Synthesis and biological evaluation of berberine derivatives as a new class of broad-spectrum antiviral agents against Coxsackievirus B.

A series of novel berberine (BBR) analogues were prepared and tested for their antiviral potencies against six different genotype Coxsackievirus B (CVB1-6) strains, taking BBR core for structural modification. Structure-activity relationship (SAR) research revealed that introduction of a primary amine through a linker at position 3 might be beneficial for both antiviral activity and safety. Compound 14c displayed most promising inhibitory potency with IC50 values of 3.08-9.94 µM against tested CVBs 2-6 strains and satisfactory SI value of 34.3 on CVB3, better than that of BBR. Also, 14c could inhibit CVB3 replication through down-regulating the expression of VP1 protein and VP1 RNA. The mechanism revealed that 14c could suppress host components JNK-MAPK, ERK-MAPK and p38-MAPK activation. Therefore, BBR derivatives were considered to be a new class of anti-CVB agents with an advantage of broad-spectrum anti-CVB potency.

Luteolin inhibits CVB3 replication through inhibiting inflammation.

Coxsackievirus B3 (CVB3) infection causes many inflammation-related diseases, such as viral myocarditis and aseptic meningitis. However, no vaccines or drugs have been approved for prevention or therapy of CVB3-induced diseases. In this study, luteolin (3,4,5,7-tetrahydroxyflavone) had been found that could dose-dependently reduce the production of viral progeny and synthesis of CVB3 RNA and protein. The luteolin-mediated inhibition of CVB3 was found to be mechanistically possible, at least in part, through depressing the phosphorylation of p38 MAPK and JNK MAPK, and inhibiting NF-κB nuclear translocation and subsequently attenuated the expression of inflammatory cytokines in CVB3-infected cells. Luteolin may be a potential agent or supplement against CVB3 infection by inhibiting inflammation.

Santin inhibits influenza A virus replication through regulating MAPKs and NF-κB pathways.

Influenza A virus (IAV) causes high morbidity and significant mortality worldwide. Given the limitations of existing vaccination and antiviral drugs, it is urgent to develop new anti-influenza drugs. Flavonoids are natural polyphenolic compounds with broad applications to treatments for influenza infection. In this study, we demonstrated that santin, a flavonoid compound, showed anti-influenza activity in MDCK and THP-1 cells. Mechanistic studies revealed that santin depressed the phosphorylation of p38 MAPK, JNK/SAPK, ERK, and NF-κB factor and subsequently attenuated the expression of inflammatory cytokines in IAV-infected cells. Thus, santin is a potential candidate for the future development of anti-IAV drugs.

Synthesis and Evolution of Berberine Derivatives as a New Class of Antiviral Agents against Enterovirus 71 through the MEK/ERK Pathway and Autophagy.

Taking berberine (BBR) as the lead, 23 new BBR derivatives were synthesized and examined for their antiviral activities against four different genotype enterovirus 71 (EV71) strains with a cytopathic effect (CPE) assay. Structure-activity relationship (SAR) studies indicated that introduction of a suitable substituent at the 9-position might be beneficial for potency. Among them, compound 2d exhibited most potent activities with IC50 values of 7.12⁻14.8 µM, similar to that of BBR. The effect of 2d was further confirmed in a dose-dependent manner both in RNA and protein level. The mechanism revealed that 2d could inhibit the activation of MEK/ERK signaling pathway. Meanwhile, it could suppress the EV71-induced autophagy by activating AKT and inhibiting the phosphorylation of JNK and PI3KIII proteins. We consider BBR derivatives to be a new family of anti-EV71 agents through targeting host components, with an advantage of broad-spectrum anti-EV71 potency.

Corydaline inhibits enterovirus 71 replication by regulating COX-2 expression.

Enterovirus 71 (EV71) is a huge threat to the worldwide public health and there is no approved antiviral drug for EV71-induced disease therapy. Corydaline exists antiallergic and antinociceptive activities, but the anti-EV71 activity of corydaline is still not reported. In this study, corydaline could suppress the expression of viral structural and non-structural proteins. Furthermore, corydaline inhibits EV71 replication by suppressing the COX-2 expression and the phosphorylation of JNK MAPK and P38 MAPK but not ERK MAPK in vitro. Based on these findings, corydaline could be a potential lead or supplement for the development of new anti-EV71 agents in the future.

