bims-antpol 2024-07-07 papers

Issue of 2024–07–07
four papers selected by
Rick Sheridan, EMSKE Phytochem

Sci Rep. 2024 07 03. 14(1): 15289

Antiviral action of aqueous extracts of propolis from Scaptotrigona aff. postica (Hymenoptera; Apidae) against Zica, Chikungunya, and Mayaro virus.

R Z Mendonça, R M Nascimento, A C O Fernandes, P I Silva.

The limited availability of antivirals for new highly pathogenic strains of virus has become a serious public health. Therefore, news products against these pathogens has become an urgent necessity. Among the multiple sources for news antibiotics and antivirals, insect exudates or their products has become an increasingly frequent option. Insects emerged 350 million years ago and have showed a high adaptability and resistance to the most varied biomes. Their survival for so long, in such different environments, is an indication that they have a very efficient protection against environmental infections, despite not having a developed immune system like mammals. Since the ancient civilizations, the products obtained from the bee have been of great pharmacological importance, being used as antimicrobial, anti-inflammatory, antitumor and several other functions. Investigations of biological activity of propolis have been carried out, mainly in the species Apis mellifera, and its product have showed activity against some important viruses. However, for the Meliponini species, known as stingless bees, there are few studies, either on their chemical composition or on their biological activities. The importance of studying these bees is because they come from regions with native forests, and therefore with many species of plants not yet studied, in addition to which they are regions still free of pesticides, which guarantees a greater fidelity of the obtained data. Previous studies by our group with crude hydroalcoholic extract of propolis demonstrated an intense antiviral activity against Herpes, influenza, and rubella viruses. In this work, we chose to use aqueous extracts, which eliminates the presence of other compounds besides those originally present in propolis, in addition to extracting substances different from those obtained in alcoholic extracts. Therefore, this study aimed to identify, isolate and characterize compounds with antiviral effects from aqueous propolis extracts from Scaptotrigona aff postica, in emerging viruses such as zicavirus, chikungunya, and mayaro virus. The evaluation of the antiviral activity of the crude and purified material was performed by reducing infectious foci in VERO cell cultures. The results obtained with crude propolis, indicate a high reduction of zica virus (64×) and mayaro (128×) when was used 10% v/v of propolis. The reduction of chikungunya virus was of 256 fold, even when was used 5% v/v of propolis. The chemical characterization of the compounds present in the extracts was performed by high-pressure liquid chromatography. Through the purification of propolis by HPLC and mass spectrometry, it was possible to identify and isolate a peak with antiviral activity. This substance showed activity against all viruses tested. When purified fraction was used, the reduction observed was of 16 fold for zicavirus, 32 fold for mayaro virus and 512 fold for chikungunya virus. Likewise, it was observed that the antiviral response was concentration dependent, being more intense when propolis was added 2 h after the viral infection. Now we are carrying out the chemical characterization of the purified compounds that showed antiviral action.

Keywords: Scaptotrigona aff postica ; Antiviral activity; Chikungunya; Mayaro virus; Propolis; Zica virus

DOI: https://doi.org/10.1038/s41598-024-65636-7

BMC Vet Res. 2024 Jul 03. 20(1): 288

Antiviral activity of luteolin against porcine epidemic diarrhea virus in silico and in vitro.

Jieru Wang, Xiaoyu Zeng, Jiaojiao Gou, Xiaojie Zhu, Dongdong Yin, Lei Yin, Xuehuai Shen, Yin Dai, Xiaocheng Pan.

BACKGROUND: Porcine epidemic diarrhea virus (PEDV) mainly causes acute and severe porcine epidemic diarrhea (PED), and is highly fatal in neonatal piglets. No reliable therapeutics against the infection exist, which poses a major global health issue for piglets. Luteolin is a flavonoid with anti-viral activity toward several viruses.
RESULTS: We evaluated anti-viral effects of luteolin in PEDV-infected Vero and IPEC-J2 cells, and identified IC50 values of 23.87 µM and 68.5 µM, respectively. And found PEDV internalization, replication and release were significantly reduced upon luteolin treatment. As luteolin could bind to human ACE2 and SARS-CoV-2 main protease (Mpro) to contribute viral entry, we first identified that luteolin shares the same core binding site on pACE2 with PEDV-S by molecular docking and exhibited positive pACE2 binding with an affinity constant of 71.6 µM at dose-dependent increases by surface plasmon resonance (SPR) assay. However, pACE2 was incapable of binding to PEDV-S1. Therefore, luteolin inhibited PEDV internalization independent of PEDV-S binding to pACE2. Moreover, luteolin was firmly embedded in the groove of active pocket of Mpro in a three-dimensional docking model, and fluorescence resonance energy transfer (FRET) assays confirmed that luteolin inhibited PEDV Mpro activity. In addition, we also observed PEDV-induced pro-inflammatory cytokine inhibition and Nrf2-induced HO-1 expression. Finally, a drug resistant mutant was isolated after 10 cell culture passages concomitant with increasing luteolin concentrations, with reduced PEDV susceptibility to luteolin identified at passage 10.
CONCLUSIONS: Our results push forward that anti-PEDV mechanisms and resistant-PEDV properties for luteolin, which may be used to combat PED.

