Limonin for COVID-19

IntroductionTraditional Chinese medicine (TCM) pharmacies in Taiwan have been a vital healthcare resource in Chinese communities, with generations of accumulated TCM knowledge playing a crucial role in infectious disease prevention and treatment. However, as proprietors age and the industry declines, this valuable ethnomedicinal knowledge faces the risk of being lost. Therefore, documenting and analyzing the knowledge used by Taiwanese TCM pharmacies in combating COVID-19 is essential for the preservation and application of ethnomedicine.MethodsThis study employed a stratified sampling method to survey 106 TCM pharmacies in Taiwan, collecting 61 TCM formulae against COVID-19. The medicinal materials were compiled, and analysis were conducted using relative frequency of citation (RFC) and the Phi correlation coefficient to examine the relationships among TCMs. Furthermore, cluster analysis was applied to establish TCM combination patterns.ResultsThis study recorded a total of 70 medicinal materials and identified 30 commonly used ones, categorizing them into four major groups: Group A (heat-clearing and detoxifying): As similar as NRICM101, suitable for moderate to severe cases. Group B (heat-clearing and tonifying): Suitable for mild cases, with both antiviral and immune-boosting effects. Group C (symptom relief): Primarily used for relieving cough, expelling phlegm, and alleviating discomfort. Group D (tonifying and strengthening): Suitable for uninfected individuals to enhance immunity.DiscussionThis study successfully documented and analyzed the TCM usage patterns of Taiwanese TCM pharmacies in combating COVID-19, revealing their alignment with modern TCM theories. The findings not only contribute to the preservation of ethnobotanical knowledge but also serve as a reference for developing herbal prevention strategies and healthcare products, ensuring that traditional medical wisdom can play a greater role within the modern healthcare system.

Viral diseases pose a serious global health threat due to their rapid transmission and widespread impact. The RNA-dependent RNA polymerase (RdRp) participates in the synthesis, transcription, and replication of viral RNA in host. The current study investigates the antiviral potential of secondary metabolites particularly those derived from bacteria, fungi, and plants to develop novel medicines. Using a virtual screening approach that combines molecular docking and molecular dynamics (MD) simulations, we aimed to discover compounds with strong interactions with RdRp of five different retroviruses. The top five compounds were selected for each viral RdRp based on their docking scores, binding patterns, molecular interactions, and drug-likeness properties. The molecular docking study uncovered several metabolites with antiviral activity against RdRp. For instance, cytochalasin Z8 had the lowest docking score of –8.9 (kcal/mol) against RdRp of SARS-CoV-2, aspulvinone D (–9.2 kcal/mol) against HIV-1, talaromyolide D (–9.9 kcal/mol) for hepatitis C, aspulvinone D (–9.9 kcal/mol) against Ebola and talaromyolide D also maintained the lowest docking score of –9.2 kcal/mol against RdRp enzyme of dengue virus. These compounds showed remarkable antiviral potential comparable to standard drug (remdesivir –7.4 kcal/mol) approved to target RdRp and possess no significant toxicity. The molecular dynamics simulation confirmed that the best selected ligands were firmly bound to their respective target proteins for a simulation time of 200 ns. The identified lead compounds possess distinctive pharmacological characteristics, making them potential candidates for repurposing as antiviral drugs against SARS-CoV-2. Further experimental evaluation and investigation are recommended to ascertain their efficacy and potential.

Abstract SARS-CoV-2, a newly discovered coronavirus, has been linked to the COVID-19 pandemic and is currently an important public health issue. Despite all the work done to date around the world, there is still no viable treatment for COVID-19. This study examined the most recent evidence on the efficacy and safety of several therapeutic options available including natural substances, synthetic drugs and vaccines in the treatment of COVID-19. Various natural compounds such as sarsapogenin, lycorine, biscoclaurine, vitamin B12, glycyrrhizic acid, riboflavin, resveratrol and kaempferol, various vaccines and drugs such as AZD1222, mRNA-1273, BNT162b2, Sputnik V, and remdesivir, lopinavir, favipiravir, darunavir, oseltamivir, and umifenovir, resp., have been discussed comprehensively. We attempted to provide exhaustive information regarding the various prospective therapeutic approaches available in order to assist researchers and physicians in treating COVID-19 patients.