[Recombinant human interferon alpha 2b broad-spectrum anti-respiratory viruses pharmacodynamics study in vitro].

This study is to investigate the effect of recombinant human interferon alpha 2b against broad-spectrum respiratory viruses in vitro. At the cellular level, the effect of the recombinant human interferon alpha 2b on influenza A virus was detected using real-time fluorescence quantitative RT-PCR. The effects of the recombinant human interferon alpha 2b on influenza B virus, parainfluenza virus, respiratory syncytial virus (RSV) and coronavirus were detected using cytopathic effect (CPE) method. In this study, the therapeutic index of recombinant human interferon alpha 2b anti-HPIV was 1476.63, the therapeutic index of recombinant human interferon alpha 2b anti-RSV was 141.37, the therapeutic index of recombinant human interferon alpha 2b anti-coronavirus was more than 2820.76, and the antiviral effect of recombinant human interferon alpha 2b was better than ribavirin (RBV). Recombinant human interferon alpha 2b has a stronger inhibitory effect on different influenza A virus RNA than drug control. The therapeutic index of recombinant human interferon alpha 2b anti-influenza B virus was 2.74, with modest effect. Recombinant human interferon alpha 2b in vitro has broad spectrum antiviral activities, low toxicity and high therapeutic index. Recombinant human interferon alpha 2b is expected to become the efficient medicine in clinical against respiratory viruses, as well as provide better services for prevention and treatment of respiratory viruses' infections.

The antiviral effect of 7-hydroxyisoflavone against Enterovirus 71 in vitro.

Enterovirus 71 (EV71) is the major causative agent of hand foot and mouth disease. And EV71 causes epidemics worldwide, particularly in the Asia-Pacific region. Unfortunately, currently there is no approved vaccine or antiviral drug for EV71-induced disease prevention and therapy. In screening for anti-EV71 candidates, we found that 7-hydroxyisoflavone was active against EV71. 7-Hydroxyisoflavone exhibited strong antiviral activity against three different EV71 strains. The 50% inhibitory concentration range was between 3.25 and 4.92 µM by cytopathic effect assay. 7-Hydroxyisoflavone could reduce EV71 viral RNA and protein synthesis in a dose-dependent manner. Time course study showed that treatment of Vero cells with 7-hydroxyisoflavone at indicated times after EV71 inoculation (0-6 h) resulted in significant antiviral activity. Results showed that 7-hydroxyisoflavone acted at an early step of EV71 replication. 7-Hydroxyisoflavone also exhibited strong antiviral activity against coxsackievirus B2, B3, and B6. In short, 7-hydroxyisoflavone may be used as a lead compound for anti-EV71 drug development.

Synthesis and anti-influenza virus activities of a novel class of gastrodin derivatives.

A series of substituted aryl glycoside analogues of gastrodin have been identified as potential anti-influenza agents. The most potent inhibitor 1a exhibited moderate inhibitory activity against the A/Hanfang/359/95(H3N2) and A/FM/1/47(H1N1) strains of the influenza A virus (IC(50) values of 44.40 and 34.45 µM, respectively) and the oseltamivir-null B/Jifang/13/97 strain of influenza B (IC(50) value of 33.01 µM). In this article, multiple doses of compound 1a (80 mg/kg/day, oral administration) were used for the treatment of mice infected with influenza A/FM/1/47-MA (H1N1), and surprisingly we found that compound 1a significantly increased the number of survivors and prolonged the mean survival time. The preliminary studies on the mechanism of antiviral activity showed no interaction between compound 1a and the neuraminidase or the M2 protein. The novel target to overcome drug resistance combined with its good in vivo profile support compound 1a to be a new lead for further development of antiviral agents.

Synthesis and antiviral activity of N-phenylbenzamide derivatives, a novel class of enterovirus 71 inhibitors.

