bims-antpol Biomed News
on Antiviral properties of polyphenols
Issue of 2024–11–17
five papers selected by
Rick Sheridan, EMSKE Phytochem



  1. Int J Mol Sci. 2024 Oct 23. pii: 11397. [Epub ahead of print]25(21):
      Chikungunya and Mayaro fevers are viral infectious diseases characterized by fever and arthralgia, for which there are currently no effective vaccines or treatments. The urgent need for novel antiviral agents against Chikungunya virus (CHIKV) and Mayaro virus (MAYV) has led to interest in plant-based compounds that can disrupt the viral replication cycle. Chiococca alba (L.) Hitchc., a Neotropical plant traditionally used by Yucatec Maya healers as an antipyretic and antirheumatic, may hold potential as a source of antiviral agents. This study aimed to evaluate the antiviral potential of C. alba methanolic extracts (CAH21 and CAH24) against CHIKV and MAYV through preliminary in vitro and in silico analyses. The cytotoxicity of two methanolic extracts from C. alba roots was assessed in Vero cells using the neutral red assay, and their viral activity was determined via plaque assay post-treatment. Given the observed antiviral effects, we used computational predictions to explore interactions between the multifunctional nsP2 proteases and secondary metabolites identified in C. alba extracts. The metabolites were identified using high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Phytochemical analysis revealed the presence of flavonoids, coumarins, and phenolic acids in the C. alba extracts. In vitro assays demonstrated that both extracts inhibited over 70% of activity against CHIKV and MAYV at a concentration of 60 µg/mL. In silico predictions suggested that the flavonoids naringin and vitexin had the highest affinity for the nsP2 proteases of CHIKV and MAYV, indicating their potential as viral inhibitors. Our findings revealed that C. alba extract represents a promising source of novel antiviral compounds.
    Keywords:  Alphavirus; cainca plants; flavonoids; nsP2 protease; viral infections
    DOI:  https://doi.org/10.3390/ijms252111397
  2. Molecules. 2024 Nov 04. pii: 5218. [Epub ahead of print]29(21):
      Viruses play a significant role in human health, as they can cause a wide range of diseases, from mild illnesses to severe and life-threatening conditions. Cellular and animal experiments have demonstrated that the functional components in tea, such as catechins, theaflavins, theanine, and caffeine, exhibit significant inhibitory effects on a diverse array of viruses, including influenza, rotavirus, hepatitis, HPV, and additional types. The inhibition mechanisms may involve blocking virus-host recognition, interfering with viral replication, enhancing host immune responses, and inhibiting viral enzyme activity. This article reviews the research progress on the antiviral effects of tea's functional components and their related mechanisms, hoping to contribute to future studies in this field.
    Keywords:  antiviral activity; functional components; mechanisms of antiviral activity; tea
    DOI:  https://doi.org/10.3390/molecules29215218
  3. Arch Pharm (Weinheim). 2024 Nov 14. e2400607
      This study deals with the comprehensive phytochemical composition and antiviral activity against SARS-CoV-2 of acidic (non-decarboxylated) and neutral (decarboxylated) ethanolic extracts from seven high-cannabidiol (CBD) and two high-Δ9-tetrahydrocannabinol (Δ9-THC) Cannabis sativa L. genotypes. Their secondary metabolite profiles, phytocannabinoid, terpenoid, and phenolic, were determined by LC-UV, GC-MS, and LC-MS/MS analyses, respectively. All three secondary metabolite profiles, cannabinoid, terpenoid, and phenolic, varied significantly among cannabinoid extracts of different genotypes. The dose-response analyses of their antiviral activity against SARS-CoV-2 showed that only the single predominant phytocannabinoids (CBD or THC) of the neutral extracts exhibited antiviral activity (all IC50 < 10.0 μM). The correlation matrix between phytoconstituent levels and antiviral activity revealed that the phenolic acids, salicylic acid and its glucoside, chlorogenic acid, and ferulic acid, and two flavonoids, abietin, and luteolin, in different cannabinoid extracts from high-CBD genotypes are implicated in the genotype-distinct antagonistic effects on the predominant phytocannabinoid. On the other hand, these analyses also suggested that the other phytocannabinoids and the flavonoid orientin can enrich the extract's pharmacological profiles. Thus, further preclinical studies on cannabinoid extract formulations with adjusted non-phytocannabinoid compositions are warranted to develop supplementary antiviral treatments.
