Explore chapters and articles related to this topic
The Role of Natural Products in COVID-19
Published in Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga, The Covid-19 Pandemic, 2023
Iqra Akhtar, Sumera Javad, Tehreema Iftikhar, Amina Tariq, Hammad Majeed, Asma Ahmad, Muhammad Arfan, M. Zia-Ul-Haq
This plant belongs to the family Amaryllidaceae and found commonly in Korea, China, and Nepal. It contains a toxic, crystalline alkaloid known as lycorine. It shows broad-spectrum antiviral activities [137]. Lycorine has the ability to inhibit RNA synthesis and protein synthesis. It has been found very active against zika virus [138], poliovirus [139], HSV [140] and SARS-CoV [141]. There are different mechanisms of this single potent alkaloid molecule to inhibit the infectious activities of different viruses. Lycorine has also been tested against SARS COV-2 infection in vitro with very promising results. It, along with oxysophoridine and gemcitabine, stopped the viral replication. It was further explained that doses of these compounds were safe for human cell lines as well (Figure 11.11) [142].
Synthetic Compounds vs. Phytochemicals for the Treatment of Human Cutaneous Malignant Melanoma
Published in Namrita Lall, Medicinal Plants for Cosmetics, Health and Diseases, 2022
Jacqueline Maphutha, Namrita Lall
Magnolol, isolated from Magnolia officinalis Rehder & E.H. Wilson, induced cell death in NRAS-mutant WM1366 and BRAF mutant WM164 melanoma cells in a dose- and time-dependent manner. Western blotting analysis revealed significant downregulation of p-Akt, p-mTOR and p-ERK (Emran et al., 2019). Methylwogonin, isolated from Scutellaria baicalensis Georgi, significantly reduced the viability of human melanoma (A375) cells treated with methylwogonin with an IC50 of 72.9 µM (24 hours treatment) and 54.2 µM (48 hours treatment), respectively. Western blotting analysis revealed decreased expression of p-PI3K, p-Akt and p-mTOR (Chen et al., 2019). Plantamajoside, isolated from Plantago asiatica L., reduced the viability of the malignant melanoma cell line (A2058) in a dose- and time-dependent manner. Western blotting analysis revealed that Plantamajoside significantly inhibited the expression of p-Akt (Wang et al., 2020). Lycorine, isolated from Lycoris radiate (L’HÉR.) Herb. at 50 µM, significantly decreased the viability of A375 cells. Western blotting analysis revealed that lycorine significantly inhibited p-Akt and p-mTOR, suggesting that the anti-proliferative activity was due to the inhibition of the PI3K/Akt/mTOR pathway (Jiang and Liu, 2018).
Biobased Products for Viral Diseases
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Gleice Ribeiro Orasmo, Giovanna Morghanna Barbosa do Nascimento, Maria Gabrielly de Alcântara Oliveira, Jéssica Missilany da Costa
Many medicinal plants have been reported as antivirals for influenza virus. The Sambucus nigra L. species showed antiviral activity against influenza A and B viruses (Krawitz et al. 2011) and the caffeic acid compound from this elderberry showed a strong inhibitory effect on influenza A virus replication (Porter and Bode 2017). The methanol extract of alder (Alnus japonica T.) has strong antiviral activity against the avian influenza virus subtype H9N2 (Tung et al. 2010). Houttuynia cordata T. extract inhibited influenza A virus (Choi et al. 2009), as well as its compounds methyl n-nonyl ketone, lauryl aldehyde and capryl aldehyde, showed anti-Influenza activity (Hayashi et al. 1995). Rasool et al. (2017) found the effectiveness of ginger (Zingiber officinale R.) in the treatment of avian influenza (H9N2). The active compound licorine, obtained from Lycoris radiata (L’Her.) Herb, inhibited the avian influenza virus (H5N1) (He et al. 2012; Yang et al. 2019).
