Lower COVID-19 mortality in Italian forested areas suggests immunoprotection by Mediterranean plants

The effect of the urban exposome on COVID-19 health outcomes: A systematic review and meta-analysis

BACKGROUND

The global severity of SARS-CoV-2 illness has been associated with various urban characteristics, including exposure to ambient air pollutants. This systematic review and meta-analysis aims to synthesize findings from ecological and non-ecological studies to investigate the impact of multiple urban-related features on a variety of COVID-19 health outcomes.

METHODS

On December 5, 2022, PubMed was searched to identify all types of observational studies that examined one or more urban exposome characteristics in relation to various COVID-19 health outcomes such as infection severity, the need for hospitalization, ICU admission, COVID pneumonia, and mortality.

RESULTS

A total of 38 non-ecological and 241 ecological studies were included in this review. Non-ecological studies highlighted the significant effects of population density, urbanization, and exposure to ambient air pollutants, particularly PM2.5. The meta-analyses revealed that a 1 μg/m3 increase in PM2.5 was associated with a higher likelihood of COVID-19 hospitalization (pooled OR 1.08 (95% CI:1.02-1.14)) and death (pooled OR 1.06 (95% CI:1.03-1.09)). Ecological studies, in addition to confirming the findings of non-ecological studies, also indicated that higher exposure to nitrogen dioxide (NO2), ozone (O3), sulphur dioxide (SO2), and carbon monoxide (CO), as well as lower ambient temperature, humidity, ultraviolet (UV) radiation, and less green and blue space exposure, were associated with increased COVID-19 morbidity and mortality.

CONCLUSION

This systematic review has identified several key vulnerability features related to urban areas in the context of the recent COVID-19 pandemic. The findings underscore the importance of improving policies related to urban exposures and implementing measures to protect individuals from these harmful environmental stressors.

Environmental, meteorological and pandemic restriction-related variables affecting SARS-CoV-2 cases

Three years have passed since the outbreak of Coronavirus Disease 2019 (COVID-19) brought the world to standstill. In most countries, the restrictions have ended, and the immunity of the population has increased; however, the possibility of new dangerous variants emerging remains. Therefore, it is crucial to develop tools to study and forecast the dynamics of future pandemics. In this study, a generalized additive model (GAM) was developed to evaluate the impact of meteorological and environmental variables, along with pandemic-related restrictions, on the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Córdoba, Argentina. The results revealed that mean temperature and vegetation cover were the most significant predictors affecting SARS-CoV-2 cases, followed by government restriction phases, days of the week, and hours of sunlight. Although fine particulate matter (PM2.5) and NO2 were less related, they improved the model's predictive power, and a 1-day lag enhanced accuracy metrics. The models exhibited strong adjusted coefficients of determination (R2adj) but did not perform as well in terms of root-mean-square error (RMSE). This suggests that the number of cases may not be the primary variable for controlling the spread of the disease. Furthermore, the increase in positive cases related to policy interventions may indicate the presence of lockdown fatigue. This study highlights the potential of data science as a management tool for identifying crucial variables that influence epidemiological patterns and can be monitored to prevent an overload in the healthcare system.

Movement Asymmetries: From Their Molecular Origin to the Analysis of Movement Asymmetries in Athletes

Asymmetry plays a major role in biology at all scales. This can be seen in the helix of DNA, the fact that the human heart is on the left side, or that most people use their right hand. A single protein such as Myosin 1D can induce helical motion in another molecule. This causes cells, organs, and even entire bodies to twist in a domino effect, causing left-right behaviour. More generally, athlete movements are often asymmetric and, during the physical rehabilitation after injury, the asymmetry is visually discernible. Herein, we review the molecular basis of the movement asymmetries and report on the available knowledge on the few therapeutics investigated so far such as meloxicam. From a more rehabilitative perspective, it is very important to use effective methods to control the process of resolving the injury-related movement asymmetry through the complex use of specialised exercises, measurements, and gait analysis, which can all provide useful information on the effectiveness of the rehabilitation plans. If for each athlete, the normal range of asymmetry is known, the asymmetry can be individually treated and the evolution can be monitored over time. Appropriate measures should be taken if the movement asymmetry is outside this range. In addition, genetic, physiological, and psychological factors relevant to athlete health should be considered in the process of assessing and improving exercise asymmetry, which we also discuss in this review. The main proposal of this work is that the movement asymmetries in athletes should be individually treated, while taking into account the athlete's genetics, physical condition, and previous injuries.

Local and regional factors of spatial differentiation of the excess mortality related to the COVID-19 pandemic in Romania

COVID-19 revealed some major weaknesses and threats that are related to the level of territorial development. In Romania, the manifestation and the impact of the pandemic were not homogenous, which was influenced, to a large extent, by a diversity of sociodemographic, economic, and environmental/geographic factors. The paper is an exploratory analysis focused on selecting and integrating multiple indicators that could explain the spatial differentiation of COVID-19-related excess mortality (EXCMORT) in 2020 and 2021. These indicators include, among others, health infrastructure, population density and mobility, health services, education, the ageing population and distance to the closest urban center. We analyzed the data from local (LAU2) and county level (NUTS3) by applying multiple linear regression and geographically weighted regression models. The results show that mobility and lower social distancing were far more critical factors for higher mortality than the intrinsic vulnerability of the population, at least in the first two years of COVID-19. However, the highly differentiated patterns and specificities of different areas of Romania resulting from the modelling of EXCMORT factors drive to the conclusion that the decision-making approaches should be place-specific in order to have more efficiency in case of pandemics.

Interaction of Laurusides 1 and 2 with the 3C-like Protease (Mpro) from Wild-Type and Omicron Variant of SARS-CoV-2: A Molecular Dynamics Study

Laurus nobilis (bay laurel) is a natural source of biological compounds, and some of its extracts and phytocompounds are also endowed with antiviral activity toward the family of the severe acute respiratory syndrome (SARS)-associated β-coronaviruses. Some glycosidic laurel compounds such as laurusides were proposed as inhibitors of important protein targets of SARS-CoV-2, which clearly recalls their potential as anti-COVID-19 drugs. Due to the frequent genomic variations of the β-coronaviruses and the consequent importance of evaluating a new drug candidate with respect to the variants of the target β-coronavirus, we decided to investigate at an atomistic level the molecular interactions of the potential laurel-derived drugs laurusides 1 and 2 (L01 and L02, respectively) toward a well-conserved and crucial target, the 3C-like protease (Mpro), using the enzymes of both the wild-type of SARS-CoV-2 and of the more recent Omicron variant. Thus, we performed molecular dynamic (MD) simulations of laurusides-SARS-CoV-2 protease complexes to deepen the knowledge on the stability of the interaction and compare the effects of the targeting among the two genomic variants. We found that the Omicron mutation does not significantly impact the lauruside binding and that L02 connects more stably with respect to L01 in the complexes from both variants, even though both compounds prevalently interact within the same binding pocket. Although purely in silico, the current study highlights the potential role of bay laurel phytocompounds in the antiviral and specifically anti-coronavirus research and shows their potential binding toward Mpro, corroborating the important commitment of bay laurel as functional food and disclosing novel scenarios of lauruside-based antiviral therapies.

Forest bathing and hiking benefits for mental health during the COVID-19 pandemic in Mediterranean regions

Forest bathing (FB) has evidenced positive effects on individuals' mental health and well-being, but its benefits have mainly been studied in Asian biomes. The present study aimed to evaluate whether its benefits are also generalisable to other forests and biomes of the world, such as the Mediterranean. Eighty-six healthy adults of the general population were assessed before and after a FB near Barcelona (Spain) during the COVID-19 pandemic. A control-hiking group of participants was also analysed to contrast the FB effects on anxiety, affect, mood states and mindfulness. Results show that the guided practice of FB in Mediterranean-Catalan forests increases mindfulness states and positive affect and reduces anxiety and negative affect, with effect sizes being large to very large. Hiking also induced significant changes in all variables tested, but FB showed higher effect sizes. An exploratory analysis also revealed a different profile of the FB participants compared to the hiking practitioners, being highly educated women living in urban areas and with lower basal levels of psychological well-being. Accordingly, it is concluded that both Mediterranean FB and hiking (to a lesser degree) might be cost-effective strategies to promote and restore psychological well-being after the COVID-19 pandemic and to promote sustainable tourism in Mediterranean biomes of the European forested and protected areas.

