Berbamine hydrochloride inhibits bovine viral diarrhea virus replication via interfering in late-stage autophagy

Berbamine inhibits porcine epidemic diarrhea virus in vitro and in vivo

Porcine epidemic diarrhea virus (PEDV) is a significant contributor to high mortality rates in piglets, posing a serious threat to the global pig industry. The absence of effective control measures and vaccines against circulating PEDV variants underscores the urgent need for new treatment strategies. In this study, we screened a compound library and identified Berbamine as a potential anti-PEDV drug through molecular docking techniques. In vitro experiments demonstrated that Berbamine significantly inhibits PEDV proliferation in Vero and IPEC-J2 cells in a dose-dependent manner, primarily targeting the replication phase of the PEDV life cycle. Furthermore, in vivo experiments revealed that Berbamine effectively alleviates intestinal damage caused by PEDV infection in piglets, leading to a reduction in viral load and cytokine levels, including IL-6, IL-8, IL-1β, and TNF-α. Additionally, autodock predictions indicate that viral non-structural proteins 3 and 16 (Nsp3 and Nsp16) are potential targets for Berbamine. Consequently, Berbamine holds significant promise for application and development as an antiviral treatment against PEDV.

Silybin prevented avermectin-induced cardiotoxicity in carp by modulating oxidative stress, inflammation, endoplasmic reticulum stress, mitochondrial apoptosis, and autophagy

Avermectin is one of the widely used anthelmintics in aquaculture and exhibits substantial toxicity to aquatic organisms. Silybin is extensively used for its anti-inflammatory, antioxidant and anti-apoptotic biological properties. Heart is essential for the survival of fish and plays a vital role in pumping blood oxygen and nutrients. Residual avermectin in water poses harm to carp. However, there is still insufficient research on whether silybin can mitigate the toxicity of avermectin to carp heart tissues. In this research, we established a model involving carp subjected to acute avermectin exposure and administered diets containing silybin to explore the potential protective effects of silybin against avermectin-induced cardiotoxicity. The results revealed that avermectin induced oxidative stress, inflammation, endoplasmic reticulum (ER) stress, mitochondrial pathway apoptosis and autophagy in the cardiac tissues of carp. Compared with the avermectin group, silybin significantly reduced ROS accumulation in cardiac tissues, restored antioxidant enzyme activity, inhibited mRNA transcript levels of pro-inflammatory-related factors, and attenuated ER stress, mitochondrial pathway apoptosis and autophagy. Protein-protein interaction (PPI) analysis demonstrated that silybin mitigated avermectin-induced cardiac oxidative stress, inflammation, ER stress, mitochondrial pathway apoptosis and autophagy. Silybin exerted anti-inflammatory effects through the Nuclear Factor kappa B (NF-κB) pathway, antioxidant effects through the Nuclear factor erythroid 2-related factor 2 (Nrf2) - Kelch-like ECH-associated protein 1 (Keap1) pathway, alleviated cardiac ER stress through the Glucose-regulated protein 78 (GRP78)/Activating Transcription Factor 6 (ATF6)/C/EBP homologous protein (CHOP) axis, suppressed apoptosis through the mitochondrial pathway, and inhibited excessive autophagy initiation through the PTEN-induced putative kinase 1 (PINK1)/Parkin RBR E3 ubiquitin protein ligase (PARKIN) signaling pathway. This study provided evidence supporting the protective effect of silybin against avermectin-induced cardiotoxicity in carp, highlighting its potential as a dietary additive to protect fish from adverse effects caused by avermectin exposure.

ARHGEF18 can promote BVDV NS5B activation of the host NF-κB signaling pathway by combining with the NS5B-palm domain

Rho guanine nucleotide exchange factor 18 (ARHGEF18) is a member of the Rho guanine nucleotide exchange factor (RhoGEF) family. RhoGEF plays an important role in the occurrence of tumors and neurological diseases; however, its involvement in host cell resistance against pathogenic microorganisms is mostly unknown. Herein, we report that bovine viral diarrhea virus (BVDV) nonstructural protein 5B (NS5B) can activate the nuclear factor kappa B (NF-κB) signaling pathway to induce an immune response. To clarify the functional domains of NS5B that activate NF-κB signaling, the six structural domains of NS5B were expressed separately: NS5B-core, NS5B-finger, NS5B-palm, NS5B-thumb, NS5B-N and NS5B-c domain. We preliminarily determined that the functional domains of NS5B that activate NF-κB signaling are the finger and palm domains. We used a bovine kidney cell cDNA library and yeast two-hybrid technology to identify that the host protein ARHGEF18 interacts with NS5B. Co-immunoprecipitation assays showed that ARHGEF18 interacts strongly with NS5B-palm. Interestingly ARHGEF18 could promote NF-κB signaling activation by BVDV NS5B. In addition silencing ARHGEF18 significantly inhibited NS5B-palm activation of NF-κB signaling. We concluded that ARHGEF18 can bind to BVDV NS5B through the palm domain to activate the NF-κB pathway. These findings provide direct evidence that BVDV NS5B induces immune responses by activating NF-κB signaling.

