Inhibitory Effects of Indigowoad Root Polysaccharides on Porcine Reproductive and Respiratory Syndrome Virus Replication In Vitro
Abstract
Indigowoad root polysaccharide (IRPS) is a natural polysaccharide isolated from the traditional Chinese medicinal herb Radix Isatidis, and has many kinds of biological activities. However, the IRPS antiviral activity, especially the anti-porcine reproductive and respiratory syndrome virus (PRRSV) effect, has not been evaluated.
PRRSV was propagated in the MARC-145 cell line, and viral titre was determined by cytopathic effect and expressed as the 50% tissue culture infection dose (TCID(50)) in the current study. The cell cytotoxic effect of IRPS toward MARC-145 was evaluated by MTT assay firstly, then the inhibitory effects of IRPS on PRRSV replication in vitro were investigated by determining the effect of IRPS upon a single replicative cycle of PRRSV in MARC-145 cells. The effects of IRPS on viral RNA and protein synthesis in PRRSV-infected cells were investigated using real-time PCR and double-antibody (sandwich) ELISA.
IRPS was able to effectively suppress the infectivity of the PRRSV in a dose-dependent manner, especially by adding IRPS during the PRRSV infection. IRPS could affect the attachment of PRRSV to MARC-145 cells, and also inhibit the viral RNA and protein synthesis.
IRPS has an antiviral effect on PRRSV replication in MARC-145 cells and might be useful in medical development for antiviral research. However, the precise mechanism of the host and viral targets of IRPS are unknown, so further studies should be conducted to investigate the precise mechanism of IRPS inhibitory effect on PRRSV infection.
... Intermediate Daqingye Folium Isatidis antiviral activity [76,78] anti-Influenza viral activity [76,77] antiviral activity [76,78] anti-Influenza viral activity [75,76] Intermediate Banlangen Radix Isatidis anti-Influenza viral activity [84] antiviral activity [85][86][87][88] anti-Influenza viral activity [79][80][81][82][83][84] Intermediate Zicao Radix Arnebiae antiviral activity [89,90] Intermediate Mianmaguanzhong Dryopteridis Crassirhizomatis Rhizoma anti-Influenza viral activity [91] Intermediate Yinchen Artemisiae Scopariae antiviral activity [92,93] Intermediate Niubangzi Arctii Tosum anti-Influenza viral activity [94] anti-Influenza viral activity [94] Intermediate Huangqin Radix Scutellariae antiviral activity [112][113][114][115][116] anti-Influenza viral activity [98][99][100][101][102][103][104] antiviral activity [109,[112][113][114][115][117][118][119][120][121][122][123][124][125][126][127] anti-Influenza virus activity [98,[100][101][102][105][106][107][108][109][110][111] Intermediate Guanghuoxiang Herba Pogostemonis anti-Influenza viral activity [128] anti-Influenza viral activity [128,129] Intermediate Qinghao Artemisiae Annuae antiviral activity [133][134][135] anti-coronavirus activity [132] Intermediate Fuling Poria antiviral activity [136] and anti-Influenza viral activity [136] Intermediate Zhimu Anemarrhenae rhizoma antiviral activity [65,141] Intermediate Huanglian Rhizoma Coptidis antiviral activity [145] antiviral activity [143][144][145] anti-Influenza viral activity [75] anti-coronavirus activity [142] Intermediate Zhizi Fructus Gardeniae antiviral activity [151] anti-Influenza viral activity [147][148][149] antiviral activity [150,151] anti-Influenza viral activity [75,[146][147][148] Intermediate and severe ...
... Banlangen has anti-influenza viral activities in H1N1, H3N2, H6N2 and H9N2 [79][80][81][82][83][84]. It also has other antiviral activities in cases of pseudorabies virus, hepatitis B virus and porcine reproductive and respiratory syndrome virus [85][86][87][88]. Zicao has antiviral activities in adenovirus type 3 and HIV1 [89,90]. ...
