Article

Antiviral Activity of the Zinc Ionophores Pyrithione and Hinokitiol against Picornavirus Infections

November 2008
Journal of Virology 83(1):58-64

DOI:10.1128/JVI.01543-08

Source
PubMed

Authors:

Barbara Holzer

The Pirbright Institute

Kjerstin H W Lanke

Radboud University Medical Centre (Radboudumc)

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We have discovered two metal ion binding compounds, pyrithione (PT) and hinokitiol (HK), that efficiently inhibit human rhinovirus, coxsackievirus, and mengovirus multiplication. Early stages of virus infection are unaffected by these compounds. However, the cleavage of the cellular eukaryotic translation initiation factor eIF4GI by the rhinoviral 2A protease was abolished in the presence of PT and HK. We further show that these compounds inhibit picornavirus replication by interfering with proper processing of the viral polyprotein. In addition, we provide evidence that these structurally unrelated compounds lead to a rapid import of extracellular zinc ions into cells. Imported Zn2+ was found to be localized in punctate structures, as well as in mitochondria. The observed elevated level of zinc ions was reversible when the compounds were removed. As the antiviral activity of these compounds requires the continuous presence of the zinc ionophore PT, HK, or pyrrolidine-dithiocarbamate, the requirement for zinc ions for the antiviral activity is further substantiated. Therefore, an increase in intracellular zinc levels provides the basis for a new antipicornavirus mechanism.

Orsay Virus Infection of Caenorhabditis elegans Is Modulated by Zinc and Dependent on Lipids

Article

Full-text available

Nov 2022
J VIROL

Viruses utilize host lipids to promote the viral life cycle, but much remains unknown as to how this is regulated. Zinc is a critical element for life, and few studies have linked zinc to lipid homeostasis. We demonstrated that Caenorhabditis elegans infection by Orsay virus is dependent upon lipids and that mutation of the master regulator of lipid biosynthesis, sbp-1, reduced Orsay virus RNA levels by ~236-fold. Virus infection could be rescued by dietary supplementation with lipids downstream of fat-6/fat-7. Mutation of a zinc transporter encoded by sur-7, which suppresses the lipid defect of sbp-1, also rescued Orsay virus infection. Furthermore, reducing zinc levels by chemical chelation in the sbp-1 mutant also increased lipids and rescued Orsay virus RNA levels. Finally, increasing zinc levels by dietary supplementation led to an ~1,620-fold reduction in viral RNA. These findings provide insights into the critical interactions between zinc and host lipids necessary for virus infection. IMPORTANCE Orsay virus is the only known natural virus pathogen of Caenorhabditis elegans, which shares many evolutionarily conserved pathways with humans. We leveraged the powerful genetic tractability of C. elegans to characterize a novel interaction between zinc, lipids, and virus infection. Inhibition of the Orsay virus replication in the sbp-1 mutant animals, explained by the lipid depletion, can be rescued by a genetic and pharmacological approach that reduces the zinc accumulation and rescues the lipid levels in this mutant animal. Interestingly, the human ortholog of sbp-1, srebp-1, has been reported to play a role for virus infection, and zinc has been shown to inhibit the virus replication of multiple viruses. However, the mechanism through which zinc is acting is not well understood. These results suggest that the lipid regulation mediated by zinc may play a relevant role during mammalian virus infection.

Журнал №2(93) 2 Ekonomika i sotsium

Article

Full-text available

Feb 2022

The development of science and technology proves once again how infinite human needs are. The concentration of the population in large cities, on the one hand, accelerates the process of urbanization and affects the level of development of the state, on the other hand, the state of the environment has a negative impact on urban ecology. From ancient times the population has been striving to create favourable conditions for themselves, and such a process is still going on, especially when the negative consequences of this are clearly felt in the health of the population living in cities. Solving this problem is one of the main tasks of urboecology. The development of modern methods of geo-ecological monitoring of the ecological condition of cities, especially in areas with high industrial specialization, the development of measures to improve the health of the population in ecologically critical areas is of great importance today. To this end, this article discusses in detail the industrialized Navoi region and its urban and ecological situation, the factors affecting it.

FACTORS AFFECTING THE ECOLOGICAL STATUS OF INDUSTRIALIZED CITIES AND MEASURES TO MONITOR THEM (ON THE EXAMPLE OF NAVOI REGION)

Article

Full-text available

Jan 2022

Abstract: The development of science and technology proves once again how infinite human needs are. The concentration of the population in large cities, on the one hand, accelerates the process of urbanization and affects the level of development of the state. On the other hand, the state of the environment has a negative impact on urban ecology. From ancient times the population has been striving to create favourable conditions for themselves and such a process is still going on, especially when the negative consequences of this are clearly felt in the health of the population living in cities. Solving this problem is one of the main tasks of urboecology. The development of modern methods of geo-ecological monitoring of the ecological condition of cities, especially in areas with high industrial specialization. The development of measures to improve the health of the population in ecologically critical areas is of a great importance today. To this end, this article discusses in detail the industrialized Navoi region and its urban and ecological situation, the factors affecting it.

Role of Zinc and Zinc Ionophores in Brain Health and Depression Especially during the COVID-19 Pandemic

Chapter

Full-text available

Feb 2022

Zinc is a trace metal ion that has a role in both physiological and pathological processes, making it one of the most common and necessary components involved in brain function. Besides, zinc is required for cell proliferation control in a variety of mechanisms, including hormonal regulation of cell division. Also, zinc serves as a biochemical signal to immune cells and transcription factors involved in the synthesis of inflammatory cytokines. On the other hand, zinc has a variety of crucial roles in neurogenesis and also acts as a neuromodulator on a wide range of membrane receptors, ion channels, and transporters. Zinc is produced by neurons under several conditions to activate microglia. The link between zinc dysregulation and psychiatric disorder was that zinc acts as an inhibitory modulator at the N-methyl-D aspartic acid (NMDA) glutamate receptor. Ionophores are ion carrier molecules that reversibly bind and transport ions through biological membranes. Ionophores can be natural or synthetic products. Zinc ionophores such as quercetin, epigallocatechin gallate (EGCG), hinokitol, and proanthocyanidins have been shown to protect brain health, particularly in depression clinically significant depression and depressive symptoms in post-COVID-19 syndrome may have severe implications as it relates to life outcomes quality, herein according to previous research studies, we showed zinc deficiency as a possible risk factor for depression symptoms, which were commonly observed following severe infection of COVID-19.

Possible Benefits of Zinc supplement in CVD and COVID-19 Comorbidity

Article

Full-text available

Oct 2021

As far as comorbidity is concerned, cardiovascular diseases (CVD) appear to be accounted for the highest prevalence, severity, and fatality among COVID 19 patients. A wide array of causal links connecting CVD and COVID-19 baffle the overall prognosis as well as the efficacy of the given therapeutic interventions. At the centre of this puzzle lies ACE2 that works as a receptor for the SARS-CoV-2, and functional expression of which is also needed to minimize vasoconstriction otherwise would lead to high blood pressure. Furthermore, SARS-CoV-2 infection seems to reduce the functional expression of ACE2. Given these circumstances, it might be advisable to consider a treatment plan for COVID-19 patients with CVD in an approach that would neither aggravate the vasodeleterious arm of the renin-angiotensinogen-aldosterone system (RAAS) nor compromise the vasoprotective arm of RAAS but is effective to minimize or if possible, inhibit the viral replication. Given the immune modulatory role of Zn in both CVD and COVID-19 pathogenesis, zinc supplement to the selective treatment plan for CVD and COVID-19 comorbid conditions, to be decided by the clinicians depending on the cardiovascular conditions of the patients, might greatly improve the therapeutic outcome. Notably, ACE2 is a zinc metalloenzyme and zinc is also known to inhibit viral replication.

Health Benefits and Pharmacological Properties of Hinokitiol

Article

Full-text available

Oct 2021

Hinokitiol is a natural bioactive compound found in several aromatic and medicinal plants. It is a terpenoid synthetized and secreted by different species as secondary metabolites. This volatile compound was tested and explored for its different biological properties. In this review, we report the pharmacological properties of hinokitiol by focusing mainly on its anticancer mechanisms. Indeed, it can block cell transformation at different levels by its action on the cell cycle, apoptosis, autophagy via inhibiting gene expression and dysregulating cellular signaling pathways. Moreover, hinokitiol also exhibits other pharmacological properties, including antidiabetic, anti-inflammatory, and antimicrobial effects. It showed multiple and several effects through its inhibition, interaction and/or activation of the main cellular targets inducing these pathologies.

Dietary and Physiological Effects of Zinc on the Immune System

Article

Sep 2021

Evidence for the importance of zinc for all immune cells and for mounting an efficient and balanced immune response to various environmental stressors has been accumulating in recent years. This article describes the role of zinc in fundamental biological processes and summarizes our current knowledge of zinc's effect on hematopoiesis, including differentiation into immune cell subtypes. In addition, the important role of zinc during activation and function of immune cells is detailed and associated with the specific immune responses to bacteria, parasites, and viruses. The association of zinc with autoimmune reactions and cancers as diseases with increased or decreased immune responses is also discussed. This article provides a broad overview of the manifold roles that zinc, or its deficiency, plays in physiology and during various diseases. Consequently, we discuss why zinc supplementation should be considered, especially for people at risk of deficiency. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Twice daily oral zinc in the treatment of patients with Coronavirus Disease-19 A randomized double-blind controlled trial

Article

Nov 2022

BACKGROUND Zinc supplementation has been considered one of the potential therapies for coronavirus disease-19 (COVID-19). We aimed to examine zinc efficacy in adult patients with COVID-19 infection. METHODS We conducted a prospective, randomized, double-blind, placebo-controlled, multicenter trial. Patients tested positive for COVID-19 without end organ failure were randomized to oral zinc (n = 231) or matching placebo (n = 239) for 15 days. The primary combined outcome was death due to COVID-19 or ICU admission within 30 days after randomization. Secondary outcomes included length of hospital stay for inpatients and duration of COVID-19 symptoms with COVID-19 related hospitalization for outpatients. FINDINGS One hundred ninety patients (40.4%) were ambulatory and 280 patients (59.6%) were hospitalized. Mortality at 30-day was 6.5% in Zinc group and 9.2% in Placebo group [odds ratio (OR) 0.70 (0.37-1.32)]; ICU admission rate was respectively 5.2% and 11.3% [OR 0.46 (0.23-0.88)]. Combined outcome was lower in zinc group compared to placebo group [OR 0.62 (0.38-0.99)]. Consistent results were observed in prespecified subgroups of patients with age < 65 years, those with comorbidity, and those who needed oxygen therapy at baseline. Length of hospital stay was shorter in zinc group compared to placebo group [difference 3.5 days, 95% CI (2.76-4.23)] in inpatients group; duration of COVID-19 symptoms decreased with zinc treatment compared to placebo in outpatients [difference 1.9 days, 95% CI (0.62-2.6)]. No severe adverse events were observed during the study. INTERPRETATION Our results showed that in COVID-19 patients, oral zinc can decrease 30-day death and ICU admission rate and can shorten symptoms duration.

Advances in Nanomaterial-Based Platforms to Combat COVID-19: Diagnostics, Preventions, Therapeutics, and Vaccine Developments

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May 2022

The COVID-19 pandemic caused by the SARS-CoV-2, a Ribonucleic acid (RNA) virus that emerged less than two years but has caused nearly 6.1 million deaths to date. Recently developed variants of the SARS-CoV-2 virus have been shown to be more potent and expanded at a faster rate. Till now there is no specific and effective treatment for SARS-CoV-2 in terms of reliable and sustainable recovery. Precaution, prevention, and vaccinations are the only ways to keep the pandemic situation under control. Medical and scientific professionals are now focusing on the repurposing of previous technology and trying to develop more fruitful methodologies to detect the presence of viruses, treat the patients, precautionary items, and vaccine developments. Nanomedicine or nano-based platforms can play a crucial role in these fronts. Researchers are working on many effective approaches by nanosized particles to combat SARS-CoV-2. The role of a nano-based platform to combat SARS- CoV-2 is extremely diverse (i.e., mark to personal protective suit, rapid diagnostic tool to targeted treatment, and vaccine developments). Although there are many theoretical possibilities of a nano- based platform to combat SARS-CoV-2, till now there is an inadequate number of research targeting SARS-CoV-2 to explore such scenarios. This unique mini-review aims to compile and elaborate on the recent advances of nano-based approaches from prevention, diagnostics, treatment to vaccine developments against SARS-CoV-2 and associated challenges.