Exploring the Protective Effect of Food Drugs against Viral Diseases: Interaction of Functional Food Ingredients and SARS-CoV-2, Influenza Virus, and HSV

A complex network of processes inside the human immune system provides resistance against a wide range of pathologies. These defenses form an innate and adaptive immunity, in which certain immune components work together to counteract infections. In addition to inherited variables, the susceptibility to diseases may be influenced by factors such as lifestyle choices and aging, as well as environmental determinants. It has been shown that certain dietary chemical components regulate signal transduction and cell morphologies which, in turn, have consequences on pathophysiology. The consumption of some functional foods may increase immune cell activity, defending us against a number of diseases, including those caused by viruses. Here, we investigate a range of functional foods, often marketed as immune system boosters, in an attempt to find indications of their potential protective role against diseases caused by viruses, such as the influenza viruses (A and B), herpes simplex virus (HSV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in some cases mediated by gut microbiota. We also discuss the molecular mechanisms that govern the protective effects of some functional foods and their molecular constituents. The main message of this review is that discovering foods that are able to strengthen the immune system can be a winning weapon against viral diseases. In addition, understanding how the dietary components function can aid in the development of novel strategies for maintaining human bodily health and keeping our immune systems strong.

Association of greenness with COVID-19 deaths in India: An ecological study at district level

BACKGROUND

The world has witnessed a colossal death toll due to the novel coronavirus disease-2019 (COVID-19). A few environmental epidemiology studies have identified association of environmental factors (air pollution, greenness, temperature, etc.) with COVID-19 incidence and mortality, particularly in developed countries. India, being one of the most severely affected countries by the pandemic, still has a dearth of research exploring the linkages of environment and COVID-19 pandemic.

OBJECTIVES

We evaluate whether district-level greenness exposure is associated with a reduced risk of COVID-19 deaths in India.

METHODS

We used average normalized difference vegetation index (NDVI) from January to March 2019, derived by Oceansat-2 satellite, to represent district-level greenness exposure. COVID-19 death counts were obtained through May 1, 2021 (around the peak of the second wave) from an open portal: covid19india.org. We used hierarchical generalized negative binomial regressions to check the associations of greenness with COVID-19 death counts. Analyses were adjusted for air pollution (PM2.5), temperature, rainfall, population density, proportion of older adults (50 years and above), sex ratio over age 50, proportions of rural population, household overcrowding, materially deprived households, health facilities, and secondary school education.

RESULTS

Our analyses found a significant association between greenness and reduced risk of COVID-19 deaths. Compared to the districts with the lowest NDVI (quintile 1), districts within quintiles 3, 4, and 5 have respectively, around 32% [MRR = 0.68 (95% CI: 0.51, 0.88)], 39% [MRR = 0.61 (95% CI: 0.46, 0.80)], and 47% [MRR = 0.53 (95% CI: 0.40, 0.71)] reduced risk of COVID-19 deaths. The association remains consistent for analyses restricted to districts with a rather good overall death registration (>80%).

CONCLUSION

Though cause-of-death statistics are limited, we confirm that exposure to greenness was associated with reduced district-level COVID-19 deaths in India. However, material deprivation and air pollution modify this association.

Unanswered questions on the airborne transmission of COVID-19

Policies and measures to control pandemics are often failing. While biological factors controlling transmission are usually well explored, little is known about the environmental drivers of transmission and infection. For instance, respiratory droplets and aerosol particles are crucial vectors for the airborne transmission of the severe acute respiratory syndrome coronavirus 2, the causation agent of the coronavirus 2019 pandemic (COVID-19). Once expectorated, respiratory droplets interact with atmospheric particulates that influence the viability and transmission of the novel coronavirus, yet there is little knowledge on this process or its consequences on virus transmission and infection. Here we review the effects of atmospheric particulate properties, vortex zones, and air pollution on virus survivability and transmission. We found that particle size, chemical constituents, electrostatic charges, and the moisture content of airborne particles can have notable effects on virus transmission, with higher survival generally associated with larger particles, yet some viruses are better preserved on small particles. Some chemical constituents and surface-adsorbed chemical species may damage peptide bonds in viral proteins and impair virus stability. Electrostatic charges and water content of atmospheric particulates may affect the adherence of virion particles and possibly their viability. In addition, vortex zones and human thermal plumes are major environmental factors altering the aerodynamics of buoyant particles in air, which can strongly influence the transport of airborne particles and the transmission of associated viruses. Insights into these factors may provide explanations for the widely observed positive correlations between COVID-19 infection and mortality with air pollution, of which particulate matter is a common constituent that may have a central role in the airborne transmission of the novel coronavirus.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10311-022-01557-z.

COVID-19: Reducing the risk via diet and lifestyle

This review shows that relatively simple changes to diet and lifestyle can significantly, and rapidly, reduce the risks associated with coronavirus disease 2019 (COVID-19) in terms of infection risk, severity of disease, and even disease-related mortality. A wide range of interventions including regular exercise, adequate sleep, plant-based diets, maintenance of healthy weight, dietary supplementation, and time in nature have each been shown to have beneficial effects for supporting more positive health outcomes with COVID-19, in addition to promoting better overall health. This paper brings together literature from these areas and presents the argument that non-pharmaceutical approaches should not be overlooked in our response to COVID-19. It is noted that, in several cases, interventions discussed result in risk reductions equivalent to, or even greater than, those associated with currently available vaccines. Where the balance of evidence suggests benefits, and the risk is minimal to none, it is suggested that communicating the power of individual actions to the public becomes morally imperative. Further, many lives could be saved, and many harms from the vaccine mandates avoided, if we were willing to embrace this lifestyle-centred approach in our efforts to deal with COVID-19.

Spike in pollution to ignite the bursting of COVID-19 second wave is more dangerous than spike of SAR-CoV-2 under environmental ignorance in long term: a review

Specific areas in many countries such as Italy, India, China, Brazil, Germany and the USA have witnessed that air pollution increases the risk of COVID-19 severity as particulate matters transmit the virus SARS-CoV-2 and causes high expression of ACE2, the receptor for spike protein of the virus, especially under exposure to NO2, SO2 and NOx emissions. Wastewater-based epidemiology of COVID-19 is also noticed in many countries such as the Netherlands, the USA, Paris, France, Australia, Spain, Italy, Switzerland China, India and Hungary. Soil is also found to be contaminated by the RNA of SARS-CoV-2. Activities including defecation and urination by infected people contribute to the source for soil contamination, while release of wastewater containing cough, urine and stool of infected people from hospitals and home isolation contributes to the source of SARS-CoV-2 RNA in both water and soil. Detection of the virus early before the outbreak of the disease supports this fact. Based on this information, spike in pollution is found to be more dangerous in long-term than the spike protein of SARS-CoV-2. It is because the later one may be controlled in future within months or few years by vaccination and with specific drugs, but the former one provides base for many diseases including the current and any future pandemics. Although such predictions and the positive effects of SARS-CoV-2 on environment was already forecasted after the first wave of COVID-19, the learnt lesson as spotlight was not considered as one of the measures for which 2nd wave has quickly hit the world.