Coronavirus disease 2019 (COVID-19) is a novel, human-infecting β-coronavirus enveloped, positive-sense single-stranded RNA viruses, similar to the severe acute respiratory syndrome (SARS) infection that emerged in November 2002. In traditional Chinese medicine (TCM), the epidemic disease concepts of "febrile epidemics" (wenyi) or "warm diseases" (wenbing) are based on geographic and cultural aspects, and Chinese herbal medicine (CHM) played an important role in the treatment of epidemic diseases. CHM was widely used to treat patients suffered with SARS almost two decades ago during outbreak of SARS, with proven safety and potential benefits. TCM has also been widely used to treat cancer patients for a long history and much of them associate with immunomodulatory activity and are used to treat coronavirus-related diseases. We propose the use of CHM treatment principles for clinical practice, based on four main stages of COVID-19 infection: early, intermediate, severe, and convalescence. We suggest corresponding decoctions that exhibit antiviral activity and anti-inflammatory effects in the early stage of infection; preventing the disease from progressing from an intermediate to severe stage of infection; restoring normal lung function and improving consciousness in the severe stage; and ameliorating pulmonary and vascular injury in the convalescent stage. We summarize the pharmaceutical mechanisms of CHM for treating coronavirus via antiviral, anti-inflammatory and immunomodulatory effects.
... In the experiment of PRRSV replication induced by different concentrations of indigo woad root polysaccharides (10, 20, 40, 80 μg/ml), the results show that IRPS can well resist PRRSV replication in Marc-145 cells, mainly by affecting the adsorption of the virus to cells, thereby reducing the amount of viral RNA and protein synthesis in the infected cell. [20]. The results of this experiment were the same, with the increase of GCP concentration, the content of viral RNA gradually decreased. ...
Glycyrrhiza polysaccharide (GCP) is a natural plant active polysaccharide extracted from traditional Chinese medicine licorice. In this research, we studied the antiviral activity of glycyrrhiza polysaccharide against porcine reproductive and respiratory syndrome virus (PRRSV), a virus of the Arteriviridae family, with a high rate of variation and has caused huge economic losses to the pig industry in various countries since its discovery. Our results show that GCP can inhibit PRRSV replication in a dose-dependent manner. Furthermore, GCP could inhibit the mRNA expression of receptor genes CD163 and NF-κB p65 and promote the mRNA expression of the SLA-7 gene. Because of these results, GCP can be used as a candidate drug to prevent and treat PRRS.
... According to qPCR diagnosis, all piglets have not been vaccinated or infected with common porcine pathogens. The methyl thiazolyl tetrazolium (MTT) assay was used to evaluate the cytotoxicity effect of IRPS in Marc-145 cells [23,52]. Marc-145 cells were inoculated into 96-well culture plates with 2.4 × 10 4 cells/well. ...
(1) Background: In recent years, the porcine reproductive and respiratory syndrome virus (PRRSV) has become a virulent pathogen that has caused devastating diseases and economic losses worldwide in the swine industry. IRPS has attracted extensive attention in the field of virology. However, it is not clear that IRPS has an antiviral effect on PRRSV at gene and protein levels. (2) Methods: We used transcriptomic and proteomic analysis to investigate the antiviral effect of IRPS against PRRSV. Additionally, a microbiome was used to explore the effects of IRPS on gut microbes. (3) Results: IRPS significantly extenuated the pulmonary pathological lesions and inflammatory response. We used transcriptomic and proteomic analysis to investigate the antiviral effect of IRPS against PRRSV. In the porcine model, 1669 differentially expressed genes (DEGs) and 370 differentially expressed proteins (DEPs) were identified. Analysis of the DEG/DEP-related pathways indicated immune-system and infectious-disease (viral) pathways, such as the NOD-like receptor (NLR) signaling pathway, toll-like receptor (TLR) signaling pathway, and Influenza A-associated signaling pathways. It is noteworthy that IRPS can inhibit NLR-dependent gene expression, then reduce the inflammatory damage. IRPS could exert beneficial effects on the host by regulating the structure of intestinal flora. (4) Conclusions: The antiviral effect of IRPS on PRRSV can be directly achieved by omics techniques. Specifically, the antiviral mechanism of IPRS can be better elucidated by screening target genes and proteins using transcriptome and proteome sequencing, and then performing enrichment and classification according to DEGs and DEPs.
... Porcine reproductive and respiratory syndrome virus (PRRSV) is a critical pathogen in pig and can trigger a serious negative impact on the economic development of pigs (26,27), which mainly causes sow reproductive disorders and piglets respiratory diseases, thus resulting in serious economic losses in the world (28). It is a variety of capsule single-stranded positive-chain virus of arteritis virus (29). ...
... Different chemical constituents of R. isatidis have been isolated, including alkaloids, nucleosides, amino acids, organic acids, sterols, flavonoids, lignanoids, volatile oils and polysaccharides (14). Among these, RIP has been demonstrated to serve broad antiviral activity (15)(16)(17)(18), immunomodulation (19)(20)(21), antioxidant activity and anti-inflammatory activity (22). ...