The Potential Impact of Ayurvedic traditional Bhasma on SARS-CoV-2 Induced Pathogenesis

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Mar 2022

In India, the presently ongoing infectious COVID-19 wave is caused by the delta variant of SARS-CoV-2 which has also led thousands of causalities across the globe. The government and healthcare agencies are hovering for effective strategies to counter the pandemic. The application of nanotechnology and repurposing of drugs are found an effective approach, not obsolete but partly in managing the COVID-19 disease. It has also immensely boomed the search of productive, reliable, cost-effective, and bio-assimilable alternative solutions. Since ancient times, the traditionally employed Ayurvedic bhasmas opted for diverse infectious diseases, which are now justified as a nanomedicine that could be applied for managing COVID-19 related health anomalies. Like currently existing engineered metal nanoparticles (NPs), the bhasma nanoparticles (BNPs) are also packed with unique physicochemical properties including multi-elemental nanocrystalline composition, size, shape, dissolution, surface charge, hydrophobicity, multi-pathway regulatory, and modulatory effects. Here, it is hypothesized that due to these conformational- and configurational- based physicochemical advantages, bhasma NPs might have promising potential to manage the COVID-19 pandemic and can reduce the incidence of pneumonia-like common lung infections in children as well as old-age-related inflammatory diseases by immunomodulatory, anti-inflammatory, antiviral, and adjuvant-related characteristics.

Coronavirus: Role of zinc as an immune booster

Article

Full-text available

Jan 2022

The global pandemic coronavirus disease has created a chaotic situation all over the world. This is happened due to SARS-CoV-2 infection, which is spread through we human to human connection. Now different countries have discovered vaccines for coronavirus. At the same time our body needs its own immune system. For these reasons immune boosting substance are also required. This review paper indicates that zinc acts as an immune booster in our body against the coronavirus disease. In addition, it is also an immunomodulatory and immunosuppressive component. On one hand zinc has antioxidant properties, which can remove the free radicals from our body with increasing fluidity of the cell membrane. This may result, improve the lymphocyte's function. Depending on this information it is clear that zinc have the power of create resistance barrier against coronavirus infection.

Zinc ionophores: chemistry and biological applications

Article

Dec 2021
J INORG BIOCHEM

Zinc can play a pathophysiological role in several diseases and can interfere in key processes of microbial growth. This evidence justifies the efforts in applying Zinc ionophores to restore Zinc homeostasis and treat bacterial/viral infections such as coronavirus diseases. Zinc ionophores increase the intracellular concentration of Zinc ions causing significant biological effects. This review provides, for the first time, an overview of the applications of the main Zinc ionophores in Zinc deficiency, infectious diseases, and in cancer, discussing the pharmacological and coordination properties of the Zinc ionophores.

The antimicrobial and immunomodulatory effects of Ionophores for the treatment of human infection

Article

Nov 2021
J INORG BIOCHEM

Ionophores are a diverse class of synthetic and naturally occurring ion transporter compounds which demonstrate both direct and in-direct antimicrobial properties against a broad panel of bacterial, fungal, viral and parasitic pathogens. In addition, ionophores can regulate the host-immune response during communicable and non-communicable disease states. Although the clinical use of ionophores such as Amphotericin B, Bedaquiline and Ivermectin highlight the utility of ionophores in modern medicine, for many other ionophore compounds issues surrounding toxicity, bioavailability or lack of in vivo efficacy studies have hindered clinical development. The antimicrobial and immunomodulating properties of a range of compounds with characteristics of ionophores remain largely unexplored. As such, ionophores remain a latent therapeutic avenue to address both the global burden of antimicrobial resistance, and the unmet clinical need for new antimicrobial therapies. This review will provide an overview of the broad-spectrum antimicrobial and immunomodulatory properties of ionophores, and their potential uses in clinical medicine for combatting infection.

Drug Design Strategies for the Treatment of Viral Disease. Plant Phenolic Compounds and Their Derivatives

Article

Full-text available

Jul 2021

The coronavirus pandemic (SARS CoV-2) that has existed for over a year, constantly forces scientists to search for drugs against this virus. In silico research and selected experimental data have shown that compounds of natural origin such as phenolic acids and flavonoids have promising antiviral potential. Phenolic compounds inhibit multiplication of viruses at various stages of the viral life cycle, e.g., attachment (disturbance of the interaction between cellular and viral receptors), penetration (inhibition of viral pseudo-particle fusion to the host membrane), replication (inhibition of integrase and 3C-like protease), assembly and maturation (inhibition of microsomal triglyceride transfer protein (MTP) activity hydrolysis) and release (inhibition of secretion of apolipoprotein B (apoB) from infected cells). Phenolic compounds also indirectly influence on the viral life cycle by affecting the host cell’s biochemical processes that viruses use for their own benefit. Phenolic compounds may inhibit the proteasomes and cellular deubiquitinating activity that causes an increase in the ubiquitinated proteins level in host cells. This, in turn, contributes to the lowering the available ubiquitin molecules that viruses could use for their own replication. One of the drug design strategy for the treatment of viral diseases may be an enhancement of the antiviral properties of phenolic compounds by metal complexation. Many studies have shown that the presence of a metal ion in the structure can significantly affect the affinity of the compound to key structural elements of the SARS CoV-2, such as Mpro protease, RNA-dependent RNA polymerase (RdRp) and spike protein. We believe that in the era of coronavirus pandemic, it is necessary to reconsider the search for therapeutics among well-known compounds of plant origin and their metal complexes.

Potential molecular mechanisms of zinc- and copper-mediated antiviral activity on COVID-19

Article

Jun 2021
NUTR RES

Novel coronavirus disease 2019 (COVID-19) has spread across the globe; and surprisingly, no potentially protective or therapeutic antiviral molecules are available to treat severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, zinc (Zn) and copper (Cu) have been shown to exert protective effects due to their antioxidant, anti-inflammatory and antiviral properties. Therefore, it is hypothesized that supplementation with Zn and Cu alone or as an adjuvant may be beneficial with promising efficacy and a favorable safety profile to mitigate symptoms, as well as halt progression of the severe form of SARS-CoV-2 infection. The objective of this review is to discuss the proposed underlying molecular mechanisms and their implications for combating SARS-CoV-2 infection in response to Zn and Cu administration. Several clinical trials have also included the use of Zn as an adjuvant therapy with dietary regimens/antiviral drugs against COVID-19 infection. Overall, this review summarizes that nutritional intervention with Zn and Cu may offer an alternative treatment strategy by eliciting their virucidal effects through several fundamental molecular cascades, such as, modulation of immune responses, redox signaling, autophagy, and obstruction of viral entry and genome replication during SARS-CoV-2 infection.

Zinc Supplementation Associated With a Decrease in Mortality in COVID-19 Patients: A Meta-Analysis

Article

Jun 2023

The COVID-19 pandemic has had a significant impact on the world, resulting in millions of deaths worldwide and imposing economic, political, and social problems. The use of nutritional supplementation for the prevention and mitigation of COVID-19 remains controversial. This meta-analysis aims to investigate the association between zinc supplementation, mortality, and symptomatology, among COVID-19-infected patients. A meta-analysis was conducted to compare the outcomes of mortality and symptomology of patients with COVID-19 receiving zinc supplementation and those not receiving zinc supplementation. PubMed/Medline, Cochrane, Web of Science, and CINAHL Complete were independently searched with the search terms "zinc" AND "covid" OR "sars-cov-2" "COVID-19" OR "coronavirus". After duplicates were removed, 1215 articles were identified. Five of these studies were used to assess mortality outcomes, and two were used to assess symptomatology outcomes. The meta-analysis was conducted through R 4.2.1 software (R Foundation, Vienna, Austria). Heterogeneity was evaluated by calculating the I2 index. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used. It was found that COVID-19-infected individuals treated with zinc supplements had a reduced risk of mortality compared with individuals not treated with a zinc supplement RR=0.63 (95%CI;0.52,0.77), p=0.005. For symptomology, it was found that COVID-19-infected individuals treated with zinc had no difference in symptomology than individuals not treated with a zinc supplement RR=0.52 (95%CI;0.00,24315.42), p=0.578. This data indicates that zinc supplementation is associated with decreased mortality in those with COVID-19 but does not change symptomatology. This is promising as zinc is widely available and may be valuable as a cost-effective way to prevent poor outcomes for those with COVID-19.

The role of micronutrients in maintaining women’s reproductive potential reduced due to infectious diseases

Article

Oct 2022

The human immune system, which is in close connection with other organs and systems including the reproductive one, is required for the body’s defence against infections, as well as other external and internal factors. A balanced diet with a sufficient content of not only macro-, but also micronutrients is necessary for the normal function of the immune system. Various studies showed a relationship between the deficiency of various vitamins and trace elements and decreased activity of the immune system. Thus, the immune response can be impaired by malnutrition and trace element deficiency, which increases the body’s susceptibility to infectious factors. In its turn, the infectious process can lead to an increased demand for micronutrients, which is met by exogenous substances, and in case of not enough consumption of them – by endogenous reserves. Infections are one of the main factors deteriorating human reproductive health. Pelvic inflammatory diseases (PID) hold leading positions in the gynecological pathology pattern, and their prevalence does not show a downward trend. This literature review considers the impact of major infections on women’s reproductive health, presents data on the role of micronutrients in preventing infectious diseases and rehabilitating after them, as well as in preserving reproductive functions after infections. The importance of vitamin C, E, B vitamins, zinc, L-arginine for the preservation and restoration of women’s fertility is considered, and the results of studies on the issue are presented.

Molecular Mechanisms and therapeutic effects of different vitamins and minerals in COVID-19 patients

Article

Jul 2022
J TRACE ELEM MED BIO

COVID-19 is a rapidly spreading disease, which has caught the world by surprise. Millions of people suffer from illness, and the mortality rates are dramatically high. Currently, there is no specific and immediate treatment for this disease. Remedies are limited to supportive regiments and few antiviral and anti-inflammatory drugs. The lack of a definite cure for COVID-19 is the reason behind its high mortality and global prevalence. COVID-19 can lead to a critical illness with severe respiratory distress and cytokine release. Increased oxidative stress and excessive production of inflammatory cytokines are vital components of severe COVID-19. Micronutrients, metalloids, and vitamins such as iron, manganese, selenium, Zinc, Copper, vitamin A, B family, and C are among the essential and trace elements that play a pivotal role in human nutrition and health. They participate in metabolic processes that lead to energy production. In addition, they support immune functions and act as antioxidants. Therefore, maintaining an optimal level of micronutrients intake, particularly those with antioxidant activities, is essential to fight against oxidative stress, modulate inflammation, and boost the immune system. Therefore, these factors could play a crucial role in COVID-19 prevention and treatment. In this review, we aimed to summarize antiviral properties of different vitamins and minerals. Moreover, we will investigate the correlation between them and their effects in COVID-19 patients.

Reszinate—A Phase 1/2 Randomized Clinical Trial of Zinc and Resveratrol Utilizing Home Patient-Obtained Nasal and Saliva Viral Sampling

Article

Full-text available

Jul 2022

Background: Safe, effective, and inexpensive treatment for COVID-19 is an urgent unmet medical need. Zinc and resveratrol have been reported to have antiviral activity, and resveratrol may increase zinc activity at the site of replication by increasing intracellular zinc concentrations. Methods: A 1:1 randomized, placebo-controlled trial of zinc 150 mg plus resveratrol 4 g daily for 5 days versus placebos in outpatients with SARS-CoV-2 was carried out from 9/21/2020–1/22/2021 in Seattle, Washington. Viral shedding was followed with patient self-collected nasal and saliva samples by measuring qRT-PCR for SARS-CoV-2 N gene days 1–7, 10, and 14. Patients filled out a web-based questionnaire on days 1–14 to report symptoms, vital signs and adherence to the study intervention. The study was posted as Clinical Trials.gov NCT04542993 on 9 September 2020. Results: A total of 30 participants (14 treatment; 16 placebos) had ≥1 day of the protocol treatment and were evaluable for the primary or secondary outcome. There was no difference in viral shedding between groups, nor in the resolution of symptoms. There was a trend toward a more rapid decrease in symptoms in the treatment group, though this was not statistically significant in the GLM model. Viral shedding was similar between patient self-collected mid-turbinate nasal swabs and expectorated saliva samples with a good correlation. Conclusion: SARS-CoV-2 shedding and COVID-19 symptoms were not statistically significantly decreased by treatment. Viral shedding correlates well between patient-obtained home nasal swabs and saliva sampling.

REVIEW ON PREVENTION OF COVID-19: MIRACULOUS NATURAL HERBS

Article

Full-text available

Jul 2022

Currently, the novel and major life-threatening cause all over the world is COVID-19 (Coronavirus disease 2019) which is started at the end of 2019 in Wuhan, China, and spread all over the world today. The infection of COVID-19 severity is variable which affects all ages' people and especially elderly persons whose immune system is very weak. Fatigue, fever, respiratory illness, dry cough, loss of appetite, olfactory dysfunction are the most common symptoms of this disease along with the decrease of certain cells of the immune system like helper T cells, monocytes/macrophages, etc. and an increase in pro-inflammatory cytokines are some of the major characteristics of this disease. Some natural herbal products are a successive option to combat SARS-Cov-2 disease. Herbs have various potential compound which is used as a dietary product that strongly influences immunity and maintenance of the homeostasis of inflammatory/anti-inflammatory. In the present review, we describe the potential of three herbal products as Turmeric (Haldi), Heart-leaved moonseed (Giloy), and Black cumin (Kalonji) that can be used for preventative or nutritional therapy of COVID-19.

