Artemisia annua L. extracts inhibit the in vitro replication of SARS-CoV-2 and two of its variants

Differential Anti-Fibrotic and Remodeling Responses of Human Dermal Fibroblasts to Artemisia sp., Artemisinin, and Its Derivatives

Fibrosis is a ubiquitous pathology, and prior studies have indicated that various artemisinin (ART) derivatives (including artesunate (AS), artemether (AM), and dihydroartemisinin (DHA)) can reduce fibrosis in vitro and in vivo. The medicinal plant Artemisia annua L. is the natural source of ART and is widely used, especially in underdeveloped countries, to treat a variety of diseases including malaria. A. afra contains no ART but is also antimalarial. Using human dermal fibroblasts (CRL-2097), we compared the effects of A. annua and A. afra tea infusions, ART, AS, AM, DHA, and a liver metabolite of ART, deoxyART (dART), on fibroblast viability and expression of key fibrotic marker genes after 1 and 4 days of treatment. AS, DHA, and Artemisia teas reduced fibroblast viability 4 d post-treatment in up to 80% of their respective controls. After 4 d of treatment, AS DHA and Artemisia teas downregulated ACTA2 up to 10 fold while ART had no significant effect, and AM increased viability by 10%. MMP1 and MMP3 were upregulated by AS, 17.5 and 32.6 fold, respectively, and by DHA, 8 and 51.8 fold, respectively. ART had no effect, but A. annua and A. afra teas increased MMP3 5 and 16-fold, respectively. Although A. afra tea increased COL3A1 5 fold, MMP1 decreased >7 fold with no change in either transcript by A. annua tea. Although A. annua contains ART, it had a significantly greater anti-fibrotic effect than ART alone but was less effective than A. afra. Immunofluorescent staining for smooth-muscle α-actin (α-SMA) correlated well with the transcriptional responses of drug-treated fibroblasts. Together, proliferation, qPCR, and immunofluorescence results show that treatment with ART, AS, DHA, and the two Artemisia teas yield differing responses, including those related to fibrosis, in human dermal fibroblasts, with evidence also of remodeling of fibrotic ECM.

Plant-derived compounds as potential leads for new drug development targeting COVID-19

COVID-19, which was first identified in 2019 in Wuhan, China, is a respiratory illness caused by a virus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although some patients infected with COVID-19 can remain asymptomatic, most experience a range of symptoms that can be mild to severe. Common symptoms include fever, cough, shortness of breath, fatigue, loss of taste or smell and muscle aches. In severe cases, complications can arise including pneumonia, acute respiratory distress syndrome, organ failure and even death, particularly in older adults or individuals with underlying health conditions. Treatments for COVID-19 include remdesivir, which has been authorised for emergency use in some countries, and dexamethasone, a corticosteroid used to reduce inflammation in severe cases. Biological drugs including monoclonal antibodies, such as casirivimab and imdevimab, have also been authorised for emergency use in certain situations. While these treatments have improved the outcome for many patients, there is still an urgent need for new treatments. Medicinal plants have long served as a valuable source of new drug leads and may serve as a valuable resource in the development of COVID-19 treatments due to their broad-spectrum antiviral activity. To date, various medicinal plant extracts have been studied for their cellular and molecular interactions, with some demonstrating anti-SARS-CoV-2 activity in vitro. This review explores the evaluation and potential therapeutic applications of these plants against SARS-CoV-2. This review summarises the latest evidence on the activity of different plant extracts and their isolated bioactive compounds against SARS-CoV-2, with a focus on the application of plant-derived compounds in animal models and in human studies.

The Potential of Anti-coronavirus Plant Secondary Metabolites in COVID-19 Drug Discovery as an Alternative to Repurposed Drugs: A Review

In early 2020, a global pandemic was announced due to the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), known to cause COVID-19. Despite worldwide efforts, there are only limited options regarding antiviral drug treatments for COVID-19. Although vaccines are now available, issues such as declining efficacy against different SARS-CoV-2 variants and the aging of vaccine-induced immunity highlight the importance of finding more antiviral drugs as a second line of defense against the disease. Drug repurposing has been used to rapidly find COVID-19 therapeutic options. Due to the lack of clinical evidence for the therapeutic benefits and certain serious side effects of repurposed antivirals, the search for an antiviral drug against SARS-CoV-2 with fewer side effects continues. In recent years, numerous studies have included antiviral chemicals from a variety of plant species. A better knowledge of the possible antiviral natural products and their mechanism against SARS-CoV-2 will help to develop stronger and more targeted direct-acting antiviral agents. The aim of the present study was to compile the current data on potential plant metabolites that can be investigated in COVID-19 drug discovery and development. This review represents a collection of plant secondary metabolites and their mode of action against SARS-CoV and SARS-CoV-2.

Treating COVID-19 with Medicinal Plants: Is It Even Conceivable? A Comprehensive Review

In 2020, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) challenged the world with a global outbreak that led to millions of deaths worldwide. Coronavirus disease 2019 (COVID-19) is the symptomatic manifestation of this virus, which can range from flu-like symptoms to utter clinical complications and even death. Since there was no clear medicine that could tackle this infection or lower its complications with minimal adverse effects on the patients' health, the world health organization (WHO) developed awareness programs to lower the infection rate and limit the fast spread of this virus. Although vaccines have been developed as preventative tools, people still prefer going back to traditional herbal medicine, which provides remarkable health benefits that can either prevent the viral infection or limit the progression of severe symptoms through different mechanistic pathways with relatively insignificant side effects. This comprehensive review provides scientific evidence elucidating the effect of 10 different plants against SARS-CoV-2, paving the way for further studies to reconsider plant-based extracts, rich in bioactive compounds, into more advanced clinical assessments in order to identify their impact on patients suffering from COVID-19.

Traditional uses, Phytochemistry, Pharmacology, and Toxicology of the Genus Artemisia L. (Asteraceae): A High-value Medicinal Plant

Biologically active secondary metabolites, essential oils, and volatile compounds derived from medicinal and aromatic plants play a crucial role in promoting human health. Within the large family Asteraceae, the genus Artemisia consists of approximately 500 species. Artemisia species have a rich history in traditional medicine worldwide, offering remedies for a wide range of ailments, such as malaria, jaundice, toothache, gastrointestinal problems, wounds, inflammatory diseases, diarrhoea, menstrual pains, skin disorders, headache, and intestinal parasites. The therapeutic potential of Artemisia species is derived from a multitude of phytoconstituents, including terpenoids, phenols, flavonoids, coumarins, sesquiterpene lactones, lignans, and alkaloids that serve as active pharmaceutical ingredients (API). The remarkable antimalarial, antimicrobial, anthelmintic, antidiabetic, anti-inflammatory, anticancer, antispasmodic, antioxidative and insecticidal properties possessed by the species are attributed to these APIs. Interestingly, several commercially utilized pharmaceutical drugs, including arglabin, artemisinin, artemether, artesunate, santonin, and tarralin have also been derived from different Artemisia species. However, despite the vast medicinal potential, only a limited number of Artemisia species have been exploited commercially. Further, the available literature on traditional and pharmacological uses of Artemisia lacks comprehensive reviews. Therefore, there is an urgent need to bridge the existing knowledge gaps and provide a scientific foundation for future Artemisia research endeavours. It is in this context, the present review aims to provide a comprehensive account of the traditional uses, phytochemistry, documented biological properties and toxicity of all the species of Artemisia and offers useful insights for practitioners and researchers into underutilized species and their potential applications. This review aims to stimulate further exploration, experimentation and collaboration to fully realize the therapeutic potential of Artemisia in augmenting human health and well-being.

Antiviral, virucidal and antioxidant properties of Artemisia annua against SARS-CoV-2

Natural products are a rich source of bioactive molecules that have potential pharmacotherapeutic applications. In this study, we focused on Artemisia annua (A. annua) and its enriched extracts which were biologically evaluated in vitro as virucidal, antiviral, and antioxidant agents, with a potential application against the COVID-19 infection. The crude extract showed virucidal, antiviral and antioxidant effects in concentrations that did not affect cell viability. Scopoletin, arteannuin B and artemisinic acid (single fractions isolated from A. annua) exerted a considerable virucidal and antiviral effect in vitro starting from a concentration of 50 µg/mL. Data from Surface Plasmon Resonance (SPR) showed that the inhibition of the viral infection was due to the interaction of these compounds with the 3CLpro and Spike proteins of SARS-CoV-2, suggesting that the main interaction of compounds may interfere with the viral pathways during the insertion and the replication process. The present study suggests that natural extract of A. annua and its components could have a key role as antioxidants and antiviral agents and support the fight against SARS-CoV-2 variants and other possible emerging Coronaviruses.

