Protocatechuic acid for COVID-19

SARS-CoV-2 main protease (Mpro) is essential for viral polyprotein processing and represents a prime target for antiviral drug discovery. However, most available screening strategies rely on computational predictions or cell-free biochemical approaches that provide limited functional context and often require specialized instrumentation, while mammalian cell-based models remain costly and require high biosafety levels. Accordingly, there remains a shortage of simple, rapid, and biosafe functional screening tools suitable for early-stage prioritization of potential Mpro inhibitors, particularly those derived from natural sources and in urgent situations such as the COVID-19 pandemic. In this study, a bacterial colorimetric reporter assay was developed that directly links SARS-CoV-2 Mpro activity to β-galactosidase function in Escherichia coli. To the best of our knowledge, the developed assay represents the first bacterial colorimetric model for functional detection of SARS-CoV-2 Mpro inhibition based on a phenotypic readout. The assay enables the rapid visual detection of protease inhibition on X-gal-containing medium and provides a cost-effective and biosafe platform for prioritizing candidate inhibitors, under standard laboratory conditions, prior to further validation. Due to its bacterial expression context, this assay is intended for functional screening to provide the most promising candidate compounds and/or extracts for subsequent biochemical or mammalian cell-based validation; it is not intended to determine quantitative potency or to replace further validation approaches. It should be noted that the selective compound uptake in E. coli restricts the range of chemical compositions that can be evaluated using this method. Therefore, proof-of-concept application was demonstrated using pomegranate juice, a representative natural inhibitor source, rather than most currently known specific Mpro inhibitors. In addition, other plant-derived preparations, including rhubarb, grape, and red/black currant juices, were tested demonstrating the assay’s applicability to diverse natural matrices.

Introduction Coronavirus disease 2019 (COVID-19) is an epidemic respiratory disease caused due to the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In China, the National Health Commission of China announced that patients with COVID-19 who were treated with traditional Chinese medicines (TCMs) combined with antiviral drugs effectively alleviated their symptoms and recovered. Among these TCMs, Xuebijing (XBJ) injection plays an important role in the treatment of patients with COVID-19. However, this was a puzzle that what will be the clinical efficacy and safety of XBJ injection for COVID-19 treatment, and what are the potential mechanisms behind XBJ injection? Methods To search for articles on “Xuebijing injection in the treatment of COVID-19” in PubMed, use the following query: (Xuebijing injection OR Xuebijing) AND (COVID-19 OR SARS-CoV-2 OR severe pneumonia). We added filters for “Clinical Trial,” “Randomized Controlled Trial,” or “Review” to focus on specific study types, and limit the search to recent years (2010–2025) and English-language articles for more targeted results. Results XBJ injection in combination with regular therapy has been shown to improve overall efficacy, reduce 28-day mortality, improve lung CT recovery and reduce pro-inflammatory markers in patients with COVID-19. The high affinity for angiotensin converting enzyme 2, inhibition of neutrophil extracellular trap release and prevention of cell death and inflammation may be the main molecular mechanisms of XBJ injection in the treatment of COVID-19. Conclusion This review synthesizes the current evidence on the clinical efficacy and safety of XBJ injection in the treatment of COVID-19. Our analysis indicates that XBJ injection, when used in combination with standard therapy, significantly improves overall efficacy, reduces 28-day mortality, enhances lung CT recovery, and decreases pro-inflammatory markers such as C-reactive protein (CRP) and interleukin-6 (IL-6). These findings suggest that Xuebijing injection is a promising adjunctive treatment for COVID-19, particularly in severe cases, although it must be confirmed through rigorous pharmacological and clinical studies.

