Potential of amentoflavone with antiviral properties in COVID-19 treatment

The potential role of Hypericum perforatum in wound healing: A literature review on the phytochemicals, pharmacological approaches, and mechanistic perspectives

St. John's Wort, commonly known as Hypericum perforatum L., is a flowering plant in the Clusiaceae family that traditionally been employed for treating anxiety, depression, wounds, burns, sunburn, irritation, and stomach ailments. This review provides a synopsis of H. perforatum L. phytoconstituents and their biological effects, highlighting its beneficial therapeutic properties for dermatological indications, as well as its antioxidant, antimicrobial, anti-inflammatory, and anti-angiogenic activity in various applications including wound healing and skin conditions such as eczema, sun burn and minor burns also spastic paralysis, stiff neck and mood disorders as anti-depressant and nerve pains such as neuralgia. The data were collected from several databases as Web of Science PubMed, ScienceDirect, Scopus and Google Scholar using the terms: "H. perforatum L.", "H. perforatum L. /phytochemistry," and "H. perforatum extracts/wound healing" collected from 1994 to 2023. The findings suggest H. perforatum L. acts through various mechanisms and plays a role in each phase of the wound healing process, including re-epithelialization, angiogenesis, wound contraction, and connective tissue regeneration. H. perforatum L. enhances collagen deposition, decreases inflammation, inhibits fibroblast migration, and promotes epithelialization by increasing the number of fibroblasts with polygonal shape and the number of collagen fibers within fibroblasts. H. Perforatum L. extracts modulate the immune response and reduce inflammation were found to accelerate the wound healing process via inhibition of inflammatory mediators' production like interleukin-6, tumor necrosis factor-α, cyclooxygenase-2 gene expression, and inducible nitric oxide synthase. Thus, H. perforatum L. represents a potential remedy for a wide range of dermatological problems, owing to its constituents with beneficial therapeutic properties. H. perforatum L. could be utilized in the development of novel wound healing therapies.

Emerging trends of phytochemicals as ferroptosis modulators in cancer therapy

Ferroptosis, a novel form of regulated cell death characterized by dependence on iron and lipid peroxidation, has been implicated in a wide range of clinical conditions including neurological diseases, cardiovascular disorders, acute kidney failure, and various types of cancer. Therefore, it is critical to suppress cancer progression and proliferation. Ferroptosis can be triggered in cancer cells and some normal cells by synthetic substances, such as erastin, Ras-selective lethal small molecule-3, or clinical pharmaceuticals. Natural bioactive compounds are traditional drug discovery tools, and some have been therapeutically used as dietary additives or pharmaceutical agents against various malignancies. The fact that natural products have multiple targets and minimal side effects has led to notable advances in anticancer research. Research has indicated that ferroptosis can also be induced by natural compounds during cancer treatment. In this review, we focused on the most recent developments in emerging molecular processes and the significance of ferroptosis in cancer. To provide new perspectives on the future development of ferroptosis-related anticancer medications, we also provide a summary of the implications of natural phytochemicals in triggering ferroptosis through ROS production and ferritinophagy induction in a variety of malignancies.

Role of Cytochrome P450 2C9 in COVID-19 Treatment: Current Status and Future Directions