An updated review on distribution, biosynthesis and pharmacological effects of artemisinin: A wonder drug

Plant-based drugs have been used for centuries for treating different ailments. Malaria, one of the prevalent threats in many parts of the world, is treated mainly by artemisinin-based drugs derived from plants of genus Artemisia. However, the distribution of artemisinin is restricted to a few species of the genus; besides, its yield depends on ontogeny and the plant's geographical location. Here, we review the studies focusing on biosynthesis and distributional pattern of artemisinin production in species of the genus Artemisia. We also discussed various agronomic and in vitro methods and molecular approaches to increase the yield of artemisinin. We have summarized different mechanisms of artemisinin involved in its anti-malarial, anti-cancer, anti-inflammatory and anti-viral activities (like against Covid-19). Overall the current review provides a synopsis of a global view of the distribution of artemisinin, its biosynthesis, and pharmacological potential in treating various diseases like malaria, cancer, and coronavirus, which may provoke future research efforts in drug development. Nevertheless, long-term trials and molecular approaches, like CRISPR-Cas, are required for in-depth research.

Five Different Artemisia L. Species Ethanol Extracts' Phytochemical Composition and Their Antimicrobial and Nematocide Activity

Among the plants that exhibit significant or established pharmacological activity, the genus Artemisia L. deserves special attention. This genus comprises over 500 species belonging to the largest Asteraceae family. Our study aimed at providing a comprehensive evaluation of the phytochemical composition of the ethanol extracts of five different Artemisia L. species (collected from the southwest of the Russian Federation) and their antimicrobial and nematocide activity as follows: A. annua cv. Novichok., A. dracunculus cv. Smaragd, A. santonica cv. Citral, A. abrotanum cv. Euxin, and A. scoparia cv. Tavrida. The study of the ethanol extracts of the five different Artemisia L. species using the methods of gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-MS/MS) allowed establishing their phytochemical profile. The obtained data on the of five different Artemisia L. species ethanol extracts' phytochemical composition were used to predict the antibacterial and antifungal activity against phytopathogenic microorganisms and nematocidal activity against the free-living soil nematode Caenorhabditis elegans. The major compounds found in the composition of the Artemisia L. ethanol extracts were monoterpenes, sesquiterpenes, flavonoids, flavonoid glycosides, coumarins, and phenolic acids. The antibacterial and antifungal activity of the extracts began to manifest at a concentration of 150 µg/mL. The A. dracunculus cv. Smaragd extract had a selective effect against Gram-positive R. iranicus and B. subtilis bacteria, whereas the A. scoparia cv. Tavrida extract had a selective effect against Gram-negative A. tumefaciens and X. arboricola bacteria and A. solani, R. solani and F. graminearum fungi. The A. annua cv. Novichok, A. dracunculus cv. Smaragd, and A. santonica cv. Citral extracts in the concentration range of 31.3-1000 µg/mL caused the death of nematodes. It was established that A. annua cv. Novichok affects the UNC-63 protein, the molecular target of which is the nicotine receptor of the N-subtype.

Effects of Artemisia annua L. Water Extract on Growth Performance and Intestinal Related Indicators in Broilers

Artemisia annua L. is a natural herb with a variety of bioactive substances, which can play a variety of biological functions such as anti-inflammatory, antioxidant, antibacterial and antiviral, and can be used as a potential feed additive. The purpose of this study was to investigate the effects of different doses of Artemisia annua L. water extract (AAWE) on growth performance and intestinal related indicators in broilers. A total of 200 one-day-old Arbor Acre broilers were selected and randomly divided into five treatment groups, with five replicates in each group and eight birds per replicate. The control group was fed a basal diet, whereas the other groups were fed a basal diet supplemented with 0.5, 1.0, 1.5, or 2.0 g/kg AAWE. On d 21, with the increase in AAWE dose, final body weight and feed efficiency showed a quadratic increase effect, whereas feed intake showed a linear reduction effect; however, the apparent metabolic rate of dry matter, crude protein, and ether extract increased quadratically on d 42. In addition, the activity of duodenal chymotrypsin and trypsin, and of jejunal lipase quadratically increased, whereas the intestine crypt depth linearly decreased on d 42. The number of total anaerobic bacteria increased quadratically, whereas the number of Escherichia coli decreased quadratically. The number of Lactobacillus increased linearly, whereas H2S emission linearly decreased on d 21; moreover, NH3 emission (24 h) quadratically decreased on d 42. In conclusion, AAWE promoted the growth performance and intestinal related indicators of broilers.

Anti-SARS-CoV-2 Agents in Artemisia Endophytic Fungi and Their Abundance in Artemisia vulgaris Tissue

Coronavirus disease 2019 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therapeutic agents for the disease are being developed. Endophytes are diverse and produce various secondary metabolites and bioactive substances. We isolated 13 endophytes from the leaves and stems of Artemisia vulgaris. Antiviral testing using the culture extracts of these endophytic fungi revealed that five isolates effectively inhibited the replication of SARS-CoV-2. These extracts were used to study the inhibitory effect of SARS-CoV-2 on 3C-like protease, and two isolates proved useful. Both isolates were from the genus Colletotrichum; therefore, the percentage of Artemisia endophytic fungi in the plant tissue was observed to be an important factor in plant site selection. Thus, we conducted a macroanalysis using next-generation sequencing to analyze the percentage of endophytes in the stems (whole, skin, and inner), leaves, roots, and cultivating soil, as well as to determine the location of each genus. To the best of our knowledge, this study is the first to report that Colletotrichum spp. are abundant in stems and that stem-based methods are the most efficient for isolating endophytes targeting Colletotrichum spp.

Inhibition of Cysteine Proteases via Thiol-Michael Addition Explains the Anti-SARS-CoV-2 and Bioactive Properties of Arteannuin B

Artemisia annua is the plant that produces artemisinin, an endoperoxide-containing sesquiterpenoid used for the treatment of malaria. A. annua extracts, which contain other bioactive compounds, have been used to treat other diseases, including cancer and COVID-19, the disease caused by the virus SARS-CoV-2. In this study, a methyl ester derivative of arteannuin B was isolated when A. annua leaves were extracted with a 1:1 mixture of methanol and dichloromethane. This methyl ester was thought to be formed from the reaction between arteannuin B and the extracting solvent, which was supported by the fact that arteannuin B underwent 1,2-addition when it was dissolved in deuteromethanol. In contrast, in the presence of N-acetylcysteine methyl ester, a 1,4-addition (thiol-Michael reaction) occurred. Arteannuin B hindered the activity of the SARS CoV-2 main protease (nonstructural protein 5, NSP5), a cysteine protease, through time-dependent inhibition. The active site cysteine residue of NSP5 (cysteine-145) formed a covalent bond with arteannuin B as determined by mass spectrometry. In order to determine whether cysteine adduction by arteannuin B can inhibit the development of cancer cells, similar experiments were performed with caspase-8, the cysteine protease enzyme overexpressed in glioblastoma. Time-dependent inhibition and cysteine adduction assays suggested arteannuin B inhibits caspase-8 and adducts to the active site cysteine residue (cysteine-360), respectively. Overall, these results enhance our understanding of how A. annua possesses antiviral and cytotoxic activities.

Artemisinin as a therapeutic vs. its more complex Artemisia source material

Covering: up to 2017-2022Many small molecule drugs are first discovered in nature, commonly the result of long ethnopharmacological use by people, and then characterized and purified from their biological sources. Traditional medicines are often more sustainable, but issues related to source consistency and efficacy present challenges. Modern medicine has focused solely on purified molecules, but evidence is mounting to support some of the more traditional uses of medicinal biologics. When is a more traditional delivery of a therapeutic appropriate and warranted? What studies are required to establish validity of a traditional medicine approach? Artemisia annua and A. afra are two related but unique medicinal plant species with long histories of ethnopharmacological use. A. annua produces the sesquiterpene lactone antimalarial drug, artemisinin, while A. afra produces at most, trace amounts of the compound. Both species also have an increasing repertoire of modern scientific and pharmacological data that make them ideal candidates for a case study. Here accumulated recent data on A. annua and A. afra are reviewed as a basis for establishing a decision tree for querying their therapeutic use, as well as that of other medicinal plant species.

An Estimation of the Antiviral Activity and Toxicity of Biologically Active Substances Obtained from the Raw Materials of Artemisia cina Berg. In Vitro and In Vivo

Species of the genus Artemisia are well known for their use as ingredients in ancient medicine. The advantage of using plant extracts compared to individual pharmaceutical ingredients is the rate of adaptation of the pathogenic microorganisms to the drug. Due to the rapid development of multidrug-resistance in microorganisms in the field, it is essential to search for novel, effective drugs with low toxicity. Therefore, the purpose of this study was to isolate and study the biologically active substances obtained from various substances in the raw materials of Artemisia cina Berg. The identification of the main biologically active components was performed using the method of chromato-mass spectrometry. Moreover, the antiviral activity of several extracts was studied using the method of measuring limiting dilutions (the Reed-Mench method), with some modifications. For the first time, the biological activity of extracts from the raw material of Artemisia cina Berg. upon the SARS-CoV-2 virus was confirmed. All the obtained extracts exhibited nontoxic effects in animals, with an LD₅₀ greater than 2 g/kg. Comprehensive toxicological analyses are also presented in the study, such as those of the biochemical parameters of urine after one day and one week of the extracts' administration in mice at a dose of 2 g/kg body weight. In all groups of animals that received extracts of Artemisia cina Berg., a slight increase in the presence of red blood cells in their urine was observed one day following the administration of the extracts. This increase decreased somewhat after a week; however, it remained higher than the levels observed in the control animals. In the three groups, there was also a slight increase in the amount of ketones in the urine. Two weeks following the administration of the extracts to these groups, the internal organs of the animals were examined. The examination showed that the internal organs of the animals that received the extracts were not visibly different from those of the control animals in terms of their size or appearance. The weight of the internal organs of the animals that received the extracts was also similar to the weight of the internal organs of the control animals, illustrating the absence of toxicity.