Antiviral Activity of Zinc Oxide Nanoparticles and Tetrapods Against the Hepatitis E and Hepatitis C Viruses

Article

Full-text available

Jun 2022

Hepatitis E virus (HEV) causes an acute, self-limiting hepatitis. The disease takes a severe form in pregnant women, leading to around 30% mortality. Zinc is an essential micronutrient that plays a crucial role in multiple cellular processes. Our earlier findings demonstrated the antiviral activity of zinc salts against HEV infection. Zinc oxide (ZnO) and its nanostructures have attracted marked interest due to their unique characteristics. Here we synthesized ZnO nanoparticles [ZnO(NP)] and tetrapod-shaped ZnO nanoparticles [ZnO(TP)] and evaluated their antiviral activity. Both ZnO(NP) and ZnO(TP) displayed potent antiviral activity against hepatitis E and hepatitis C viruses, with the latter being more effective. Measurement of cell viability and intracellular reactive oxygen species levels revealed that both ZnO(NP) and ZnO(TP) are noncytotoxic to the cells even at significantly higher doses, compared to a conventional zinc salt (ZnSO4). Our study paves the way for evaluation of the potential therapeutic benefit of ZnO(TP) against HEV and HCV.

Association of Recent and Long-Term Supplement Intakes With Laboratory Indices in Patients With COVID-19 in Tehran, Iran, During 2020

Article

Full-text available

Jun 2022

Background Although previous studies observed the relationship between individual dietary supplements and enhancing body resistance against viruses, few studies have been conducted regarding the role of different supplements in treatment of COVID-19. This article aims to determine the association of recent and long-term supplement consumption on the biochemical indices and impatient duration among patients with COVID-19. Methods In this cross-sectional study on 300 adult men and women with COVID-19, recent and long-term supplement intakes were investigated by using a questionnaire. In addition, lifestyle was also assessed in aspects of fruits and vegetable consumption, physical activity, sleeping duration, fluid intake, and smoking status. Furthermore, the laboratory and paraclinical parameters were obtained from medical records. The relationship between supplement intake with the length of hospitalization and clinical laboratory tests was investigated by one-way analysis of variance (ANOVA). Results Those patients with supplement intake in the last 2 months had a significantly lower amount of blood urea nitrogen (BUN) (31.31 ± 13.87 vs. 37.57 ± 19.77 mg/dL, P : 0.002) and higher serum 25(OH)D (28.13 ± 14.09 vs. 23.81 ± 13.55 ng/mL, P : 0.03). Subjects with long-term supplement intake had a significantly lower invasive oxygen support (0.00 vs 5.10 %, P : 0.05), lactate dehydrogenase (LDH) (498.11 ± 221.43 vs. 576.21 ± 239.84 U/L, P: 0.02), fewer days of fever (0.49 ± 3.54 vs. 2.64 ± 9.21, P : 0.02), and higher serum 25(OH)D (31.03 ± 13.20 vs. 22.29± 13.42 ng/mL, P < 0.001). The length of hospital stay was practically the same between groups who received and did not receive supplementation during the 2 months prior to hospitalization (6.36 ± 3.32 vs. 6.71 ± 4.33 days, P : 0.004). Similarly, people who took supplements during the past year had practically similar hospitalization lengths (6.29 ± 4.13 vs. 6.74 ± 3.55 days, P : 0.004). Conclusion In conclusion, although practically the length of hospital stay was the same in both groups of supplement consumers and others, immune-boosting supplements were associated with improved several laboratory indices. However, due to the cross-sectional nature of our study, further longitudinal studies seem to be essential.

Hinokitiol Dysregulates Metabolism of Carcinoma Cell Lines and Induces Downregulation of HPV16E6 and E7 Oncogenes and p21 Upregulation in HPV Positive Cell Lines

Article

Full-text available

Apr 2022

Background: Hinokitiol (β-thujaplicin), isolated from the wood of Chamaecyparis taiwanensis, has a wide variety of biological properties including anti-inflammatory, anti-microbial, and anti-tumor effects. Therefore, hinokitiol has become a frequent additive in oral and other healthcare products. Objectives: Our goal was to determine the anti-tumor activity of hinokitiol on human papillomavirus (HPV) positive (n = 3) and negative (n = 2) cell lines derived from cervical or head and neck squamous cell carcinoma (HNSCC) and keratinocyte cell lines (n = 3) transformed spontaneously or with HPV16E6 and E7 oncogenes. Methods: The cell-lines were exposed to hinokitiol at different concentrations (0–200 µM) for 24 h. Cell metabolism, proliferation, and the cell cycle distribution were assessed by MTT- and 3H-thymidine incorporation and flow cytometry. Expressions of p21 and on HPV16E6 and E7 oncogenes were assessed by qPCR. Results: In all carcinoma cell lines, hinokitiol treatment declined the metabolic activity irrespective of the HPV status. This decline was statistically significant, however, only in HPV-positive cell lines CaSki and UD-SCC-2 when exposed to hinokitiol concentrations at 100 and 200 µM, respectively (p < 0.05). Immortalized cell lines, HMK and HPV-positive IHGK, were more sensitive as a similar metabolic effect was achieved at lower hinokitiol concentrations of 3.1, 6.25, and 50 µM, respectively. Hinokitiol blocked DNA synthesis of all carcinoma cell lines without evident association with HPV status. G1 cell cycle arrest and p21 upregulation was found in all cell lines after hinokitiol treatment at higher concentration. However, when the p21 results of all HPV-positive cells were pooled together, the increase in p21 expression was statistically significantly higher in HPV-positive than in HPV-negative cell lines (p = 0.03), but only at the highest hinokitiol concentration (200 µM). In HPV-positive cell lines hinokitiol declined the expression of HPV16E7 and E6 along the increase of p21 expression. The dose-dependent inverse correlation between p21 and E7 was statistically significant in SiHa cells (r = −0.975, p-value = 0.03) and borderline in UD-SCC-2 cells (r = −0.944, p-value = 0.06), in which p21 and E6 were also inversely correlated (r = −0.989). Conclusions: Our results indicate that hinokitiol might have potential in preventing the progress of immortalized cells toward malignancy and the growth of malignant lesions. Hinokitiol can also influence on the progression of HPV-associated lesions by downregulating the E6 and E7 expression.

Antiviral potential of nanoparticles for the treatment of Coronavirus infections

Article

Mar 2022
J TRACE ELEM MED BIO

Background On 31st December 2019 in Wuhan, China, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), was acknowledged. This virus spread quickly throughout the world causing a global pandemic. The World Health Organization declared COVID-19 a pandemic disease on 11th March 2020. Since then, the whole world has come together and have developed several vaccines against this deadly virus. Similarly, several alternative searches for pandemic disease therapeutics are still ongoing. One of them has been identified as nanotechnology. It has demonstrated significant promise for detecting and inhibiting a variety of viruses, including coronaviruses. Several nanoparticles, including gold nanoparticles, silver nanoparticles, quantum dots, carbon dots, graphene oxide nanoparticles, and zinc oxide nanoparticles, have previously demonstrated remarkable antiviral activity against a diverse array of viruses. Objective This review aims to provide a basic and comprehensive overview of COVID-19's initial global outbreak and its mechanism of infiltration into human host cells, as well as the detailed mechanism and inhibitory effects of various nanoparticles against this virus. In addition to nanoparticles, this review focuses on the role of several antiviral drugs used against COVID-19 to date. Conclusion COVID-19 has severely disrupted the social and economic lives of people all over the world. Due to a lack of adequate medical facilities, countries have struggled to maintain control of the situation. Neither a drug nor a vaccine has a 100% efficacy rate. As a result, nanotechnology may be a better therapeutic alternative for this pandemic disease.

Hypozincemia in COVID-19 Patients Correlates With Stronger Antibody Response

Article

Full-text available

Jan 2022

Zinc ion as an enzyme cofactor exhibits antiviral and anti-inflammatory activity during infection, but circulating zinc ion level during Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection is unclear. This study aimed to evaluate serum zinc ion level in Coronavirus Disease 2019 (COVID-19) patients and healthy subjects, as well as its correlation with antibodies against SARS-CoV-2. 114 COVID-19 patients and 48 healthy subjects (38 healthy volunteers and 10 close contacts of patients with COVID-19) were included. Zinc ion concentration and levels of antibodies against SARS-CoV-2 Spike 1 + Spike 2 proteins, nucleocapsid protein, and receptor-binding domain in serum were measured. Results showed that the concentration of zinc ion in serum from COVID-19 patients [median: 6.4 nmol/mL (IQR 1.5 – 12.0 nmol/mL)] were significantly lower than that from the healthy subjects [median: 15.0 nmol/mL (IQR 11.9 – 18.8 nmol/mL)] ( p < 0.001) and the difference remained significant after age stratification ( p < 0.001) or when the patients were at the recovery stage ( p < 0.001). Furthermore, COVID-19 patients with more severe hypozincemia showed higher levels of IgG against the receptor-binding domain of SARS-CoV-2 spike protein. Further studies to confirm the effect of zinc supplementation on improving the outcomes of COVID-19, including antibody response against SARS-CoV-2, are warranted.

Beneficial Effects of Vitamins, Minerals, and Bioactive Peptides on Strengthening the Immune System Against COVID-19 and the Role of Cow’s Milk in the Supply of These Nutrients

Article

Full-text available

Nov 2021
BIOL TRACE ELEM RES

The COVID-19 pandemic, which causes severe respiratory tract infections in humans, has become a global health concern and is spreading rapidly. At present, the most important issue associated with COVID-19 is the immune system and the factors that affect it. It is well known that cow’s milk is highly rich in micronutrients that increase and strengthen the immune system. Research shows that the administration of these nutrients is very effective in fighting COVID-19, and a deficiency in any of them can be a weakness in the fight against the virus. On the other hand, cow’s milk is accessible to the whole population, and drinking colostrum, raw, and micro-filtered milk from cows vaccinated against SARS-CoV-2 could provide individuals with short-term protection against the SARS-CoV-2 infection until vaccines become commercially available. This review aimed to discuss the effects of milk vitamins, minerals, and bioactive peptides on general health in humans to combat viral diseases, especially COVID-19, and to what extent cow’s milk consumption plays a role in providing these metabolites. Cow’s milk contains many bioactive compounds that include vitamins, minerals, biogenic amines, nucleotides, oligosaccharides, organic acids, and immunoglobulins. Humans can meet a significant portion of their requirements for vitamins and minerals through the consumption of cow’s milk. Recent studies have shown that micronutrients such as vitamins D, E, B, C, and A as well as minerals Zn, Cu, Mg, I, and Se and bioactive peptides, each can have positive and significant effects on strengthening the immune system and general health in humans.

Natural Immunomodulators Treat the Cytokine Storm in SARS-CoV-2

Article

Full-text available

Oct 2021

Recently, the world has been dealing with a destructive global pandemic COVID-19 infection, since 2020; there were millions of infections and hundreds of thousands of deaths worldwide. With sequencing generations of the virus, around 60 % are expected to become infected during the pandemic. Unfortunately, no drug or vaccine has been approved because no real evidence from clinical trials in treatment was reached. According to current thinking, SARS-COV-2 mortality is caused by a cytokine storm syndrome in patients with hyper-inflammatory conditions, resulting in acute respiratory distress and finally death. In this review, we discuss the various types of natural immune-modulatory agents and their role in the management of SARS-COV-2, and cytokine storm syndrome. For example, Polyphenols as natural products can block the binding of SARS-CoV-2 spike protein to host cell receptor ACE2, stop viral entry into the host cell and block viral RNA replication. Also, Saikosaponins (A, B2, C, and D), triterpene glycosides, which are isolated from medicinal plants exert antiviral action against HCoV-22E9, and Houttuynia cordata water extract has antiviral effects on SARS-CoV. Moreover, eucalyptus oil has promising potential for COVID-19 prevention and treatment. There is an urgent need for research to improve the function of the human immune system all over the world. As a result, actions for better understanding and improving the human immune system are critical steps toward mitigating risks and negative outcomes. These approaches will be strongly recommended for future emerging viruses and pathogens.

