The untargeted phytochemical profile of Verbascum thapsus L. with potent antiviral, antibacterial and anticancer activities
Yasser M. Okasha, Fify I. Fathy, Fathy M. Soliman, Nesrin M. Fayek
Abstract
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. 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. 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%). 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. • Chemical makeup and health benefits of Verbascum thapsus. • Differentiation between flowers and leaves of the great mullein is presented. • Potent antiviral effect of the flowers against HCov-229E, HBV, and HSV II. • The leaves proved higher antibacterial activity (50–62%) due to its richness with phenyl-ethanoid glycosides.