prrsv is the pathogen of porcine reproductive and respiratory syndrome (prrs). (d) there is neither attachment nor infection in the absence of cd169 and cd163. tnf, il-1β, and il-6 are essential activators of the nuclear transcription factor, nf-κb (christman et al., 2000; mori et al., 2011). see figure 2 for a simplified summary of activities of the innate and adaptive immune system against viral (prrsv) infection. it comprises of the synthesis of the nested set of mrnas and replication of the viral genomic rna. viral attachment and entry into host cells is the first stage of the viral life cycle. for prrsv, the process can be inhibited by curcumin due to the inhibition of prrsv membrane fusion, n protein and viral progeny production in marc-145 and pam cells (du et al., 2017b). the entry phase of prrsv is made up of early viral attachment and internalization (gao et al., 2013). the expression of n-protein leads to the expression of tnf-α, a proinflammatory cytokine and the activation of nf-κb pathway with a concomitant up-regulation of interleukin-10 (il-10) in pams (wongyanin et al., 2012; song et al., 2013). il-10 is pleiotropic, and it is produced by many types of cells, including monocytes/macrophages, cells that play a critical role in the inflammatory process (moore et al., 2001). some researchers have reported that a host of proteins interact with nsp9 and influence the replication of the virus (dong et al., 2014; li et al., 2014; zhao et al., 2015). (2013) revealed that aqueous extracts from c. volvatus the inhibited the replication of prrsv by targeting and interfering with the activity of viral rdrp. pd impaired the entry and replication of prrsv in marc-145 cells in a dose-dependent manner. and interestingly, treatment with pt caused a significant increase in the level of hs present on the surface of prrsv infected cells. the following have been reported as the roles of tcms in the modulation of cytokines and inhibition of prrsv. the up-regulation of il-1β in prrsv infected pams is mediated by the tlr4/myd88 pathway and nlrp3 inflammasome (bi et al., 2014). pa2 significantly reduced the numbers of prrsv particles in treated marc 145 and pam cells. one of the most ubiquitous and notorious viral diseases that pose a perennial threat to the survival of the global swine industry is prrs. antimicrobial and antioxidant activity of the essential oil and methanol extract of nepeta cataria. interferon-alpha response to swine arterivirus (poav), the porcine reproductive and respiratory syndrome virus. immune response development after vaccination of 1-day-old naïve pigs with a porcine reproductive and respiratory syndrome 1-based modified live virus vaccine. interferon alpha inhibits replication of a live-attenuated porcine reproductive and respiratory syndrome virus vaccine preventing development of an adaptive immune response in swine. “physiology and pathology of innate immune response against pathogens,” in physiology and pathology of immunology, ed. in vitro screening for compounds derived from traditional chinese medicines with antiviral activities against porcine reproductive and respiratory syndrome virus. overview of direct-acting antiviral drugs and drug resistance of hepatitis c virus. the interaction of nonstructural protein 9 with retinoblastoma protein benefits the replication of genotype 2 porcine reproductive and respiratory syndrome virus in vitro. suppression of porcine reproductive and respiratory syndrome virus proliferation by glycyrrhizin. “arterivirus structural proteins and assembly,” in nidoviruses, eds s. perlman, t. gallagher, and e. j. snijder (washington, dc: asm press), 433. fine, a. m. (2000). overview of antibacterial, antitoxin, antiviral, and antifungal activities of tea flavonoids and teas. cryptoporus volvatus extract inhibits porcine reproductive and respiratory syndrome virus (prrsv) in vitro and in vivo. multiple antiviral approaches of (-)-epigallocatechin-3-gallate (egcg) against porcine reproductive and respiratory syndrome virus infection in vitro. pyrithione inhibits porcine reproductive and respiratory syndrome virus replication through interfering with nf-κb and heparanase. porcine reproductive and respiratory syndrome virus nonstructural protein 4 antagonizes beta interferon expression by targeting the nf-κb essential modulator. doi: 10.1007/s12013-011-9271-8 huber, j. p., and farrar, j. d. (2011).