Role of The Zinc And Selenium As Nutrients Elements For Immune Boosting Against COVID-19

Article

Full-text available

Jun 2021

Manal F Al-Khakani

Zn & Se

Punicalagin and zinc (II) ions inhibit the activity of SARS-CoV-2 3CL-protease in vitro

Article

Full-text available

May 2021
EUR REV MED PHARMACO

Abstract. – OBJECTIVE: Coronavirus 2019 (COVID-19) has now been declared as a world-wide pandemic. Currently, no drugs have been endorsed for its treatment; in this manner, a pressing need has been developed for any antiviral drugs that will treat COVID-19. Coronaviruses require the SARS-CoV-2 3CL-Protease (3CL-protease) for cleavage of its polyprotein to yield a single useful protein and assume a basic role in the disease progression. In this study, we demonstrated that punicalagin, the fundamental active element of pomegranate in addition to the combination of punicalagin with zinc (Zn) II, appear to show powerful inhibitory activity against SARS-CoV-2. MATERIALS AND METHODS: The 3CL protease assay kit was used to quantify 3CL protease action. The tetrazolium dye, MTS, was used to evaluate cytotoxicity. RESULTS: Punicalagin showed inhibitory action against the 3CL-protease in a dose-dependent manner, and IC50 was found to be 6.192 μg/ml for punicalagin. Punicalagin (10 µg/mL) demonstrated a significant inhibitory activity toward 3CL-protease activity (p < 0.001), yet when punicalagin is combined with zinc sulfate monohydrate (punicalagin/Zn-II) extremely strong 3CL-protease activity (p < 0.001) was obtained. The action of 3CL-protease with punicalagin/Zn-II was decreased by approximately 4.4-fold in contrast to only punicalagin (10 µg/mL). Likewise, we did not notice any significant cytotoxicity caused by punicalagin, Zn-II, or punicalagin/Zn-II. CONCLUSIONS: We suggest that these compounds could be used as potential antiviral drugs against COVID-19. Key Words: Punicalagin, Zinc II, SARS-CoV-2 3CL-Protease, SARS-CoV-2, COVID-19

Punicalagin and zinc (II) ions inhibit the activity of SARS-CoV-2 3CL-protease in vitro

Article

Full-text available

May 2021

Wael Abu Dayyih

OBJECTIVE: Coronavirus 2019 (COVID-19) has now been declared as a worldwide pandemic. Currently, no drugs have been endorsed for its treatment; in this manner, a pressing need has been developed for any an-tiviral drugs that will treat COVID-19. Corona-viruses require the SARS-CoV-2 3CL-Protease (3CL-protease) for cleavage of its polyprotein to yield a single useful protein and assume a basic role in the disease progression. In this study, we demonstrated that punicalagin, the fundamental active element of pomegranate in addition to the combination of punicalagin with zinc (Zn) II, appear to show powerful inhibitory activity against SARS-CoV-2. MATERIALS AND METHODS: The 3CL prote-ase assay kit was used to quantify 3CL protease action. The tetrazolium dye, MTS, was used to evaluate cytotoxicity. RESULTS: Punicalagin showed inhibitory action against the 3CL-protease in a dose-dependent manner, and IC50 was found to be 6.192 μg/ml for punicalagin. Punicalagin (10 µg/ mL) demonstrated a significant inhibitory activity toward 3CL-protease activity (p < 0.001), yet when punicalagin is combined with zinc sul-fate monohydrate (punicalagin/Zn-II) extremely strong 3CL-protease activity (p < 0.001) was obtained. The action of 3CL-protease with pu-nicalagin/Zn-II was decreased by approximately 4.4-fold in contrast to only punicalagin (10 µg/ mL). Likewise, we did not notice any significant cytotoxicity caused by punicalagin, Zn-II, or pu-nicalagin/Zn-II. CONCLUSIONS: We suggest that these compounds could be used as potential antiviral drugs against COVID-19.

Punicalagin and zinc (II) ions inhibit the activity of SARS-CoV-2 3CL-protease in vitro

Article

Full-text available

May 2021

Mohamed Jamal Saadh

Objective: Coronavirus 2019 (COVID-19) has now been declared as a worldwide pandemic. Currently, no drugs have been endorsed for its treatment; in this manner, a pressing need has been developed for any antiviral drugs that will treat COVID-19. Coronaviruses require the SARS-CoV-2 3CL-Protease (3CL-protease) for cleavage of its polyprotein to yield a single useful protein and assume a basic role in the disease progression. In this study, we demonstrated that punicalagin, the fundamental active element of pomegranate in addition to the combination of punicalagin with zinc (Zn) II, appear to show powerful inhibitory activity against SARS-CoV-2. Materials and methods: The 3CL protease assay kit was used to quantify 3CL protease action. The tetrazolium dye, MTS, was used to evaluate cytotoxicity. Results: Punicalagin showed inhibitory action against the 3CL-protease in a dose-dependent manner, and IC50 was found to be 6.192 μg/ml for punicalagin. Punicalagin (10 µg/mL) demonstrated a significant inhibitory activity toward 3CL-protease activity (p < 0.001), yet when punicalagin is combined with zinc sulfate monohydrate (punicalagin/Zn-II) extremely strong 3CL-protease activity (p < 0.001) was obtained. The action of 3CL-protease with punicalagin/Zn-II was decreased by approximately 4.4-fold in contrast to only punicalagin (10 µg/mL). Likewise, we did not notice any significant cytotoxicity caused by punicalagin, Zn-II, or punicalagin/Zn-II. Conclusions: We suggest that these compounds could be used as potential antiviral drugs against COVID-19.

Antiviral Uses of Ivermectin

Chapter

Sep 2023

Hinokitiol Attenuates LPS-Induced Arthritic Inflammation: A Preclinical Perspective

Chapter

Jun 2023

The purpose of this research was to investigate the efficacy of the natural monoterpenoid hinokitiol in mitigating lipopolysaccharide (LPS)-induced arthritic inflammation in animal models. Arthritis was produced by intraplantar infusion of LPS (1 mg/Kg), and the effects of hinokitiol at doses of 0.2 mg/Kg (H-1) and 0.4 mg/Kg were evaluated. To test for an anti-arthritic effect, the animals’ paw volumes, arthritis indices, paw thicknesses, and percent changes, as well as their average body weights on days 0–7, 14–21, and 28, were measured. On day 28, we tested for changes in marker enzyme levels (serum glutamic-oxaloacetic transaminase (SGOT), alkaline phosphatase (ALP), and serum glutamic pyruvic transaminase (SGPT)), performed an antioxidant enzyme assay (superoxide dismutase (SOD), catalases (CAT), glutathione peroxidase (GPx)), tested for cartilage degrading enzymes (myeloperoxidase (MPO), cathepsin-D (CAT-D), elastase (ELA)), and examined red blood cells, white blood cells, and erythrocyte sedimentation rate (ESR). Paw volume, arthritic index, paw thickness, and percent change were all shown to be significantly reduced (P 0.05) in H-1, and H-2 treated rats, whereas body weight was found to be significantly restored. Animals treated with H-1 and H-2 had significantly lower levels of SGOT, ALP, SGPT, MPO, CAT-D, and ELA compared to controls (P 0.05). Lipoperoxidation inhibition and SOD activity were both significantly improved in H-1 and H-2 (P 0.05). Red blood cell (RBC) count increases significantly (P 0.05) in H-1 and H-2-treated animals, while white blood cell (WBC) and ESR drop significantly (P 0.05).KeywordsHinokitiolLPSOxidative stressArthritisInflammation

Zinc Trafficking. 1,10-Phenanthroline, Glutathione, and Other Metal Binding Ligands Form Adducts with Proteomic Zn2

Article

Apr 2023
METALLOMICS

Hypotheses were tested that the proteome of pig kidney LLC-PK1 cells (i) contains Zn-proteins that react with a diversity of native and pharmacologically active metal-binding ligands to form ternary complexes and (ii) includes proteins that bind Zn2+ non-specifically and together form ternary adducts with a variety of metal-binding agents. The method to observe ternary complex formation with Zn-proteins and proteome•Zn involved preformation of fluorescent TSQ-Zn-proteins and/or proteome•Zn-TSQ adducts followed by competitive reaction with selected ligands. The loss of TSQ-dependent fluorescence signaled the replacement of TSQ by the competing ligand in the starting adducts. In vitro, 1,10-phenanthroline competed effectively with TSQ for binding to Zn-proteins in the proteome. The successful competition of 1,10-phenanthroline with TSQ-Zn-proteins was also observed in cells. Similarly, 1,10-phenanthroline was shown to bind to a sizable fraction of Zn2+ associated adventitiously with proteome (proteome•Zn). Other synthetic ligands that bind to Zn-proteins and proteome•Zn include 2,2-bipyridyl, 8-hydroxyquinoline, 2,2'-dicarboxypyridine, and pyrithione. Such results suggest that ligand binding to such sites may play a role in the observed biological effects of these and other metal binding molecules. Although cysteine does not significantly compete with TSQ, glutathione displaces TSQ from Zn-proteins and proteome•Zn at concentrations well below those found in cells, implying that ternary complex formation involving glutathione may be physiologically significant.

Identification and characterization of odorant‐binding protein genes in the brown‐winged green bug, Plautia stali

Article

Mar 2023

The brown‐winged green bug, Plautia stali Scott (Hemiptera: Pentatomidae), is a major pest in orchards in Japan and Korea. Large numbers of adults are attracted by aggregation pheromone [methyl ( E , E , Z )‐2,4,6‐decatrienoate] and cause extensive damage to the fruit. To identify olfactory‐related genes in P . stali , we performed RNA sequencing (RNA‐seq) of adult antennae. Among the 27299 contigs, 16 putative odorant‐binding protein (OBP) genes were identified and designated as PstaOBP1–16 , including 10 classic (i.e., containing six conserved cysteines) and six Plus‐C (i.e., containing more than six cysteines) OBP genes. Quantitative reverse‐transcription polymerase chain reaction (qRT‐PCR) revealed that four genes ( PstaOBP1 , 3 , 6 , and 7 ) were strongly expressed in the antennae. PstaOBP2 was detected throughout the insect body, with higher expression in the antennae, stylet, and tarsus. The remaining OBP genes were expressed in very small amounts. PstaOBP1 , which showed the highest expression in adult antennae, was expressed in Escherichia coli (Migula) Castellani & Chalmers cells and the recombinant protein was subjected to a ligand‐binding competitive assay. PstaOBP1 bound to methyl ( E , E , Z )‐2,4,6‐decatrienoate with high affinity. Of the other 26 compounds tested, hinokitiol and tropolone bound strongly to PstaOBP1. Hinokitiol is an odor component of hinoki cypress, a host tree of P . stali . Electrophysiological responses to methyl ( E , E , Z )‐2,4,6‐decatrienoate and hinokitiol were detected using adult P . stali antennae. Combined, these results suggest that PstaOBP1 is involved in P . stali responses to pheromone and host plant volatiles.

Association of Serum Zinc and Inflammatory Markers with the Severity of COVID-19 Infection in Adult Patients

Article

Full-text available

Jan 2023

COVID-19 infection can spread in the host body without any adequate immune response. Zinc is an essential trace element with strong immunoregulatory and antiviral properties and its deficiency might lead to inflammation and oxidative stress. The aim of the current study was to determine the association of serum zinc and inflammatory markers with the severity of COVID-19 infection. This was a prospective observational study in which 123 COVID-19-positive adult patients and 48 controls were recruited. The initial comparative analysis was conducted between COVID-19 patients and controls. COVID-19-positive patients were further divided into three different groups (mild, moderate, and severe) based on the severity of COVID-19 infection. COVID-19 patients showed significantly lower serum zinc levels (8.8 ± 2.3 µmol/L) compared to healthy controls (11.9 ± 1.8 µmol/L). There was a negative correlation between serum zinc levels and the severity of COVID-19 infection (r = −0.584, p < 0.0001) and this effect was independent of age (r = −0.361, p < 0.0001). Furthermore, inflammatory markers showed a positive correlation with the severity of COVID-19 infection and a negative correlation with the levels of serum zinc. The study demonstrated an association between COVID-19 infection with low serum zinc levels and elevated inflammatory markers. Further studies to assess the significance of this observation are needed, which may justify zinc supplementation to mitigate the severity of COVID-19 infection.

Molecular mechanism of the unusual biphasic effects of the natural compound hinokitiol on iron-induced cellular DNA damage

Article

Dec 2022
FREE RADICAL BIO MED

Hinokitiol is a natural monoterpene compound found in the heartwood of cupressaceous plants that have anticancer and anti-inflammatory properties. However, few studies have focused on its effect on iron-mediated cellular DNA damage. Here we show that hinokitiol exhibited unusual biphasic effects on iron-induced DNA damage in a molar ratio (hinokitiol/iron) dependent manner in HeLa cells. Under low ratios (<3:1), hinokitiol markedly enhanced DNA damage induced by Fe(II) or Fe(II)–H2O2; However, when the ratios increased over 3:1, the DNA damage was progressively inhibited. We found that the total cytoplasmic and nuclear iron concentration increased as the ratios of hinokitiol/iron increased. However, the cellular level of labile iron pool (LIP) only increased at ratios lower than 3, and the ROS generation is consistent with LIP change. Hinokitiol was found to interact with iron to form lipophilic hinokitiol-iron complexes with different stoichiometry and redox-activity by complementary applications of various analytical methods. Taken together, we propose that the enhancement of iron-induced cellular DNA damage by hinokitiol at low ratios (<3:1) was due to formation of lipophilic and redox-active iron complexes which facilitated cellular iron uptake and •OH production, while the inhibition at ratios higher than 3 was due to formation of redox-inactive iron complexes. These new findings will help us to design more effective drugs for the prevention and treatment of a series of iron-related diseases via regulating the two critical physicochemical factors (lipophilicity and redox activity of iron complexes) by simple natural compounds with iron-chelating properties.