The major human liver drug metabolising cytochrome P450 (CYP) enzymes are downregulated during inflammation and infectious disease state, especially during coronavirus disease 2019 (COVID-19) infection. The influx of proinflammatory cytokines, known as a 'cytokine storm', during severe COVID-19 leads to the downregulation of CYPs and triggers new cytokine release, which further dampens CYP expression. Impaired drug metabolism, along with the inevitable co-administration of drugs or 'combination therapy' in patients with COVID-19 with various comorbidities, could cause drug-drug interactions, thus worsening the disease condition. Genetic variability or polymorphism in CYP2C9 across different ethnicities could contribute to COVID-19 susceptibility. A number of drugs used in patients with COVID-19 are inducers or inhibitors of, or are metabolised by, CYP2C9, and co-administration might cause pharmacokinetic and pharmacodynamic interactions. It is also worth mentioning that some of the COVID-19 drug interactions are due to altered activity of other CYPs including CYP3A4. Isoniazid/rifampin for COVID-19 and tuberculosis co-infection; lopinavir/ritonavir and cobicistat/remdesivir combination therapy; or multi-drug therapy including ivermectin, azithromycin, montelukast and acetylsalicylic acid, known as TNR4 therapy, all improved recovery in patients with COVID-19. However, a combination of CYP2C9 inducers, inhibitors or both, and plausibly different CYP isoforms could lead to treatment failure, hepatotoxicity or serious side effects including thromboembolism or bleeding, as observed in the combined use of azithromycin/warfarin. Further, herbs that are CYP2C9 inducers and inhibitors, showed anti-COVID-19 properties, and in silico predictions postulated that phytochemical compounds could inhibit SARS-CoV-2 virus particles. COVID-19 vaccines elicit immune responses that activate cytokine release, which in turn suppresses CYP expression that could be the source of compromised CYP2C9 drug metabolism and the subsequent drug-drug interaction. Future studies are recommended to determine CYP regulation in COVID-19, while recognising the involvement of CYP2C9 and possibly utilising CYP2C9 as a target gene to tackle the ever-mutating SARS-CoV-2.

Elsholtzia: A genus with antibacterial, antiviral, and anti-inflammatory advantages

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Elsholtzia (family Labiaceae) is an important source of folk traditional Chinese medicine, mainly used to relieve the symptoms of cold, fever, pneumonia and so on. However, currently available data on its traditional and pharmacological advantages have not been comprehensively reviewed.

AIM OF THE REVIEW

This review provides up-to-date and comprehensive information on the ethnopharmacological, phytochemical, pharmacological properties and toxicity of Elsholtzia, highlights the antibacterial, antiviral, and anti-inflammatory advantages of the genus, and explores its therapeutic potential.

MATERIALS AND METHODS

Use Google Scholar, Scifinder, PubMed, Springer, Elsevier, Wiley, Web of Science and other online database search to collect the research literatures on application, chemistry and biological activity of Elsholtzia published before December 2021. Their scientific names have been verified using The Plant List and World Flora Online websites.

RESULTS

A total of 42 species of Elsholtzia are widely distributed all over the world, especially in Yunnan Province (China). Since Elsholtzia genus is commonly used in the folk to treat respiratory infectious diseases such as cold and fever, growing numbers of studies have confirmed their antiviral, antibacterial and anti-inflammatory activities. So far, about 221 non-volatile compounds and 1008 volatile compounds have been identified from Elsholtzia plants, mainly containing flavonoids and terpenoids showing convincing antibacterial, antiviral and anti-inflammatory activities. Further research found that their antibacterial and antiviral spectrums are broad, and volatile oils are considered to be the main antibacterial components. Their anti-inflammatory mechanism is mainly through the inhibition of NF-κB and MAPKs signaling pathways. Toxicological studies have not established its toxicity.

CONCLUSIONS

By summarizing the latest information on genus Elsholtzia, their traditional uses, material basis and mechanisms of action in antiviral, antibacterial and anti-inflammatory aspects were described, providing new insights for the genus and its importance as a potential natural resource of antiviral and anti-inflammatory drugs, giving evidence and new ideas for the development of herbal medicines.