Elucidating the role of environmental management of forests, air quality, solid waste and wastewater on the dissemination of SARS-CoV-2

The increasing frequency of zoonotic diseases is amongst several catastrophic repercussions of inadequate environmental management. Emergence, prevalence, and lethality of zoonotic diseases is intrinsically linked to environmental management which are currently at a destructive level globally. The effects of these links are complicated and interdependent, creating an urgent need of elucidating the role of environmental mismanagement to improve our resilience to future pandemics. This review focused on the pertinent role of forests, outdoor air, indoor air, solid waste and wastewater management in COVID-19 dissemination to analyze the opportunities prevailing to control infectious diseases considering relevant data from previous disease outbreaks. Global forest management is currently detrimental and hotspots of forest fragmentation have demonstrated to result in zoonotic disease emergences. Deforestation is reported to increase susceptibility to COVID-19 due to wildfire induced pollution and loss of forest ecosystem services. Detection of SARS-CoV-2 like viruses in multiple animal species also point to the impacts of biodiversity loss and forest fragmentation in relation to COVID-19. Available literature on air quality and COVID-19 have provided insights into the potential of air pollutants acting as plausible virus carrier and aggravating immune responses and expression of ACE2 receptors. SARS-CoV-2 is detected in outdoor air, indoor air, solid waste, wastewater and shown to prevail on solid surfaces and aerosols for prolonged hours. Furthermore, lack of protection measures and safe disposal options in waste management are evoking concerns especially in underdeveloped countries due to high infectivity of SARS-CoV-2. Inadequate legal framework and non-adherence to environmental regulations were observed to aggravate the postulated risks and vulnerability to future waves of pandemics. Our understanding underlines the urgent need to reinforce the fragile status of global environmental management systems through the development of strict legislative frameworks and enforcement by providing institutional, financial and technical supports.

Modern drug discovery applications for the identification of novel candidates for COVID-19 infections

In early December 2019, a large pneumonia epidemic occurred in Wuhan, China. The World Health Organization is concerned about the outbreak of another coronavirus with the powerful, rapid, and contagious transmission. Anyone with minor symptoms like fever and cough or travel history to contaminated places might be suspected of having COVID-19. COVID-19 therapy focuses on treating the disease's symptoms. So far, no such therapeutic molecule has been shown effective in treating this condition. So the treatment is mostly supportive and plasma. Globally, numerous studies and researchers have recently started fighting this virus. Vaccines and chemical compounds are also being investigated against infection. COVID-19 was successfully diagnosed using RNA detection and very sensitive RT-PCR (reverse transcription-polymerase chain reaction). The evolution of particular vaccinations is required to reduce illness severity and spread. Numerous computational analyses and molecular docking have predicted various target compounds that might stop this condition. This paper examines the main characteristics of coronavirus and the computational analyses necessary to avoid infection.

Outdoor Recreation Habits of People in Latvia: General Trends, and Changes during the COVID-19 Pandemic

Outdoor recreation opportunities are crucial for sustaining people’s physical and mental health, and forests are important recreational venues in Europe, especially in its northern part. Our study sought to characterise outdoor recreation patterns and their changes in Latvia due to the COVID-19 pandemic. We conducted a representative population survey with public participatory GIS elements that allowed the respondents to map their favoured recreation destinations. Our results revealed increased visitor numbers to nature areas during COVID-19. The main stated psychosocial factors behind the increased frequency of nature visits are health benefits and lower perceived risks in the context of the pandemic. Forests as areas simultaneously providing multiple ecosystem services have significant importance in providing space for outdoor recreation. Outdoor recreation hotspots concentrate around major urban areas and in some of the largest and most popular nature areas.

Nucleic Acids as Biotools at the Interface between Chemistry and Nanomedicine in the COVID-19 Era

The recent development of mRNA vaccines against the SARS-CoV-2 infection has turned the spotlight on the potential of nucleic acids as innovative prophylactic agents and as diagnostic and therapeutic tools. Until now, their use has been severely limited by their reduced half-life in the biological environment and the difficulties related to their transport to target cells. These limiting aspects can now be overcome by resorting to chemical modifications in the drug and using appropriate nanocarriers, respectively. Oligonucleotides can interact with complementary sequences of nucleic acid targets, forming stable complexes and determining their loss of function. An alternative strategy uses nucleic acid aptamers that, like the antibodies, bind to specific proteins to modulate their activity. In this review, the authors will examine the recent literature on nucleic acids-based strategies in the COVID-19 era, focusing the attention on their applications for the prophylaxis of COVID-19, but also on antisense- and aptamer-based strategies directed to the diagnosis and therapy of the coronavirus pandemic.

Diabetes and COVID-19: The potential role of mTOR

Diabetes is the most frequent comorbidity among patients with COVID-19. COVID-19 patients with diabetes have a more severe prognosis than patients without diabetes. However, the etiopathogenetic mechanisms underlying this more unfavorable outcome in these patients are not clear. Probably the etiopathogenetic mechanisms underlying diabetes could represent a favorable substrate for a greater development of the inflammatory process already dysregulated in COVID-19 with a more severe evolution of the disease. In the attempt to shed light on the possible etiopathogenetic mechanisms, we wanted to evaluate the possible role of mTOR (mammalian Target Of Rapamycin) pathway in this context. We searched the PubMed and Scopus databases to identify articles involving diabetes and the mTOR pathway in COVID-19. The mTOR pathway could be involved in this etiopathogenetic mechanism, in particular, the activation and stimulation of this pathway could favor an inflammatory process that is already dysregulated in itself, while its inhibition could be a way to regulate this dysregulated inflammatory process. However, much remains to be clarified about the mechanisms of the mTOR pathway and its role in COVID-19. The aim of this review is to to understand the etiopathogenesis underlying COVID-19 in diabetic patients and the role of mTOR pathway in order to be able to search for new weapons to deal with this disease.

Forest Bathing Is Better than Walking in Urban Park: Comparison of Cardiac and Vascular Function between Urban and Forest Parks

Forest bathing is beneficial for human health. To investigate whether walking in forest or urban parks affects cardiovascular functions (CVFs), the present study was conducted in five forest trails in the Xitou Experimental Forest and in five urban parks in Taipei city. We recruited 25 adult volunteers for an observational pilot study in forest parks (n = 14) and urban parks (n = 11). CVFs were assessed by measuring the arterial pressure waveform using an oscillometric blood pressure (BP) device. The baseline and paired differences of systolic BP (SBP), central end SBP, heart rate, left ventricle (LV) dP/dt max and cardiac output in participants were lower before and after walking in a forest park than those in an urban park. In addition, the systemic vascular compliance and brachial artery compliance of those who walked in a forest park were significantly higher compared with those in an urban park. Linear mixed models demonstrated lower levels of SBP by 5.22 mmHg, heart rate by 2.46 beats/min, and cardiac output by 0.52 L/min, and LV dP/dt max by 146.91 mmHg/s among those who walked in forest compared to those in an urban park after controlling covariates. This study provides evidence of the potential beneficial effects of walking exercise in forest parks on CVFs.

The Healing Power of Clean Rivers: In Silico Evaluation of the Antipsoriatic Potential of Apiin and Hyperoside Plant Metabolites Contained in River Waters

Humanity may benefit greatly from intact riverine ecosystems not only because they supply water to be used in the most common human activities, but also for the effects that clean rivers can have on human health. Herein, we used a computational approach to show that some phytochemicals produced by riparian plants as secondary metabolites, which are naturally released into river waters, can have therapeutic properties. These include antipsoriatic activities which we demonstrated in silico by modelling the interaction of apiin, guanosine and hyperoside, a few main river plant metabolites, with NF-kB, IL-17 and IL-36, which are recognized targets involved in psoriasis disease. In particular, we found that apiin and hyperoside are endowed with docking energies and binding affinities which are more favorable than the known reference inhibitors of the three protein targets whilst, in silico, guanosine shows comparable activity with respect to the inhibitors of IL-36 and NF-kB. The low skin permeation (logKp < −8) we predicted for apiin and hyperoside led us to hypothesize their possible utilization as topic antipsoriatic therapeutics, and in particular after PAINS (pan-assay interference compounds) score evaluation, we reached the conclusion that apiin, with no predicted tendency to react nonspecifically with the numerous targets involved in the biological cellular pathways, is particularly interesting for the desired therapeutic application.