In-silico and in-detail experimental interaction studies of new antitumor Zn(II) complex with CT-DNA and serum albumin

Article

Nov 2022

In this study, a novel Zn(II) complex with the formula [Zn(pyrr-ac)2] (pyrr-ac: pyrrolidineacetate) was synthesized and characterized through molar conductivity, elemental analysis, ¹H Nuclear Magnetic Resonance (¹H NMR), UV-Visible spectroscopy, and Fourier transform infrared (FT-IR) methods. B3LYP level of DFT method along with aug-cc-pVTZ-PP/6-311G(d,p) basis set was utilized to perform the geometry optimization and HOMO-LUMO analysis. In addition, MEP, NLO and NBO computations were also performed at the same level of theory. In vitro antitumor activity of the mentioned complex on leukemia cell line, K562, was investigated using the MTT assay which surprisingly revealed the effective antitumor activity of the studied zinc complex. Interaction of this compound with biological macromolecules viz., CT-DNA and BSA was studied via different spectroscopic methods. The results of fluorescence experiment displayed that the metal complex binds to both macromolecules through hydrogen bond (H-bond) and van der Waals (vdW) forces. UV-Vis tests indicated a decline in the absorption spectra of CT-DNA/BSA in the presence of the compound. The interaction was further corroborated for CT-DNA via gel electrophoresis, CD spectroscopy and viscosity experiments and for BSA using CD spectroscopy. Furthermore, molecular docking simulation was done to evaluate the nature of interaction between the aforementioned zinc complex and CT-DNA/BSA. These results were in agreement with experimental findings and demonstrated that the main interaction is hydrogen bonding. The above type of investigations may provide a pathway through which zinc complexes join the anticancer category. The in-silico and in-vitro results confirm that the newly made [Zn(pyrr-ac)2] complex interacts with CT-DNA than BSA. Communicated by Ramaswamy H. Sarma

Combating coxsackievirus B infections

Article

Nov 2022

Coxsackieviruses B (CVB) are small, non‐enveloped, single‐stranded RNA viruses belonging to the Enterovirus genus of the Picornaviridae family. They are common worldwide and cause a wide variety of human diseases ranging from those having relatively mild symptoms to severe acute and chronic pathologies such as cardiomyopathy and type 1 diabetes. The development of safe and effective strategies to combat these viruses remains a challenge. The present review outlines current approaches to control CVB infections and associated diseases. Various drugs targeting viral or host proteins involved in viral replication as well as vaccines have been developed and shown potential to prevent or combat CVB infections in vitro and in vivo in animal models. Repurposed drugs and alternative strategies targeting miRNAs or based on plant extracts and probiotics and their derivatives have also shown antiviral effects against CVB. In addition, clinical trials with vaccines and drugs are underway and offer hope for the prevention or treatment of CVB‐induced diseases.

Zinc in the treatment of severe acute respiratory syndrome-related coronavirus-2 infection: A systematic review and meta-analysis

Article

Jan 2022

Neuronal signalling of zinc: from detection and modulation to function

Article

Full-text available

Sep 2022

Zinc is an essential trace element that stabilizes protein structures and allosterically modulates a plethora of enzymes, ion channels and neurotransmitter receptors. Labile zinc (Zn 2+) acts as an intracellular and intercellular signalling molecule in response to various stimuli, which is especially important in the central nervous system. Zincergic neurons, characterized by Zn 2+ deposits in synaptic vesicles and presynaptic Zn 2+ release, are found in the cortex, hippocampus, amygdala, olfactory bulb and spinal cord. To provide an overview of synaptic Zn 2+ and intracellular Zn 2+ signalling in neurons, the present paper summarizes the fluorescent sensors used to detect Zn 2+ signals, the cellular mechanisms regulating the generation and buffering of Zn 2+ signals, as well as the current perspectives on their pleio-tropic effects on phosphorylation signalling, synapse formation, synaptic plasticity, as well as sensory and cognitive function.

Neuronal signalling of zinc: from detection and modulation to function

Article

Full-text available

Sep 2022

Zinc is an essential trace element that stabilizes protein structures and allosterically modulates a plethora of enzymes, ion channels and neurotransmitter receptors. Labile zinc (Zn²⁺) acts as an intracellular and intercellular signalling molecule in response to various stimuli, which is especially important in the central nervous system. Zincergic neurons, characterized by Zn²⁺ deposits in synaptic vesicles and presynaptic Zn²⁺ release, are found in the cortex, hippocampus, amygdala, olfactory bulb and spinal cord. To provide an overview of synaptic Zn²⁺ and intracellular Zn²⁺ signalling in neurons, the present paper summarizes the fluorescent sensors used to detect Zn²⁺ signals, the cellular mechanisms regulating the generation and buffering of Zn²⁺ signals, as well as the current perspectives on their pleiotropic effects on phosphorylation signalling, synapse formation, synaptic plasticity, as well as sensory and cognitive function.

Metal-based strategies for the fight against COVID-19

Article

Jun 2022
CHEM COMMUN

The emerging COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has claimed over six million lives globally to date. Despite the availability of vaccines, the pandemic still cannot be fully controlled owing to rapid mutation of the virus that renders enhanced transmissibility and antibody evasion. This is thus an unmet need to develop safe and effective therapeutic options for COVID-19, in particular, remedies that can be used at home. Considering the great success of multi-targeted cocktail therapy for the treatment of viral infections, metal-based drugs might represent a unique and new source of antivirals that resemble a cocktail therapy in terms of their mode of actions. In this review, we first summarize the role that metal ions played in SARS-CoV-2 viral replication and pathogenesis, then highlight the chemistry of metal-based strategies in the fight against SARS-CoV-2 infection, including both metal displacement and chelation based approaches. Finally, we outline a perspective and direction on how to design and develop metal-based antivirals for the fight against the current or future coronavirus pandemic.

Tropolone derivative hinokitiol ameliorates cerulein-induced acute pancreatitis in mice

Article

Jun 2022

Hinokitiol is a natural bio-active tropolone derivative with promising antioxidant and anti-inflammatory properties. This study was conducted to evaluate the ameliorative effects of hinokitiol against acute pancreatitis induced by cerulein. Mice were pre-treated with hinokitiol intraperitoneally for 7 days (50 and 100 mg/kg), and on the final day of study, cerulein (6 × 50 μg/kg) was injected every hour for six times. Six hours after the last dose of cerulein, blood was collected from the mice through retro-orbital plexus for biochemical analysis. After blood collection, mice were euthanized and the pancreas was harvested for studying effects on oxidative stress, pro-inflammatory cytokines, immunohistochemistry and histopathology of tissue sections. Hinokitiol treatment significantly reduced edema of the pancreas and reduced the plasma levels of lipase and amylase in mice with cerulein-induced acute pancreatitis. It also attenuated the oxidative and nitrosative stress related damage as evident from the reduced malondialdehyde (MDA) and nitrite levels, which were significantly increased in the mice with acute pancreatitis. Furthermore, hinokitiol administration significantly reduced the pancreatitis-evoked decrease in the activity of catalase, glutathione (GSH) and superoxide dismutase (SOD) in the pancreatic tissue. Pre-treatment with hinokitiol significantly reduced the elevated levels of pro-inflammatory cytokines like interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α) as well as increased the levels of anti-inflammatory cytokine interleukin-10 (IL-10) in the pancreatic tissue of mice with acute pancreatitis. The immunohistochemical expression of nuclear factor kappa light chain enhancer of activated B cells (NF-κB), cyclooxygenase (COX-2) and TNF-α were significantly decreased by hinokitiol in mice with cerulein-induced acute pancreatitis. In conclusion, the results of the present study demonstrate that hinokitiol has significant potential to prevent cerulein-induced acute pancreatitis.

Brief History, Pathophysiology, Transmission of SARS-CoV-2 Virus, and Recent Advances on Transition Metal Complexes and Nanocomposites as the Potent Antiviral Agents from COVID-19 Perspectives

Chapter

Jan 2022

The outbreak of SARS-CoV-2 has resulted in an unprecedented and greatest global health crisis in the present century affecting more than 220 countries with 3.7 million deaths and 173.5 million individual infections till now. This pandemic has had an enormous impact on global healthcare, economy, and society, which has prompted extensive research on exploring the biology of SARS-CoV-2 and the discovery of new drugs for COVID-19. The lack of effective antiviral drugs for COVID-19 has initiated the effort to repurpose selected FDA-approved antiviral drugs for the treatment of COVID-19 along with plasma therapy. Vaccination has proven to be the effective prevention strategy against the SARS-CoV-2 virus, although mutations in the SARS-CoV-2 virus have become the major concern due to the decreasing effectiveness of the vaccines Therefore, an effective cure for COVID-19 is still an elusive goal. Transition metal complexes by a broad spectrum of formal charge and oxidation states, wide range of coordination number and geometry, tunable kinetic, thermodynamic, and redox properties, diverse reaction pathways have emerged as the alternative and viable tools in the medicinal domain from therapeutics to diagnostics. Several transition metal complexes proved their efficacy against various types of viruses and recent advances on the potent transition metal complexes or nanoconjugates are reviewed in this chapter. The present chapter also aims to discuss the perspectives on the potential utility of transition metal complexes or the nanoconjugates against SARS-CoV-2.KeywordsSARS-CoV-2Historypathophysiologytransmissionrepurposed drugsTransition metal and nanoconjugate-based antiviral agentsPerspectives of transition metal complexes or nanoconjugates on COVID-19

Inhibition of SARS-CoV-2 replication by zinc gluconate in combination with hinokitiol

Article

Mar 2022
J INORG BIOCHEM

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic is currently the major challenge to global public health. Two proteases, papain-like protease (PLpro) and the 3-chymotrypsin-like protease (3CLpro or Mpro), are indispensable for SARS-CoV-2 replication, making them attractive targets for antiviral therapy development. Here we screened a panel of essential metal ions using a proteolytic assay and identified that zinc gluconate, a widely-used zinc supplement, strongly inhibited the proteolytic activities of the two proteases in vitro. Biochemical and crystallographic data reveal that zinc gluconate exhibited the inhibitory function via binding to the protease catalytic site residues. We further show that treatment of zinc gluconate in combination with a small molecule ionophore hinokitiol, could lead to elevated intracellular Zn²⁺ level and thereby significantly impaired the two protease activities in cellulo. Particularly, this approach could also be applied to rescue SARS-CoV-2 infected mammalian cells, indicative of potential application to combat coronavirus infections. Our studies provide the direct experimental evidence that elevated intracellular zinc concentration directly inhibits SARS-CoV-2 replication and suggest the potential benefits to use the zinc supplements for coronavirus disease 2019 (COVID-19) treatment.

Bioinorganic Chemistry of Zinc in Relation to the Immune System

Article

Dec 2021

Kasper P. Kepp

Zinc is well‐known to have a central role in human inflammation and immunity and is itself an antiinflammatory and antiviral agent. Despite its massively documented role in such processes, the underlying chemistry of zinc in relation to specific proteins and pathways of the immune system has not received much focus. This short review provides an overview of this topic, with emphasis on the structures of key proteins, zinc coordination chemistry, and probable mechanisms involved in zincbased immunity, with some focus points for future chemical and biological research.

Vitamins, supplements and COVID-19: a review of currently available evidence

Article

Full-text available

Oct 2021

Background: In the midst of the COVID-19 pandemic, there has been an information overload of health data (both accurate and inaccurate) available to the public. With vitamins and supplements being readily accessible, many have turned to using them in an effort to combat the virus. The purpose of this review was to analyse clinical trials regarding vitamins and supplements for the treatment of COVID-19 infections. Methods: Articles were identified through a literature search utilizing online databases and bibliographic review. Results: A total of seven articles were identified for review. All articles evaluated the use of vitamins and supplements for the treatment of COVID-19. Drug therapies included oral vitamin D, intravenous and oral vitamin C, oral vitamin D/magnesium/vitamin B12, oral zinc, oral combination zinc/ascorbic acid, and intravenous alpha-lipoic acid. The end points of each study varied, including the Sequential Organ Failure Assessment score, mortality, rate of intensive care unit (ICU) admissions, negativity of COVID-19 tests, oxygen requirements, and symptom burden. Conclusion: Of the vitamins and supplements that were studied, vitamin D presented the most promising data demonstrating significant decreases in oxygen requirements, need for ICU treatment, SARS-CoV-2 RNA test positivity, and mortality. All of these benefits were exhibited in hospitalized patients. Other vitamins and supplements that were evaluated in studies did not demonstrate any statistically significant benefits. Common shortcomings of the articles included generally small sample sizes, varying sites of study (which could determine the virus variant), a lack of standard of care as background therapy, and utilization of doses that were higher than standard.