A New Cellular Interactome of SARS-CoV-2 Nucleocapsid Protein and Its Biological Implications

There is still much to uncover regarding the molecular details of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. As the most abundant protein, coronavirus nucleocapsid (N) protein encapsidates viral RNAs, serving as the structural component of ribonucleoprotein and virion, and participates in transcription, replication, and host regulations. Virus-host interaction might give clues to better understand how the virus affects or is affected by its host during infection and identify promising therapeutic candidates. Considering the critical roles of N, we here established a new cellular interactome of SARS-CoV-2 N by using a high-specific affinity purification (S-pulldown) assay coupled with quantitative mass spectrometry and immunoblotting validations, uncovering many N-interacting host proteins unreported previously. Bioinformatics analysis revealed that these host factors are mainly involved in translation regulations, viral transcription, RNA processes, stress responses, protein folding and modification, and inflammatory/immune signaling pathways, in line with the supposed actions of N in viral infection. Existing pharmacological cellular targets and the directing drugs were then mined, generating a drug-host protein network. Accordingly, we experimentally identified several small-molecule compounds as novel inhibitors against SARS-CoV-2 replication. Furthermore, a newly identified host factor, DDX1, was verified to interact and colocalize with N mainly by binding to the N-terminal domain of the viral protein. Importantly, loss/gain/reconstitution-of-function experiments showed that DDX1 acts as a potent anti-SARS-CoV-2 host factor, inhibiting the viral replication and protein expression. The N-targeting and anti-SARS-CoV-2 abilities of DDX1 are consistently independent of its ATPase/helicase activity. Further mechanism studies revealed that DDX1 impedes multiple activities of N, including the N-N interaction, N oligomerization, and N-viral RNA binding, thus likely inhibiting viral propagation. These data provide new clues to better depiction of the N-cell interactions and SARS-CoV-2 infection and may help inform the development of new therapeutic candidates.

Potential herb‒drug interactions between anti-COVID-19 drugs and traditional Chinese medicine

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide. Effective treatments against COVID-19 remain urgently in need although vaccination significantly reduces the incidence, hospitalization, and mortality. At present, antiviral drugs including Nirmatrelvir/Ritonavir (Paxlovid^TM), Remdesivir, and Molnupiravir have been authorized to treat COVID-19 and become more globally available. On the other hand, traditional Chinese medicine (TCM) has been used for the treatment of epidemic diseases for a long history. Currently, various TCM formulae against COVID-19 such as Qingfei Paidu decoction, Xuanfei Baidu granule, Huashi Baidu granule, Jinhua Qinggan granule, Lianhua Qingwen capsule, and Xuebijing injection have been widely used in clinical practice in China, which may cause potential herb-drug interactions (HDIs) in patients under treatment with antiviral drugs and affect the efficacy and safety of medicines. However, information on potential HDIs between the above anti-COVID-19 drugs and TCM formulae is lacking, and thus this work seeks to summarize and highlight potential HDIs between antiviral drugs and TCM formulae against COVID-19, and especially pharmacokinetic HDIs mediated by metabolizing enzymes and/or transporters. These well-characterized HDIs could provide useful information on clinical concomitant medicine use to maximize clinical outcomes and minimize adverse and toxic effects.

COVID-19 Therapeutic Potential of Natural Products

Despite the fact that coronavirus disease 2019 (COVID-19) treatment and management are now considerably regulated, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still one of the leading causes of death in 2022. The availability of COVID-19 vaccines, FDA-approved antivirals, and monoclonal antibodies in low-income countries still poses an issue to be addressed. Natural products, particularly traditional Chinese medicines (TCMs) and medicinal plant extracts (or their active component), have challenged the dominance of drug repurposing and synthetic compound libraries in COVID-19 therapeutics. Their abundant resources and excellent antiviral performance make natural products a relatively cheap and readily available alternative for COVID-19 therapeutics. Here, we deliberately review the anti-SARS-CoV-2 mechanisms of the natural products, their potency (pharmacological profiles), and application strategies for COVID-19 intervention. In light of their advantages, this review is intended to acknowledge the potential of natural products as COVID-19 therapeutic candidates.

SARS-CoV-2 omicron variants are susceptible in vitro to Artemisia annua hot water extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia annua L. has >2000 yr of history in treating fever a symptom common to many infectious diseases including viruses. The plant is widely used as a tea infusion in many areas of the globe to thwart many infectious diseases.

AIM OF THE STUDY

The SARS-CoV-2 (COVID-19) virus continues to infect millions while rapidly evolving new variants that are more transmissible and evade vaccine-elicited antibodies, e.g., omicron and its subvariants. Having shown potency against all previously tested variants, A. annua L. extracts were further tested against highly infectious omicron and its recent subvariants.

MATERIALS AND METHODS

Using Vero E6 cells, we measured the in vitro efficacy (IC50) of stored (frozen) dried-leaf hot-water A. annua L. extracts of four cultivars (A3, BUR, MED, and SAM) against SARS-CoV-2 variants: original WA1 (WT), BA.1 (omicron), BA.2, BA.2.12.1, and BA.4. End point virus titers of infectivity in cv. BUR-treated human lung A459 cells overexpressing hu-ACE2 were determined for both WA1 and BA.4 viruses.

RESULTS

When normalized to the artemisinin (ART) or leaf dry weight (DW) equivalent of the extract, the IC50 values ranged from 0.5 to 16.5 μM ART and from 20 to 106 μg DW. IC50 values were within limits of assay variation of our earlier studies. End-point titers confirmed a dose-response inhibition in ACE2 overexpressing human lung cells to the BUR cultivar. Cell viability losses were not measurable at leaf dry weights ≤50 μg for any cultivar extract.

CONCLUSIONS

A. annua hot-water extracts (tea infusions) continue to show efficacy against SARS-CoV-2 and its rapidly evolving variants and deserve greater attention as a possible cost-effective therapeutic.

Phylogenomics and morphological evolution of the mega-diverse genus Artemisia (Asteraceae: Anthemideae): implications for its circumscription and infrageneric taxonomy

BACKGROUND AND AIMS

Artemisia is a mega-diverse genus consisting of ~400 species. Despite its medicinal importance and ecological significance, a well-resolved phylogeny for global Artemisia, a natural generic delimitation and infrageneric taxonomy remain missing, owing to the obstructions from limited taxon sampling and insufficient information on DNA markers. Its morphological characters, such as capitulum, life form and leaf, show marked variations and are widely used in its infrageneric taxonomy. However, their evolution within Artemisia is poorly understood. Here, we aimed to reconstruct a well-resolved phylogeny for global Artemisia via a phylogenomic approach, to infer the evolutionary patterns of its key morphological characters and to update its circumscription and infrageneric taxonomy.

METHODS

We sampled 228 species (258 samples) of Artemisia and its allies from both fresh and herbarium collections, covering all the subgenera and its main geographical areas, and conducted a phylogenomic analysis based on nuclear single nucleotide polymorphisms (SNPs) obtained from genome skimming data. Based on the phylogenetic framework, we inferred the possible evolutionary patterns of six key morphological characters widely used in its previous taxonomy.

KEY RESULTS

The genus Kaschgaria was revealed to be nested in Artemisia with strong support. A well-resolved phylogeny of Artemisia consisting of eight highly supported clades was recovered, two of which were identified for the first time. Most of the previously recognized subgenera were not supported as monophyletic. Evolutionary inferences based on the six morphological characters showed that different states of these characters originated independently more than once.

CONCLUSIONS

The circumscription of Artemisia is enlarged to include the genus Kaschgaria. The morphological characters traditionally used for the infrageneric taxonomy of Artemisia do not match the new phylogenetic tree. They experienced a more complex evolutionary history than previously thought. We propose a revised infrageneric taxonomy of the newly circumscribed Artemisia, with eight recognized subgenera to accommodate the new results.

Exploration of the Shared Molecular Mechanisms between COVID-19 and Neurodegenerative Diseases through Bioinformatic Analysis

The COVID-19 pandemic has caused millions of deaths and remains a major public health burden worldwide. Previous studies found that a large number of COVID-19 patients and survivors developed neurological symptoms and might be at high risk of neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD). We aimed to explore the shared pathways between COVID-19, AD, and PD by using bioinformatic analysis to reveal potential mechanisms, which may explain the neurological symptoms and degeneration of brain that occur in COVID-19 patients, and to provide early intervention. In this study, gene expression datasets of the frontal cortex were employed to detect common differentially expressed genes (DEGs) of COVID-19, AD, and PD. A total of 52 common DEGs were then examined using functional annotation, protein-protein interaction (PPI) construction, candidate drug identification, and regulatory network analysis. We found that the involvement of the synaptic vesicle cycle and down-regulation of synapses were shared by these three diseases, suggesting that synaptic dysfunction might contribute to the onset and progress of neurodegenerative diseases caused by COVID-19. Five hub genes and one key module were obtained from the PPI network. Moreover, 5 drugs and 42 transcription factors (TFs) were also identified on the datasets. In conclusion, the results of our study provide new insights and directions for follow-up studies of the relationship between COVID-19 and neurodegenerative diseases. The hub genes and potential drugs we identified may provide promising treatment strategies to prevent COVID-19 patients from developing these disorders.