Matrine and icariin can inhibit bovine viral diarrhoea virus replication by promoting type I interferon response in vitro

Introduction

Bovine viral diarrhoea virus (BVDV) can cause diarrhoea (BVD) in an animal herd, leading to heavy economic losses. There are limited drugs available for treating and controlling BVD. This research aims to investigate the antiviral and immunoregulatory effects of two traditional Chinese herb extracts against BVDV infection. The extracts are matrine and icariin, which have been proved to have immunostimulant and antiviral effects.

Material and Methods

A cell counting kit-8 assay was used to analyse the toxicity of matrine and icariin to Madin-Darby bovine kidney (MDBK) cells. The model of MDBK cells infected with BVDV was utilised to uncover the antiviral mechanism of matrine and icariin, which along with their immunoregulatory ability was evaluated by quantitative reverse-transcription PCR and ELISA.

Results

The results showed that matrine and icariin can significantly inhibit the gene expression level of the BVDV 5' untranslated region through various pathways. Both matrine and icariin can statistically upregulate the gene expression level of interferon alpha, interferon beta (IFN-β), toll-like receptor 3, retinoic acid-inducible gene I and interferon regulatory factor 3, and raise the concentration of IFN-β after BVDV infection.

Conclusion

This study proves that both matrine and icariin have inhibitory effects on BVDV replication by activating IFN production and the IFN signalling pathway. The finding is promising and should open up the possibility of larger-scale in vitro research followed by in vivo experiments evaluating matrine and icariin as therapeutic agents in BVD cases.

Berbamine, a bioactive alkaloid, suppresses equine herpesvirus type 1 in vitro and in vivo

Equine herpesvirus type 1 (EHV-1) poses a global threat to equines. The anticancer agent berbamine (BBM), a bioactive alkaloid, has been shown to inhibit viral infection. However, whether BBM can inhibit EHV-1 infection remains unclear. This study investigated the effect of BBM treatment on EHV-1 infection. Quantitative PCR (qPCR), immunoblotting, the Reed-Muench method, and pathological examination were employed to study the ability of BBM to inhibit EHV-1 infection, viral DNA replication, viral protein production, virion secretion, and cytopathogenesis in vitro and in vivo. The in vitro studies revealed that 10 μM BBM effectively suppressed EHV-1 viral entry into cells, viral DNA replication, and virion secretion, while the in vivo studies verified the ability of BBM to suppress EHV-1-induced damage of brain and lung tissues and animal mortality. These findings strongly suggest that BBM could be a serious contender in the therapeutic control of EHV-1 infection of equines.

Ethyl Gallate Inhibits Bovine Viral Diarrhea Virus by Promoting IFITM3 Expression, Lysosomal Acidification and Protease Activity

Bovine viral diarrhea virus (BVDV) is a highly contagious viral disease which causes economic losses to the cattle industry. Ethyl gallate (EG) is a phenolic acid derivative which has various potentials to modulate the host response to pathogens, such as via antioxidant activity, antibacterial activity, inhibition of the production of cell adhesion factors, and so on. This study aimed to evaluate if EG influences BVDV infection in Madin-Darby Bovine Kidney (MDBK) cells, and to understand the antiviral mechanism. Data indicated that EG effectively inhibited BVDV infection by co-treatment and post-treatment in MDBK cells with noncytotoxic doses. In addition, EG suppressed BVDV infection at an early stage of the viral life cycle by blocking entry and replication steps but not viral attachment and release. Moreover, EG strongly inhibited BVDV infection by promoting interferon-induced transmembrane protein 3 (IFITM3) expression, which localized to the cytoplasm. The protein level of cathepsin B was significantly reduced by BVDV infection, whereas with treatment with EG, it was significantly enhanced. The fluorescence intensities of acridine orange (AO) staining were significantly decreased in BVDV-infected cells but increased in EG-treated cells. Finally, Western blot and immunofluorescence analyses demonstrated that EG treatment significantly enhanced the protein levels of autophagy markers LC3 and p62. Chloroquine (CQ) significantly increased IFITM3 expression, and Rapamycin significantly decreased it. Thus, EG may regulate IFITM3 expression through autophagy. Our results showed that EG could have a solid antiviral activity on BVDV replication in MDBK cells via increased IFITM3 expression, lysosomal acidification, protease activity, and regulated autophagy. EG might have value for further development as an antiviral agent.