    Keywords:  Cannabis sativa; SARS‐CoV‐2; antiviral activity; chemical composition; phytocannabinoids
    DOI:  https://doi.org/10.1002/ardp.202400607
  4. Plants (Basel). 2024 Nov 01. pii: 3077. [Epub ahead of print]13(21):
      Medicinal plants have been explored worldwide as potential alternatives for the prevention and treatment of different diseases, including viral infections. Baccharis crispa Spreng. (Asteraceae) is a native medicinal species widely used in South America. Given the influence of genetic and environmental factors on secondary metabolites biosynthesis and accumulation, this study aimed to evaluate the in vitro antiviral activity of four wild populations of B. crispa from Córdoba, Argentina, and assess the variability in their bioactivity and chemical composition. The cytotoxicity of chloroform, ethanol, and aqueous extracts from aerial parts was evaluated by the neutral red uptake method. Antiviral and virucidal activity against herpes simplex virus type 1 (HSV-1) and chikungunya virus (CHIKV) were assessed via plaque-forming unit (PFU) reduction assay. Phytochemical analyses of the extracts were conducted using HPLC-ESI- MS/MS. The Puesto Pedernera population showed the strongest antiviral activity, with inhibition rates of 82% for CHIKV and 79% against HSV-1, as well as potent virucidal effects, reducing PFU formation by up to 5 logarithms for both viruses. Remarkably, ethanol extract exhibited the least toxicity and strongest inhibitory activity. Villa del Parque population was inactive. We identified 38 secondary metabolites, predominantly phenolic acids (12) and flavonoids (18), in varying proportions. Delphinidin and delphinidin-3-glucoside are described for the first time in the species. Differences in phytochemical profiles were observed among extract types and populations. Key phenolic compounds showed moderate positive correlations with the evaluated bioactivities, emphasizing the complexity of phytochemical properties and interactions. These results highlight the therapeutic potential of B. crispa extracts against viral infections and underscore the importance of considering the geographical source of plant material in bioactivity evaluations.
    Keywords:  bioactivities; chikungunya virus; herpes simplex virus; natural products; population variability
    DOI:  https://doi.org/10.3390/plants13213077
  5. Trop Dis Travel Med Vaccines. 2024 Nov 15. 10(1): 23
      Dengue virus (DENV) is a mosquito-borne virus that causes dengue fever, a significant public health concern in many tropical and subtropical regions. Dengue is endemic in more than 100 countries, primarily in tropical and subtropical regions of the world. Each year, up to 400 million people get infected with dengue. Approximately 100 million people get sick from infection, and 40,000 die from severe dengue. Unfortunately, dengue vaccine development is also marred with various complicating factors, as the forefront candidate vaccine performed unsatisfactorily. Moreover, the only licensed vaccine (Dengvaxia) for children 9 through 16 years of age is available in just a few countries. The treatment difficulties are compounded by the absence of an effective antiviral agent. Exploring plant-based therapeutics for dengue from the laboratory to clinical application involves a multi-stage process, encompassing various scientific disciplines. Individual investigators have screened a wide range of plant extracts or compounds for potential antiviral activity against DENV. In vitro studies help identify candidates that exhibit inhibitory effects on viral replication. Some of the most promising medicinal plants showing in vitro activity against DENV include Andrographis paniculate, Acorus calamus, and Cladogynos orientalis. Further laboratory studies, both in vitro and in animal models (in vivo), elucidate the mechanisms of action by which the identified compounds exert antiviral effects. Medicinal plants such as Carica papaya, Cissampelos pareira, and Ipomea batata exhibited potent platelet-enhancing activities while Azadirachta indica and Curcuma longa showed promising effects in both in vitro and in vivo studies. Based on positive preclinical results, researchers design clinical trials. This involves careful planning of trial phases, patient recruitment criteria, ethical considerations, and endpoints. The most important medicinal plants showing efficacy and safety in clinical trials include Carica papaya and Cissampelos pareira. This review suggests that several promising medicinal plants exist that have the potential to be turned into clinical drugs to treat dengue infection. However, in addition to developing synthetic and plant-based therapies against dengue infection, vector management strategies should be made robust, emphasizing the need to focus on reducing disease incidence.
    Keywords:   Aedes ; Dengue; Flavivirus; Inflammation; Natural products; Pathogenesis; Phytocompound
    DOI:  https://doi.org/10.1186/s40794-024-00232-1