Plants as Biofactories for Therapeutic Proteins and Antiviral Compounds to Combat COVID-19

The outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had a profound impact on the world's health and economy. Although the end of the pandemic may come in 2023, it is generally believed that the virus will not be completely eradicated. Most likely, the disease will become an endemicity. The rapid development of vaccines of different types (mRNA, subunit protein, inactivated virus, etc.) and some other antiviral drugs (Remdesivir, Olumiant, Paxlovid, etc.) has provided effectiveness in reducing COVID-19's impact worldwide. However, the circulating SARS-CoV-2 virus has been constantly mutating with the emergence of multiple variants, which makes control of COVID-19 difficult. There is still a pressing need for developing more effective antiviral drugs to fight against the disease. Plants have provided a promising production platform for both bioactive chemical compounds (small molecules) and recombinant therapeutics (big molecules). Plants naturally produce a diverse range of bioactive compounds as secondary metabolites, such as alkaloids, terpenoids/terpenes and polyphenols, which are a rich source of countless antiviral compounds. Plants can also be genetically engineered to produce valuable recombinant therapeutics. This molecular farming in plants has an unprecedented opportunity for developing vaccines, antibodies, and other biologics for pandemic diseases because of its potential advantages, such as low cost, safety, and high production volume. This review summarizes the latest advancements in plant-derived drugs used to combat COVID-19 and discusses the prospects and challenges of the plant-based production platform for antiviral agents.

Artemisia afra and Artemisia annua Extracts Have Bactericidal Activity against Mycobacterium tuberculosis in Physiologically Relevant Carbon Sources and Hypoxia

Mycobacterium tuberculosis (Mtb) is a deadly pathogen and causative agent of human tuberculosis, causing ~1.5 million deaths every year. The increasing drug resistance of this pathogen necessitates novel and improved treatment strategies. A crucial aspect of the host-pathogen interaction is bacterial nutrition. In this study, Artemisia annua and Artemisia afra dichloromethane extracts were tested for bactericidal activity against Mtb strain mc26230 under hypoxia and various infection-associated carbon sources (glycerol, glucose, and cholesterol). Both extracts showed significant bactericidal activity against Mtb, regardless of carbon source. Based on killing curves, A. afra showed the most consistent bactericidal activity against Mtb for all tested carbon sources, whereas A. annua showed the highest bactericidal activity in 7H9 minimal media with glycerol. Both extracts retained their bactericidal activity against Mtb under hypoxic conditions. Further investigations are required to determine the mechanism of action of these extracts and identify their active constituent compounds.

Comparative docking studies of drugs and phytocompounds for emerging variants of SARS-CoV-2

In the last three years, COVID-19 has impacted the world with back-to-back waves leading to devastating consequences. SARS-CoV-2, the causative agent of COVID-19, was first detected in 2019 and since then has spread to 228 countries. Even though the primary focus of research groups was diverted to fight against COVID-19, yet no dedicated drug has been developed to combat the emergent life-threatening medical conditions. In this study, 35 phytocompounds and 43 drugs were investigated for comparative docking analysis. Molecular docking and virtual screening were performed against SARS-CoV-2 spike glycoprotein of 13 variants using AutoDock Vina tool 1.5.6 and Discovery Studio, respectively, to identify the most efficient drugs. Selection of the most suitable compounds with the best binding affinity was done after screening for toxicity, ADME (absorption, distribution, metabolism and excretion) properties and drug-likeliness. The potential candidates were discovered to be Liquiritin (binding affinities ranging between -7.0 and -8.1 kcal/mol for the 13 variants) and Apigenin (binding affinities ranging between -6.8 and -7.3 kcal/mol for the 13 variants) based on their toxicity and consistent binding affinity with the Spike protein of all variants. The stability of the protein-ligand complex was determined using Molecular dynamics (MD) simulation of Apigenin with the Delta plus variant of SARS-CoV-2. Furthermore, Liquiritin and Apigenin were also found to be less toxic than the presently used drugs and showed promising results based on in silico studies, though, confirmation using in vitro studies is required. This in-depth comparative investigation suggests potential drug candidates to fight against SARS-CoV-2 variants.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03450-6.

Inhibitory activity of dry ethanol extracts of <i>Artemisia</i> spp. on SARS‐CoV‐2 replication <i>in vitro</i>

Aim. In vitro analysis of the inhibitory activity of dry ethanol extracts of some Artemisia spp. growing in the Novosibirsk region for SARS‐CoV‐2 replication.

Materials and Methods. The laboratory strain SARS‐CoV‐2/human/RUS/Nsk‐FRCFTM‐1/2020 was passed on Vero cell culture. Dry ethanol extracts of plant parts (stems, flowers, leaves) of six types of Artemisia were prepared. The types used were: A. vulgaris L.; A. glauca (Pall. Ex Willd.); A. dracunculus L. (from three growth locations); A. absinthium L.; A. frigida Willd.; and A. sieversiana Ehrh. ex Willd. Dry extracts were dissolved in DMSO. In vitro analysis of the inhibitory activity of extracts against SARS‐CoV‐2 (an infectious titer of 103 TCID50/ml) replication was performed in a Vero E6 cell culture. To do this, the method of direct inactivation (neutralization) of virions, as well as schemes of “preventive” and “therapeutic” of cells, were used. Comparison samples were dry ethanol extracts of Inonotus obliquus, Syzygium aromaticum L. and Camellia sinensis L.

Results. Extracts of leaves of Artemisia spp. proved to be most effective in direct inactivation of virions. By equal and decreasing activity these are the species: A. vulgaris; A. dracunculus*; A. absinthium; A. dracunculus***; A. dracunculus**; A. frigidа; A. glauca; and A. sieversiana with a 50% effective concentration of range 1.10±0.24 – 11.72±2.89 μg/ml. Extracts of flowers of A. vulgaris, A.glauca, A. dracunculus*, A. dracunculus**, A. dracunculus***, A. frigida and A. sieversiana also contain biologically active substances which act both destructively on virions and after the virus has entered cells. For extracts of stems consistently high values of EC50 were found for A. glauca (6.84±1.35; 7.81±2.00 and 14.06±3.06 μg/ml) according to the results of three experimental schemes.

Conclusion. The results obtained can become the basis for the development of inexpensive domestic drugs for the treatment and/or prevention of COVID‐19.

The Trimeric Artesunate Analog TF27, a Broadly Acting Anti-Infective Model Drug, Exerts Pronounced Anti-SARS-CoV-2 Activity Spanning Variants and Host Cell Types

Starting in 2019, the spread of respiratory syndrome coronavirus 2 (SARS-CoV-2) and the associated pandemic of the corona virus disease (COVID-19) has led to enormous efforts in the development of medical countermeasures. Although innovative vaccines have scaled back the number of severe COVID cases, the emergence of the omicron variant (B.1.1.529) illustrates how vaccine development struggles to keep pace with viral evolution. On the other hand, while the recently approved antiviral drugs remdesivir, molnupiravir, and Paxlovid are considered as broadly acting anti-coronavirus therapeutics, only molnupiravir and Paxlovid are orally available and none of these drugs are recommended for prophylactic use. Thus, so far unexploited small molecules, targeting strategies, and antiviral mechanisms are urgently needed to address issues in the current pandemic and in putative future outbreaks of newly emerging variants of concern. Recently, we and others have described the anti-infective potential and particularly the pronounced antiviral activity of artesunate and related compounds of the trioxane/sesquiterpene class. In particular, the trimeric derivative TF27 demonstrated strong anti-cytomegalovirus activity at nanomolar concentrations in vitro as well as in vivo efficacy after oral administration in therapeutic and even prophylactic treatment settings. Here, we extended this analysis by evaluating TF27 for its anti-SARS-CoV-2 potential. Our main findings are as follows: (i) compound TF27 exerted strong anti-SARS-CoV-2 activity in vitro (EC₅₀ = 0.46 ± 0.20 µM), (ii) antiviral activity was clearly distinct from the induction of cytotoxicity, (iii) pretreatment with TF27 prevented virus replication in cultured cells, (iv) antiviral activity has likewise been demonstrated in Calu-3 human lung and Caco-2 human colon cells infected with wild-type, delta, or omicron SARS-CoV-2, respectively, and (v) analysis of TF27 combination treatments has revealed synergistic interaction with GC376, but antagonistic interaction with EIDD-1931. Combined, the data demonstrated the pronounced anti-SARS-CoV-2 activity of TF27 and thus highlight the potential of trioxane compounds for further pharmacologic development towards improved options for COVID-specific medication.