The Effects of Urban Green Space on Depressive Symptoms of Mid-Aged and Elderly Urban Residents in China: Evidence from the China Health and Retirement Longitudinal Study

The aim of this study is to assess the impacts of urban green space on depressive symptoms among Chinese urban residents aged 45 and older. In total, 7397 urban respondents were included in this study. Each respondent participated in the China Health and Retirement Longitudinal Study Wave 3 (2015). Environmental-level variables were retrieved from the National Bureau of Statistics database. Both unadjusted and adjusted methods were used in the multilevel regression analysis. Almost one-third of the sample population suffered from depressive symptoms (31.20%). The multilevel logistic regression model showed that green coverage ratio of city-built districts is negatively associated with the prevalence of depressive symptoms among urban mid-aged (OR = 0.79, p < 0.05) and elderly (OR = 0.75, p < 0.05) residents, and the public recreational green space helps to reduce elderly people’s depressive symptoms (OR = 0.77, p < 0.05). This study adds insights about the impact of green space and other environmental factors on depressive symptoms among mid-aged and elderly urban dwellers. It is important to provide enough and accessible overall urban green spaces; additionally, attention should also be paid to specific green space forms such as public recreational green space.

Old growth forests and large old trees as critical organisms connecting ecosystems and human health. A review

Old forests containing ancient trees are essential ecosystems for life on earth. Mechanisms that happen both deep in the root systems and in the highest canopies ensure the viability of our planet. Old forests fix large quantities of atmospheric CO2, produce oxygen, create micro-climates and irreplaceable habitats, in sharp contrast to young forests and monoculture forests. The current intense logging activities induce rapid, adverse effects on our ecosystems and climate. Here we review large old trees with a focus on ecosystem preservation, climate issues, and therapeutic potential. We found that old forests continue to sequester carbon and fix nitrogen. Old trees control below-ground conditions that are essential for tree regeneration. Old forests create micro-climates that slow global warming and are irreplaceable habitats for many endangered species. Old trees produce phytochemicals with many biomedical properties. Old trees also host particular fungi with untapped medicinal potential, including the Agarikon, Fomitopsis officinalis, which is currently being tested against the coronavirus disease 2019 (COVID-19). Large old trees are an important part of our combined cultural heritage, providing people with aesthetic, symbolic, religious, and historical cues. Bringing their numerous environmental, oceanic, ecological, therapeutic, and socio-cultural benefits to the fore, and learning to appreciate old trees in a holistic manner could contribute to halting the worldwide decline of old-growth forests.

Longitudinal investigation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in older patients in the province of Palermo (Southern Italy) during the early wave of the pandemic

INTRODUCTION

Clinical presentation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in old adults from Southern Italy is little known. This study aims to investigate the mortality risk related to risk factors, therapy and clinical course and to suggest prognostic indicators based on day-to-day follow-up of clinical and laboratory findings.

MATERIAL AND METHODS

It was designed as a retrospective longitudinal cohort study of adult SARS-CoV-2 patients admitted at Partinico COVID Hospital in Palermo, Southern Italy. Patients were recruited between 4 March and 25 April and followed up until 31 May 2020, day-to-day until death or hospital discharge. Clinical data, laboratory tests and treatment data were extracted from medical records and epidemiologic information was obtained by clinical history and the medical interview.

RESULTS

Forty-seven patients (median age = 75 IQR: 59.50-86.00) were followed up during a 87 days observation period, accounting for a total of 1,035 person days. At the end of follow-up, 28 (60%) patients were discharged and 19 (40%) died, so that the estimated incidence density rate was 0.018 deaths per day (18 SARS-CoV-2-related deaths per 1,000 patient days). Diabetes (HR = 8.13, 95% CI: 1.91-34.67), chronic kidney failure (HR = 5.86, 95% CI: 1.36-25.21), dementia (HR = 7.84, 95% CI: 1.80-34.20), and neutrophil/lymphocyte ratio > 7 (HR = 10.37, 95% CI: 2.24-48.14) were found as significant prognostic factors.

CONCLUSIONS

The joint evaluation of dementia, diabetes, chronic kidney failure and neutrophil/lymphocyte ratio showed an optimal prognostic value already in the first week of follow-up. The day-to-day follow-up provides essential information for clinical monitoring and treatment of the disease in a hospital setting and improves the disease's home management, especially for older patients with frailty.

Forest-bathing and physical activity as weapons against COVID-19: a review

Strengthening the immune system in order to better withstand the threat of COVID-19 is an important way to ensure the protection of our health against the current pandemic associated with SARS-CoV-2. There are many ways to achieve this, but with current circumstances, certain modalities stand out as being the most valid and are certainly worth greater consideration. Here we review the effects that particular immuno-strengthening activities can have on limiting the severity of COVID-19 disease as well as preventing virus infection. Physical activity, in particular, should not be discounted as an important method of prevention of viral diseases as it triggers many biological processes within the human body which in turn lead to heightened natural defences against viral infections. When exercise is performed in forested areas, these protective health benefits may be increased since many plant species emit biogenic volatile compounds (VOCs) which, when inhaled, have many protective properties. These VOCs have been shown in particular to have immunostimulatory effects on the human body and, thus, they could be of use in the prevention and/or treatment of COVID-19. Being amongst trees may also help to alleviate stress and anxiety, lowering cortisol levels and consequently helping the proper functioning of the immune system. In the following work, we have performed an analysis of the available scientific literature which looks at the effects of physical exercise as well as 'forest-bathing' on the immune system's ability to fight disease, especially of course as it relates to COVID-19. Our review aims at shedding light on the benefits of exercising outdoors in green areas and suggests reforestation as a protective measure against future outbreaks.

Links between chronic exposure to outdoor air pollution and cardiovascular diseases: a review

Acute exposure to air pollution is associated with an increasing risk of death and cardiovascular disorders. Nonetheless, the impact of chronic exposure to air pollution on the circulatory system is still debated. Here, we review the links of chronic exposure to outdoor air pollution with mortality and most common cardiovascular diseases, in particular during the coronavirus disease 2019 event (COVID-19). We found that recent studies provide robust evidence for a causal effect of chronic exposure to air pollution and cardiovascular mortality. In terms of mortality, the strongest relationship was noted for fine particulate matter, nitrogen dioxide, and ozone. There is also increasing evidence showing that exposure to air pollution, mainly fine particulate matter and nitrogen dioxide, is associated with the development of atherosclerosis, hypertension, stroke, and heart failure. However, available scientific evidence is not strong enough to support associations with cardiac arrhythmias and coagulation disturbances. Noteworthy, for some pollutants, the risk of negative health effects is high for concentrations lower than the limit values recommended by the European Union and Word Health Organization. Efforts to diminish exposure to air pollution and to design optimal methods of air pollution reduction should be urgently intensified and supported by effective legislation and interdisciplinary cooperation.

Less COVID-19 deaths in southern and insular Italy explained by forest bathing, Mediterranean environment, and antiviral plant volatile organic compounds

The coronavirus disease 2019 (COVID-19) is causing major sanitary and socioeconomic issues, yet some locations are less impacted than others. While densely populated areas are likely to favor viral transmission, we hypothesize that other environmental factors could explain lower cases in some areas. We studied COVID-19 impact and population statistics in highly forested Mediterranean Italian regions versus some northern regions where the amount of trees per capita is much lower. We also evaluated the affinity of Mediterranean plant-emitted volatile organic compounds (VOCs) isoprene, α-pinene, linalool and limonene for COVID-19 protein targets by molecular docking modeling. Results show that while mean death number increased about 4 times from 2020 to 2021, the percentage of deaths per population (0.06-0.10%) was lower in the greener Mediterranean regions such as Sardinia, Calabria and Basilica versus northern regions with low forest coverage, such as Lombardy (0.33%) and Emilia Romagna (0.29%). Data also show that the pandemic severity cannot be explained solely by population density. Modeling reveals that plant organic compounds could bind and interfere with the complex formed by the receptor binding domain of the coronavirus spike protein with the human cell receptor. Overall, our findings are likely explained by sea proximity and mild climate, Mediterranean diet and the abundance of non-deciduous Mediterranean plants which emit immunomodulatory and antiviral compounds. Potential implications include 'forest bathing' as a therapeutic practice, designing nasal sprays containing plant volatile organic compounds, and preserving and increasing forest coverage.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10311-021-01309-5.

