ABSTRACT
Introduction: Although antiviral medications are commonly used to treat virus patients, their use in individuals is restricted due to critical aspects such as toxicity, virus resistance to antiviral agents, and host phenotypic responses against antiviral therapies. As a result, efforts are now being made to discover bioactive compounds in natural antiviral plants. For a long time, Verbascum thapsus L. has been used to relieve various lung illnesses and is traditionally used to treat certain respiratory diseases. Methods: In this study, we examined the antiviral activities (against the HCov-229E, HBV, and HSV II) by real-time RT–PCR, antibacterial activities (against Streptococcus pneumonia ATCC 1659, Pseudomonas aeruginosa ATCC 27853, and Haemophilus influenza ATCC 10211) by disk diffusion method, and anticancer activities (against prostate and colorectal cancer cell lines) by SRB assay of the methanol extract of V. thapsus L. leaves and flowers. The ultra-high-performance liquid chromatography-mass spectrometry is performed to annotate the secondary metabolites in leaves and flowers. Results: The latter analysis reported the annotation of 31 secondary metabolites classified into different classes. Among these metabolites, 12 tentatively identified metabolites were reported for the first time in V. thapsus L., but some had previously been found in other Verbascum species. Some flavonoids, phenyl-ethanoid glycoside, and iridoids enhanced the flowers extract as a potent antiviral activity against the HCov-229E, HBV, and HSV II, reaching about 8-folds, 2-folds, and 4-folds reductions, respectively than that of the leaves extract, upon compared to the positive control. On the other hand, the leaves extract had a 5-fold higher antiviral impact against HCV than the flowers extract. Due to its richness in particular phenyl-ethanoid glycosides, phenolic acids, and terpenoid, the methanol extract of leaves had slightly stronger antibacterial activity (50–62%) than that of the flowers (42–54%). Both leaves and flower extracts demonstrated weak cytotoxic activity (≤10%). Conclusion: This plant has emerged as a strong future alternative for testing against numerous enveloped viruses as a natural, affordable, accessible, and compelling medication or adjuvant. © 2023 SAAB
ABSTRACT
The massive production of polymer-based respiratory masks during the COVID-19 pandemic has rekindled the issue of environmental pollution from nonrecyclable plastic waste. To mitigate this problem, conventional filters should be redesigned with improved filtration performance over the entire operational life while also being naturally degradable at the end. Herein, we developed a functional and biodegradable polymeric filter membrane consisting of a polybutylene adipate terephthalate (PBAT) matrix blended with cetyltrimethylammonium bromide (CTAB) and montmorillonite (MMT) clay, whose surface properties have been modified through cation exchange reactions for good miscibility with PBAT in an organic solvent. Particularly, the spontaneous evolution of a partial core-shell structure (i.e., PBAT core encased by CTAB-MMT shell) during the electrospinning process amplified the triboelectric effect as well as the antibacterial/antiviral activity that was not observed in naive PBAT. Unlike the conventional face mask filter that relies on the electrostatic adsorption mechanism, which deteriorates over time and/or due to external environmental factors, the PBAT@CTAB-MMT nanofiber membrane (NFM)-based filter continuously retains electrostatic charges on the surface due to the triboelectric effect of CTAB-MMT. As a result, the PBAT@CTAB-MMT NFM-based filter showed high filtration efficiencies (98.3%, PM0.3) even at a low differential pressure of 40 Pa or less over its lifetime. Altogether, we not only propose an effective and practical solution to improve the performance of filter membranes while minimizing their environmental footprint but also provide valuable insight into the synergetic functionalities of organic-inorganic hybrid materials for applications beyond filter membranes.