Therapeutic effects of saponin components on porcine reproductive and respiratory syndrome virus-infected piglets

Screening and comparative study of four anti-PEDV candidate drugs in vitro

Piglets afflicted with Porcine Epidemic Diarrhea Virus (PEDV) experience severe diarrhea and elevated death rates, leading to substantial financial losses in the pig farming sector. The objective of this study is to investigate the impact of polyphenols on PEDV within Vero cells by utilizing different methodologies to evaluate their anti-PEDV effect. By producing 30 polyphenols, we have discovered that No.2, No.5, No.7 and No.17 exhibit properties that make them effective against PEDV, serving as potential drugs. The findings showed that in a clear dose-dependent manner, the mRNA levels of PEDV were significantly inhibited in the high, middle, and low-dose groups of No.2, No.5, No.7 and No.17, when compared to the PEDV control. The four tested polyphenols significantly inhibited the levels of PEDV N contents and viral titers. Furthermore, concentration of cytotoxicity 50 % (CC50) values for No.2, No.5, No.7 and No.17 polyphenols were 42.84 μM, 16.78 μM, 39.01 μM and 28.86 μM, respectively, demonstrating the safety of these medications in clinical environments. While they exert their anti-PEDV activity all specifically at the viral replication stage. Collectively, these findings indicate that the four examined polyphenols could efficiently modulate the immune response against PEDV and hold promise for utilization in antiviral treatments.

Saponin components exhibit antiviral properties against porcine epidemic diarrhea virus in vitro

Piglets afflicted with porcine epidemic diarrhea virus (PEDV) experience severe diarrhea and elevated death rates, leading to substantial financial losses in the pig farming sector. The objective of this study is to investigate the impact of saponins on PEDV within Vero cells by utilizing different methodologies to evaluate their anti-PEDV effect. By producing 40 saponins, we have discovered that No. 29, No. 31, No. 35, and No. 38 exhibit properties that make them effective against PEDV, serving as potential drugs. The findings showed that in a clear dose-dependent manner, the mRNA levels of PEDV were significantly inhibited in the high, middle, and low-dose groups of No. 29, No. 31, No. 35, and No. 38, when compared to the PEDV control. The four tested saponins significantly inhibited the levels of PEDV N contents and viral titers. Furthermore, concentration of cytotoxicity 50% (CC50) values for No. 29, No. 31, No. 35, and No. 38 saponins were 37.13 μM, 52.86 μM, 44.98 μM, and 43.81 μM, respectively, demonstrating the safety of these medications in clinical environments. Collectively, these findings indicate that the four examined saponins could efficiently modulate the immune response against PEDV and hold promise for utilization in antiviral treatments.

Pharmacokinetics and metabolite identification of 23-hydroxybetulinic acid in rats by using liquid chromatography-mass spectrometry method

23-hydroxybetulinic acid (23-HA), a main bioactive component isolated from Pulsatilla chinensis (Bunge) Regel, exhibits various pharmacological activities, such as antimelanoma, antileukemia, anti-colon cancer, and antihepatotoxicity. Although the main active ingredient anemoside B4 (AB4) from this plant has been well studied, research on its active metabolite 23-HA is limited. In the present study, a validated HPLC-QQQ-MS/MS method was established for the quantification of 23-HA in rat plasma. Pharmacokinetics analysis showed that the absorption and elimination of 23-HA in rats were rapid, with an oral bioavailability as 12.9 %. After oral administration with 50 mg/kg 23-HA for SD rats, the plasma, urine, feces, and bile samples were collected and analyzed by UPLC-Q Exactive Plus MS and HPLC-QQQ-MS/MS. Seventeen metabolites of 23-HA were identified, and its major metabolic pathways included oxidation, hydration, sulfation, and glucuronidation. This study highlights the first detailed investigation of 23-HA's pharmacokinetics in rats along with its metabolism in vivo, and will provide robust evidence for further research and clinical application of 23-HA.

