinum complexes with antitumor activity and silver complexes with antimicrobial action. Aim of the project was to investigate [Cu(2,4,5-triphenyl-1H- imidazole)2 (H2O)2].Cl2 as antiviral compound that was further tested for inhibitory effect on the replication of dengue virus type 2 (DENV-2) in Vero cell. DENV-2 were infected in Vero cells and replication of virus was measured by Viral ToxGlo with selectivity index value (SI) and determined as the ratio of cytotoxic concentration 50 (CC50) to inhibitory concentration 50 (IC50) for com- pound. The standard curve between concentration of compound (μg/mL) and %viability of cells was analyzed by logarithmic cor- relation regression with regression equation. For infection rates, t-test was used to exam- ine the statistical significances among the concentrations of compound. P<0.05 was considered to be significant. The maximum inhibitory concentration (IC50) of [Cu(2,4,5- triphenyl-1H-imidazole)2 (H2O)2].Cl2 against DENV-2 was 98.62 μg/mL. The cytotoxic concentration (CC50) of compound against Vero cells was 300.36μg/mL. The SI values for [Cu(2,4,5-triphenyl-1H-imidazole)2 (H2O)2].Cl2 1.86. Based on selectivity index values, [Cu(2,4,5-triphenyl-1H-imidazole)2 (H2O)2].Cl2 can inhibit the growth of DENV- 2 and has low toxicity values for Vero cells.


1974 ◽  
Vol 32 (02/03) ◽  
pp. 704-713 ◽  
Author(s):  
F. N McKenzie ◽  
K.-E Arfors ◽  
N. A Matheson

SummaryA study has been made of the biochemical factors underlying the platelet response to laser-induced microvascular injury. A platelet aggregating substance is produced at sites of laser-induced injury which markedly stimulates platelet activity at a site of injury inflicted a short distance downstream. Distal sites of injury are not similarly influenced if the distance between the injuries is increased or if the proximal site no longer shows platelet-stimulating activity. The stimulating effect of an adjacent proximal injury on platelet activity at a distal site is inhibited by local intra-arterial infusion of adenosine. Measurements of arterial blood pressure and microvascular blood flow velocity during adenosine infusion showed that its inhibitory effect on platelet activity is largely independent of its vasodilator properties. The effect of infusion of different adenosine phosphates (AMP, ADP, ATP) was also studied. Very small amounts of ADP markedly stimulated platelet activity and the emboli formed were similar to those normally produced at sites of laser injury. At high concentration AMP inhibited while ATP stimulated platelet activity in vivo. The results emphasise the fundamental role of ADP as a mediator of the platelet response at sites of laser- induced microvascular injury.


Planta Medica ◽  
2021 ◽  
Author(s):  
Birgit Waltenberger ◽  
Françoise Lohézic-Le Dévéhat ◽  
Thi Huyen Vu ◽  
Olivier Delalande ◽  
Claudia Lalli ◽  
...  

AbstractProtein tyrosine phosphatase 1B plays a significant role in type 2 diabetes mellitus and other diseases and is therefore considered a new drug target. Within this study, an acetone extract from the lichen Stereocaulon evolutum was identified to possess strong protein tyrosine phosphatase 1B inhibition in a cell-free assay (IC50 of 11.8 µg/mL). Fractionation of this bioactive extract led to the isolation of seven known molecules belonging to the depsidones and the related diphenylethers and one new natural product, i.e., 3-butyl-3,7-dihydroxy-5-methoxy-1(3H)-isobenzofurane. The isolated compounds were evaluated for their inhibition of protein tyrosine phosphatase 1B. Two depsidones, lobaric acid and norlobaric acid, and the diphenylether anhydrosakisacaulon A potently inhibited protein tyrosine phosphatase 1B with IC50 values of 12.9, 15.1, and 16.1 µM, respectively, which is in the range of the protein tyrosine phosphatase 1B inhibitory activity of the positive control ursolic acid (IC50 of 14.4 µM). Molecular simulations performed on the eight compounds showed that i) a contact between the molecule and the four main regions of the protein is required for inhibitory activity, ii) the relative rigidity of the depsidones lobaric acid and norlobaric acid and the reactivity related to hydrogen bond donors or acceptors, which interact with protein tyrosine phosphatase 1B key amino acids, are involved in the bioactivity on protein tyrosine phosphatase 1B, iii) the cycle opening observed for diphenylethers decreased the inhibition, except for anhydrosakisacaulon A where its double bond on C-8 offsets this loss of activity, iv) the function present at C-8 is a determinant for the inhibitory effect on protein tyrosine phosphatase 1B, and v) the more hydrogen bonds with Arg221 there are, the more anchorage is favored.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 297.2-297
Author(s):  
Y. Akhverdyan ◽  
E. Papichev ◽  
В. Zavodovsky ◽  
L. Seewordova ◽  
J. Polyakova