Anti-BVDV Activity of Traditional Chinese Medicine Monomers Targeting NS5B (RNA-Dependent RNA Polymerase) In Vitro and In Vivo

Natural products have emerged as "rising stars" for treating viral diseases and useful chemical scaffolds for developing effective therapeutic agents. The nonstructural protein NS5B (RNA-dependent RNA polymerase) of NADL strain BVDV was used as the action target based on a molecular docking technique to screen herbal monomers for anti-BVDV viral activity. The in vivo and in vitro anti-BVDV virus activity studies screened the Chinese herbal monomers with significant anti-BVDV virus effects, and their antiviral mechanisms were initially explored. The molecular docking screening showed that daidzein, curcumin, artemisinine, and apigenin could interact with BVDV-NADL-NS5B with the best binding energy fraction. In vitro and in vivo tests demonstrated that none of the four herbal monomers significantly affected MDBK cell activity. Daidzein and apigenin affected BVDV virus replication mainly in the attachment and internalization phases, artemisinine mainly in the replication phase, and curcumin was active in the attachment, internalization, replication, and release phases. In vivo tests demonstrated that daidzein was the most effective in preventing and protecting BALB/C mice from BVDV infection, and artemisinine was the most effective in treating BVDV infection. This study lays the foundation for developing targeted Chinese pharmaceutical formulations against the BVDV virus.

Mechanisms regarding respiratory toxicity triggered by accumulation of ROS in carp exposed to difenoconazole

Difenoconazole is a widely used but difficult-to-degrade fungicide that can directly affect aquatic ecosystems. Here, two doses (0.488 mg/L, 1.953 mg/L) of difenoconazole were used to study the toxicity to the respiratory system of carp at an exposure time of 96 h. The results showed that difenoconazole exposure resulted in severe structural damage to carp gill tissue with extensive inflammatory cell infiltration. Mechanistically, difenoconazole exposure led to excessive accumulation of ROS in carp gill tissue, which induced an inflammatory response in the gill tissue. Meanwhile, the activities of SOD and CAT were reduced and the NRF2 signaling pathway was activated to regulate the imbalance between oxidation and antioxidation. In addition, difenoconazole exposure further activated the mitochondrial pathway of apoptosis by upregulating cytochrome C, BAX, cleaved-caspase 9, and downregulating Bcl-2. More interestingly, exposure to difenoconazole increased autophagosomes, but lysosomal dysfunction prevented the late stages of autophagy from proceeding smoothly, resulting in a protective autophagic response that is not properly initiated. In summary, difenoconazole exposure caused respiratory toxicity including inflammation response, oxidative stress, apoptosis, and autophagy in carp through the accumulation of ROS. The present study expanded our understanding of the toxic effects of difenoconazole on organisms and its possible threat to the aquatic environment.

Berbamine Hydrochloride Inhibits African Swine Fever Virus Infection In Vitro

African swine fever virus (ASFV) causes a viral disease in swine with a mortality rate of approximately 100%, threatening the global pig industry's economic development. However, vaccines are not yet commercially available, and other antiviral therapeutics, such as antiviral drugs, are urgently needed. In this study, berbamine hydrochloride, a natural bis-benzylisoquinoline alkaloid isolated from the traditional Chinese herb Berberis amurensis, showed significant antiviral activity against ASFV. The 50% cytotoxic concentration (CC₅₀) of berbamine hydrochloride in porcine alveolar macrophages (PAMs) was 27.89 μM. The antiviral activity assay demonstrated that berbamine hydrochloride inhibits ASFV in a dose-dependent manner. In addition, a 4.14 log TCID₅₀ decrease in the viral titre resulting from non-cytotoxic berbamine hydrochloride was found. Moreover, the antiviral activity of berbamine hydrochloride was maintained for 48h and took effect at multiplicities of infection (MOI) of 0.01, 0.1, and 1. The time-of-addition analysis revealed an inhibitory effect throughout the entire virus life-cycle. A subsequent viral entry assay verified that berbamine hydrochloride blocks the early stage of ASFV infection. Moreover, similar anti-ASFV activity of berbamine hydrochloride was also found in PK-15 and 3D4/21 cells. In summary, these results indicate that berbamine hydrochloride is an effective anti-ASFV natural product and may be considered a novel antiviral drug.