Evaluating In Silico the Potential Health and Environmental Benefits of Houseplant Volatile Organic Compounds for an Emerging 'Indoor Forest Bathing' Approach

The practice of spending time in green areas to gain the health benefits provided by trees is well known, especially in Asia, as ‘forest bathing’, and the consequent protective and experimentally detectable effects on the human body have been linked to the biogenic volatile organic compounds released by plants. Houseplants are common in houses over the globe and are particularly appreciated for aesthetic reasons as well for their ability to purify air from some environmental volatile pollutants indoors. However, to the best of our knowledge, no attempt has been made to describe the health benefits achievable from houseplants thanks to the biogenic volatile organic compounds released, especially during the day, from some of them. Therefore, we performed the present study, based on both a literature analysis and in silico studies, to investigate whether the volatile compounds and aerosol constituents emitted by some of the most common houseplants (such as peace lily plant, Spathiphyllum wallisii, and iron plant, Aspidistra eliator) could be exploited in ‘indoor forest bathing’ approaches, as proposed here for the first time not only in private houses but also public spaces, such as offices, hospitals, and schools. By using molecular docking (MD) and other in silico methodologies for estimating vapor pressures and chemico-physical/pharmacokinetic properties prediction, we found that β-costol is an organic compound, emitted in appreciable amounts by the houseplant Spathiphyllum wallisii, endowed with potential antiviral properties as emerged by our MD calculations in a SARS-CoV-2 M^pro (main protease) inhibition study, together with sesquirosefuran. Our studies suggest that the anti-COVID-19 potential of these houseplant-emitted compounds is comparable or even higher than known M^pro inhibitors, such as eugenol, and sustain the utility of houseplants as indoor biogenic volatile organic compound emitters for immunity boosting and health protection.

Effect of Green Space Environment on Air Pollutants PM2.5, PM10, CO, O3, and Incidence and Mortality of SARS-CoV-2 in Highly Green and Less-Green Countries

Worldwide, over half of the global population is living in urban areas. The metropolitan areas are highly populated and environmentally non-green regions on the planet. In green space regions, plants, grass, and green vegetation prevent soil erosion, absorb air pollutants, provide fresh and clean air, and minimize the burden of diseases. Presently, the entire world is facing a turmoil situation due to the COVID-19 pandemic. This study investigates the effect of the green space environment on air pollutants particulate matter PM2.5, PM10, carbon monoxide (CO), ozone (O₃), incidence and mortality of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) in environmentally highly green and less-green countries. We randomly selected 17 countries based on the Environmental Performance Index (EPI) data. The 60% of the EPI score is based on seven categories: "biodiversity and habitat, ecosystem, fisheries, climate change, pollution emissions, agriculture, and water resources". However, 40% of the score is based on four categories: "air quality, sanitation and drinking water, heavy metals, and waste management". The air pollutants and SARS-CoV-2 cases and deaths were recorded from 25 January 2020, to 11 July 2021. The air pollutants "PM2.5, PM10, CO, and O₃" were recorded from the metrological websites, Air Quality Index-AQI, 2021. The COVID-19 daily cases and deaths were obtained from the World Health Organization. The result reveals that air pollutants mean values for PM2.5 110.73 ± 1.09 vs. 31.35 ± 0.29; PM10 80.43 ± 1.11 vs. 17.78 ± 0.15; CO 7.92 ± 0.14 vs. 2.35 ± 0.03 were significantly decreased (p < 0.0001) in environmentally highly green space countries compared to less-green countries. Moreover, SARS-CoV-2 cases 15,713.61 ± 702.42 vs. 3445.59 ± 108.09; and deaths 297.56 ± 11.27 vs. 72.54 ± 2.61 were also significantly decreased in highly green countries compared to less-green countries. The green environment positively impacts human wellbeing. The policymakers must implement policies to keep the living areas, surroundings, towns, and cities clean and green to minimize air pollution and combat the present pandemic of COVID-19.

Forest Recreational Services in the Face of COVID-19 Pandemic Stress

Forest ecosystems provide numerous services and benefits to both humans and biodiversity. Similarly, urban forests services play a vital role by providing urban dwellers with recreational and leisure space, mental health relief, and meditation. In the wake of the COVID-19 epidemic, many people living in the urban areas could benefit from the forest and park recreational services to relieve psychological stress due to lockdown rules. The study examined existing literature simultaneously; however, very few studies have presented the relationships between forest services’ role on COVID-19 stress relief. Furthermore, we examined forest visitors’ frequency at the Training Forest Enterprise (TFE) Masaryk Forest Křtiny in the outskirts of Brno City in the Czech Republic. The study collected data using a TRAFx infrared trail counter before the pandemic (2015–2018) and during the COVID-19 period (2021). As in other studies of the subject, we observed an increasing trend in forest visits during the COVID-19 lockdown in 2021, compared to the same months before the pandemic in 2016 and 2017. We recommend further research to focus on scientific analysis of the relationship between forest ecosystem services and COVID-19 stress and mental health. Moreover, given the spike in visitors during the COVID-19 lockdown in 2021 in March and April, our data provide evidence regarding the role of nature for relieving stress and supporting mental and physical health. Policy, decision-makers and medical advisors could use such data and study to guide future lockdowns and pandemic situations regarding nature and forest recreational use and importance.

The mediterranean diet: Healthy and sustainable dietary pattern in the time of Sars-Cov-2

COVID-19, first reported in Wuhan, China in December 2019 quickly spread worldwide leading to serious health, social and economic consequences. A crucial role in the pathogenesis of severe disease has been attributed to the inflammatory status, that in more severe cases may evolve in an overproduction of pro-inflammatory cytokines (“cytokine storm)” and fatal outcome. Non-communicable diseases, nutritional disorders and advanced age, conditions associated with a low-grade systemic inflammation and immune function alterations, have been identified as major risks for severe COVID-19. General recommendations for fighting COVID-19 highlighted the paramount importance of adopting a healthy plant-based dietary pattern and healthy lifestyle. The Mediterranean dietary pattern is considered as one of the healthiest dietary patterns, and its benefits are supported by a large body of evidence. Furthermore, it is considered as a sustainable lifestyle model. The aim of this research was to update the multiple benefits of the Mediterranean dietary pattern on physical and mental health, focusing on the effects that it may have in combating COVID-19. The potential effects and mechanisms of action of the main bioactive components of Mediterranean diet were also analyzed. Considering its effects in modulating inflammation and oxidative stress and supporting the immune system, the Mediterranean dietary pattern may be considered the most promising dietary approach to combat COVID-19.