Background:The main mechanism of the effect of fetuin-A (FeA) on bone metabolism is its ability to bind calcium and proteins of the TGF-β family. It has been proven that the optimal concentration of TGF-β is necessary for the differentiation of bone tissue, and a high concentration inhibits bone mineralization. Thus, adequate osteogenesis is based on a complex balance between FeA and TGF-β levels. It can be assumed that the determination of the FeA level in the blood of patients with rheumatoid arthritis (RA) will help to optimize the diagnosis and predict the severity of osteoporosis (OP).Objectives:to study the possibility of predicting the development of osteoporosis and osteoporetic fractures in patients with RA, depending on the level of FeA in blood serum.Methods:We examined two groups of patients (52 patients with RA complicated by OP, 58 patients with RA without OP) and 30 apparently healthy individuals. The age of the surveyed ranged from 18 to 72 years, the average duration of the disease was 7.53±0.89 years. In both groups, the FeA level was determined by an indirect enzyme-linked immunosorbent assay using a commercial test. Bone mineral density (BMD) was also measured in both groups (Lunar DPX-NT GE).Results:The average FeA level in the group of RA patients was lower than in the group of conventionally healthy individuals (731.21±109.9 μg/ml and 812.9±76.2 μg/ml, respectively; F=13.34; p=0,0004). The normal FeA level was calculated using the formula M±2σ in the group of apparently healthy individuals and ranged from 653.55 μg/ml to 972.19 μg/ml.A decreased level of FeA was found in 20 patients (86.96%) in the group of patients with OP and only in 3 (13.04%) patients with RA who did not suffer from OP (p<0.001). It can be concluded that patients with RA and a low concentration of FeA in the blood serum have a higher risk of developing OP.In the group of patients with normal FeA level, osteoporetic fractures were observed in 12 (13.79%) patients and were absent in 75 (86.21%) patients (p<0.001). Thus, RA patients with normal serum FeA levels have a lower risk of osteoporetic fractures.We also found a positive significant correlation between the level of FeA and BMD in the femoral neck area. In the group of patients with a reduced FeA level (23 people), the mean BMD values were 0.732±0.022 g/cm2, and in the group of patients with a normal FeA level (87 patients) - 0.890±0.014 g/cm2 (p<0.001, F=27.663). The obtained values are in agreement with the literature data on the effect of the serum FeA concentration on the BMD values.Conclusion:We consider it expedient to determine the serum FeA concentration in patients with RA. At a FeA level of 653.55 μg/ml and below, a higher risk of developing OP and osteoporetic fractures can be predicted. In this case, the patient is shown a standard examination for osteoporosis. At values of 653.55 μg/ml and above, a more expectant management of the patient is allowed. Thus, by determining the serum concentration of FeA, it is possible to implement an integrated approach to the patient and to optimize the schemes for the diagnosis of OP in patients with RA.Disclosure of Interests:None declared


1995 ◽  
Vol 22 (1) ◽  
pp. 7 ◽  
Author(s):  
JA Campbell ◽  
BR Loveys ◽  
VWK Lee ◽  
S Strother

An inhibitory effect on the growth of Lemna minor L. cultures has been demonstrated in xylem exudate from Vitis vinifera L. var. Waltham Cross bled from canes cut near the time of budburst. Most inhibitory activity was detected up to the time of maximal daily exudation, which corresponded closely with budburst. After this time the inhibitory activity rapidly disappeared. A similar pattern occurred in each of the 3 years of the study, 1988-1990. Using ultrafiltration, it was shown that most of the growth inhibitor activity of the crude exudate was located in the 0.5-10 kDa fraction. This fraction exhibited a seasonal variation in its bioactivity similar to that ofthe crude exudate samples. The 0.5-10 kDa fraction was found to contain abscisic acid but not in a sufficient quantity to account for the inhibitory effects. When chromatographically separated fractions corresponding to oligosaccharides were pooled, biological activity equivalent to that of the crude exudate was retained, which provides evidence that the inhibitor is possibly an oligosaccharide.


2003 ◽  
Vol 10 (2) ◽  
pp. 317-322 ◽  
Author(s):  
Angel Balmaseda ◽  
María G. Guzmán ◽  
Samantha Hammond ◽  
Guillermo Robleto ◽  
Carolina Flores ◽  
...  