Small molecules in the treatment of COVID-19

The outbreak of COVID-19 has become a global crisis, and brought severe disruptions to societies and economies. Until now, effective therapeutics against COVID-19 are in high demand. Along with our improved understanding of the structure, function, and pathogenic process of SARS-CoV-2, many small molecules with potential anti-COVID-19 effects have been developed. So far, several antiviral strategies were explored. Besides directly inhibition of viral proteins such as RdRp and M^pro, interference of host enzymes including ACE2 and proteases, and blocking relevant immunoregulatory pathways represented by JAK/STAT, BTK, NF-κB, and NLRP3 pathways, are regarded feasible in drug development. The development of small molecules to treat COVID-19 has been achieved by several strategies, including computer-aided lead compound design and screening, natural product discovery, drug repurposing, and combination therapy. Several small molecules representative by remdesivir and paxlovid have been proved or authorized emergency use in many countries. And many candidates have entered clinical-trial stage. Nevertheless, due to the epidemiological features and variability issues of SARS-CoV-2, it is necessary to continue exploring novel strategies against COVID-19. This review discusses the current findings in the development of small molecules for COVID-19 treatment. Moreover, their detailed mechanism of action, chemical structures, and preclinical and clinical efficacies are discussed.

Phytochemicals in the Prevention and Treatment of SARS-CoV-2-Clinical Evidence

The first case of SARS-CoV-2 infection was reported in December 2019. Due to the rapid spread of the disease and the lack of adequate therapy, the use of plants that have a long history in the treatment of viral infections has often been considered. The aim of this paper is to provide a brief review of the literature on the use of phytochemicals during the new pandemic. An extensive search of published works was performed through platforms Google Scholar, PubMed, Science Direct, Web of Science and Clinicaltrials.gov. Numerous preclinical studies on the use of phytochemicals (quercetin, curcumin, baicalin, kaempferol, resveratrol, glycyrrhizin, lycorine, colchicine) against SARS-CoV-2 have shown that these components can be effective in the prevention and treatment of this infection. Clinical research has proven that the use of black cumin and green propolis as well as quercetin has positive effects. As for other phytochemicals, in addition to preclinical testing which has already been carried out, it would be necessary to conduct clinical tests in order to assert their effectiveness. For those phytochemicals whose clinical efficacy has been proven, it would be necessary to conduct research on a larger number of patients, so that the conclusions are more representative.

A comprehensive update on CIDO: the community-based coronavirus infectious disease ontology

Background

The current COVID-19 pandemic and the previous SARS/MERS outbreaks of 2003 and 2012 have resulted in a series of major global public health crises. We argue that in the interest of developing effective and safe vaccines and drugs and to better understand coronaviruses and associated disease mechenisms it is necessary to integrate the large and exponentially growing body of heterogeneous coronavirus data. Ontologies play an important role in standard-based knowledge and data representation, integration, sharing, and analysis. Accordingly, we initiated the development of the community-based Coronavirus Infectious Disease Ontology (CIDO) in early 2020.

Results

As an Open Biomedical Ontology (OBO) library ontology, CIDO is open source and interoperable with other existing OBO ontologies. CIDO is aligned with the Basic Formal Ontology and Viral Infectious Disease Ontology. CIDO has imported terms from over 30 OBO ontologies. For example, CIDO imports all SARS-CoV-2 protein terms from the Protein Ontology, COVID-19-related phenotype terms from the Human Phenotype Ontology, and over 100 COVID-19 terms for vaccines (both authorized and in clinical trial) from the Vaccine Ontology. CIDO systematically represents variants of SARS-CoV-2 viruses and over 300 amino acid substitutions therein, along with over 300 diagnostic kits and methods. CIDO also describes hundreds of host-coronavirus protein-protein interactions (PPIs) and the drugs that target proteins in these PPIs. CIDO has been used to model COVID-19 related phenomena in areas such as epidemiology. The scope of CIDO was evaluated by visual analysis supported by a summarization network method. CIDO has been used in various applications such as term standardization, inference, natural language processing (NLP) and clinical data integration. We have applied the amino acid variant knowledge present in CIDO to analyze differences between SARS-CoV-2 Delta and Omicron variants. CIDO's integrative host-coronavirus PPIs and drug-target knowledge has also been used to support drug repurposing for COVID-19 treatment.

Conclusion

CIDO represents entities and relations in the domain of coronavirus diseases with a special focus on COVID-19. It supports shared knowledge representation, data and metadata standardization and integration, and has been used in a range of applications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13326-022-00279-z.

Antiviral activity of medicinal plant-derived products against SARS-CoV-2

This review presents information from several studies that have demonstrated the antiviral activity of extracts (Andrographis paniculata, Artemisia annua, Artemisia afra, Cannabis sativa, Curcuma longa, Echinacea purpurea, Olea europaea, Piper nigrum, and Punica granatum) and phytocompounds derived from medicinal plants (artemisinins, glycyrrhizin, and phenolic compounds) against SARS-CoV-2. A brief background of the plant products studied, the methodology used to evaluate the antiviral activity, the main findings from the research, and the possible mechanisms of action are presented. These plant products have been shown to impede the adsorption of SARS-CoV-2 to the host cell, and prevent multiplication of the virus post its entry into the host cell. In addition to antiviral activity, the plant products have also been demonstrated to exert an immunomodulatory effect by controlling the excessive release of cytokines, which is commonly associated with SARS-CoV-2 infections.

Pharmacological Potential of Flavonoids against Neurotropic Viruses

Flavonoids are a group of natural compounds that have been described in the literature as having anti-inflammatory, antioxidant, and neuroprotective compounds. Although they are considered versatile molecules, little has been discussed about their antiviral activities for neurotropic viruses. Hence, the present study aimed to investigate the pharmacological potential of flavonoids in the face of viruses that can affect the central nervous system (CNS). We carried out research from 2011 to 2021 using the Pubmed platform. The following were excluded: articles not in the English language, letters to editors, review articles and papers that did not include any experimental or clinical tests, and papers that showed antiviral activities against viruses that do not infect human beings. The inclusion criteria were in silico predictions and preclinical pharmacological studies, in vitro, in vivo and ex vivo, and clinical studies with flavonoids, flavonoid fractions and extracts that were active against neurotropic viruses. The search resulted in 205 articles that were sorted per virus type and discussed, considering the most cited antiviral activities. Our investigation shows the latest relevant data about flavonoids that have presented a wide range of actions against viruses that affect the CNS, mainly influenza, hepatitis C and others, such as the coronavirus, enterovirus, and arbovirus. Considering that these molecules present well-known anti-inflammatory and neuroprotective activities, using flavonoids that have demonstrated both neuroprotective and antiviral effects could be viewed as an alternative for therapy in the course of CNS infections.

In Silico Evaluation of Sesquiterpenes and Benzoxazinoids Phytotoxins against Mpro, RNA Replicase and Spike Protein of SARS-CoV-2 by Molecular Dynamics. Inspired by Nature

In the work described here, a number of sesquiterpenes and benzoxazinoids from natural sources, along with their easily accessible derivatives, were evaluated against the main protease, RNA replicase and spike glycoprotein of SARS-CoV-2 by molecular docking. These natural products and their derivatives have previously shown remarkable antiviral activities. The most relevant compounds were the 4-fluoro derivatives of santamarine, reynosin and 2-amino-3H-phenoxazin-3-one in terms of the docking score. Those compounds fulfill the Lipinski’s rule, so they were selected for the analysis by molecular dynamics, and the kinetic stabilities of the complexes were assessed. The addition of the 4-fluorobenzoate fragment to the natural products enhances their potential against all of the proteins tested, and the complex stability after 50 ns validates the inhibition calculated. The derivatives prepared from reynosin and 2-amino-3H-phenoxazin-3-one are able to generate more hydrogen bonds with the M^pro, thus enhancing the stability of the protein–ligand and generating a long-term complex for inhibition. The 4-fluoro derivate of santamarine and reynosin shows to be really active against the spike protein, with the RMSD site fluctuation lower than 1.5 Å. Stabilization is mainly achieved by the hydrogen-bond interactions, and the stabilization is improved by the 4-fluorobenzoate fragment being added. Those compounds tested in silico reach as candidates from natural sources to fight this virus, and the results concluded that the addition of the 4-fluorobenzoate fragment to the natural products enhances their inhibition potential against the main protease, RNA replicase and spike protein of SARS-CoV-2.

