Effect of andrographolide and deep eutectic solvent extracts of Andrographis paniculata on human coronavirus organ culture 43 (HCoV-OC43)

Background Andrographis paniculata (Burm. f.) Nees has demonstrated potential for treating infections caused by coronaviruses. However, no antiviral activity of andrographolide or A. paniculata extracts against human coronavirus organ culture 43 (HCoV-OC43) has been reported. Purpose This study aimed to evaluate the anti-HCoV-OC43 effect of andrographolide and A. paniculata as well as the correlation between andrographolide concentration and the anti-HCoV-OC43 activity of A. paniculata extracts. Methods This study evaluated and compared the in vitro anti-HCoV-OC43 activities of various A. paniculata extracts and andrographolide. To obtain A. paniculata extracts with different concentrations of andrographolide and its components, methanol and deep eutectic solvents (DES) were used to extract the aerial parts of A. paniculata. Andrographolide content was determined using UV-HPLC, and antiviral activity was assessed in HCT-8 colon cells. Results The methanol and five acidic DES (containing malic acid or citric acid) extracts of A. paniculata exerted anti-HCoV-OC43 activity. Antiviral activity had a moderately strong positive linear relationship (r = 0.7938) with andrographolide content. Although the methanol extract contained the highest andrographolide content (2.34 mg/ml), its anti-HCoV-OC43 activity was lower than that of the DES extracts containing lower andrographolide concentrations (0.92-1.46 mg/ml). Conclusion Methanol and the five acidic DES extracts of A. paniculata exhibited anti-HCoV-OC43 activity. However, the in vitro antiviral activity of A. paniculata extracts did not have a very strong positive linear relationship (r < 0.8) with andrographolide concentration in the extract. As a result, when comparing A. paniculata extracts, the anti-HCoV-OC43 test could provide a different result from the andrographolide concentration determination. Graphical Image, graphical

Effect of andrographolide and deep eutectic solvent extracts of Andrographis paniculata on human coronavirus organ culture 43 (HCoV-OC43).

BACKGROUND: Andrographis paniculata (Burm. f.) Nees has demonstrated potential for treating infections caused by coronaviruses. However, no antiviral activity of andrographolide or A. paniculata extracts against human coronavirus organ culture 43 (HCoV-OC43) has been reported. PURPOSE: This study aimed to evaluate the anti-HCoV-OC43 effect of andrographolide and A. paniculata as well as the correlation between andrographolide concentration and the anti-HCoV-OC43 activity of A. paniculata extracts. METHODS: This study evaluated and compared the in vitro anti-HCoV-OC43 activities of various A. paniculata extracts and andrographolide. To obtain A. paniculata extracts with different concentrations of andrographolide and its components, methanol and deep eutectic solvents (DES) were used to extract the aerial parts of A. paniculata. Andrographolide content was determined using UV-HPLC, and antiviral activity was assessed in HCT-8 colon cells. RESULTS: The methanol and five acidic DES (containing malic acid or citric acid) extracts of A. paniculata exerted anti-HCoV-OC43 activity. Antiviral activity had a moderately strong positive linear relationship (r = 0.7938) with andrographolide content. Although the methanol extract contained the highest andrographolide content (2.34 mg/ml), its anti-HCoV-OC43 activity was lower than that of the DES extracts containing lower andrographolide concentrations (0.92-1.46 mg/ml). CONCLUSION: Methanol and the five acidic DES extracts of A. paniculata exhibited anti-HCoV-OC43 activity. However, the in vitro antiviral activity of A. paniculata extracts did not have a very strong positive linear relationship (r < 0.8) with andrographolide concentration in the extract. As a result, when comparing A. paniculata extracts, the anti-HCoV-OC43 test could provide a different result from the andrographolide concentration determination.

Evaluating the in Vitro Efficacy of Quassinoids from Eurycoma longifolia and Eurycoma harmandiana against Common Cold Human Coronavirus OC43 and SARS-CoV-2 Using In-Cell Enzyme-Linked Immunosorbent Assay.