ABSTRACT To evaluate alternative approaches to the serological diagnosis of dengue virus (DEN) infection, the detection of DEN-specific immunoglobulin M (IgM) and IgA antibodies in serum and saliva specimens was assessed in 147 patients with symptoms of DEN infection seen at the Ministry of Health in Nicaragua. Seventy-two serum samples were determined to be positive for anti-DEN antibodies by IgM capture enzyme-linked immunosorbent assay, the routine diagnostic procedure. Serum and saliva specimens were obtained from 50 healthy adults as additional controls. IgM was detected in the saliva of 65 of the 72 serum IgM-positive cases, 6 of the 75 serum IgM-negative cases, and none of the control group, resulting in a sensitivity of 90.3% and a specificity of 92.0% and demonstrating that salivary IgM is a useful diagnostic marker for DEN infection. Detection of IgA in serum may be another feasible alternative for the diagnosis of DEN infection, with serum IgA found in 68 (94.4%) of the IgM-positive cases. In contrast, detection of IgA in saliva was not found to be a useful tool for DEN diagnosis in the present study. Further studies of the kinetics of antibody detection in another set of 151 paired acute- and convalescent-phase serum samples showed that DEN-specific IgA antibodies were detected in more acute-phase samples than were IgM antibodies. Thus, we conclude that DEN-specific IgA in serum is a potential diagnostic target. Furthermore, given that saliva is a readily obtainable, noninvasive specimen, detection of DEN-specific salivary IgM should be considered a useful, cheaper diagnostic modality with similar sensitivity and specificity to IgM detection in serum.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Laura C. Laurella ◽  
Fernanda M. Frank ◽  
Andrea Sarquiz ◽  
María R. Alonso ◽  
Gustavo Giberti ◽  
...  

The aim of this study was to investigate the antiprotozoal and antiviral activities of four ArgentineanMikaniaspecies. The organic and aqueous extracts ofMikania micrantha, M. parodii, M. periplocifolia,andM. cordifoliawere tested onTrypanosoma cruziepimastigotes,Leishmania braziliensispromastigotes, and dengue virus type 2. The organic extract ofM. micranthawas the most active againstT. cruziandL. braziliensisexhibiting a growth inhibition of77.6±4.5% and84.9±6.1%, respectively, at a concentration of 10 μg/ml. The bioguided fractionation ofM. micranthaorganic extract led to the identification of two active fractions. The chromatographic profile and infrared analysis of these fractions revealed the presence of sesquiterpene lactones. None of the tested extracts were active against dengue virus type 2.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yucong Ma ◽  
Mohd Talha ◽  
Qi Wang ◽  
Zhonghui Li ◽  
Yuanhua Lin

Purpose The purpose of this paper is to study systematically the corrosion behavior of AZ31 magnesium (Mg) alloy with different concentrations of bovine serum albumin (BSA) (0, 0.5, 1.0, 1.5, 2.0 and 5.0 g/L). Design/methodology/approach Electrochemical impedance spectroscopy and potential dynamic polarization tests were performed to obtain corrosion parameters. Scanning electrochemical microscopy (SECM) was used to analyze the local electrochemical activity of the surface film. Atomic force microscope (AFM), Scanning electron microscope-Energy dispersive spectrometer and Fourier transform infrared spectroscopy were used to determine the surface morphology and chemical composition of the surface film. Findings Experimental results showed the presence of BSA in a certain concentration range (0 to 2.0 g/L) has a greater inhibitory effect on the corrosion of AZ31, however, the presence of high-concentration BSA (5.0 g/L) would sharply reduce the corrosion resistance. Originality/value When the concentration of BSA is less than 2.0 g/L, the corrosion resistance of AZ31 enhances with the concentration. The adsorption BSA layer will come into being a physical barrier to inhibit the corrosion process. However, high-concentration BSA (5.0 g/L) will chelate with dissolved metal ions (such as Mg and Ni) to form soluble complexes, which increases the roughness of the surface and accelerates the corrosion process.


Author(s):  
Fabrício Freitas Fernandes ◽  
Amanda Latercia Tranches Dias ◽  
Cíntia Lacerda Ramos ◽  
Masaharu Ikegaki ◽  
Antonio Martins de Siqueira ◽  
...  

Cryptococcosis is a worldwide disease caused by the etiological agent Cryptococcus neoformans. It affects mainly immunocompromised humans. It is relatively rare in animals only affecting those that have received prolonged antibiotic therapy. The propolis is a resin that can present several biological properties, including antibacterial, antifungal and antiviral activities. The standard strain C. neoformans ATTC 90112 was used to the antifungal evaluation. The tests were realized with propolis ethanol extract (PEE) G12 in concentrations from 0.1 to 1.6 mg mL-1. The evaluation of MIC and MFC were done according to DUARTE (2002)5. The inhibitory effect of PEE G12 on the fungal growing was seen at the concentration of 0.2 mg mL-1 and 1.6 mg mL-1 was considered a fungicidal one.


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