Traditional Use, Phytochemical Profiles and Pharmacological Properties of Artemisia Genus from Central Asia

The flora of Kazakhstan is characterized by its wide variety of different types of medicinal plants, many of which can be used on an industrial scale. The Traditional Kazakh Medicine (TKM) was developed during centuries based on the six elements of ancient Kazakh theory, associating different fields such as pharmacology, anatomy, pathology, immunology and food nursing as well as disease prevention. The endemic Artemisia L. species are potential sources of unique and new natural products and new chemical structures, displaying diverse bioactivities and leading to the development of safe and effective phytomedicines against prevailing diseases in Kazakhstan and the Central Asia region. This review provides an overview of Artemisia species from Central Asia, particularly traditional uses in folk medicine and the recent numerous phytochemical and pharmacological studies. The review is done by the methods of literature searches in well-known scientific websites (Scifinder and Pubmed) and data collection in university libraries. Furthermore, our aim is to search for promising and potentially active Artemisia species candidates, encouraging us to analyze Protein Tyrosine Phosphatase 1B (PTP1B), α-glucosidase and bacterial neuraminidase (BNA) inhibition as well as the antioxidant potentials of Artemisia plant extracts, in which endemic species have not been explored for their secondary metabolites and biological activities so far. The main result of the study was that, for the first time, the species Artemisia scopiformis Ledeb. Artemisia albicerata Krasch., Artemisia transiliensis Poljakov, Artemisia schrenkiana Ledeb., Artemisia nitrosa Weber and Artemisia albida Willd. ex Ledeb. due to their special metabolites, showed a high potential for α-glucosidase, PTP1B and BNA inhibition, which is associated with diabetes, obesity and bacterial infections. In addition, we revealed that the methanol extracts of Artemisia were a potent source of polyphenolic compounds. The total polyphenolic contents of Artemisia extracts were correlated with antioxidant potential and varied according to plant origin, the solvent of extraction and the analytical method used. Consequently, oxidative stress caused by reactive oxygen species (ROS) may be managed by the dietary intake of current Artemisia species. The antioxidant potentials of the species A. schrenkiana, A. scopaeformis, A. transiliensis and Artemisia scoparia Waldst. & Kitam. were also promising. In conclusion, the examination of details between different Artemisia species in our research has shown that plant materials are good as an antioxidant and eznyme inhibitory functional natural source.

Friend or Foe? Implication of the autophagy-lysosome pathway in SARS-CoV-2 infection and COVID-19

There is increasing amount of evidence indicating the close interplays between the replication cycle of SARS-CoV-2 and the autophagy-lysosome pathway in the host cells. While autophagy machinery is known to either assist or inhibit the viral replication process, the reciprocal effects of the SARS-CoV-2 on the autophagy-lysosome pathway have also been increasingly appreciated. More importantly, despite the disappointing results from the clinical trials of chloroquine and hydroxychloroquine in treatment of COVID-19, there is still ongoing effort in discovering new therapeutics targeting the autophagy-lysosome pathway. In this review, we provide an update-to-date summary of the interplays between the autophagy-lysosome pathway in the host cells and the pathogen SARS-CoV-2 at the molecular level, to highlight the prognostic value of autophagy markers in COVID-19 patients and to discuss the potential of developing novel therapeutic strategies for COVID-19 by targeting the autophagy-lysosome pathway. Thus, understanding the nature of such interactions between SARS-CoV-2 and the autophagy-lysosome pathway in the host cells is expected to provide novel strategies in battling against this global pandemic.

SARS-CoV-2 omicron variants succumb in vitro to Artemisia annua hot water extracts

The SARS-CoV-2 (COVID-19) global pandemic continuous to infect and kill millions while rapidly evolving new variants that are more transmissible and evading vaccine-elicited antibodies. Artemisia annua L. extracts have shown potency against all previously tested variants. Here we further queried extract efficacy against omicron and its recent subvariants. Using Vero E6 cells, we measured the in vitro efficacy (IC 50 ) of stored (frozen) dried-leaf hot-water A. annua L. extracts of four cultivars (A3, BUR, MED, and SAM) against SARS-CoV-2 variants: original WA1 (WT), BA.1.1.529+R346K (omicron), BA.2, BA.2.12.1, and BA.4. IC 50 values normalized to the extract artemisinin (ART) content ranged from 0.5-16.5 µM ART. When normalized to dry mass of the extracted A. annua leaves, values ranged from 20-106 µg. Although IC 50 values for these new variants are slightly higher than those reported for previously tested variants, they were within limits of assay variation. There was no measurable loss of cell viability at leaf dry weights ≤50 µg of any cultivar extract. Results continue to indicate that oral consumption of A. annua hot-water extracts (tea infusions) could potentially provide a cost-effective approach to help stave off this pandemic virus and its rapidly evolving variants.

Anti-Coronavirus Efficiency and Redox-Modulating Capacity of Polyphenol-Rich Extracts from Traditional Bulgarian Medicinal Plants

Background: The use of various herbal therapists as part of traditional medicine in different parts of the world, including Bulgaria, is due to the knowledge accumulated over the centuries by people about their valuable biological activities. In this study, we investigate extracts from widely used Bulgarian medicinal plants for their ability to prevent the coronavirus infection of cells by testing different mechanisms of antiviral protection, their polyphenol content, and redox-modulating capacity. Methods: The influence on the stage of viral adsorption, the inhibition of extracellular virions, and the protective effect on uninfected cells of the plant’s extracts were reported by the end-point dilution method, and virus titer (in Δ lgs) was determined as compared to the untreated controls. The total content of polyphenols and flavonoids was also determined. We tested the antioxidant power of the extracts by their ability to inhibit the generation of superoxide anionic radicals and to scavenge DPPH radicals. We determined their iron-reducing, copper-reducing, and metal-chelating antioxidant powers. Results: Most of the extracts tested suppress the extracellular virions of HCov. They also inhibit the stage of viral adsorption to the host cell to varying degrees and have a protective effect on healthy cells before being subjected to viral invasion. The examined extracts contained significant levels of polyphenols and quercetin-like flavonoids and showed remarkable antioxidant, radical, and redox-modulating effects. Conclusions: All of these 13 extracts from Bulgarian medicinal plants tested can act as antioxidants and antiviral and symptomatic drugs for the management of coronavirus infection.

Re-Du-Ning injection ameliorates radiation-induced pneumonitis and fibrosis by inhibiting AIM2 inflammasome and epithelial-mesenchymal transition

BACKGROUND

Radiation-induced lung injury (RILI) is a common side effect in chest radiotherapy patients, and there is no good medicine to treat it. Re-Du-Ning (RDN) injection is a traditional Chinese medicine that is clinically used to treat upper respiratory tract infections and acute bronchitis. RDN has the advantage of high safety and mild side effects. The mechanism of most traditional Chinese medicine preparations is unknown.

PURPOSE

To illustrate the mechanisms of RDN for the treatment of RILI.

METHODS

Female C57BL/6 mice were used to establish a RILI model via irradiation, and RDN injection was intraperitoneally administered at doses of 5, 10, and 20 ml/kg. The cytokines were measured by ELISA and qPCR. The data related to Absent in melanoma 2 (AIM2) inflammasome were analyzed via ELISA and a network pharmacological approach. In addition, the data related to epithelial-mesenchymal transition (EMT) were analyzed via immunofluorescence, Western blotting, and a network pharmacological approach.

RESULTS

RDN robustly alleviated RILI. Meanwhile, RDN downregulated inflammatory cells' infiltration and the expression of pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α. Next, the potential molecular mechanisms of RDN were predicted through network pharmacology analysis. RDN may ameliorate radiation pneumonitis (RP) by inhibiting AIM2-mediated pyroptosis. Moreover, RDN treatment inhibited EMT and phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) pathway. The active compounds from Lonicera japonica Thunb. decreased the phosphorylation of Akt.

CONCLUSION

These findings demonstrate that RDN, as a traditional Chinese medicine preparation, will be a candidate drug for treating RILI.

Use of Tox21 Screening Data to Evaluate the COVID-19 Drug Candidates for Their Potential Toxic Effects and Related Pathways

Currently, various potential therapeutic agents for coronavirus disease-2019 (COVID-19), a global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are being investigated worldwide mainly through the drug repurposing approach. Several anti-viral, anti-bacterial, anti-malarial, and anti-inflammatory drugs were employed in randomized trials and observational studies for developing new therapeutics for COVID-19. Although an increasing number of repurposed drugs have shown anti-SARS-CoV-2 activities in vitro, so far only remdesivir has been approved by the US FDA to treat COVID-19, and several other drugs approved for Emergency Use Authorization, including sotrovimab, tocilizumab, baricitinib, paxlovid, molnupiravir, and other potential strategies to develop safe and effective therapeutics for SARS-CoV-2 infection are still underway. Many drugs employed as anti-viral may exert unwanted side effects (i.e., toxicity) via unknown mechanisms. To quickly assess these drugs for their potential toxicological effects and mechanisms, we used the Tox21 in vitro assay datasets generated from screening ∼10,000 compounds consisting of approved drugs and environmental chemicals against multiple cellular targets and pathways. Here we summarize the toxicological profiles of small molecule drugs that are currently under clinical trials for the treatment of COVID-19 based on their in vitro activities against various targets and cellular signaling pathways.

Bulgarian Medicinal Extracts as Natural Inhibitors with Antiviral and Antibacterial Activity

Background: Bulgaria is a country with a wide range of medicinal plants, with uses in traditional medicine dating back for centuries. Methods: Disc diffusion assay was used to evaluate the antimicrobial activity of the plant extracts. A cytopathic effect inhibition test was used for the assessment of the antiviral activity of the extracts. The virucidal activity of the extracts, their influence on the stage of viral adsorption, and their protective effect on uninfected cells were reported using the end-point dilution method, and Δlgs was determined as compared to the untreated controls. Results: The results of the study reveal that the antibacterial potential of G. glabra and H. perforatum extracts in Gram-positive bacteria is more effective than in Gram-negative bacteria. When applied during the replication of HSV-1 and HCov-OC-43, only some of the extracts showed weak activity, with SI between 2 to 8.5. Almost all tested extracts inhibited the extracellular virions of the studied enveloped viruses (HSV-1 and HCov-OC-43) to a greater extent than of the non-enveloped viruses (PV-1 and HAdV-5). They inhibited the stage of viral adsorption (HSV-1) in the host cell (MDBK) to varying degrees and showed a protective effect on healthy cells (MDBK) before they were subjected to viral invasion (HSV-1). Conclusion: The antipathogenic potential of extracts of H. perforatum and G. glabra suggests their effectiveness as antimicrobial agents. All 13 extracts of the Bulgarian medicinal plants studied can be used to reduce viral yield in a wide range of viral infections.