Phytonutrient Inhibitors of SARS-CoV-2/NSP5-Encoded Main Protease (Mpro) Autocleavage Enzyme Critical for COVID-19 Pathogenesis
Published in Journal of Dietary Supplements, 2023
Sreus A. G. Naidu, Yamini B. Tripathi, Priya Shree, Roger A. Clemens, A. Satyanarayan Naidu
Phenolic extracts of Chinese herb Isatis indigotica were frequently used as antiviral agents during the SARS outbreak in 2002. Several bioactive phytonutrients from I. indigotica root (Radix isatidis) have been identified as promiscuous chymotrypsin inhibitors (32). In later studies, Sinigrin (IC50: 217 μM), β-sitosterol (IC50: 1210 μM), and Indigo (IC50: 752 μM) from I. indigotica root extracts were shown to inhibit the cleavage activities of SARS-CoV Mpro in a dose-dependent manner (33). Two phenolic compounds, Aloe-emodin (IC50: 132 μM) and Hesperetin (IC50: 60 μM) were also identified as anti-Mpro agents in cell-free and cell-based assays (33). Sinigrin is a powerful antioxidant that appears to modulate quinine reductase and glutathione S-transferase, the human redox enzymes (34). Lycorine extracted from Chinese medical herb Lycoris radiata also demonstrated potent anti-SARS-CoV activity (IC50=15.7 nM) (35). Furthermore, two natural polyphenols from green tea, i.e. Tannic acid (IC50= 3 µM) and 3-Isotheaflavin-3-gallate (IC50= 7 µM) strongly inhibited SARS-CoV Mpro (36). Alkylated Chalcone-6, isolated from the traditional herb, Angelica keiskei also showed strong inhibitory activity (IC50= 11.4 µM) against SARS-CoV Mpro (37).
Plant-Derived Natural Non-Nucleoside Analog Inhibitors (NNAIs) against RNA-Dependent RNA Polymerase Complex (nsp7/nsp8/nsp12) of SARS-CoV-2
Published in Journal of Dietary Supplements, 2023
Sreus A. G. Naidu, Ghulam Mustafa, Roger A. Clemens, A. Satyanarayan Naidu
Lycorine, a bioactive pyrrolidine alkaloid isolated from the bulbs of Lycoris radiata, exhibits several pharmacological and broad-spectrum antiviral effects (125). Lycorine effectively inhibits several CoV pathogens (126, 127), including SARS-CoV (IC50 = 1.02 µM), MERS-CoV (IC50 = 2.12 µM) and SARS-CoV-2 (IC50 = 0.88 µM), more effective than the antiviral activity of remdesivir (IC50 = 6.5 µM) (128). The binding affinity of lycorine (ΔG = −6.2 kcal/mol) with SARS-CoV-2 RdRp protein is stronger than that of remdesivir (ΔG = −4.7 kcal/mol). Remdesivir is known to inhibit SARS-CoV-2 RdRp activity via non-obligate RNA chain termination by targeting the core catalytic active site on the RdRp enzyme (38). Lycorine shows similar binding position that overlaps with the nucleoside rings of remdesivir in the same pocket region of the catalytic active site on the viral polymerase. Lycorine forms H-bonds with Asp623, Asn691, and Ser759 residues on RdRp protein, similar to remdesivir. Lycorine is a potent NNAI against RdRp activity of several CoV pathogens and more effectively on SARS-CoV-2; therefore, may be a promising candidate for COVID-19 management.
An overview of the recent progress in Middle East Respiratory Syndrome Coronavirus (MERS-CoV) drug discovery
Published in Expert Opinion on Drug Discovery, 2023
Lycorine, an alkaloid derived from Lycoris radiate, has been identified as a potential MERS-RdRp inhibitor [109]. Lycorine has been found to block the replication of the H5N1 virus [110], EV71 virus [110], and poliovirus [111] and to have broad-spectrum activity against CoVs [109]. Lycorine inhibited MERS-RdRp with an IC50 value of 1.406 ± 0.26 µM [109]. Similar to remdesivir, lycorine binds to the active site of MERS-RdRp. In contrast to remdesivir, lycorine has a higher binding affinity for MERS-RdRp, making it a more intriguing compound.