Identification, molecular characterization and phylogenetic analysis of a novel nucleorhabdovirus infecting Paris polyphylla var. yunnanensis

A novel betanucleorhabdovirus infecting Paris polyphylla var. yunnanensis, tentatively named Paris yunnanensis rhabdovirus 1 (PyRV1), was recently identified in Yunnan Province, China. The infected plants showed vein clearing and leaf crinkle at early stage of infection, followed by leaf yellowing and necrosis. Enveloped bacilliform particles were observed using electron microscopy. The virus was mechanically transmissible to Nicotiana bethamiana and N. glutinosa. The complete genome of PyRV1 consists of 13,509 nucleotides, the organization of which was typical of rhabdoviruses, containing six open reading frames encoding proteins N-P-P3-M-G-L on the anti-sense strand, separated by conserved intergenic regions and flanked by complementary 3'-leader and 5'-trailer sequences. The genome of PyRV1 shared highest nucleotide sequence identity (55.1%) with Sonchus yellow net virus (SYNV), and the N, P, P3, M, G, and L proteins showed 56.9%, 37.2%, 38.4%, 41.8%, 56.7%, and 49.4% amino acid sequence identities with respective proteins of SYNV, suggesting RyRV1 belongs to a new species of the genus Betanucleorhabdovirus.

Antiviral Potential of the Genus Panax: An updated review on their effects and underlying mechanism of action

Viral infections are known as one of the major factors causing death. Ginseng is a medicinal plant that demonstrated a wide range of antiviral potential, and saponins are the major bioactive ingredients in the genus Panax with vast therapeutic potential. Studies focusing on the antiviral activity of the genus Panax plant-derived agents (extracts and saponins) and their mechanisms were identified and summarized, including contributions mainly from January 2016 until January 2022. P. ginseng, P. notoginseng, and P. quinquefolius were included in the review as valuable medicinal herbs against infections with 14 types of viruses. Reports from 9 extracts and 12 bioactive saponins were included, with 6 types of protopanaxadiol (PPD) ginsenosides and 6 types of protopanaxatriol (PPT) ginsenosides. The mechanisms mainly involved the inhibition of viral attachment and replication, the modulation of immune response by regulating signaling pathways, including the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, cystathionine γ-lyase (CSE)/hydrogen sulfide (H₂S) pathway, phosphoinositide-dependent kinase-1 (PDK1)/ protein kinase B (Akt) signaling pathway, c-Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) pathway, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. This review includes detailed information about the mentioned antiviral effects of the genus Panax extracts and saponins in vitro and in vivo, and in human clinical trials, which provides a scientific basis for ginseng as an adjunctive therapeutic drug or nutraceutical.

A novel strategy for optimal component formula of anti-PRRSV from natural compounds using tandem mass tag labeled proteomic analyses

BACKGROUND

Porcine Reproductive and Respiratory Syndrome (PRRS) is one of the most important porcine viral diseases which have been threatening the pig industry in China. At present, most commercial vaccines fail to provide complete protection because of highly genetic diversity of PRRSV strains. This study aimed to optimize a component formula from traditional Chinese medicine(TCM)compounds with defined chemical characteristics and clear mechanism of action against PRRSV.

METHODS

A total of 13 natural compounds were screened for the anti-PRRSV activity using porcine alveolar macrophages (PAMs). Three compounds with strong anti-PRRSV activity were selected to identify their potential protein targets by proteomic analysis. The optimal compound formula was determined by orthogonal design based on the results of proteomics. MTT assay was used to determine the maximum non-cytotoxic concentration (MNTC) of each compound using PAMs. QPCR and western blot were used to investigate the PRRSV N gene and protein expression, respectively. The Tandem Mass Tag (TMT) technique of relative quantitative proteomics was used to detect the differential protein expression of PAMs treated with PRRSV, matrine (MT), glycyrrhizic acid (GA) and tea saponin (TS), respectively. The three concentrations of these compounds with anti-PRRSV activity were used for orthogonal design. Four formulas with high safety were screened by MTT assay and their anti-PRRSV effects were evaluated.

RESULTS

MT, GA and TS inhibited PRRSV replication in a dose-dependent manner. CCL8, IFIT3, IFIH1 and ISG15 were the top four proteins in expression level change in cells treated with MT, GA or TS. The relative expression of IFIT3, IFIH1, ISG15 and IFN-β mRNAs were consistent with the results of proteomics. The component formula (0.4 mg/mL MT + 0.25 mg/mL GA + 1.95 μg/mL TS) showed synergistic anti-PRRSV effect.