PM2.5, NO2, wildfires, and other environmental exposures are linked to higher Covid 19 incidence, severity, and death rates

Numerous studies have linked outdoor levels of PM_2.5, PM₁₀, NO₂, O₃, SO₂, and other air pollutants to significantly higher rates of Covid 19 morbidity and mortality, although the rate in which specific concentrations of pollutants increase Covid 19 morbidity and mortality varies widely by specific country and study. As little as a 1-μg/m³ increase in outdoor PM_2.5 is estimated to increase rates of Covid 19 by as much as 0.22 to 8%. Two California studies have strongly linked heavy wildfire burning periods with significantly higher outdoor levels of PM_2.5 and CO as well as significantly higher rates of Covid 19 cases and deaths. Active smoking has also been strongly linked significantly increased risk of Covid 19 severity and death. Other exposures possibly related to greater risk of Covid 19 morbidity and mortality include incense, pesticides, heavy metals, dust/sand, toxic waste sites, and volcanic emissions. The exact mechanisms in which air pollutants increase Covid 19 infections are not fully understood, but are probably related to pollutant-related oxidation and inflammation of the lungs and other tissues and to the pollutant-driven alternation of the angiotensin-converting enzyme 2 in respiratory and other cells.

Effectiveness of plants and green infrastructure utilization in ambient particulate matter removal

Air pollution is regarded as an increasingly threatening, major environmental risk for human health. Seven million deaths are attributed to air pollution each year, 91% of which is due to particulate matter. Vegetation is a xenobiotic means of removing particulate matter. This review presents the mechanisms of PM capture by plants and factors that influence PM reduction in the atmosphere. Vegetation is ubiquitously approved as a PM removal solution in cities, taking various forms of green infrastructure. This review also refers to the effectiveness of plant exploitation in GI: trees, grasslands, green roofs, living walls, water reservoirs, and urban farming. Finally, methods of increasing the PM removal by plants, such as species selection, biodiversity increase, PAH-degrading phyllospheric endophytes, transgenic plants and microorganisms, are presented.

The viral phoenix: enhanced infectivity and immunity evasion of SARS-CoV-2 variants

SARS-CoV-2 pandemic continues with emergence of new variants of concerns. These variants are fueling the third and fourth waves of pandemic across many nations. Here we describe the new emerging variants of SARS-CoV-2 and why they have enhanced infectivity and possess the ability to evade immunity.

In Silico Investigation on the Interaction of Chiral Phytochemicals from Opuntia ficus-indica with SARS-CoV-2 Mpro

Opuntia ficus-indica is a cactaceous plant native to America but, nowadays, widely found worldwide, having been the most common domesticated species of cactus grown as a crop plant in semiarid and arid parts of the globe, including several Mediterranean basin countries. Opuntia ficus-indica can be regarded as a medicinal plant, being source of numerous bioactive phytochemicals such as vitamins, polyphenols, and amino acids. The urgent need for therapeutic treatments for the COronaVIrus Disease 19 (COVID-19), caused by the Severe Acute Respiratory Syndrome (SARS)-Coronavirus (CoV)-2, justifies the great attention currently being paid not only to repurposed antiviral drugs, but also to natural products and herbal medications. In this context, the anti-COVID-19 utility of Opuntia ficus-indica as source of potential antiviral drugs was investigated in this work on the basis of the activity of some of its phytochemical constituents. The antiviral potential was evaluated in silico in docking experiments with Mpro, i.e., the main protease of SARS-CoV-2, that is one of the most investigated protein targets of therapeutic strategies for COVID-19. By using two web-based molecular docking programs (1-Click Mcule and COVID-19 Docking Server), we found, for several flavonols and flavonol glucosides isolated from Opuntia ficus-indica, good binding affinities for Mpro, and in particular, binding energies lower than −7.0 kcal/mol were predicted for astragalin, isorhamnetin, isorhamnetin 3-O-glucoside, 3-O-caffeoyl quinic acid, and quercetin 5,4′-dimethyl ether. Among these compounds, the chiral compound astragalin showed in our in silico studies the highest affinity for Mpro (−8.7 kcal/mol) and also a low toxicity profile, emerging, thus, as an interesting protease inhibitor candidate for anti-COVID-19 strategies.

Smarter cures to combat COVID-19 and future pathogens: a review

Prevention is better than cure. A milestone of the anthropocene is the emergence of a series of epidemics and pandemics often characterized by the transmission of a pathogen from animals to human in the past two decades. In particular, the coronavirus disease 2019 (COVID-19) has made a profound impact on emergency responding and policy-making in a public health crisis. Classical solutions for controlling the virus, such as travel restrictions, lockdowns, repurposed drugs and vaccines, are socially unpopular and medically limited by the fast mutation and adaptation of the virus. This is exacerbated by microbial resistance to therapeutic drugs and the slowness of vaccine development. In other words, microbial pathogens are somehow 'smarter' and faster than us, thus calling for more intelligent cures to combat future pandemics. Here, we compare therapeutics for COVID-19 such as synthetic drugs, vaccines, antibodies and phages. We present the strength and limitations of antibiotic and antiviral drugs, vaccines, and antibody-based therapeutics. We describe smarter, cheaper and preventive cures such as bacteriophages, food medicine using probiotics and prebiotics, sports, healthy diet, music, yoga, Tai Chi, dance, reading, knitting, cooking and outdoor activities. Some of these preventive cures have been intuitively developed since thousands of years ago, as illustrated by the fascinating similarity of the Chinese characters for 'music' and 'herbal medicine.'

Molecular Basis of the Therapeutical Potential of Clove (Syzygium aromaticum L.) and Clues to Its Anti-COVID-19 Utility

The current COronaVIrus Disease 19 (COVID-19) pandemic caused by SARS-CoV-2 infection is enormously affecting the worldwide health and economy. In the wait for an effective global immunization, the development of a specific therapeutic protocol to treat COVID-19 patients is clearly necessary as a short-term solution of the problem. Drug repurposing and herbal medicine represent two of the most explored strategies for an anti-COVID-19 drug discovery. Clove (Syzygium aromaticum L.) is a well-known culinary spice that has been used for centuries in folk medicine in many disorders. Interestingly, traditional medicines have used clove since ancient times to treat respiratory ailments, whilst clove ingredients show antiviral and anti-inflammatory properties. Other interesting features are the clove antithrombotic, immunostimulatory, and antibacterial effects. Thus, in this review, we discuss the potential role of clove in the frame of anti-COVID-19 therapy, focusing on the antiviral, anti-inflammatory, and antithrombotic effects of clove and its molecular constituents described in the scientific literature.

Perceptions of Urban Green Areas during the Social Distancing Period for COVID-19 Containment in Italy

The scientific community recognizes that urban green areas play an important role in supporting human wellbeing. Green spaces are used differently by citizens accordingly to their age, gender, education, or lifestyle. During the coronavirus disease (COVID-19) pandemic period in 2020, public green areas were closed due to the limitations imposed by social distancing in Italy and people were forced to stay at home. The aim of this research was to investigate the importance of public green areas in the life of the population in relation to the limits imposed during the first lockdown in Italy. A participatory approach was used, and an online questionnaire focused on people’s perceptions about the public attendance in green areas and their main uses pre-, during, and post-COVID-19 emergency period was administrated randomly to the adult population. The questions focused on the habit, frequency, and duration of park visits and about the individual perceptions and feelings about the green areas close (maximum 200 m distance) to their residences. A total of 3286 responses were obtained and analyzed at national and regional levels (Piemonte). In order to have a general national overview, a basic descriptive statistic was applied using all answers, elaborated in the form of percentages. At the regional level, questions were selected and compared to determine if answers were in related. Statistical analyses with chi-square tests and correspondence analyses were performed. The results indicated that the social distancing period for COVID-19 containment in Italy influenced perceptions about urban green areas. The importance of having outdoor green spaces was highlighted and an increase in interest about urban green areas was observed. Future planning strategies will have to consider the need of designing urban green areas for having more livable cities.

COVID-19 into Chemical Science Perspective: Chemical Preventive Measures and Drug Development

COVID-19 facts and literature are discussed into chemical science intuition highlighting the direct role of chemistry to the ongoing global pandemic by covering structural identification of the virus, chemical preventive measures and development of drugs. We reviewed the four most promising repurposed drugs which are presently being investigated in mass clinical trials on COVID-19 infected persons and synthetic routes of these drugs with their recent advancement. Chemical preventive measures such as soap water, hand sanitizer and disinfectant are the only available options in the arsenal to fight against COVID-19, till an effective medicine or vaccine will be made available. As such the present review will focus on the mode of action of the major chemical preventives.