Keywords: Drug resistant mutant; Luteolin; Mpro; PEDV; Porcine ACE2; Pro-inflammatory cytokine; Spike

DOI: https://doi.org/10.1186/s12917-024-04053-4

F1000Res. 2023 ;12 1214

In vitro analysis of quercetin-like compounds from mistletoe Dendrophthoe pentandra (L.) Miq as a potential antiviral agent for Newcastle disease.

Lazuardi Mochamad, Selvaraja Malarvili, Khairat Jasmine, Vuanghao Lim.

Background: Recent evidence suggests that some flavonoid compounds obtained from crude methanol extract of mistletoe leaves ( Dendrophthoe pentandra L. Miq), also known as Benalu Duku (BD), have antimicrobial effects. Thus, the plant has the potential to eliminate viruses that may cause outbreaks in chicken farms. This study aimed to prove the in vitro ability of flavonoid compounds, namely quercetin-like compounds (QLCs), to eliminate field viruses, specifically the Newcastle disease virus (NDV). Methods: This research was performed in two stages. An in vitro test was used with a post-test of the control groups designed at a significance of 0.05. BD leaves (5 kg) were extracted using a maceration method with methanol and then separated into hexane, chloroform, ethyl acetate, and methanol fractions. The final extracted products were separated using semi-preparative high-performance liquid chromatography (HPLC) to obtain QLCs. The QLCs were identified and compared with quercetin using HPLC, proton and carbon nuclear magnetic resonance spectrometry, Fourier transform infrared spectrophotometry, and ultra-performance liquid chromatography-mass spectrometry. The activity of QLCs was tested in vitro against the NDV at a virulency titer of 10 -5 Tissue Culture Infectious Dose 50% (TCID50) and in chicken kidney cell culture. Results: Solutions of 0.05% (w/v) QLCs were discovered to have antiviral activity against NDVs, with an average cytopathogenic effect antigenicity at a 10 -5 dilution (p<0.05). Conclusions: QLCs from flavonoids from the leaves of BD have antiviral bioactivity against NDVs and may have the potential to be developed as medicinal compounds for the treatment of other human or animal viral infections.

Keywords: Antiviral agents; Benalu Duku; Health life; Herbal medicine; Inactivant

DOI: https://doi.org/10.12688/f1000research.133489.2

Virology. 2024 Jun 18. pii: S0042-6822(24)00165-X. [Epub ahead of print]597 110144

In vitro evaluation of antiviral activity in carnivorous plant species.

Keely Puchalski, Bertram L Jacobs, Jeffrey O Langland.

Sarracenia purpurea is a carnivorous plant historically used to treat smallpox infections. Our previous data found S. purpurea had broad spectrum antiviral activity in vitro. S. purpurea is one of several hundred identified carnivorous species of plants. Carnivorous plants have evolved through convergent evolution in at least ten independent events, usually in response to harsh environments where nutrition from prey is required for growth. These prey are known vectors of plant viruses that might introduce novel biotic stressors and defense pathways in carnivorous plants. This study evaluated the antiviral activity of several non-carnivorous and carnivorous plants from four evolutionarily distinct clades. Results demonstrated that carnivorous plants have evolved antiviral activity, a trait that is not present in related species of non-carnivorous plants. The antiviral trait may be due to the plant-prey relationship with insect vectors and an evolutionary need for carnivorous plants to have more robust antiviral defense systems.

Keywords: Anti-viral; Carnivorous; Evolution; Sarracenia purpurea

DOI: https://doi.org/10.1016/j.virol.2024.110144