Rhinovirus Inhibitors: Including a New Target, the Viral RNA

Article

Full-text available

Sep 2021

Rhinoviruses (RVs) are the main cause of recurrent infections with rather mild symptoms characteristic of the common cold. Nevertheless, RVs give rise to enormous numbers of absences from work and school and may become life-threatening in particular settings. Vaccination is jeopardised by the large number of serotypes eliciting only poorly cross-neutralising antibodies. Conversely, antivirals developed over the years failed FDA approval because of a low efficacy and/or side effects. RV species A, B, and C are now included in the fifteen species of the genus Enteroviruses based upon the high similarity of their genome sequences. As a result of their comparably low pathogenicity, RVs have become a handy model for other, more dangerous members of this genus, e.g., poliovirus and enterovirus 71. We provide a short overview of viral proteins that are considered potential drug targets and their corresponding drug candidates. We briefly mention more recently identified cellular enzymes whose inhibition impacts on RVs and comment novel approaches to interfere with infection via aggregation, virus trapping, or preventing viral access to the cell receptor. Finally, we devote a large part of this article to adding the viral RNA genome to the list of potential drug targets by dwelling on its structure, folding, and the still debated way of its exit from the capsid. Finally, we discuss the recent finding that G‑quadruplex stabilising compounds impact on RNA egress possibly via obfuscating the unravelling of stable secondary structural elements.

Zinc thiotropolone combinations as inhibitors of the SARS-CoV-2 main protease

Article

Jan 2021

Numerous organic molecules are known to inhibit the main protease of SARS-CoV-2, (SC2Mpro), a key component in viral replication of the 2019 novel coronavirus. We explore the hypothesis that zinc...

Pyrithione, a Zinc Ionophore, Inhibits NF-B Activation

Article

Full-text available

Jun 1999

Pyrrolidine dithiocarbamate (PDTC) suppresses NF-B activity and exhibits cytotoxic effects in bovine cerebral endothelial cells (BCECs), and we have previously reported that these PDTC effects were accompanied by an increase in intracellular zinc levels. To further explore the role of zinc in the modulation of NF-B activation, we studied the effect of pyrithione, a zinc ionophore, on NF-B activation in BCECs. Pyri-thione inhibited NF-B activity in a time-and dose-dependent manner. Ca-EDTA, but not Zn-EDTA, prevented pyrithione inhibition of NF-B activity. Pyrithione increased the intracellular zinc level within 15 min. This effect was also abolished by Ca-EDTA, but not by Zn-EDTA. The potency of pyrithione on NF-B inhibition and zinc influx was approximately one order of magnitude more potent than PDTC. These findings establish the regulatory role of intracellular zinc levels on NF-B activity in BCECs.

A Novel Functional Human Eukaryotic Translation Initiation Factor 4G

Article

Full-text available

Feb 1998

Mammalian eukaryotic translation initiation factor 4F (eIF4F) is a cap-binding protein complex consisting of three subunits: eIF4E, eIF4A, and eIF4G. In yeast and plants, two related eIF4G species are encoded by two different genes. To date, however, only one functional eIF4G polypeptide, referred to here as eIF4GI, has been identified in mammals. Here we describe the discovery and functional characterization of a closely related homolog, referred to as eIF4GII. eIF4GI and eIF4GII share 46% identity at the amino acid level and possess an overall similarity of 56%. The homology is particularly high in certain regions of the central and carboxy portions, while the amino-terminal regions are more divergent. Far-Western analysis and coimmunoprecipitation experiments were used to demonstrate that eIF4GII directly interacts with eIF4E, eIF4A, and eIF3. eIF4GII, like eIF4GI, is also cleaved upon picornavirus infection. eIF4GII restores cap-dependent translation in a reticulocyte lysate which had been pretreated with rhinovirus 2A to cleave endogenous eIF4G. Finally, eIF4GII exists as a complex with eIF4E in HeLa cells, because eIF4GII and eIF4E can be purified together by cap affinity chromatography. Taken together, our findings indicate that eIF4GII is a functional homolog of eIF4GI. These results may have important implications for the understanding of the mechanism of shutoff of host protein synthesis following picornavirus infection.

Amino acid sequence of the human protein synthesis initiation factor eIF-4F

Article

Full-text available

Dec 1992

Eukaryotic protein synthesis initiation factor (eIF) 4 gamma, also known as p220, is a component of the protein complex eIF-4, which is involved in the recognition of the mRNA cap, ATP-dependent unwinding of 5'-terminal secondary structure and recruitment of mRNA to the ribosome. Peptide sequence data from rabbit reticulocyte eIF-4 gamma was used to synthesize oligonucleotide probes and polymerase chain reaction primers. These were used to screen lambda-cDNA libraries from rabbit and human brain, yielding a partial rabbit and a complete human cDNA sequence of 5.1 kilobases. Northern blot and primer extension analysis indicated that the cDNA sequence was complete. To confirm that the cDNA represented that of eIF-4 gamma, three peptides were synthesized based on cDNA sequences and used to produce anti-peptide antibodies. The antibodies specifically recognized intact eIF-4 gamma and its cleavage products following poliovirus infection. The eIF-4 gamma mRNA contains AUG codons at nucleotides 6, 67, 90, 165, and 369, but only the last is followed by a long open reading frame. The eIF-4 gamma polypeptide is 154 kDa (1396 amino acid residues) and contains sequence motifs of potential interest: a sequence (AGLGPR) that is similar to the substrate recognition sequence of protease 2A from rhinovirus serotype 14, five PEST regions with scores greater than 10, which are characteristic of rapidly degraded proteins, stretches of polyglutamic acid, and numerous potential phosphorylation sites.

A Neutralizing Epitope on Human Rhinovirus Type 2 Includes Amino Acid Residues between 153 and 164 of Virus Capsid Protein VP2

Article

Full-text available

Mar 1987

Use has been made of a monoclonal antibody (designated 8F5) to map a neutralizing epitope on the viral capsid protein VP2 of human rhinovirus 2 (HRV2). This antibody which was raised against the native virus, neutralizes HRV2 and is also capable of recognizing denatured VP2 on Western blots. To examine the binding site of 8F5, VP2 of HRV2 was expressed in Escherichia coli. Deletions starting at the 3' end were then introduced into the gene for VP2 using Bal-31 nuclease. Polypeptides shortened at the carboxy terminus of VP2 were obtained from the deletions and were blotted onto nitrocellulose. The samples were then probed with monoclonal antibody 8F5. Recognition by 8F5 was maintained as long as the expressed polypeptide contained the VP2 sequence up to amino acid 164 or beyond. However, when the VP2 sequence was truncated to amino acid 153 or less 8F5 was no longer able to bind. The neutralization epitope (or part of it) recognized by 8F5 on VP2 is therefore located between amino acids 153 and 164.

Inhibition of HeLa cell protein synthesis following poliovirus infection correlates with the proteolysis of a 220,000-dalton polypeptide associated with eucaryotc initiation factor 3 and a cap binding protein complex

Article

Full-text available

Jan 1983

Following poliovirus infection of HeLa cells, the synthesis of cellular proteins is inhibited but translation of poliovirus mRNA proceeds. The defect in the recognition of host cell mRNA may be due to a change in a cap recognition complex which, when added to an infected cell lysate, restores the ability to translate capped mRNAs. We employed immunoblotting techniques to examine initiation factors in crude lysates from uninfected and poliovirus-infected HeLa cells. Using an antiserum against eucaryotic initiation factor 3, we detected an antigen of approximate molecular weight 220,000 in uninfected cell lysates but not in infected cell lysates. Antigenically related polypeptides of 100,000 to 130,000 daltons, presumably degradation products, were detected in the infected cell lysate. The time course for degradation of the 220,000-dalton polypeptide correlates with that for inhibition of cellular protein synthesis in vivo. A portion of the population of 220,000-dalton polypeptides apparently associates with initiation factor eIF3 but is readily dissociated in buffers containing high salt. Affinity-purified antibodies against the polypeptide recognize a protein of the same size in a purified preparation of a cap binding protein complex obtained by cap-affinity chromatography. We postulate that the 220,000-dalton polypeptide is an essential component of the cap recognition complex and that its degradation in poliovirus-infected cells results in the inhibition of host cell translation. These results are in the first demonstration of a specific structural defect in an initiation factor resulting from poliovirus infection.

Cytotoxic Effect of Hinokitiol and Tropolone on the Growth of Mammalian Cells and on Blastogenesis of Mouse Splenic T Cells.

Article

Full-text available

Jun 1993

Hinokitiol (I) and tropolone (II) showed characteristic cytotoxic effects in vitro on five kinds of human and murine cell lines and blastic lymphocytes from mouse splenocytes. The cytotoxic effect of I on the growth of murine and human tumor cell lines, including RL male-1, MH134, HL60, K562 and KATO-III was definite when examined by thymidine incorporation into DNA and its 50% inhibitory concentration (IC50) on all cells was 0.3-0.6 microgram/ml. Compound II also showed comparable cytotoxic effects on these cell lines, indicating a little lower activity when compared to I. Furthermore, I and II also completely suppressed the [3H]thymidine ([3H]TdR) incorporation of mitogen-induced blastic lymphocytes. The suppressive activity on mouse lymphocyte proliferative response to concanavaline-A was also found with both compounds at a low concentration of 0.32 microgram/ml. As compound I is known to be of fairly low toxicity (LD50: 453 + 24 mg/kg in mice), the antitumor and immuno-suppressive effect of hinokitiol (I) should be further investigated.

Measurement of Intracellular Free Zinc in Living Cortical Neurons: Routes of Entry

Article

Full-text available

Jan 1998

We used the ratioable fluorescent dye mag-fura-5 to measure intracellular free Zn2+ ([Zn2+]i) in cultured neocortical neurons exposed to neurotoxic concentrations of Zn2+ in concert with depolarization or glutamate receptor activation and identified four routes of Zn2+ entry. Neurons exposed to extracellular Zn2+ plus high K+ responded with a peak cell body signal corresponding to a [Zn2+]i of 35-45 nM. This increase in [Zn2+]i was attenuated by concurrent addition of Gd3+, verapamil, omega-conotoxin GVIA, or nimodipine, consistent with Zn2+ entry through voltage-gated Ca2+channels. Furthermore, under conditions favoring reverse operation of the Na+-Ca2+ exchanger, Zn2+ application induced a slow increase in [Zn2+]i and outward whole-cell current sensitive to benzamil-amiloride. Thus, a second route of Zn2+ entry into neurons may be via transporter-mediated exchange with intracellular Na+. Both NMDA and kainate also induced rapid increases in neuronal [Zn2+]i. The NMDA-induced increase was only partly sensitive to Gd3+ or to removal of extracellular Na+, consistent with a third route of entry directly through NMDA receptor-gated channels. The kainate-induced increase was highly sensitive to Gd3+ or Na+ removal in most neurons but insensitive in a minority subpopulation ("cobalt-positive cells"), suggesting that a fourth route of neuronal Zn2+ entry is through the Ca2+-permeable channels gated by certain subtypes of AMPA or kainate receptors.

Antiviral Effects of Pyrrolidine Dithiocarbamate on Human Rhinoviruses

Article

Full-text available

Jul 2002

Human rhinoviruses (HRVs) are the predominant cause of the common cold. The frequency of HRV infections in industrial countries and the lack of effective therapeutical treatment underline the importance of research for new antiviral substances. As viral infections are often accompanied by the generation of oxidative stress inside the infected cells, several redox-active substances were tested as potential antivirals. In the course of these studies it was discovered that pyrrolidine dithiocarbamate (PDTC) is an extremely potent compound against HRV and poliovirus infection in cell culture. Besides the ability to dramatically reduce HRV production by interfering with viral protein expression, PDTC promotes cell survival and abolishes cytopathic effects in infected cells. PDTC also protects cells against poliovirus infection. These effects were highly specific, as several other antioxidants (vitamin C, Trolox, 2-mercaptoethanol, and N-acetyl-l-cysteine) are inactive against HRV infection. Synthesis of HRV proteins and cleavage of eucaryotic initiation factor 4G responsible for host cell shutoff of cellular protein synthesis are severely inhibited in the presence of PDTC.