Rapamycin: Drug Repurposing in SARS-CoV-2 Infection

Since December 2019, SARS-CoV-2 (COVID-19) has been a worldwide pandemic with enormous consequences for human health and the world economy. Remdesivir is the only drug in the world that has been approved for the treating of COVID-19. This drug, as well as vaccination, still has uncertain effectiveness. Drug repurposing could be a promising strategy how to find an appropriate molecule: rapamycin could be one of them. The authors performed a systematic literature review of available studies on the research describing rapamycin in association with COVID-19 infection. Only peer-reviewed English-written articles from the world’s acknowledged databases Web of Science, PubMed, Springer and Scopus were involved. Five articles were eventually included in the final analysis. The findings indicate that rapamycin seems to be a suitable candidate for drug repurposing. In addition, it may represent a better candidate for COVID-19 therapy than commonly tested antivirals. It is also likely that its efficiency will not be reduced by the high rate of viral RNA mutation.

Nucleoside Analogs and Nucleoside Precursors as Drugs in the Fight against SARS-CoV-2 and Other Coronaviruses

Coronaviruses (CoVs) are positive-sense RNA enveloped viruses, members of the family Coronaviridae, that cause infections in a broad range of mammals including humans. Several CoV species lead to mild upper respiratory infections typically associated with common colds. However, three human CoV (HCoV) species: Severe Acute Respiratory Syndrome (SARS)-CoV-1, Middle East Respiratory Syndrome (MERS)-CoV, and SARS-CoV-2, are responsible for severe respiratory diseases at the origin of two recent epidemics (SARS and MERS), and of the current COronaVIrus Disease 19 (COVID-19), respectively. The easily transmissible SARS-CoV-2, emerging at the end of 2019 in China, spread rapidly worldwide, leading the World Health Organization (WHO) to declare COVID-19 a pandemic. While the world waits for mass vaccination, there is an urgent need for effective drugs as short-term weapons to combat the SARS-CoV-2 infection. In this context, the drug repurposing approach is a strategy able to guarantee positive results rapidly. In this regard, it is well known that several nucleoside-mimicking analogs and nucleoside precursors may inhibit the growth of viruses providing effective therapies for several viral diseases, including HCoV infections. Therefore, this review will focus on synthetic nucleosides and nucleoside precursors active against different HCoV species, paying great attention to SARS-CoV-2. This work covers progress made in anti-CoV therapy with nucleoside derivatives and provides insight into their main mechanisms of action.

Fluoxetine Can Inhibit SARS-CoV-2 In Vitro

An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resulted in the coronavirus disease pandemic, drastically affecting global health and economy. Though the understanding of the disease has improved, fighting the virus remains challenging. One of the strategies is repurposing existing drugs as inhibitors of SARS-CoV-2. Fluoxetine (FLX), a selective serotonin reuptake inhibitor, reportedly inhibits the replication of RNA viruses, especially Coxsackieviruses B (CVB), such as CV-B4 in vitro and in vivo. Therefore, in this study, we investigated the in vitro antiviral activity of FLX against SARS-CoV-2 in a model of acute infection. When 10 μM of FLX was added to SARS-CoV-2-infected Vero E6 cells, the virus-induced cytopathic effect was not observed. In this model, the level of infectious particles in the supernatant was lower than that in controls. The level was below the limit of detection of the assay up to day 3 post-infection when FLX was administered before viral inoculation or simultaneously followed by daily inoculation. In conclusion, FLX can inhibit SARS-CoV-2 in vitro. Further studies are needed to investigate the potential value of FLX to combat SARS-CoV-2 infections, treat SARS-CoV-2-induced diseases, and explain the antiviral mechanism of this molecule to pave way for novel treatment strategies.

COVID-19 Prophylaxis Efforts Based on Natural Antiviral Plant Extracts and Their Compounds

During the time of the novel coronavirus disease 2019 (COVID-19) pandemic, it has been crucial to search for novel antiviral drugs from plants and well as other natural sources as alternatives for prophylaxis. This work reviews the antiviral potential of plant extracts, and the results of previous research for the treatment and prophylaxis of coronavirus disease and previous kinds of representative coronaviruses group. Detailed descriptions of medicinal herbs and crops based on their origin native area, plant parts used, and their antiviral potentials have been conducted. The possible role of plant-derived natural antiviral compounds for the development of plant-based drugs against coronavirus has been described. To identify useful scientific trends, VOSviewer visualization of presented scientific data analysis was used.

Role of indoor aerosols for COVID-19 viral transmission: a review

The relationship between outdoor atmospheric pollution by particulate matter and the morbidity and mortality of coronavirus disease 2019 (COVID-19) infections was recently disclosed, yet the role of indoor aerosols is poorly known . Since people spend most of their time indoor, indoor aerosols are closer to human occupants than outdoors, thus favoring airborne transmission of COVID-19. Therefore, here we review the characteristics of aerosol particles emitted from indoor sources, and how exposure to particles affects human respiratory infections and transport of airborne pathogens. We found that tobacco smoking, cooking, vacuum cleaning, laser printing, burning candles, mosquito coils and incenses generate large quantities of particles, mostly in the ultrafine range below 100 nm. These tiny particles stay airborne, are deposited in the deeper regions of human airways and are difficult to be removed by the respiratory system. As a consequence, adverse effects can be induced by inhaled aerosol particles via oxidative stress and inflammation. Early epidemiological evidence and animal studies have revealed the adverse effects of particle exposure in respiratory infections. In particular, inhaled particles can impair human respiratory systems and immune functions, and induce the upregulation of angiotensin-converting enzyme 2, thus inducing higher vulnerability to COVID-19 infection. Moreover, co-production of inflammation mediators by COVID-19 infection and particle exposure magnifies the cytokine storm and aggravates symptoms in patients. We also discuss the role of indoor aerosol particles as virus carriers. Although many hypotheses were proposed, there is still few knowledge on interactions between aerosol articles and virus-laden droplets or droplet nuclei.

How human thermal plume influences near-human transport of respiratory droplets and airborne particles: a review

With mounting evidence and notable cases of large clustered infections, airborne transmission via droplets and particles has been recently acknowledged as an effective mode of transmission for COVID-19. How droplets and aerosol particles disperse are being transported into the human breathing zone-the last few inches for airborne transmission to effectuate-remains a key question which has been widely overlooked. Human thermal plume refers to the constantly rising airflows around the boundary layer of human body due to persisting temperature gradients between the body surfaces and the ambient air. Ample evidence indicated that the thermal plume controls the dispersion and transport of aerosols in the human microenvironment. Given that in calm indoor environments most air inhaled by human comes from the boundary layer where thermal plume flows through constantly, the role of thermal plume needs to be scrutinized to predict the diffusion of droplets, aerosols and other airborne carriers of the novel coronavirus around the human body for prioritizing infection control strategies. Here, we assessed the potential influences of the thermal plume on the transmission of COVID-19 and other airborne pathogens by reviewing the most pertinent evidence and analyzing key variables in the formation of thermal plume in indoor environments, e.g., ambient temperature, human posture and type of clothing. Our reviewed evidence and data indicate that the human thermal plume should facilitate the airborne transmission of COVID-19 in enclosed spaces by elevating small droplets and airborne particles into the breathing zone from lower regions and ascending respiratory droplets from the sources into the upper atmosphere. By drawing attention to aerosol transport dynamics in the human microenvironment, these insights may be useful for understanding COVID-19 transmission in enclosed spaces, especially those intended for public use.

Comparison of antiviral effect for mild-to-moderate COVID-19 cases between lopinavir/ritonavir versus hydroxychloroquine: A nationwide propensity score-matched cohort study

OBJECTIVES

We aimed to compare the antiviral effect of hydroxychloroquine (HCQ) and lopinavir/ritonavir (LPV/r) in patients with COVID-19.