Radix isatidis (R. isatidis) is a commonly used traditional Chinese herbal medicine, which has been used for thousands of years in China and is believed to have the pharmacological properties of heat-clearing and detoxification. Heat-clearing and detoxification are theories of traditional Chinese medicine meaning that R. isatidis could treat febrile disease by clearing heat and reducing swelling. Polysaccharides isolated from R. isatidis by water extraction and alcohol precipitation have exhibited numerous biological activities, including antiviral and immunomodulatory effects. The present study was performed to investigate the immunomodulatory effects of water-soluble R. isatidis polysaccharides (RIPs) on RAW264.7 macrophages and murine splenocytes, and attempt to preliminarily identify the mechanism of immunomodulation. In vitro, RIPs had a low cytotoxicity, as shown by CellTiter 96® AQueous One Solution Cell Proliferation Assay. RAW264.7 cells treated with different concentrations of RIP displayed different morphological changes, from a round shape and aggregation to polygonal shape and dispersion in a dose-dependent manner. In the 5 mg/ml RIP-treated group, the changes of morphology were as same as the lipopolysaccharide-treated group. RIP also significantly enhanced the release of nitric oxide as shown by Griess method, and the secretion of TNF-α and IL-6 in RAW264.7 cells was confirmed by ELISA assay. Western blotting revealed a significant increase of toll-like receptor-4 (TLR-4) in RIP-treated RAW264.7, suggesting that TLR-4 may be associated with the immunomodulatory mechanism of RIP. Animal experiments also demonstrated through ELISA assays a significant increase in IFN-γ and IL-10 levels after the splenocytes of RIP-immunized mice were stimulated by inactivated herpes simplex virus type 2. The immune function of RIP-immunized mice was improved. The present study suggested that RIP could be potentially used as a novel immunomodulator.
... Porcine reproductive and respiratory syndrome virus (PRRSV) is a critical pathogen in pig and can trigger a serious negative impact on the economic development of pigs (26,27), which mainly causes sow reproductive disorders and piglets respiratory diseases, thus resulting in serious economic losses in the world (28). It is a variety of capsule single-stranded positive-chain virus of arteritis virus (29). ...
As transcriptional co-activator of AP-1/Jun, estrogen receptors and NF-κB, nuclear protein RBM39 also involves precursor mRNA (pre-mRNA) splicing. Porcine reproductive and respiratory syndrome virus (PRRSV) causes sow reproductive disorders and piglet respiratory diseases, which resulted in serious economic losses worldwide. In this study, the up-regulated expression of RBM39 and down-regulated of inflammatory cytokines (IFN-β, TNFα, NF-κB, IL-1β, IL-6) were determined in PRRSV-infected 3D4/21 cells, and accompanied with the PRRSV proliferation. The roles of RBM39 altering phosphorylation of c-Jun to inhibit the AP-1 pathway to promote PRRSV proliferation were further verified. In addition, the nucleocytoplasmic translocation of RBM39 and c-Jun from the nucleus to cytoplasm was enhanced in PRRSV-infected cells. The three RRM domain of RBM39 are crucial to support the proliferation of PRRSV. Several PRRSV RNA (nsp4, nsp5, nsp7, nsp10-12, M and N) binding with RBM39 were determined, which may also contribute to the PRRSV proliferation. Our results revealed a complex mechanism of RBM39 by altering c-Jun phosphorylation and nucleocytoplasmic translocation, and regulating binding of RBM39 with viral RNA to prompt PRRSV proliferation. The results provide new viewpoints to understand the immune escape mechanism of PRRSV infection.
Introduction
Drug development has a great deal to gain from the therapeutic and preventative actions of medicinal plants and their derivatives. In order to introduce active medicinal herbs and phytochemicals against viral infections of the respiratory system, we tried to focus on a vast amount of data.
Methods
From 2000 to the present, articles from Web of Science, Scopus, ScienceDirect, PubMed, and Google Scholar were taken into consideration. A combination of respiratory viral infection with keywords of medicinal plants, phytochemicals, flavonoids, saponins, phenolics, terpenoids, alkaloids, and natural products has been used, as well as keywords of antiviral medicinal plants, and antiviral phytochemicals. Pure antiviral compounds and plants with activity against viruses other than respiratory viruses were disregarded and excluded from consideration.