A new mitochondrial fluorescent zinc sensor

Article

Full-text available

Oct 2003
CELL CALCIUM

A novel cationic fluorescent zinc (Zn2+) indicator (RhodZin-3) with nanomolar affinity for Zn2+ has been synthesized. RhodZin-3 exhibits large pH-independent fluorescence increases in the orange region of the visible wavelength spectrum with increasing zinc concentrations, and no sensitivity to physiologically relevant Ca2+ concentrations. Experiments in neuronal cell cultures show that RhodZin-3 effectively localizes into mitochondria and detects changes of intramitochondrial free Zn2+ ([Zn2+]m).

A Proline-Rich Region in the Coxsackievirus 3A Protein Is Required for the Protein To Inhibit Endoplasmic Reticulum-to-Golgi Transport

Article

Full-text available

May 2005

The ability of the 3A protein of coxsackievirus B (CVB) to inhibit protein secretion was investigated for this study. Here we show that the ectopic expression of CVB 3A blocked the transport of both the glycoprotein of vesicular stomatitis virus, a membrane-bound secretory marker, and the alpha-1 protease inhibitor, a luminal secretory protein, at a step between the endoplasmic reticulum (ER) and the Golgi complex. CVB 3A contains a conserved proline-rich region in its N terminus. The importance of this proline-rich region was investigated by introducing Pro-to-Ala substitutions. The mutation of Pro19 completely abolished the ability of 3A to inhibit ER-to-Golgi transport. The mutation of Pro14, Pro17, or Pro20 also impaired this ability, but to a lesser extent. The mutation of Pro18 had no effect. We also investigated the possible importance of this proline-rich region for the function of 3A in viral RNA replication. To this end, we introduced the Pro-to-Ala mutations into an infectious cDNA clone of CVB3. The transfection of cells with in vitro-transcribed RNAs of these clones gave rise to mutant viruses that replicated with wild-type characteristics. We concluded that the proline-rich region in CVB 3A is required for its ability to inhibit ER-to-Golgi transport, but not for its function in viral RNA replication. The functional relevance of the proline-rich region is discussed in light of the proposed structural model of 3A.

Pyrrolidine Dithiocarbamate Reduces Coxsackievirus B3 Replication through Inhibition of the Ubiquitin-Proteasome Pathway

Article

Full-text available

Aug 2005

Coxsackievirus B3 (CVB3) is one of the most common pathogens for viral myocarditis. The lack of effective therapeutics for CVB3-caused viral diseases underscores the importance of searching for antiviral compounds. Pyrrolidine dithiocarbamate (PDTC) is an antioxidant and is recently reported to inhibit ubiquitin-proteasome-mediated proteolysis. Previous studies have shown that PDTC inhibits replication of rhinovirus, influenza virus, and poliovirus. In the present study, we report that PDTC is a potent inhibitor of CVB3. Coxsackievirus-infected HeLa cells treated with PDTC showed a significant reduction of CVB3 viral RNA synthesis, viral protein VP1 expression, and viral progeny release. Similar to previous observation that divalent ions mediate the function of PDTC, we further report that serum-containing copper and zinc are required for its antiviral activity. CVB3 infection resulted in massive generation of reactive oxygen species (ROS). Although PDTC alleviated ROS generation, the antiviral activity was unlikely dependent on its antioxidant effect because the potent antioxidant, N-acetyl-L-cysteine, failed to inhibit CVB3 replication. Consistent with previous reports that PDTC inhibits ubiquitin-proteasome-mediated protein degradation, we found that PDTC treatment led to the accumulation of several short-lived proteins in infected cells. We further provide evidence that the inhibitory effect of PDTC on protein degradation was not due to inhibition of proteasome activity but likely modulation of ubiquitination. Together with our previous findings that proteasome inhibition reduces CVB3 replication (H. Luo, J. Zhang, C. Cheung, A. Suarez, B. M. McManus, and D. Yang, Am. J. Pathol. 163:381-385, 2003), results in this study suggest a strong antiviral effect of PDTC on coxsackievirus, likely through inhibition of the ubiquitin-proteasome pathway.

Evolutionary constraints on chaperone-mediated folding provide an antiviral approach refractory to development of drug resistance

Article

Full-text available

Feb 2007
GENE DEV

The genome diversity of RNA viruses allows for rapid adaptation to a wide variety of adverse conditions. Accordingly, viruses can escape inhibition by most antiviral compounds targeting either viral or host factors. Here we exploited the capacity of RNA viruses for rapid adaptation to explore the evolutionary constraints of chaperone-mediated protein folding. We hypothesized that inhibiting a host molecular chaperone required for folding of a viral protein would force the virus to evolve an alternate folding strategy. We identified the chaperone Hsp90 as an essential factor for folding and maturation of picornavirus capsid proteins. Pharmacological inhibition of Hsp90 impaired the replication of poliovirus, rhinovirus, and coxsackievirus in cell culture. Strikingly, anti-Hsp90 treatment did not yield drug-resistant viruses, suggesting that the complexity of capsid folding precludes the emergence of alternate folding pathways. These results reveal tight evolutionary constraints on chaperone-mediated protein folding, which may be exploited for viral inhibition in vivo. Indeed, Hsp90 inhibitors drastically reduced poliovirus replication in infected animals without the emergence of drug-resistant escape mutants. We propose that targeting folding of viral proteins may provide a general antiviral strategy that is refractory to development of drug resistance.

Activation of Caspase3 in HL60 Cells Treated with Pyrithione and Zinc

Article

Apr 2005

The transition metal zinc (Zn) is an endogenous regulator of apoptosis. The ability of Zn to modulate apoptosis is believed to be mediated by the regulation of caspase activity. Previously, we reported that an acute influx of labile Zn induced apoptosis via activation of caspase in human leukemia HL-60 cells treated with a Zn ionophore (Py, pyrithione) and Zn at 1 and 25 μM, respectively. In the present study, we investigated the involvement of caspase-3 in Py (1 μM)/Zn (25 μM)-induced apoptosis in HL-60 cells. Pro-caspase-3 is an inactive form of caspase-3. The processing of pro-caspase-3, a sign of caspase-3 activation, occurred 6 h after treatment with Py/Zn. Proteolysis of poly (ADP-ribose) polymerase (PARP), a substrate of caspase-3, was also observed 6 h after treatment with Py/Zn. We also confirmed the elevation of caspase-3 activity as an index of the cleavage of amino acid sequences recognized by activated caspase-3. An inhibitor of caspase-3 attenuated the appearance of the DNA ladder. Taken together, these results indicate that the activation of caspase-3 is partly responsible for the induction of apoptosis in Py/Zn-treated HL-60 cells.

Pyrithione, a Zinc Ionophore, Inhibits NF-??B Activation

Article

Jun 1999

Pyrrolidine dithiocarbamate (PDTC) suppresses NF-κB activity and exhibits cytotoxic effects in bovine cerebral endothelial cells (BCECs), and we have previously reported that these PDTC effects were accompanied by an increase in intracellular zinc levels. To further explore the role of zinc in the modulation of NF-κB activation, we studied the effect of pyrithione, a zinc ionophore, on NF-κB activation in BCECs. Pyrithione inhibited NF-κB activity in a time- and dose-dependent manner. Ca-EDTA, but not Zn-EDTA, prevented pyrithione inhibition of NF-κB activity. Pyrithione increased the intracellular zinc level within 15 min. This effect was also abolished by Ca-EDTA, but not by Zn-EDTA. The potency of pyrithione on NF-κB inhibition and zinc influx was approximately one order of magnitude more potent than PDTC. These findings establish the regulatory role of intracellular zinc levels on NF-κB activity in BCECs.

A Simple Method of Estimating Fifty Per Cent Endpoints

Article

Nov 1937
AM J TROP MED HYG

Antibacterial activity of ??-thujaplicin

Article

Feb 2011
CAN J MICROBIOL

The cedar extractive β-thujaplicin was shown to inhibit the growth of a wide variety of bacterial species, and to be bactericidal for several species. The compound caused the lysis of cells of several species of Gram-negative bacteria. The antibacterial activity of β-thujaplicin was quantitated by agar diffusion and tube-dilution assays, and shown to be less potent than sodium penicillin G and tetracycline hydrochloride.

Cloning and synthesis of infectious cardiovirus RNAs containing short, discrete poly(C) tracts

Article

May 1989

Mengovirus RNA transcripts with 5' noncoding poly(C) tracts of C8, C12, and C13UC10 have been synthesized in vitro from cDNA clones and shown to be infectious to HeLa cells. A chimeric clone has also been constructed which links the 5' end from one mengovirus clone (299 nucleotides, containing C13UC10) to a 7,424-base fragment derived from the 3' end of encephalomyocarditis (EMC) virus. Progeny virus isolated after transfection with the clone-derived RNAs had the same poly(C) tracts, mengovirus-specific sequences, or EMC virus-specific sequences as the transcript from which it was derived. Although the cloned poly(C) tracts were considerably shorter than those found in viral RNA from mengovirus (C50UC10) or EMC virus (C115UCUC3UC10), the growth characteristics of the progeny viruses in HeLa cells were indistinguishable from those of the parental viruses, indicating the length of this tract does not play a significant restrictive role for cardiovirus infectivity in tissue culture.

Human rhinovirus 14 infection of HeLA cells results in the proteolytic cleavage of the p220 cap-binding complex subunit and inactivates globin mRNA translation in vitro

Article

Jun 1985

One of the characteristics of picornavirus infection of cells in tissue culture is a specific inhibition of utilization of host cell mRNA for protein synthesis. In this study we show that human rhinovirus 14 is similar to poliovirus in that the inhibition of host cell translation that occurs during infection correlates with the proteolytic cleavage of an Mr 220,000 subunit of the cap-binding protein complex.

Characterization of the Large Picornaviral Polypeptides Produced in the Presence of Zinc Ion

Article

Sep 1974

Zinc ion inhibits the posttranslational cleavages of human rhinovirus-1A, encephalomyocarditis virus, and poliovirus polypeptides. Each virus displayed a different susceptibility to zinc. However, in each case the cleavages of the capsid precursor and the cleavages analogous to the C --> D --> E conversion in encephalomyocarditis virus were most sensitive to zinc. Higher concentrations of zinc resulted in the buildup of even larger precursor polypeptides of a size between 106,000 and 214,000 daltons. The sizes of these polypeptides and the relative position of their gene loci on the viral RNA were determined. These data were used to place these polypeptides in the over-all scheme of viral protein processing.

Relationship of human rhinovirus strain 2 and poliovirus as indicated by comparison of the polymerase gene regions

Article

Aug 1984

cDNA clones representing the 3'-terminal region of the human rhinovirus strain 2 genome have been obtained. The sequence of 1425 nucleotides adjacent to the poly(A) tract is presented and contains an open reading frame of 1383 nucleotides. The derived amino acid sequence corresponding to the putative RNA polymerase-coding region is compared to those of poliovirus type 1 (Mahoney) and foot-and-mouth disease virus A12. A high degree of homology between human rhinovirus strain 2 and poliovirus type 1 (Mahoney) was found within the coding sequence but not within the 3'-untranslated region.

The Highly Effective Use of Topical Zinc Pyrithione in the Treatment of Psoriasis: A Case Report

Article

Apr 1997
Dermatol Online J

Psoriasis is a common condition which, at times, can be difficult to treat. Patients with psoriasis face many social challenges and can suffer a great deal with their disease. As a result, any new topical agent is a welcomed addition to our therapeutic armamentarium. We present here a report of a case using a novel topical preparation of zinc pyrithione for the treatment of psoriasis. Topical zinc pyrithione appears to be a safe and effective treatment for psoriasis.

Thujaplicin-copper chelates inhibit replication of human influenza viruses

Article

Sep 1998
ANTIVIR RES

The effects of alpha-, beta- and gamma-thujaplicins and six of their metal chelates on human influenza virus-induced apoptosis in Madin-Darby canine kidney (MDCK) cells were examined by DNA fragmentation and flow cytometry. Among the compounds tested, thujaplicin copper chelates inhibited apoptosis induced in the infected MDCK cells with influenza A/PR/8/34(H1N1), A/Shingapol/1/57(H2N2), A/Aichi/2/68(H3N2) and B/Lee/40 viruses, at concentrations of more than 5 microM. These results indicate that the copper chelates inhibit influenza virus-induced apoptosis and that the inhibitory effects may be independent of influenza virus subtype or types. Furthermore, the copper chelates also inhibited the release of the viruses from the infected MDCK cells during apoptosis. The anti-apoptotic effects of the copper chelates may occur 2 4 h postinfection, suggesting that the copper chelates affect MDCK cells directly in the early stage of influenza virus-induced apoptosis. In this study, we demonstrated that thujaplicin-copper chelates inhibit influenza virus-induced apoptosis of MDCK cells and also inhibit virus replication and release from the infected cells.