CONCLUSIONS

The component formula possessed anti-PRRSV activity in vitro, in which the optimal dosage on PAMs was 0.4 mg/mL MT + 0.25 mg/mL GA + 1.95 μg/mL TS. Compatibility of the formula was superposition of the same target with GA and TS, while different targets of MT. IFN-β may be one of the targets of the component formula possessed anti-PRRSV activity.

Panax Notoginseng Saponins Suppress Type 2 Porcine Reproductive and Respiratory Syndrome Virus Replication in vitro and Enhance the Immune Effect of the Live Vaccine JXA1-R in Piglets

Porcine reproductive and respiratory syndrome virus (PRRSV) suppresses the innate immune response in the host, reducing and delaying neutralizing antibody production against PRRSV infection and promoting viral infection. Here, we aimed to assess the potential of Panax notoginseng saponins (PNS) for improving the immune response exerted upon PRRSV-2-modified live virus (MLV) vaccine administration. Thirty piglets were randomly divided into six groups. Group 1 piglets were injected with medium 0 days post vaccination (dpv). Group 2 piglets were fed PNS 0–28 dpv. Group 3 and group 4 piglets were administered the JXA1-R vaccine 0 dpv. Group 4 piglets were also fed PNS 0–28 dpv. Group 1–4 piglets were challenged intranasally with the PRRSV JXA1 strain 28 dpv. Group 5 piglets were fed with PNS without challenge. Group 6 piglets served as controls. During the experiment, the samples were collected regularly for 49 days. Compared with group 1 piglets, group 3 piglets showed significantly reduced viremia and clinical scores, and significantly increased average daily gain (ADWG). Compared with group 3 piglets, group 4 piglets showed significantly improved neutralizing antibody titers, IFN-α and IFN-β mRNA expression, and significantly decreased viremia and viral load in the lungs and lymph nodes, but did not demonstrate any further improvement in PRRSV-specific antibody titer, rectal temperature, ADWG, or clinical scores. PNS upregulates neutralizing antibodies against PRRSV-2 and enhances the expression of IFN-α and IFN-β, which may reduce PRRSV viremia upon PRRSV-2 MLV vaccine administration. PNS may serve as an effective immunomodulator for boosting the immune defense against PRRSV.

Anemoside B4 sensitizes human colorectal cancer to fluorouracil-based chemotherapy through src-mediated cell apoptosis

Currently, 5-Fluorouracil (5-FU) based chemotherapy is the primary option for colorectal cancer after surgery, whereas chemotherapy resistance related mortality is observed in a large proportion of patients. Anemoside B4 (AB4) is a triterpene saponin, which exhibits a considerable activity in oncotherapy. In this study, we explored the efficacy of AB4 in FU-based chemotherapy in colorectal cancer cells and the underlying molecular mechanisms. Our results indicated a significant synergistic activity of AB4 in 5-FU treated colorectal cancer cells. Furthermore, AB4 treatment eliminated colorectal cancer stem cells by promoting apoptotic cell death in 5-FU resistant colorectal cancer cells. Mechanically, AB4 activated caspase-9 pathway in 5-FU resistant colorectal cancer cells. Elevated Src activity induced cell apoptosis and cancer stem cells elimination effects in AB4 treated colorectal cancer cells. In conclusion, AB4 showed promising sensitization effect in the FU-based chemotherapy of colorectal cancer. Our study may pave a way to ameliorate FU-based chemotherapeutic efficiency in colorectal cancer.