METHODS

Nationwide retrospective case-control study was conducted to compare the effect of HCQ and LPV/r on viral shedding duration among patients with mild-to-moderate COVID-19 using the reimbursement data of National Health Insurance Service. After propensity score matching (PSM), multivariate analysis was conducted to determine statistically significant risk factors associated with prolonged viral shedding.

RESULTS

Overall, 4197 patients with mild-to-moderate COVID-19 were included. Patients were categorized into three groups: LPV/r (n = 1268), HCQ (n = 801), and standard care without HCQ or LPV/r (controls, n = 2128). The median viral shedding duration was 23 (IQR 17-32), 23 (IQR 16-32), and 18 (IQR 12-25) days in the LPV/r, HCQ, and control groups, respectively. Even after PSM, the viral shedding duration was not significantly different between LPV/r and HCQ groups: 23 (IQR, 17-32) days versus 23 (IQR, 16-32) days. On multivariate analysis, old age, malignancy, steroid use, and concomitant pneumonia were statistically significant risk factors for prolonged viral shedding.

CONCLUSION

The viral shedding duration was similar between HCQ and LPV/r treatment groups. There was no benefit in improving viral clearance compared to the control group.

A retrospective comparison of drugs against COVID-19

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Hydroxychloroquine is an efficient candidate drug against COVID-19.

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Oseltamivir can be prudently considered in combination therapy.

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Drug repurposing is a promising way to combat SARS-CoV-2 infection.

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Comparison of drug effects against COVID-19 is instructive in the pandemic.

Coronavirus disease 19 (COVID-19) has posed serious threats to the general population. To relieve the crisis, a comparison of drug effects against COVID-19 is instructive. Between January 27, 2020 and March 21, 2020, a total of 333 patients treated with arbidol, corticosteroids, hydroxychloroquine, lopinavir/ritonavir, or oseltamivir monotherapy, having definite outcomes and serological antibody detection results, were retrospectively analyzed. The hydroxychloroquine group had a significantly reduced duration of hospital stay than the arbidol and corticosteroids groups. The oseltamivir group had a significantly shorter length of hospital stay than the arbidol, corticosteroids, and lopinavir/ritonavir groups. The hydroxychloroquine group had a significantly higher IgM titer than the other four groups and exhibited significantly higher IgG levels than the arbidol, lopinavir/ritonavir, and oseltamivir groups. Our findings indicated that hydroxychloroquine might have the potential for efficient COVID-19 management, while oseltamivir should be prudently considered in combination therapy.

High Mortality Rate in Adult COVID-19 Inpatients in Eastern Sudan: A Retrospective Study

AIM

The current pandemic of coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory coronavirus syndrome 2 (SARS-CoV-2). It is a global public health concern that has resulted in the rapid growth in the number of infected patients with significant mortality rates. Hence, we conducted a retrospective study in Gadarif Hospital to evaluate the presenting manifestations, mortality rate, and the risk factors associated with mortality in hospitalized patients.

METHODS

A retrospective study was conducted at Gadarif Hospital in Eastern Sudan. Medical files of the patients admitted during the period between April and July 2020 were reviewed. All the files of the adult patients (aged 18 or above), of both sexes, who had a confirmed COVID-19-positive status via laboratory testing using PCR and who were admitted during this period were reviewed. The data extracted included patients' demographics and initial clinical presentation, symptoms, signs, and the laboratory and radiographic findings. The data were analyzed using SPSS v22.

RESULTS

Eighty-eight patients were admitted with COVID-19. The median (interquartile) age was 62 (55.00-70.00) years old, and 72 (81.8%) of them were males. Most patients (75%) experienced a one-week duration of symptoms. A fever (87.5%), cough (80.68%), and shortness of breath (77.27%) were the most common presenting symptoms. Following a clinical assessment, both the systolic and diastolic blood pressure were found to be normal in most patients, at 92.05% and 89.77%, respectively. An oxygen saturation of less than 90% was seen in 71.59% of patients. The general mortality rate was 37.5% and most deaths occurred during the first 24 h of admission (21/33 [63.64%]). There was no significant difference in the death rate between females and males (5/16 [31.3%] vs 28/72 [38.9%], P = 0.776). There was no significant difference in the body mass index, tobacco use, or education level between the patients who died and those who survived. A logistic regression showed that being older (AOR = 1.05, 95% CI = [1.01, 1.10]) and having a lower PO2 level (AOR = 1.11, 95% CI = [1.04, 1.16]) were associated with mortality.

CONCLUSION

The general mortality rate was 37.5%, and the risk factors that could predict increased mortality in hospitalized COVID-19 positive cases included old age and a lower PO2 level.

Can the coronavirus disease be transmitted from food? A review of evidence, risks, policies and knowledge gaps

The coronavirus disease 2019 (COVID-19) has brought speculations on possible transmission routes of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of the pandemic. Air pollution has been linked to increased risks of COVID-19 infection and mortality rates in regions with poor air quality, yet no retrospective study has been reported on foodborne transmission of COVID-19. While studies have shown that low temperature could dramatically prolong the persistence on SARS-CoV-2 and other coronaviruses, frozen and refrigerated foods have been widely overlooked as potential vectors in policy frameworks and risk mitigation strategies. Food transmission evidence has been disclosed in China early July 2020 by the detection of SARS-CoV-2 on frozen foods, including their packaging materials and storage environments, with two re-emergent outbreaks linked to contaminated food sources. The contamination risk is augmented by a complex farm-to-table process, which favors exposure to food workers and ambient environments. Moreover, the food cold-chain also promotes contamination because laboratory studies showed that SARS-CoV-2 remained highly stable under refrigerated, at 4 °C, and freezing conditions, from - 10 to - 80 °C, on fish, meat, poultry, and swine skin, during 14-21 days. While data are lacking on long-term survival and infectivity under these conditions, ample evidence has been shown on other coronaviruses, including SARS-CoV-1. We therefore hypothesize that contaminated cold-storage foods may present a systematic risk for SARS-CoV-2 transmission between countries and regions. Here, we review the evidence, risk factors, current policy and knowledge gaps, on food contamination and foodborne transmission of SARS-CoV-2.

Air pollution by NO2 and PM2.5 explains COVID-19 infection severity by overexpression of angiotensin-converting enzyme 2 in respiratory cells: a review

Many major cities that witnessed heavy air pollution by nitrogen dioxide (NO2) and particulate matter (PM) have experienced a high rate of infection and severity of the coronavirus disease pandemic (COVID-19). This phenomenon could be explained by the overexpression of the angiotensin converting enzyme 2 (ACE-2) on epithelial cell surfaces of the respiratory tract. Indeed, ACE-2 is a receptor for coronaviruses including the severe acute respiratory syndrome coronavirus 1 and 2 (SARS-CoV), and ACE-2 is overexpressed under chronic exposure to air pollution such as NO2 and PM2.5. In this review, we explain that ACE-2 acts as the sole receptor for the attachment of the SARS-CoV-2 via its spike protein. The fact that respiratory and vascular epithelial cells express ACE-2 has been previously observed during the 2003 epidemic of the SARS-CoV-1 in China, and during the 2012 Middle East respiratory syndrome in Saudi Arabia. High ACE-2 expression in respiratory epithelial cells under air pollution explains the positive correlation between the severity in COVID-19 patients and elevated air pollution, notably high NO2 and PM2.5 levels. Specific areas in India, China, Italy, Russia, Chile and Qatar that experience heavy air pollution also show high rates of COVID-19 infection and severity. Overall, we demonstrate a link between NO2 emissions, PM2.5 levels, ACE-2 expression and COVID-19 infection severity. Therefore, air pollution should be reduced in places where confirmed cases of COVID-19 are unexpectedly high.