Pyrrolidine Dithiocarbamate Induces Bovine Cerebral Endothelial Cell Death by Increasing the Intracellular Zinc Level

Article

May 1999

The antioxidant and metal-chelating effects of pyrrolidine dithiocarbamate (PDTC) have been extensively studied. PDTC prevents cell death induced by various insults. However, PDTC itself may cause cell death in selected experimental paradigms. PDTC induced bovine cerebral endothelial cell death. However, in serum-depleted medium, PDTC did not affect the cell viability, suggesting that certain factors in serum may mediate the cytotoxic effect of PDTC. The metal chelators bathocuproine disulfonic acid, o-phenanthroline, bathophenanthroline disulfonic acid, and N,N,N',N'-tetrakis(2-pyridyl-methyl)ethylenediamine (TPEN) prevented the cell death induced by PDTC. In a serum-deprived condition, addition of exogenous metals, copper or zinc, restored the cytotoxic effect of PDTC. These data indicate that metals such as copper or zinc in serum may mediate the cytotoxic effect of PDTC. The potency of zinc for PDTC-induced endothelial cell death was greater than that of copper. Zn-EDTA did not block PDTC-induced cell death, whereas Ca-EDTA and Cu-EDTA were able to prevent this PDTC effect. PDTC increased the intracellular fluorescence of the zinc probe dye N-(6-methoxy-8-quinolyl)-p-toluenesulfonamide, which was quenched by TPEN or various EDTA preparations but not by Zn-EDTA. Results suggest that an increase in intracellular zinc concentration is required in PDTC-induced cerebral endothelial cell death.

Zinc is required in pyrrolidine dithiocarbamate inhibition of NF-??B activation

Article

May 1999

Pyrrolidine dithiocarbamate (PDTC) is a potent inhibitor of nuclear factor kappa B (NF-kappaB) activation. PDTC inhibited basal NF-kappaB activity of endothelial cells. PDTC, however, failed to inhibit basal NF-kappaB activity after withdrawal of serum in the media, and the inhibitory effect of PDTC could be restored by addition of zinc. When various preparations of metal ion-EDTA were tested with PDTC in serum-containing media, only Zn-EDTA failed to block the inhibitory effect of PDTC. The dependence on zinc was also noted in PDTC inhibition of NF-kappaB stimulated by TNF alpha. These facts suggest that zinc is required for PDTC inhibition of NF-kappaB activation.

Pyrrolidine dithiocarbamate-induced apoptosis depends on cell type, density, and the presence of Cu2+ and Zn2+

Article

Jul 2000

Pyrrolidine dithiocarbamate (PDTC) has been found to induce or inhibit apoptosis in different cell types. Here we show that PDTC dose-dependently reduced the viability of rat smooth muscle cells (rSMC), human fibroblasts, and endothelial cells at low but not at high cell density. Endothelial cells were least sensitive, fibroblasts showed a medium sensitivity, and rSMC showed a high sensitivity to PDTC-mediated cell death. An early reduction in the mitochondrial membrane potential indicated a rapid onset of apoptosis in rSMC. Apoptosis was further confirmed by annexin V staining and DNA fragmentation analysis. Gel shift analysis demonstrated increased nuclear factor (NF)-kappaB activity in high-density rSMC compared with low-density cells. NF-kappaB has recently been shown to regulate the induction of anti-apoptotic proteins. Although PDTC is widely used as an inhibitor for NF-kappaB and a radical scavenger, our data show that PDTC rather enhanced NF-kappaB activity and, alone or in combination with menadione, induced oxygen radical generation. Notably, PDTC failed to reduce rSMC viability in medium without Cu(2+) or Zn(2+), and addition of Cu(2+) or Zn(2+) resulted in a dose-dependent increase in PDTC-induced cell death. Addition of both Cu(2+) and Zn(2+) showed synergistic effects. Our results indicate that the induction of apoptosis by PDTC requires Cu(2+) and Zn(2+) and is dependent on cell type and density. Such differential effects may have implications for studies of PDTC as an anti-atherosclerotic or immunomodulatory drug.

Warner RR, Schwartz JR, Boissy Y, Dawson TLDandruff has an altered stratum corneum ultrastructure that is improved with zinc pyrithione shampoo. J Am Acad Dermatol 45:897-903

Article

Jan 2002
J AM ACAD DERMATOL

Transmission electron microscopy of scalp tape strips indicates that dandruff scalp possesses abnormal stratum corneum (SC) ultrastructure that is normalized by treatment with small-particle zinc pyrithione (ZPT). Similar abnormalities occur throughout the scalp of those with dandruff, even where no flaking is present. SC abnormalities are consistent with hyperproliferation, including parakeratosis, lipid droplets within corneocytes, few desmosomes, corneocyte membrane interdigitation, and excessive disorganized intercellular lipid. Reversal of SC abnormalities would require treatment of the cause(s) of dandruff, not merely flake removal. A protocol was developed to quantify scalp structural abnormalities by scoring cells from scalp tape strips for yeast number, amount of intercellular lipid, normal intercellular lipid structures, prevalence of intracellular lipid droplets, parakeratotic corneocytes, and corneocyte interdigitation. This protocol was used to compare dandruff and normal SC to dandruff SC treated with either commercial ZPT-containing shampoo or a placebo. Treatment with commercial ZPT shampoo significantly returned SC ultrastructure to normal, suggesting control of the cause of dandruff.

Functions of Zinc in signaling, proliferation and differentiation of mammalian cells

Article

Sep 2001

Zinc is essential for cell proliferation and differentiation, especially for the regulation of DNA synthesis and mitosis. On the molecular level, it is a structural constituent of a great number of proteins, including enzymes of cellular signaling pathways and transcription factors. Zinc homeostasis in eukaryotic cells is controlled on the levels of uptake, intracellular sequestration in zinc storing vesicles ('zincosomes'), nucleocytoplasmic distribution and elimination. These processes involve the major zinc binding protein metallothionein as a tool for the regulation of the cellular zinc level and the nuclear translocation of zinc in the course of the cell cycle and differentiation. In addition, there is also increasing evidence for a direct signaling function for zinc on all levels of signal transduction. Zinc can modulate cellular signal recognition, second messenger metabolism, protein kinase and protein phosphatase activities, and it may stimulate or inhibit activities of transcription factors, depending on the experimental systems studied. Zinc has been shown to modify specifically the metabolism of cGMP, the activities of protein kinase C and mitogen activated protein kinases, and the activity of transcription factor MTF-1 which controls the transcription of the genes for metallothionein and the zinc transporter ZnT-1. As a conclusion of these observations new hypotheses regarding regulatory functions of zinc ions in cellular signaling pathways are proposed.

Intracellular zinc distribution and transport in C6 rat glioma cells

Article

Sep 2002

In mammalian cells, the intracellular availability of zinc influences numerous crucial processes. Its distribution has previously been visualized with several fluorescent probes, but it was unclear how these probes are compartmentalized within the cell. Here, we show that in C6 cells the zinc-specific probe Zinquin is evenly distributed. Thus, the significantly lower level of fluorescence in the nucleus and a punctuate vesicular staining are real differences in the concentrations of zinc. Chemical perturbation of the steady state by releasing intracellular protein-bound zinc with the sulfhydryl-reactive N-ethylmaleimide (NEM) resulted in a vanadate sensitive transport of zinc out of the nucleus and into zincosomes. If the zinc-release was performed with the histidine-reactive diethylpyrocarbonate, sequestration was reduced compared to treatment with NEM, indicating the importance of histidine within membrane zinc transporters. Another major factor regulating the zinc homeostasis is ion export. As determined by atomic absorption spectroscopy, up to 50% of the cellular zinc was exported by a mechanism sensitive to lanthanum ions. We conclude that different concentrations of labile zinc exist in different cellular compartments, which are maintained by export and intracellular transport of zinc.

Effect of antioxidants on apoptosis induced by influenza virus infection: Inhibition of viral gene replication and transcription with pyrrolidine dithiocarbamate

Article

Jan 2003
ANTIVIR RES

Influenza virus (IV) infection induced apoptotic DNA fragmentation and the moderate overproduction of reactive oxygen species (ROS) in primary cultured chorion cells prepared from human fetal membranes, and IV particles were released from the infected cells. The antioxidant pyrrolidine dithiocarbamate (PDTC) inhibited the induced DNA fragmentation, ROS overproduction and IV particle release. Although Trolox inhibited ROS overproduction, it did not inhibit DNA fragmentation or IV production. The inhibitory effect of PDTC on DNA fragmentation was manifested when added up to 3 h after infection or by exposing the infected cells to it for only 1 h after infection. PDTC inhibited IV hemagglutinin (HA) viral (vRNA) and complementary (cRNA and mRNA) RNAs synthesis until 6 h after infection and delayed and decreased HA protein synthesis. However, HA RNA synthesis resumed after 12 h even in the presence of PDTC. These results suggested that PDTC inhibited apoptosis by inhibiting viral macromolecule synthesis rather than through its antioxidant effect, because Trolox did not inhibit apoptosis or IV production, although ROS overproduction was inhibited. The synthesis of specific viral macromolecules at the early stage of infection may play a critical role in the mechanism of apoptosis induction and moderate ROS overproduction may not be involved in the mechanism.

Requirement of caspase and p38MAPK activation in zinc-induced apoptosis in human leukemia HL-60 cells

Article

Jan 2003

Zinc (Zn), an endogenous regulator of apoptosis, and has abilities both to induce apoptosis and inhibit the induction of apoptosis via the modulation of caspase activity. Due to the multifunctions of Zn, the intracellular Zn level is strictly regulated by a complex system in physiological and pathological conditions. The commitment of Zn to the regulation of apoptosis is not fully understood. In the present study, we investigated the role of intracellular Zn level in the induction of apoptosis in human leukemia cells (HL-60 cells) using a Zn ionophore [pyrithione (Py)]. Treatment of HL-60 cells with Zn for 6 h in the presence of Py (1 micro m) exhibited cytotoxicity in a Zn dose-dependent manner (25-200 micro m). Necrotic cells, assayed by trypan blue permeability, increased in number in a Zn dose-dependent fashion (50-100 micro m), but the appearance of apoptotic cells, assayed by formation of a DNA ladder and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end-labeling method, peaked at 25 micro m, suggesting the dependence of intracellular Zn level on the execution of apoptosis. In fact, treatment with Py resulted in increases in intracellular Zn levels, and N,N,N',N'-tetrakis (2-pyridylmethyl)ethylenediamine, a cell-permeable Zn chelator, inhibited DNA ladder formation induced by Py/Zn treatment (1 micro m Py and 25 micro m Zn). Py/Zn treatment activated the caspases, as assessed by the proteolysis of poly(ADP-ribose) polymerase (PARP), which is a substrate of caspase, and activated p38 mitogen-activated protein kinase (p38MAPK), which is a transducer of apoptotic stimuli to the apparatus of the apoptosis execution. Z-Asp-CH2-DCB, a broad-spectrum inhibitor of caspase, attenuated proteolysis of PARP and DNA ladder formation by Py/Zn, indicating that apoptosis induced by Py/Zn is mediated by caspase activation. The p38MAPK-specific inhibitor SB203580 also inhibited induction of apoptosis by Py/Zn. Although SB203580 suppressed the proteolysis of PARP, Z-Asp-CH2-DCB did not inhibit the phosphorylation of p38MAPK, raising the possibility that apoptosis triggered by Py/Zn might be mediated by the p38MAPK/caspase pathway.

Antiviral function of pyrrolidine dithiocarbamate against influenza virus: The inhibition of viral gene replication and transcription

Article

Aug 2003

In summary, the present findings yield the following conclusions: (i) influenza virus-induced moderate ROS overproduction results from apoptosis and it is not responsible for the induction of apoptosis; (ii) PDTC blocks influenza virus-induced apoptosis via the inhibition of viral gene replication and transcription at an early stage of infection rather than through its antioxidant property; (iii) synthesis of specific viral macromolecules at an early stage of infection may play a critical role in the mechanism of apoptosis induction. Finally, virus-induced apoptosis can play a beneficial role in cooperation with the host immune system in the host defence mechanism; in contrast, this process can function in a derogatory capacity, depending on the situation. If virus infection induces massive apoptosis in a broad area of tissue or in essential organs, induction of apoptosis would lead to serious consequences in the infected host. Thus, apoptosis can play a primary role in the pathogenesis of virus. Peptide inhibitors of caspases block the execution of influenza virus-induced apoptosis in vitro but not virus replication.2 Therefore, caspase activation may be involved in the execution of apoptosis by influenza virus infection; however, virus replication may not be directly involved in the process, although it is essential to the induction of apoptosis. It may be said that virus replication is the most important aspect of influenza virus pathogenicity; therefore, genuine anti-apoptosis agents, i.e. caspase inhibitors, may not be suitable for influenza chemotherapy, although these

Antiviral Activity of the Zinc Ionophores Pyrithione and Hinokitiol against Picornavirus Infections

Abstract

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