Background In search for effective prophylactic and possibly curative therapeutics against SARS-CoV-2, an historical-ethnopharmacological approach was used to select plants described in the Receptarium of Burkhard III von Hallwyl (RBH), a recipe text from 16th century Switzerland. Ten plant species were selected from the pre-established RBH database based on specific historical uses presumably linked with the treatment of viral infections. Methods From each plant aqueous and hydroethanolic extracts were produced. CellTiter-Glo® Luminescent Cell Viability Assay was used to assess antiviral activity against SARS-CoV-2 and the effect on cell viability of the extracts. Results Of the ten plants tested, four displayed an antiviral activity ≥ 50% at 16.7 μg/ml with acceptable cell viability (> 75%): Artemisia vulgaris L. (aerial parts), Geranium robertianum L. (arial parts), Sambucus nigra L. (leaves) and Viola odorata L. (leaves). The crude extracts were partitioned in aqueous and organic pre-fractions and further analyzed. The ethyl acetate pre-fractions of G. robertianum, S. nigra , and V. odorata expressed significant antiviral activity of nearly 100% at 5.6 μg/ml (P < 0.05). The most potent inhibitory activity was observed for the ethyl acetate pre-fraction of the leaves of Viola odorata with 87% at 1.9 μg/ml (P < 0.0001). Alongside bioactivity testing, phytochemical fingerprints were made, with the aim to provide a preliminary characterization of the active crude extracts. An overview of published phytochemical and antiviral data on the four active plants reveals a fragmentary picture, especially when considering the plant parts investigated. Despite of the promising antiviral effects observed in our study, further in-depth pharmacological and phytochemical investigations are required to comprehensively evaluate the potential of our candidates. Conclusions Our study suggests that an ethnopharmacological approach based on historical records of plant use in combination with a rational selection and testing procedure allows to identify interesting candidates, even among medicinal plants no longer in use. The process of selecting plants from RBH also illustrates the challenges associated with the study of historical texts, particularly the interpretation of the medicinal uses and the assessment of the botanical..

AbstractTo attain promising pharmacotherapies, researchers have applied drug repurposing (DR) techniques to discover the candidate medicines to combat the coronavirus disease 2019 (COVID-19) outbreak. Although many DR approaches have been introduced for treating different diseases, only structure-based DR (SBDR) methods can be employed as the first therapeutic option against the COVID-19 pandemic because they rely on the rudimentary information about the diseases such as the sequence of the severe acute respiratory syndrome coronavirus 2 genome. Hence, to try out new treatments for the disease, the first attempts have been made based on the SBDR methods which seem to be among the proper choices for discovering the potential medications against the emerging and re-emerging infectious diseases. Given the importance of SBDR approaches, in the present review, well-known SBDR methods are summarized, and their merits are investigated. Then, the databases and software applications, utilized for repurposing the drugs against COVID-19, are introduced. Besides, the identified drugs are categorized based on their targets. Finally, a comparison is made between the SBDR approaches and other DR methods, and some possible future directions are proposed.

Several human diseases are caused by viruses, including cancer, Type I diabetes, Alzheimer’s disease, and hepatocellular carcinoma. In the past, people have suffered greatly from viral diseases such as polio, mumps, measles, dengue fever, SARS, MERS, AIDS, chikungunya fever, encephalitis, and influenza. Recently, COVID-19 has become a pandemic in most parts of the world. Although vaccines are available to fight the infection, their safety and clinical trial data are still questionable. Social distancing, isolation, the use of sanitizer, and personal productive strategies have been implemented to prevent the spread of the virus. Moreover, the search for a potential therapeutic molecule is ongoing. Based on experiences with outbreaks of SARS and MERS, many research studies reveal the potential of medicinal herbs/plants or chemical compounds extracted from them to counteract the effects of these viral diseases. COVID-19′s current status includes a decrease in infection rates as a result of large-scale vaccination program implementation by several countries. But it is still very close and needs to boost people’s natural immunity in a cost-effective way through phytomedicines because many underdeveloped countries do not have their own vaccination facilities. In this article, phytomedicines as plant parts or plant-derived metabolites that can affect the entry of a virus or its infectiousness inside hosts are described. Finally, it is concluded that the therapeutic potential of medicinal plants must be analyzed and evaluated entirely in the control of COVID-19 in cases of uncontrollable SARS infection.