A series of novel N-phenylbenzamide derivatives were synthesized and their anti-EV 71 activities were assayed in vitro. Among the compounds tested, 3-amino-N-(4-bromophenyl)-4-methoxybenzamide (1e) was active against the EV 71 strains tested at low micromolar concentrations, with IC50 values ranging from 5.7 ± 0.8-12 ± 1.2 µM, and its cytotoxicity to Vero cells (TC50 = 620 ± 0.0 µM) was far lower than that of pirodavir (TC50 = 31 ± 2.2 µM). Based on these results, compound 1e is a promising lead compound for the development of anti-EV 71 drugs.

[Establishment of EV71 animal models with 2-week-old BALB/c mice].

Animal model is very important for anti-EV71 (enterovirus 71) drug and vaccine development. 1-day-old suckling EV71 mouse model is the main in vivo model used in China. 1-day-old suckling EV71 mouse is too small to perform antiviral experiment. And the route of administration and dosage capacity are also restricted. A strong virulence EV71 virus strain was selected after screening from five EV71 strains with 1-day-old suckling mice. A mouse-adapted EV71 strain with increased virulence in 12-day-old suckling mice, EV71-M5, was generated after five serial passages of the parental EV71 strain in mice. Virus titers of EV71 infected mice heart, liver, spleen, lung, kidney, small intestine, brain and muscle tissue were determined by cytopathic effect (CPE) assay. The virus used in this model is the first isolated EV71 strain in China. And 2-week-old suckling mice were used in this model. This is a supplement for the EV71 animal model in China. Establishment of this EV71 model will provide an attractive platform for anti-EV71 vaccine and drug development.

Synthesis, structure-activity relationship and in vitro biological evaluation of N-arylethyl isoquinoline derivatives as Coxsackievirus B3 inhibitors.

Currently, there is no approved antiviral drug for the infection caused by enteroviruses. A series of novel N-arylethyl isoquinoline derivatives defined with substituents on the ring A and C were designed, synthesized and evaluated in vitro for their activities against Coxsackievirus B3 (CVB3). The primary structure-activity relationship revealed that substituents on the ring A were not beneficial for the activity. Among these analogs synthesized, compound 7f bearing a methylenedioxy at the R(4) and R(5) positions afforded an anti-CVB3 activity and a reasonable selectivity index (SI=26.8); furthermore, 7f exhibited a moderate activity against enterovirus 71 (EV71) with SI value of 9.0. Thus it has been selected as an anti-enteroviral lead compound for further investigation.

PML Suppresses Influenza Virus Replication by Promoting FBXW7 Expression.

Influenza A viruses (IAV) are responsible for seasonal flu epidemics, which can lead to high morbidity and mortality each year. Like other viruses, influenza virus can hijack host cellular machinery for its replication. Host cells have evolved diverse cellular defense to resist the invasion of viruses. As the main components of promyelocytic leukemia protein nuclear bodies (PML-NBs), PML can inhibit the replication of many medically important viruses including IAV. However, the mechanism of PML against IAV is unclear. In the present study, we found PML was induced in response to IAV infection and ectopic expression of PML could inhibit IAV replication, whereas knockdown of endogenous PML expression could enhance IAV replication. Further studies showed that PML increased the expression of FBXW7 by inhibiting its K48-linked ubiquitination and enhanced the interaction between FBXW7 and SHP2, which negatively regulated IAV replication during infection. Moreover, PML stabilized RIG-I to promote the production of type I IFN. Collectively, these data indicated that PML inhibited IAV replication by enhancing FBXW7 expression in the antiviral immunity against influenza virus and extended the mechanism of PML in antiviral immunity.

Effect of Preoperative Double-J Ureteral Stenting before Flexible Ureterorenoscopy on Stone-free Rates and Complications.

