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.

Ultraviolet-coupled advanced oxidation processes for anti-COVID-19 drugs treatment: Degradation mechanisms, transformation products and toxicity evolution

Remdesivir (RDV), dexamethasone (DEX) and hydroxychloroquine (HCQ) were widely used in the treatment of COVID-19 pneumonia, possibly causing environmental risks and drug-resistance viruses. This study elucidated the degradation mechanisms and potential toxicity risks of the three anti-COVID-19 drugs by UV and ultraviolet-coupled advanced oxidation processes (UV/AOPs). All the drugs could be degraded by more than 98% within 3 min under the following optimal conditions: pH of 5.0 and drug-to-oxidant (H₂O₂) molar ratio of 1:200. Combined with density functional theory (DFT) analysis and high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS), twenty-four transformation products (TPs) were detected and the main degradation pathways were investigated. Based on bacterial luminescence inhibition test and the peak-area evolution of TPs, RDV and HCQ showed an obvious toxicity-increase region when TPs were generated in large quantities, while the toxicity of DEX continued to decline during degradation processes. By QSAR predictions, the main contributors to the toxicity evolution during the UV/AOPs were predicted. Halogen-containing TPs showed significantly higher toxicity than other TPs, and thus the chlorine-containing structure in HCQ presented the potential toxicity. Appropriate reaction parameters and adequate reaction time for the UV/AOPs could eliminate the toxicity of TPs and ensure environmental safety. This study could play a positive role in the treatment of anti-COVID-19 drugs and their environmental hazard assessment.

Progress in Studies on Structural and Remedial Aspects of Newly Born Coronavirus, SARS-CoV-2

The article highlights an up-to-date progress in studies on structural and the remedial aspects of novel coronavirus 2019-nCoV, renamed as SARS-CoV-2, leading to the disease COVID-19, a pandemic. In general, all CoVs including SARS-CoV-2 are spherical positive single-stranded RNA viruses containing spike (S) protein, envelope (E) protein, nucleocapsid (N) protein, and membrane (M) protein, where S protein has a Receptor-binding Domain (RBD) that mediates the binding to host cell receptor, Angiotensin Converting Enzyme 2 (ACE2). The article details the repurposing of some drugs to be tried for COVID-19 and presents the status of vaccine development so far. Besides drugs and vaccines, the role of Convalescent Plasma (CP) therapy to treat COVID-19 is also discussed.