Anemoside B4 Protects against Acute Lung Injury by Attenuating Inflammation through Blocking NLRP3 Inflammasome Activation and TLR4 Dimerization

Acute lung injury (ALI) is an acute inflammatory process in the lung parenchyma. Anemoside B4 (B4) was isolated from Pulsatilla, a plant-based drug against inflammation and commonly applied in traditional Chinese medicine. However, the anti-inflammatory effect and the mechanisms of B4 are not clear. In this study, we explored the potential mechanisms and anti-inflammatory activity of B4 both in vitro and in vivo. The results indicated that B4 suppressed the expression of iNOS, COX-2, NLRP3, caspase-1, and IL-1β. The ELISA assay results showed that B4 significantly restrained the release of inflammatory cytokines like TNF-α, IL-6, and IL-1β in macrophage cells. In addition, B4 rescued mitochondrial membrane potential (MMP) loss in (lipopolysaccharide) LPS plus ATP stimulated macrophage cells. Co-IP and molecular docking results illustrated that B4 disrupted the dimerization of TLR4. For in vivo results, B4 exhibited a protective effect on LPS and bleomycin- (BLM-) induced ALI in mice through suppressing the lesions of lung tissues, the release of inflammatory cytokines, and the levels of white blood cells, neutrophils, and lymphoid cells in the blood. Collectively, B4 has a protective effect on ALI via blocking TLR4 dimerization and NLRP3 inflammasome activation, suggesting that B4 is a potential agent for the treatment of ALI.

Therapeutic potential of triterpenoid saponin anemoside B4 from Pulsatilla chinensis

Pulsatilla Decoction (Bai-Tou-Weng-Tang) has been used medically in China for thousands of years for the treatment of diseases caused by bacteria. In recent decades, Pulsatilla Decoction is becoming a well-known formula prescription used for the treatment of ulcerative colitis in traditional Chinese medicine. Pulsatilla chinensis is the chief herbal source of Pulsatilla Decoction, and it is rich in triterpenoid saponins, such as anemoside B4, anemoside A3, and 23-hydroxybetulinic acid. Anemoside B4 is the most abundant of that group and has been used as a quality control marker for Pulsatilla chinensis. As the major active component of Pulsatilla chinensis, anemoside B4 has also received attention as a pure compound for its therapeutic potential. In this review, we systematically analyze the findings on triterpenoid saponins, especially anemoside B4, anemoside A3 and 23-hydroxybetulinic acid, included in Pulsatilla chinensis and Pulsatilla Decoction. We discuss the pharmacokinetics and tissue distribution of these triterpenoid saponins as well as their biological activities. We also summarize the pharmacological effects of anemoside B4 and its two possible metabolites, anemoside A3 and 23-hydroxybetulinic acid, as pure compounds. In summary, this review sketches a profile of the state of existing knowledge with regard to the pharmacological effects of anemoside B4, especially its anti-inflammatory and immunomodulatory effects. These findings point to the possibility that anemoside B4 has potential to be studied further as a natural compound-originated immunomodulatory agent for the treatment of inflammatory diseases such as ulcerative colitis and thus, may represent one of the most important active components of Pulsatilla Decoction responsible for its anti-ulcerative colitis efficacy.

Glycyrrhizin: An alternative drug for the treatment of COVID-19 infection and the associated respiratory syndrome?

Safe and efficient drugs to combat the current COVID-19 pandemic are urgently needed. In this context, we have analyzed the anti-coronavirus potential of the natural product glycyrrhizic acid (GLR), a drug used to treat liver diseases (including viral hepatitis) and specific cutaneous inflammation (such as atopic dermatitis) in some countries. The properties of GLR and its primary active metabolite glycyrrhetinic acid are presented and discussed. GLR has shown activities against different viruses, including SARS-associated Human and animal coronaviruses. GLR is a non-hemolytic saponin and a potent immuno-active anti-inflammatory agent which displays both cytoplasmic and membrane effects. At the membrane level, GLR induces cholesterol-dependent disorganization of lipid rafts which are important for the entry of coronavirus into cells. At the intracellular and circulating levels, GLR can trap the high mobility group box 1 protein and thus blocks the alarmin functions of HMGB1. We used molecular docking to characterize further and discuss both the cholesterol- and HMG box-binding functions of GLR. The membrane and cytoplasmic effects of GLR, coupled with its long-established medical use as a relatively safe drug, make GLR a good candidate to be tested against the SARS-CoV-2 coronavirus, alone and in combination with other drugs. The rational supporting combinations with (hydroxy)chloroquine and tenofovir (two drugs active against SARS-CoV-2) is also discussed. Based on this analysis, we conclude that GLR should be further considered and rapidly evaluated for the treatment of patients with COVID-19.