Results
More than eighty phytochemicals and sixty herbs that were subjected to in vitro and in vivo investigations were documented. The current study collects information on multiple medicinal plants, including Camellia sinensis, Sambucus nigra, Pelargonium sidoides, Echinacea purpurea, and Glycyrrhiza glabra, which have been shown to have effective antiviral properties through experimental research. The main antiviral phytochemicals were terpenoids, alkaloids, and flavonoids. Additionally, chemicals including resveratrol, quercetin, chlorogenic acid, amentoflavone A, biochanin, and glycyrrhizin demonstrated efficacy against many viral infections.
Conclusion
For the management of viral infections, the current review on the development of novel antiviral medications is strongly advised. It also provides a possibility to discover anti-Covid-19 lead compounds and can offer supportive treatment in this pandemic situation.
The novel coronavirus disease 2019 (COVID-19) has become a matter of international concern as the disease is spreading exponentially. Statistics showed that infected patients in China who received combined treatment of Traditional Chinese Medicine and modern medicine exhibited lower fatality rate and relatively better clinical outcomes. Both Lian-Hua-Qing-Wen Capsule (LHQWC) and Jin-Hua-Qing-Gan Granule (JHQGG) have been recommended by China Food and Drug Administration for the treatment of COVID-19 and have played a vital role in the prevention of a variety of viral infections. Here, we desired to analyze the broad-spectrum anti-viral capacities of LHQWC and JHQGG, and to compare their pharmacological functions for rational clinical applications. Based on literature mining, we found that both LHQWC and JHQGG were endowed with multiple antiviral activities by both targeting viral life cycle and regulating host immune responses and inflammation. In addition, from literature analyzed, JHQGG is more potent in modulating viral life cycle, whereas LHQWC exhibits better efficacies in regulating host anti-viral responses. When translating into clinical applications, oral administration of LHQWC could be more beneficial for patients with insufficient immune functions or for patients with alleviated symptoms after treatment with JHQGG.
Liquid preservation of boar semen is a preferred method in pig husbandry, and antioxidants to protect against sperm oxidative stress during periods of storage have become the focus of recent research. Through its antioxidant activity, Isatis root polysaccharide (IRPS), a plant extract, can effectively reduce the cellular lipid peroxidation caused by the accumulation of reactive oxygen species inside mitochondria. In the present study, there was examination of the effects of no supplementation (Control) of a semen extender with or supplementation in different concentrations of IRPS (0.2, 0.4, 0.6, 0.8, and 1.2 mg/mL) on sperm quality variables and antioxidant capacity during liquid storage. The results indicate that after prolonged storage (≥ 3 days), the sperm motility was greater in the group supplemented with 0.6 mg/mL IRPS than in the other groups (P < 0.05). The use of this IRPS concentration also resulted in maintanence of acrosome integrity, plasma membrane integrity, mitochondrial membrane potential, and antioxidant capacity of the sperm (P < 0.05). Furthermore, the results of an in vitro fertilization study indicate IRPS at 0.6 mg/mL markedly increased the sperm fertilization capacity (P < 0.01) and embryonic development to the blastocyst stage (P < 0.05). The addition of 0.6 mg/mL IRPS enhanced the antioxidant capacity of boar sperm, resulting in greater preservation of sperm motility and fertilization capacity during liquid storage. These findings indicate that IRPS has the potential to be used as a component of a semen-preserving diluent to maintain sperm quality during storage.
In early 1991, the Dutch pig-industry was struck by the so-called mystery swine disease. Large-scale laboratory investigations were undertaken to search for the etiological agent. We focused on isolating viruses and mycoplasmas, and we tested paired sera of affected sows for antibodies against ten known pig viruses. The mycoplasmas M. hyosynoviae, M. hyopneumoniae, and Acholeplasma laidlawii, and the viruses encephalomyocarditis virus and porcine enterovirus types 2 and 7 were isolated from individual pigs. An unknown agent, however, was isolated from 16 of 20 piglets and from 41 of 63 sows. This agent was characterised as a virus and designated Lelystad virus. No relationship between this virus and other viruses has yet been established. Of 165 sows reportedly afflicted by the disease, 123 (75 per cent) seroconverted to Lelystad virus, whereas less than 10 per cent seroconverted to any of the other virus isolates or to the known viral pathogens. Antibodies directed against Lelystad virus were also found in pigs with mystery swine disease in England, Germany, and in the United States. We conclude that infection with Lelystad virus is the likely cause of mystery swine disease.