Evaluation of apigenin-based biflavonoid derivatives as potential therapeutic agents against viral protease (3CLpro) of SARS-CoV-2 via molecular docking, molecular dynamics and quantum mechanics studies

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the causative agent of the pandemic COVID-19 disease that affects human respiratory function. Despite the scientific progression made in the development of the vaccine, there is an urgent need for the discovery of antiviral drugs for better performance at different stages of SARS-CoV-2 reproduction. The main protease (Mpro or 3CLpro) plays a pivotal role in the life cycle of the virus, making it an attractive target for the development of antiviral agents effective against the new strains of coronaviruses (CoVs). In this study, a series of apigenin-based natural biflavonoid derivatives as potential inhibitors of coronaviruses 3CLpro was investigated by in silico approaches. For this purpose, the molecular docking was performed to analyze the interaction of the natural biflavonoids with SARS-Cov-2 main protease and for further investigation, docking to the 3CLpro of SARS-CoV and MERS-CoV. Based on docking scores and comparison with the reference inhibitors (ritonavir and lopinavir), more than half of the biflavonoids had strong interactions with the residues of the binding pocket of the coronaviruses 3CLpro and exhibited better binding affinities toward the main protease than ritonavir and lopinavir. The top biflavonoids were further explored through molecular dynamics simulation, binding free energy calculation and residual energy contributions estimated by the MM-PBSA. Also, drug likeness property investigation by Swiss ADME tools and density functional theory (DFT) calculations were performed. The results confirmed that the 3CLpro-amentoflavone, 3CLpro-bilobetin, 3CLpro-ginkgetin, and 3CLpro-sotetsuflavone complexes possess a large amount of dynamic properties such as high stability, significant binding energy and fewer conformation fluctuations. Also, the pharmacokinetics and drug-likeness studies and HOMO-LUMO and DFT descriptor values indicated a promising result of the selected natural biflavonoids. Overall findings indicate that the apigenin-based biflavonoids may inhibit COVID-19 by significant interactions in the binding pocket and those results can pave the way in drug discovery although the effectiveness of these bioactive compounds should be further validated by in-vitro and in-vivo investigations. Communicated by Ramaswamy H. Sarma.

Biflavonoids: Important Contributions to the Health Benefits of Ginkgo (Ginkgo biloba L.)

Ginkgo (Ginkgo biloba L.) is one of the most distinctive plants, characterized by excellent resistance to various environmental conditions. It is used as an ornamental plant and is recognized as a medicinal plant in both traditional and Western medicine. Its bioactive potential is associated with the presence of flavonoids and terpene trilactones, but many other compounds may also have synergistic effects. Flavonoid dimers-biflavonoids-are important constituents of ginkgophytopharmaceuticals. Currently, the presence of 13 biflavonoids has been reported in ginkgo, of which amentoflavone, bilobetin, sciadopitysin, ginkgetin and isoginkgetin are the most common. Their role in plants remains unknown, but their bioactivity and potential role in the management of human health are better investigated. In this review, we have provided an overview of the chemistry, diversity and biological factors that influence the presence of biflavonoids in ginkgo, as well as their bioactive and health-related properties. We have focused on their antioxidant, anticancer, antiviral, antibacterial, antifungal and anti-inflammatory activities as well as their potential role in the treatment of cardiovascular, metabolic and neurodegenerative diseases. We also highlighted their potential toxicity and pointed out further research directions.

A Comprehensive Review about the Molecular Structure of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2): Insights into Natural Products against COVID-19

In 2019, the world suffered from the emergence of COVID-19 infection, one of the most difficult pandemics in recent history. Millions of confirmed deaths from this pandemic have been reported worldwide. This disaster was caused by SARS-CoV-2, which is the last discovered member of the family of Coronaviridae. Various studies have shown that natural compounds have effective antiviral properties against coronaviruses by inhibiting multiple viral targets, including spike proteins and viral enzymes. This review presents the classification and a detailed explanation of the SARS-CoV-2 molecular characteristics and structure-function relationships. We present all currently available crystal structures of different SARS-CoV-2 proteins and emphasized on the crystal structure of different virus proteins and the binding modes of their ligands. This review also discusses the various therapeutic approaches for COVID-19 treatment and available vaccinations. In addition, we highlight and compare the existing data about natural compounds extracted from algae, fungi, plants, and scorpion venom that were used as antiviral agents against SARS-CoV-2 infection. Moreover, we discuss the repurposing of select approved therapeutic agents that have been used in the treatment of other viruses.