Artemisia Extracts and Artemisinin-Based Antimalarials for COVID-19 Management: Could These Be Effective Antivirals for COVID-19 Treatment?

As the world desperately searches for ways to treat the coronavirus disease 2019 (COVID-19) pandemic, a growing number of people are turning to herbal remedies. The Artemisia species, such as A. annua and A. afra, in particular, exhibit positive effects against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and COVID-19 related symptoms. A. annua is a source of artemisinin, which is active against malaria, and also exhibits potential for other diseases. This has increased interest in artemisinin's potential for drug repurposing. Artemisinin-based combination therapies, so-called ACTs, have already been recognized as first-line treatments against malaria. Artemisia extract, as well as ACTs, have demonstrated inhibition of SARS-CoV-2. Artemisinin and its derivatives have also shown anti-inflammatory effects, including inhibition of interleukin-6 (IL-6) that plays a key role in the development of severe COVID-19. There is now sufficient evidence in the literature to suggest the effectiveness of Artemisia, its constituents and/or artemisinin derivatives, to fight against the SARS-CoV-2 infection by inhibiting its invasion, and replication, as well as reducing oxidative stress and inflammation, and mitigating lung damage.

Structural Characterization and In-Vitro Antioxidant and Immunomodulatory Activities of Polysaccharide Fractions Isolated from Artemisia annua L

Arimisia annua L. is an important anticancer herb used in traditional Chinese medicine. The molecular basis underpinning the anticancer activity is complex and not fully understood, but the herbal polysaccharides, broadly recognised as having immunomodulatory, antioxidant and anticancer activities, are potential key active agents. To examine the functions of polysaccharides from A. annua, their immunomodulatory and antioxidant potentials were evaluated, as well as their structural characterization. The water-soluble polysaccharides (AAPs) were fractionated using size-exclusion chromatography to obtain three dominant fractions, AAP-1, AAP-2 and AAP-3, having molecular masses centered around 1684, 455 and 5.8kDa, respectively. The antioxidant potentials of the isolated polysaccharides were evaluated by measuring radical scavenging activities against DPPH● (2,2-diphenyl-1-picrylhydrazyl radical), ABTS●+ (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid radical ion), and the OH● (hydroxyl radical). AAP-1 displayed high antioxidant activities against these radicals, which were 68%, 73% and 78%, respectively. AAP-2 displayed lower scavenging activities than the other two fractions. Immunostimulatory activities of AAPs were measured using mouse macrophages. The three polysaccharide fractions displayed significant antioxidant activities and stimulated the production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). AAP-1 showed significant immunostimulatory activity (16-fold increase in the production of IL-6 compared to the control and 13-fold increase in the production of TNF-α) with low toxicity (>60% cell viability at 125 μg/mL concentration). Preliminary structural characterization of the AAPs was carried out using gas chromatography (GC) and FTIR techniques. The results indicate that AAP-1 and AAP-2 are pyranose-containing polysaccharides with β-linkages, and AAP-3 is a β-fructofuranoside. The results suggest that these polysaccharides are potential candidates for immunotherapy and cancer treatment.

In Vitro Antifungal Antibacterial Activity of Partitions from Euphorbia tirucalli L

We determined the antifungal and antimicrobial sensitivity of Euphorbia tirucalli extracts in vitro. Antifungal and antibacterial activity was determined based on the M38-A and M26-A protocols, respectively. The methanolic and ethanolic partitions demonstrated antidermatophytic activity against Trichophyton rubrum (MIC 125 µg/mL for ethanol and MIC 125 µg/mL for methanol) and T. interdigitalis (MIC 500 µg/mL for ethanol; 125 µg/mL for methanol). These partitions also showed antibacterial activity—the ethanolic partition had an MIC of 1.56 ± 0.02 mg/mL against methicillin-resistant Staphylococcus aureus (clinical isolate), 6.25 ± 0.04 mg/mL against Staphylococcus aureus BAA-44, 3.13 ± 0.13 mg/mL against Pseudomonas aeruginosa 27853, and 3.13 ± 0.15 mg/mL against Escherichia coli ATCC 25922; the methanolic partition showed an MIC of 1.56 ± 0.02 mg/mL against P. aeruginosa 27853 and 1.56 ± 0.043 mg/mL against E. coli ATCC 25922. These partitions show promise as antimicrobial agents or adjuvants in the treatment of infections caused by these microorganisms.

Bioprospecting for Anti-COVID-19 Interventions From African Medicinal Plants: A Review

The emergence of the novel coronavirus (SARS-CoV-2) that emanated from Wuhan in China in 2019 has become a global concern. The current situation warrants ethnomedicinal drug discovery and development for delivery of phytomedicines with potential for the treatment of COVID-19. The aim of this review is to provide a detailed evaluation of available information on plant species used in African traditional medicines with antiviral, anti-inflammatory, immunomodulatory, and COVID-19 symptoms relieving effects. Literature from scientific databases such as Scopus, PubMed, Google scholar, African Journals OnLine (AJOL), Science Direct, and Web of Science were used for this review. A total of 35 of the 38 reviewed plants demonstrated a wide range of antiviral activities. Bryophyllum pinnatum, Aframomum melegueta, Garcinia kola, Sphenocentrum jollyanum, Adansonia digitata, Sutherlandia frutescens, Hibiscus sabdariffa, Moringa oleifera, and Nigella sativa possess a combination of antiviral, immunomodulatory, anti-inflammatory, and COVID-19 symptoms relieving activities. Nine, 13, and 10 of the plants representing 23.7%, 34.2%, and 26.3% of the plants studied had antiviral activity with 3 other activities, antiviral activity with 2 other activities, and antiviral with one pharmacological activity alone, respectively. The plants studied were reported to be relatively safe at the subchronic toxicity level, except for 2. The study provides baseline information on the pharmacological activities, toxicity, and chemical components of 9 African medicinal plants with antiviral, immunomodulatory, anti-inflammatory, and symptoms relieving activities, thereby making the plants candidates for further investigation for effectiveness against COVID-19.

Exogenous Strigolactone (GR24) Positively Regulates Growth, Photosynthesis, and Improves Glandular Trichome Attributes for Enhanced Artemisinin Production in Artemisia annua

Artemisia annua is a medicinal plant particularly known for the production of a sesquiterpene lactone artemisinin; a specialty metabolite known for its efficacy in the treatment of malaria by killing different strains of Plasmodium falciparum due to radicals released upon the cleavage of its endoperoxide motif. Considering these facts and the immense medicinal value of artemisinin, the enhancement of in planta production of artemisinin is highly desirable. As strigolactones are known to regulate various aspects of plant growth and development, the effects of foliar spray of different concentrations of synthetic strigolactone analog GR24 (0, 0.5, 1, 2, 4, and 8 µM) on A. annua were studied. As compared to the control group, the foliar application of GR24 had a positive impact on general growth, photosynthesis, and other physiological indices with 4 µM GR24 showing the best results. The results indicate that GR24 application increased the plant biomass and various attributes related to photosynthesis, like total chlorophyll content, chlorophyll fluorescence, stomatal conductance, internal CO2, and net photosynthetic rate. Moreover, the activity of various enzymes related to photosynthesis like carbonic anhydrase, nitrate reductase, and RuBisCO was escalated. The GR24 also improved certain attributes related to glandular trichomes, with a significant enhancement in content and yield of artemisinin as compared to untreated plants.

Can anti-parasitic drugs help control COVID-19?

Novel COVID-19 is a public health emergency that poses a serious threat to people worldwide. Given the virus spreading so quickly, novel antiviral medications are desperately needed. Repurposing existing drugs is the first strategy. Anti-parasitic drugs were among the first to be considered as a potential treatment option for this disease. Even though many papers have discussed the efficacy of various anti-parasitic drugs in treating COVID-19 separately, so far, no single study comprehensively discussed these drugs. This study reviews some anti-parasitic recommended drugs to treat COVID-19, in terms of function and in vitro as well as clinical results. Finally, we briefly review the advanced techniques, such as artificial intelligence, that have been used to find effective drugs for the treatment of COVID-19.

