Allitridin inhibits human cytomegalovirus replication in vitro.

Human cytomegalovirus (HCMV) has been associated with a wide spectrum of diseases. There is currently no effective treatment for eliminating the virus. Garlic bulb extract has been reported to possess anti-viral efficacy. This study aimed to investigate the expression of the immediate­early (IE; ul122 and ul123), early (E; ul54) and late (L; ul83) genes of HCMV as well as the inhibitory effect of allitridin on the transcription levels of these genes. The results indicated that a HCMV gene expression cascade occurred, and that the deletion of IE72 had no influence on the transcription of the ul122 gene, while it led to significant reductions of ul54 and ul83 mRNA expression levels. Additionally, allitridin effectively suppressed the transcription of the HCMV IE, E and L genes; the inhibition rates of the transcription of the ul122 and ul123 genes were higher compared with those of ul54 and ul83 mRNA expression, while the expression of the IE genes was not significantly reduced by ganciclovir (GCV). Our results indicate that the HCMV IE72 deletion mutant strain affects the transcription of the virus downstream gene, allitridin inhibits HCMV infection in vitro, and that the IE genes may be the key target of allitridin in its action against HCMV.

Allium sativum-derived allitridin inhibits Treg amplification in cytomegalovirus infection.

This study investigated the effects of allitridin compound on murine cytomegalovirus (MCMV)-induced regulatory T cell (Treg; CD4(+) CD25(+) Foxp3(+) ) amplification in vivo and in vitro. One hundred twenty MCMV-infected mice were allocated at random into two groups for treatment with allitridin or placebo. Another 120 mock-infected mice were randomly allocated as controls for the allitridin treatment and placebo treatment groups. The mice were euthanized at various time points after infection (out to 120 days) to evaluate the effects of treatment on Treg presence and function, as well as MCMV infective load. Co-culture with mouse embryo fibroblasts (MEF) and MCMV was performed to evaluate allitridin-mediated Treg and anti-CMV effects. The maximum tolerance concentration (MTC) of allitridin was used to treat cells for 3 days. Changes in Foxp3 mRNA and protein levels, percentages of T cell subsets, and Treg-related cytokines (IL-10 and TGF-ß) were measured. Allitridin treatment did not influence Foxp3 expression and Treg proportion in uninfected mice, but did down-regulate each in infected mice during the chronic infection period. Additionally, allitridin treatment reduced the MCMV load in salivary glands. MTC allitridin treatment of co-cultures partially blocked MCMV induction of Foxp3 mRNA and protein expression. In vitro treatment with allitridin also increased significantly the percentages of Tc1, Tc2, and Th1, reduced the secreted levels of IL-10 and TGF-ß1, and significantly suppressed viral loads. In conclusion, allitridin can promote MCMV-induced Treg expansion and Treg-mediated anti-MCMV immunosuppression. Therefore, allitridin may be useful as a therapeutic agent to enhance the specific cellular immune responses against CMV.

[An experimental study on the effect of allitridin on inhibiting the expression of HCMV immediate-early antigens in vitro].

OBJECTIVE: To investigate the prophylactic, blocking and therapeutic effects of Allitridin on inhibiting HCMV proliferation by measuring the expression level of HCMV IEA in vitro and explore the mechanism of Allitridin anti-HCMVactivity. METHODS: The cytotocity of Allitridin was evaluated through MTT colorimetry and cell morphology. HCMV IEA levels were quantitatively detected by Flow Cytometry respectively under the following conditions: Allitridin was given before (pretreated for 24 h), during, or after viral inoculation in which serial doses (maximum tolerant concentration, MTC for human embryo lung cells, HEL) of Allitridin was used to treat HCMV infected HLE cells for different durations (24, 48, 72, 96 h) after viral infection. RESULT: The MTC of Allitridin was 9.60 mg x L(-1). Allitridin remarkably inhibited the expression of HCMV IEA in vitro. Within MTC, the inhibitory rate had a significant correlation with its dosage (r = 0.96). At the time of IEA highest expression (72 h after infection), inhibitory effect was the greatest (inhibitory rate: 89.3%). With pretreatment of Allitridin, the inhibitory rate was 28.6%. When Allitridin was used together with HCMV inoculation, IEA inhibitory rate was only 10.3%. CONCLUSION: Allitridin can inhibit HCMV, IEA expression in vitro remarkably which is probably one of the major mechanisms of Allitridin anti-HCMV activity because IEAs are the very important regulatory factors for the expression of all HCMV genes. Its therapeutic effect is the best at the peak stage of IE1 gene expression (72 h after infection) but it has low prophylactic and little blocking effect.