Coronavirus disease-2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, has become a pandemic and public health crisis. SARS-CoV-2 and the seasonal common cold coronavirus (HCoV-OC43) belong to the beta genus of human coronaviruses (HCoVs). In-cell ELISA assays were performed using HCoV-OC43 and SARS-CoV-2 and evaluated the antiviral activity of herbal plants. Eurycoma longifolia (EL) and Eurycoma harmandiana (EH) roots (antipyretic properties) and their constituent quassinoids, especially chaparrinone and eurycomalactone, showed potent anti-HCoV-OC43 and SARS-CoV-2 activities, and the low IC50 values of the mentioned constituents were observed in the range of 0.32-0.51 µM. Eurycomanone and 13ß,21-dihydroeurycomanone may contribute to the antiviral activity of EL, whereas chaparrinone is the major and active antiviral constituent of EH root. The content of quassinoids, ß-carboline, and canthin-6-one alkaloids and the cytotoxicity profile of EL and EH extracts were varied regarding extraction solvents. The boiled water and 50% EtOH extractions of both plants were less toxic than those with 95% EtOH as the extraction solvent. Our research suggests that quassinoids, which come from EL and EH roots and are anti-coronavirus compounds, are potential treatment candidates for COVID-19 and merit further in vivo investigations.

Effectiveness of neutral electrolyzed water in inactivating HCoV-OC43 and SARS-CoV-2 on the surfaces of plastic and the medicinal plant Centella asiatica (L.) urban.

Concerns have been raised about viral contamination, including in crops due to the recent coronavirus disease 2019 pandemic. Limited evidence is available to support the use of sanitizing agents for human coronavirus-contaminated medicinal plants. Thus, we aimed to investigate the persistence of infectious human coronavirus OC43 (HCoV-OC43) as a SARS-CoV-2 surrogate in storage conditions and the capability of neutral electrolyzed water (NEW) to inactivate coronavirus, including in fresh plants such as C. asiatica. The levels of infectious HCoV-OC43 and the triterpenoid content of C. asiatica were quantified using a plaque assay and high-performance liquid chromatography, respectively. The results showed that the persistence of HCoV-OC43 on C. asiatica leaves is identical to that on inert polystyrene. When covered and kept at room temperature with high humidity (>90% RH), HCoV-OC43 can be stable on C. asiatica leaves for at least 24 h. NEW with 197 ppm of available chlorine concentration (ACC) was effective in inactivating both infectious HCoV-OC43 and SARS-CoV-2 in suspension (≥3.68 and ≥4.34 log reduction, respectively), and inactivated dried HCoV-OC43 on the surfaces of C. asiatica leaves (≥2.31 log reduction). Soaking C. asiatica leaves for 5 min in NEW with 205 ppm of ACC or water resulted in significantly higher asiaticoside levels (37.82 ± 0.29 and 35.32 ± 0.74 mg/g dry weight, respectively), compared to the unsoaked group (29.96 ± 0.78 mg/g dry weight). These findings suggest that although coronavirus-contaminated C. asiatica leaves can pose a risk of transmission, NEW could be an option for inactivation.

Improvement of stilbene production by mulberry Morus alba root culture via precursor feeding and co-elicitation.

Large amounts of Morus alba L. (MA) roots are needed as the source of active stilbenes in the industrial production of traditional medicines and cosmeceuticals. A recent investigation demonstrated resveratrol and its derivatives to be promising anti-COVID-19 agents. However, conventional cultivation of MA does not meet the demand for its stilbenes, and root quality usually varies between crops. This study established the in vitro non-GMO root culture of MA and optimized the root density, precursor feeding, and elicitors for stilbene productivity. A root culture with optimal inoculum density (3 g/flask of 30 mL medium) accumulated mulberroside A, oxyresveratrol, and resveratrol at 18.7 ± 1.00 mg/g, 136 ± 5.05 µg/g, and 41.6 ± 5.84 µg/g dry weight (DW), respectively. The feeding of L-tyrosine shortened the time required to reach the stilbene productive stage. Root cultures co-treated with 200 µM methyl jasmonate and 2 mg/mL yeast extract accumulated the highest contents of mulberroside A (30.3 ± 2.68 mg/g DW), oxyresveratrol (68.6 ± 3.53 µg/g DW), and resveratrol (10.2 ± 0.53 µg/g DW). In summary, root culture is a promising and sustainable source of stilbenes for the development of health products and agents for further investigation as potential anti-COVID-19 agents.