In 1987, porcine reproductive and respiratory syndrome (PRRS) was recognized in the USA as a new disease of swine causing late-term reproductive failure and severe pneumonia in neonatal pigs. The syndrome is caused by an RNA virus referred to as PRRS virus (PRRSV), which is classified in the family Arteriviridae. Swine macrophages are the only indigenous cell type known to support PRRSV replication. Direct contact between infected and naive pigs is the predominant route of PRRSV transmission. Exposure of a mucosal surface to PRRSV leads to virus replication in regional macrophages, a prolonged viremia and systemic distribution of virus to other macrophage populations. Reproductive failure induced by PRRSV infection in late-gestation sows is characterized by premature farrowing of stillborn, partially autolyzed, and mummified fetuses. Pneumonia caused by PRRSV infection is more severe in young pigs compared to adults and may be complicated by concurrent bacterial infections. Gross lung lesions associated with PRRSV infection vary from none to diffuse consolidation. In addition, multiple lymph nodes may be markedly enlarged. Microscopically, PRRSV-pneumonia is characterized by multifocal, interstitial thickening by macrophages and necrotic cell debris in alveoli. Other less common microscopic lesions of PRRSV infection include myocarditis, vasculitis, encephalitis, and lymphoid hypertrophy and hyperplasia. In acute or subacute PRRSV infections, serum and lung are the best specimens for diagnosis. Persistent PRRSV infections can be produced by transplacental or intranasal infection. Persistent PRRSV infections are an important factor for virus survival and transmission within a swine herd and will complicate control programs.
A tetrazolium salt has been used to develop a quantitative colorimetric assay for mammalian cell survival and proliferation. The assay detects living, but not dead cells and the signal generated is dependent on the degree of activation of the cells. This method can therefore be used to measure cytotoxicity, proliferation or activation. The results can be read on a multiwell scanning spectrophotometer (ELISA reader) and show a high degree of precision. No washing steps are used in the assay. The main advantages of the colorimetric assay are its rapidity and precision, and the lack of any radioisotope. We have used the assay to measure proliferative lymphokines, mitogen stimulations and complement-mediated lysis.
Porcine reproductive and respiratory syndrome (PRRS) virus was isolated at high frequency from the sera and lungs of pigs affected with Heko-Heko disease. In addition, a considerable amount of Mycoplasma hyorhinis (Mhr) was also isolated from the lungs. Inoculation of gnotobiote pigs with the first isolate of PRRS virus resulted in the reproduction of proliferative and interstitial pneumonia. The virus was recovered from the inoculated pigs for long periods. Superinfection with PRRS virus and Mhr appeared to produce more serious pneumonia than inoculation with PRRS virus alone. In this study, the presence of PRRS virus was confirmed in Japan, and the PRRS virus was considered as being the most important pathogen for Heko-Heko disease.
PRRS disease was first recognised in the USA in 1987 and in Europe in 1990 and since then the disease has spread widely throughout many pig-producing countries. After a severe epidemic phase, the infection has become endemic. The prevalence of infection is generally high in infected countries. However, in areas with a low density of pigs, infection may spread slowly and if infected animal movements are not significant, farm-to-farm spread can be controlled and prevalence of infection maintained at a low level. The PRRS virus (PRRSV) was completely unknown before 1986, and the question of its origin remains unanswered. The exact epidemiologic relationship between American and European strains of PRRSV is difficult to establish because different isolates appear to belong to two distinct sub-populations which are only distantly antigenically related. In the environment, virus survival is optimal when temperature is cold and when ultra-violet light exposure is low (little sunshine). These conditions are easily attained in winter and that may explain why virus spread increases during this period. Pigs of any age (including wild boars) are the only animals known to be naturally infected with PRRSV. Relatively close contact between pigs is the primary factor in virus transmission. Aerial transmission is a second mechanism of spread, particularly in winter and particularly over distances of less than 3 km. A third route of transmission is via semen. The role of fomites is not clearly documented, however since the virus is excreted in faeces and urine, slurry should be considered as a potential source of contamination. Within herds, the virus spreads rapidly with up to 85 to 95% of pigs in a herd becoming sero-positive within two to three months. Thereafter, virus activity persists for extended periods (several month to years). Nevertheless, some authors have reported spontaneous elimination of PRRSV from infected farms. For the future, there remain questions concerning the possible evolution of the disease (in terms of its sanitary and economic impacts), and the possible influence of vaccines on the epidemiological features of PRRS.