The effect of preoperative Double-J (DJ) ureteral stenting before flexible ureterorenoscopy (FURS) in the treatment for urinary stones was evaluated. We retrospectively enrolled 306 consecutive patients who underwent FURS from Jan. 2014 to Dec. 2017. All the patients were classified into two groups according to whether they had DJ ureteral stenting before FURS. Baseline characteristics (age, sex, stone location, stone size, surgical success rate, operation time, stone-free rate of the first day after surgery, stone-free rate of the first month after surgery, total complication rate) were compared using Chi-square test for categorical variables and Kruskal-Wallis test for continuous variables. In total, 306 patients were included in this study. The group of DJ stenting before FURS included 203 (66.3%) patients, and non-DJ stenting before FURS was observed in 103 (33.7%) patients. The group of DJ stenting before FURS was significantly associated with a shorter operation time (53.8 vs. 59.3 min, P<0.001), a higher stone-free rate of the first day after surgery (69.0% vs. 51.5%, P=0.003). However, statistical significant differences were not found in the age, sex, stone location, stone size, surgical success rate, stone-free rate of the first month after surgery (89.2% vs. 81.6%, P=0.065) and total complication rate (5.4% vs. 9.7%, P=0.161) between the two groups. Preoperative DJ ureteral stenting before FURS could reduce the operation time and increase stone-free rate of the first day after surgery. However, it might not benefit the stone-free rate of the first month after surgery and reduce the complication rate. Preoperative DJ stenting should be not routinely performed.

heme oxygenase-1 agonist CoPP suppresses influenza virus replication through IRF3-mediated generation of IFN-α/ß.

The innate immunity plays an essential role in defending infection of Influenza A virus (IAV). The regulatory effect of heme oxygenase-1 (HO-1), a cytoprotective enzyme, on innate immunity has been revealed. In this study, we aim to confirm the antiviral effect of CoPP (Cobaltic Protoporphyrin IX Chloride), a potent HO-1 inducer on IAV infection and elucidate the possible mechanism of HO-1-mediated host innate immune responses. Our results show that CoPP exhibits broad-spectrum antiviral activities against IAV. Furthermore, CoPP attenuates IAV replication through inducing type I IFNs response, not depending on HO-1 enzymatic activity. We also provide direct evidence that HO-1-mediated type I IFN response activation is largely due to its interaction with IRF3, which then promotes IRF3 phosphorylation and nuclear translocation. These results suggest that HO-1 agonist CoPP suppresses IAV replication through IRF3-mediated generation of IFN-α/ß. Thus, therapeutic induction of HO-1 might be a promising strategy to combat IAV epidemics.

SAR evolution and discovery of benzenesulfonyl matrinanes as a novel class of potential coxsakievirus inhibitors.

MATERIALS & METHODS: Fifty-one novel 12N-substituted matrinic acid derivatives were synthesized and evaluated for their anti-coxsackievirus B3 activities. RESULTS: Structure-activity relationship studies revealed that the 11-side chain could be determinant for the selectivity index by adjusting overall lipophilicity, and 11-butane was the best one for both potency and druggability. The optimized 35d showed the broad-spectrum anti-coxsackieviruse effects, an excellent pharmacokinetics and a good safety profile. More importantly, it displayed a potential effect for the pleconaril-resistant coxsackievirus B3 as well. Its mode of action is targeting on the viral transcription and translation stage, a different mechanism from that of pleconaril. CONCLUSION: Thus, we considered that 35d is a promising anti-enteroviral candidate for the treatment of various diseases infected with coxsackieviruses.

Rupestonic acid derivative YZH-106 suppresses influenza virus replication by activation of heme oxygenase-1-mediated interferon response.