Potential Emergence of Plasmodium Resistance to Artemisinin Induced by the Use of Artemisia annua for Malaria and COVID-19 Prevention in Sub-African Region

Plasmodium resistance to antimalarial drugs is an obstacle to the elimination of malaria in endemic areas. This situation is particularly dramatic for Africa, which accounts for nearly 92% of malaria cases worldwide. Drug pressure has been identified as a key factor in the emergence of antimalarial drug resistance. Indeed, this pressure is favoured by several factors, including the use of counterfeit forms of antimalarials, inadequate prescription controls, poor adherence to treatment regimens, dosing errors, and the increasing use of other forms of unapproved antimalarials. This resistance has led to the replacement of chloroquine (CQ) by artemisinin-based combination therapies (ACTs) which are likely to become ineffective in the coming years due to the uncontrolled use of Artemisia annua in the sub-Saharan African region for malaria prevention and COVID-19. The use of Artemisia annua for the prevention of malaria and COVID-19 could be an important factor in the emergence of resistance to Artemisinin-based combination therapies.

Instant determination of the artemisinin from various Artemisia annua L. extracts by LC-ESI-MS/MS and their in-silico modelling and in vitro antiviral activity studies against SARS-CoV-2

INTRODUCTION

Numerous efforts in natural product drug development are reported for the treatment of Coronavirus. Based on the literature, among these natural plants Artemisia annua L. shows some promise for the treatment of SARS-CoV-2.

OBJECTIVE

The main objective of our study was to determine artemisinin content by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS), to investigate the in vitro biological activity of artemisinin from the A. annua plants grown in Turkey with various extracted methods, to elaborate in silico activity against SARS-CoV-2 using molecular modelling.

METHODOLOGY

Twenty-one different extractions were applied. Direct and sequential extractions studies were compared with ultrasonic assisted maceration, Soxhlet, and ultra-rapid determined artemisinin active molecules by LC-ESI-MS/MS methods. The inhibition of spike protein and main protease (3CL) enzyme activity of SARS-CoV-2 virus was assessed by time resolved fluorescence energy transfer (TR-FRET) assay.

RESULTS

Artemisinin content in the range 0.062-0.066%. Artemisinin showed significant inhibition of 3CL protease activity but not Spike/ACE-2 binding. The 50% effective concentration (EC₅₀ ) of artemisinin against SARS-CoV-2 Spike pseudovirus was found greater than 50 μM (EC₄₅ ) in HEK293T cell line whereas the cell viability was 94% of the control (P < 0.01). The immunosuppressive effects of artemisinin on TNF-α production on both pseudovirus and lipopolysaccharide (LPS)-induced THP-1 cells were found significant in a dose dependent manner.

CONCLUSION

Further studies of these extracts for COVID-19 treatment will shed light to seek alternative treatment options. Moreover, these natural extracts can be used as an additional treatment option with medicines, as well as prophylactic use can be very beneficial for patients.

The Analogs of Furanyl Methylidene Rhodanine Exhibit Broad-Spectrum Inhibitory and Inactivating Activities against Enveloped Viruses, including SARS-CoV-2 and Its Variants

In recent years, infectious diseases caused by viral infections have seriously endangered human health, especially COVID-19, caused by SARS-CoV-2, which continues to spread worldwide. The development of broad-spectrum antiviral inhibitors is urgently needed. Here, we report a series of small-molecule compounds that proved effective against human coronaviruses (HCoV), such as SARS-CoV-2 and its variants of concern (VOCs), including Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.1.529), SARS-CoV, MERS-CoV, HCoV-OC43, and other viruses with class I viral fusion proteins, such as influenza virus, Ebola virus (EBOV), Nipah virus (NiV), and Lassa fever virus (LASV). They are also effective against class II enveloped viruses represented by ZIKV and class III enveloped viruses represented by vesicular stomatitis virus (VSV). Further studies have shown that these compounds may exert antiviral effects through a variety of mechanisms, including inhibiting the formation of the six-helix bundle, which is a typical feature of enveloped virus fusion with cell membranes, and/or targeting viral membrane to inactivate cell-free virions. These compounds are expected to become drug candidates against SARS-CoV-2 and other enveloped viruses.

Analytical Methods for the Determination of Major Drugs Used for the Treatment of COVID-19. A Review

At the beginning of the COVID-19 outbreak (end 2019 - 2020), therapeutic treatments based on approved drugs have been the fastest approaches to combat the new coronavirus pandemic. Nowadays several vaccines are available. However, the worldwide vaccination program is going to take a long time and its success will depend on the vaccine public's acceptance. Therefore, outside of vaccination, the repurposing of existing antiviral, anti-inflammatory and other types of drugs, have been considered an alternative medical strategy for the COVI-19 infection. Due to the broad clinical potential of the drugs, but also to their possible side effects, analytical methods are needed to monitor the drug concentrations in biological fluids and pharmaceutical products. This review deals with analytical methods developed in the period 2015 - July 2021 to detect potential drugs that, according to a literature survey, have been taken into consideration for the treatment of COVID-19. The drugs considered here have been selected on the basis of the number of articles published in the period January 2020-July 2021, using the combination of the keywords: COVID-19 and drugs or SARS-CoV-2 and drugs. A section is also devoted to monoclonal antibodies. Over the period considered, the analytical methods have been employed in a variety of real samples, such as body fluids (plasma, blood and urine), pharmaceutical products, environmental matrices and food.

Artemisia annua L. hot-water extracts show potent activity in vitro against Covid-19 variants including delta

ETHNOPHARMACOLOGICAL RELEVANCE

For millennia, Artemisia annua L. was used in Southeast Asia to treat "fever". This medicinal plant is effective against multiple pathogens and is used by many global communities as a source of artemisinin derivatives that are first-line drugs to treat malaria caused by Plasmodium parasites.

AIM OF THE STUDY

The SARS-CoV-2 (Covid-19) global pandemic has killed millions and evolved numerous variants, with delta being the most transmissible to date and causing break-through infections of vaccinated individuals. We further queried the efficacy of A. annua cultivars against new variants.

MATERIALS AND METHODS

Using Vero E6 cells, we measured anti-SARS-CoV-2 activity of dried-leaf hot-water A. annua L. extracts of four cultivars, A3, BUR, MED, and SAM, to determine their efficacy against five infectious variants of the virus: alpha (B.1.1.7), beta (B.1.351), gamma (P.1), delta (B.1.617.2), and kappa (B.1.617.1).

RESULTS

In addition to being effective against the original wild type (WT) WA1, A. annua cultivars A3, BUR, MED, and SAM were also potent against all five variants. IC50 and IC90 values based on measured artemisinin content ranged from 0.3 to 8.4 μM and 1.4-25.0 μM, respectively. The IC50 and IC90 values based on dried leaf weight (DW) used to make the tea infusions ranged from 11.0 to 67.7 μg DW and 59.5-160.6 μg DW, respectively. Cell toxicity was insignificant at a leaf dry weight of ≤50 μg in the extract of any cultivar.

CONCLUSIONS

Results suggest that oral consumption of A. annua hot-water extracts (tea infusions) could potentially provide a cost-effective therapy to help stave off the rapid global spread of these variants, buying time for broader implementation of vaccines.

Therapeutics for COVID-19 and post COVID-19 complications: An update

Since its inception in late December 2020 in China, novel coronavirus has affected the global socio-economic aspect. Currently, the world is seeking safe and effective treatment measures against COVID-19 to eradicate it. Many established drug molecules are tested against SARS-CoV-2 as a part of drug repurposing where some are proved effective for symptomatic relief while some are ineffective. Drug repurposing is a practical strategy for rapidly developing antiviral agents. Many drugs are presently being repurposed utilizing basic understanding of disease pathogenesis and drug pharmacodynamics, as well as computational methods. In the present situation, drug repurposing could be viewed as a new treatment option for COVID-19. Several new drug molecules and biologics are engineered against SARS-CoV-2 and are under different stages of clinical development. A few biologics drug products are approved by USFDA for emergency use in the covid management. Due to continuous mutation, many of the approved vaccines are not much efficacious to render the individual immune against opportunistic infection of SARS-CoV-2 mutants. Hence, there is a strong need for the cogent therapeutic agent for covid management. In this review, a consolidated summary of the therapeutic developments against SARS-CoV-2 are depicted along with an overview of effective management of post COVID-19 complications.

Artesunate induces substantial topological alterations in the SARS-CoV-2 Nsp1 protein structure

The need for novel antiviral treatments for coronavirus disease 2019 (COVID-19) continues with the widespread infections and fatalities throughout the world. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the deadly disease, relies on the non-structural protein Nsp1 for multiplication within the host cells and disarms the host immune defences by various mechanisms. Herein, we investigated the potential of artemisinin and its derivatives as possible inhibitors of SARS-CoV-2 Nsp1 through various computational approaches. Molecular docking results show that artemisinin (CID68827) binds to Nsp1 with a binding energy of -6.53 kcal/mol and an inhibition constant of 16.43 µM. The top 3 derivatives Artesunate (CID6917864), Artemiside (CID53323323) and Artemisone (CID11531457) show binding energies of -7.92 kcal/mol, -7.46 kcal/mol and -7.36 kcal/mol respectively. Hydrophobic interactions and hydrogen bonding with Val10, Arg11, and Gln50 helped to stabilize the protein-ligand complexes. The pharmacokinetic properties of these molecules show acceptable properties. The geometric parameters derived from large-scale MD simulation studies provided insights into the changes in the structural topology of Nsp1 upon binding of Artesunate. Thus, the findings of our research highlight the importance of artemisinin and its derivatives in the development of drugs to inhibit SARS-CoV-2 Nsp1 protein.