In vitro anti-reovirus activity of kuraridin isolated from Sophora flavescens against viral replication and hemagglutination

Abstract

In this study, we evaluated the anti-reovirus activity of kuraridin isolated from the roots of Sophora flavescens. In particular, we focused on whether this property is attributable to direct inhibition of reovirus attachment and/or inhibition of viral replication with the aid of time-of-addition (pre-treatment, simultaneous treatment, and post-treatment) experiments. No significant antiviral activity of kuraridin was detected in the pre-treatment assay. In the simultaneous assay, the 50% effective inhibitory concentrations (EC50) of kuraridin were 15.3-176.9 μM against human type 1-3 reoviruses (HRV1-3) and Korean porcine reovirus (PRV). Kuraridin completely blocked binding of viral sigma 1 protein to sialic acids at concentrations lower than 82.5 μM in the hemagglutination inhibition assay. Moreover, kuraridin inhibited HRV1-3 and PRV viral replication with EC50 values of 14.0-62.0 μM. Quantitative real-time PCR analysis disclosed strong suppression of reovirus RNA synthesis at the late stage (18 h) of virus replication by kuraridin. The viral yields of kuraridin-treated cells were significantly reduced at 24 h post-infection, compared with DMSO-treated cells. Our results collectively suggest that kuraridin inhibits virus adsorption and replication by inhibiting hemagglutination, viral RNA and protein synthesis and virus shedding, supporting its utility as a viable candidate antiviral drug against reoviruses.

Genipin inhibits rotavirus-induced diarrhea by suppressing viral replication and regulating inflammatory responses

“…Genipin also suppressed rotavirus replication at two distinct stages of the viral replication cycle: the rotavirus RNA replication cycle in MA104 cells was significantly inhibited at the early stage in pre-treatment and the late stage in post-treatment. These results are supported by previous studies, which indicated that kuraridin isolated from Sophora flavescens and iridoid glycosides extracted from Fructus Gardeniae have inhibited reovirus and influenza virus by replication cycles in pre-and post-treatment 37,38 . Additionally, genipin showed viricidal effects against rotavirus.…”

Susceptibility of Campylobacter Strains to Selected Natural Products and Frontline Antibiotics

“…The MIC of Kuradin against all isolates was 48 µg/mL which is more or less similar to the value of 50 µg/mL reported for S. aureus [ 55 ], but higher than a value of 20 µg/mL previously reported for different bacteria [ 35 ]. Kuraridin, from Sophora flavescens , has been previously reported as a potential antimicrobial compound [ 35 , 36 , 56 ]. The MIC of emodin against C. jejuni was 50 µg/mL, which is slightly lower than the 70–90 µg/mL previously reported for P. aeruginosa and S. aureus [ 34 ].…”

“…Clove oil and its major phytochemical eugenol are known for their antimicrobial and virulence-modulating activities against Campylobacter species [ 28 , 33 ]. Emodin has been found to inhibit Pseudomonas aeruginosa [ 34 ], while kuraridin had activity against different pathogenic bacteria [ 35 ] and reoviruses [ 36 ]. Cinnamaldehyde has been reported to possess antimicrobial properties against various pathogens [ 37 ].…”

Biologically active prenylated flavonoids from the genus Sophora and their structure–activity relationship—A review

“…The Xinjiang Chinese Herbal Medicine Handbook has reported that it exerts detoxification, pain relief, and insecticidal effects. Local people use it to treat dysentery, stomachache, leucorrhea disorder, eczema, psoriasis, and so on (Huang, Wang, Zhu, Zhang, & Zhang, ; Iinuma et al, ; Krishna, Rao, & Banji, ; Kwon, Basnet, et al, ; Ruangrungsi et al, ; Toda & Shirataki, ).…”