Given the limitation of available antiviral drugs and vaccines, there remains to be a pressing need for novel anti-influenza drugs. Rupestonic acid derivatives were reported to have an anti-influenza virus activity, but their mechanism remains to be elucidated. Herein, we aim to evaluate the antiviral activity of YZH-106, a rupestonic acid derivative, against a broad-spectrum of influenza viruses and to dissect its antiviral mechanisms. Our results demonstrated that YZH-106 exhibited a broad-spectrum antiviral activity against influenza viruses, including drug-resistant strains in vitro. Furthermore, YZH-106 provided partial protection of the mice to Influenza A virus (IAV) infection, as judged by decreased viral load in lungs, improved lung pathology, reduced body weight loss and partial survival benefits. Mechanistically, YZH-106 induced p38 MAPK and ERK1/2 phosphorylation, which led to the activation of erythroid 2-related factor 2 (Nrf2) that up-regulated heme oxygenase-1 (HO-1) expression in addition to other genes. HO-1 inhibited IAV replication by activation of type I IFN expression and subsequent induction of IFN-stimulated genes (ISGs), possibly in a HO-1 enzymatic activity-independent manner. These results suggest that YZH-106 inhibits IAV by up-regulating HO-1-mediated IFN response. HO-1 is thus a promising host target for antiviral therapeutics against influenza and other viral infectious diseases.

Antiviral Activities of Several Oral Traditional Chinese Medicines against Influenza Viruses.

Influenza is still a serious threat to human health with significant morbidity and mortality. The emergence of drug-resistant influenza viruses poses a great challenge to existing antiviral drugs. Traditional Chinese medicines (TCMs) may be an alternative to overcome the challenge. Here, 10 oral proprietary Chinese medicines were selected to evaluate their anti-influenza activities. These drugs exhibit potent inhibitory effects against influenza A H1N1, influenza A H3N2, and influenza B virus. Importantly, they demonstrate potent antiviral activities against drug-resistant strains. In the study of mechanisms, we found that Xiaoqinglong mixture could increase antiviral interferon production by activating p38 MAPK, JNK/SAPK pathway, and relative nuclear transcription factors. Lastly, our studies also indicate that some of these medicines show inhibitory activities against EV71 and CVB strains. In conclusion, the 10 traditional Chinese medicines, as kind of compound combination medicines, show broad-spectrum antiviral activities, possibly also including inhibitory activities against strains resistant to available antiviral drugs.

Geldanamycin, a ligand of heat shock protein 90, inhibits herpes simplex virus type 2 replication both in vitro and in vivo.

Previously, we discovered geldanamycin, a ligand of heat shock protein 90, effectively inhibited herpes simplex virus type 1 replication in vitro and in vivo (mouse encephalitis model). In this study, we demonstrate that geldanamycin has very strong activities against herpes simplex virus type 2 in vitro and in vivo (mouse vagina model). In mouse vagina model, administration of geldanamycin suspension to vagina after virus infection protected the infected mice from death and increased the average survival days in a dose-dependent manner. Geldanamycin also significantly reduced virus shedding from mouse vagina. All geldanamycin-treated groups were statistically significant when compared with the infected control group. The high-dose group of geldanamycin (5.72 mg kg(-1)) was better than acyclovir group (2.86 mg kg(-1)). All geldanamycin vaginal administration mock-infected groups did not show significant body weight loss. Although geldanamycin has strong antiviral activities against various DNA and RNA viruses, geldanamycin is not suitable for systemic administration because of its high toxicity. We consider that geldanamycin is a candidate of topical usage for the treatment of herpes simplex virus type infections.

Synthesis and antiviral activity of substituted bisaryl amide compounds as novel influenza virus inhibitors.

The influenza virus is a persistent cause of mortality and morbidity on an annual basis and thus presents itself as an important target for pharmaceutical investigation. In this work, substituted bisaryl amide compounds were found to be a new class of potential anti-influenza agents, and a series of substituted bisaryl amide compounds were synthesised and evaluated for their anti-influenza virus activities. The analysis of the results produced a preliminary structure-activity relationship study (SAR). Compounds 1a, 1g, 1h, 1j, 1l and 1n exhibited clear antiviral activities against the influenza A (A/Guangdong Luohu/219/2006, H1N1) virus with 50% inhibitory concentrations (IC(50)) for virus growth ranging from 12.5 to 59.0 µM. Specifically, compound 1j also possessed antiviral activity against both oseltamivir-resistant influenza (A/Jinnan/15/2009) virus and influenza B (B/Jifang/13/97) virus with IC(50) values of 9.2 µM and 21.4 µM, respectively. Compound 1j is thus worth further investigation as an anti-influenza virus candidate.