Identification of the crucial parameters regarding the efficacy of ribavirin therapy in Crimean-Congo haemorrhagic fever (CCHF) patients: a systematic review and meta-analysis.

OBJECTIVES: Recently, ribavirin has been suggested as a therapeutic approach in Crimean-Congo haemorrhagic fever (CCHF) patients; however, there are controversial findings about its efficacy. In the current study, a meta-analysis was systematically performed to assess the effectiveness of ribavirin administration regarding CCHF patient survival and to explore the most important influential parameters for its efficacy. METHODS: All of the outcomes of the clinically studied CCHF patients who were treated with ribavirin were included in the meta-analysis. RESULTS: Overall, 24 studies met our criteria. Although the studies did not have high quality there was no heterogeneity and publication bias across studies. The results indicated that the administration of ribavirin to CCHF patients significantly decreased the mortality rate (by 1.7-fold) compared with those who did not receive this medication. Furthermore, it was found that the prescription of ribavirin in the initial phase of disease was more effective, and a delay in the start of treatment resulted in a 1.6-fold increase in mortality rate. In addition, interventional therapy resulted in an ∼2.3-fold reduction in the mortality rate of those who received ribavirin along with corticosteroids compared with those who were treated with ribavirin monotherapy. CONCLUSIONS: This meta-analysis reveals that ribavirin should be considered as a crucial antiviral drug in the therapeutic approach used for CCHF patients, especially in early phases of the disease. Additionally, it seems that the administration of corticosteroids alongside ribavirin can play an effective role in alleviation of the disease status, particularly in haemorrhagic phases.

In vitro evaluation of anti-herpes simplex-1 activity of three standardized medicinal plants from Lamiaceae.

BACKGROUND: Rosmarinic acid (RA) is a phenolic acid with antioxidant and anti-viral effects. We have studied anti-herpes simplex virus type 1 (HSV-1) effect of three medicinal plants from Lamiaceae family which have been standardized on the basis of RA content. MATERIALS AND METHODS: Methanolic extract of Teucrium polium, Ziziphora clinopoides, and Salvia rhytidea was prepared by maceration method and RA content of the plants was determined using a spectrophotometric method. Maximum nontoxic concentration (MNTC) of the extracts was determined using neutral red method. Serial dilutions of extracts up to MNTC were examined on Vero cells for anti-HSV-1 effect by plaque assay in comparison to acyclovir as a positive control. RESULTS: Among the tested extracts, T. polium contained the highest percentage of RA (1.8%w/w) and exhibited the least toxicity (MNTC = 1000 µg/ml). The greatest anti-HSV-1 was shown by T. polium and Z. clinopoides extracts which exhibited both time and concentration-dependent plaque inhibition. CONCLUSION: Considering the low toxicity and significant anti-viral effect of T. polium extract, this plant would prove valuable as an active anti-viral drug.

Anti herpes simplex-1 activity of a standard extract of Zataria multiflora Boiss.

In Rosmarinic Acid (RA) is a phenolic acid which has many biological activities such as antioxidant, anti inflammatory and anti viral effects. In the present study, we have studied the anti Herpes simplex type 1 (HSV-1) effect of methanolic extract of Zataria multiflora which has been standardized on the basis of RA content. Methanolic extract of Zatria multiflora was prepared by maceration method. RA content of plant extract was measured by spectrophotometry method using the calibration curve of RA. Maximum non Toxic Concentration (MNTC) of the plant was determined by neutral red method. MNTC and lower serial dilutions of extract were examined in vitro on vero cells for their effect against HSV-1 using a plaque reduction assay. Acyclovir was used as positive control. Time-dependent antiviral effect of Z. multiflora was studied by adding the extract to HSV-1 infected vero cells at different stages of infection. The percentage of RA was determined as 2.2% in Z. multiflora. This plant was effective in all used concentrations and significantly reduced plaque formation up to 100% at concentrations of 800 and 1000 microg mL(-1). Clearly Z. multiflora revealed both a time and concentration inhibition. It seems that the presence of rosmarinic acid would be a determining factor for anti HSV activity of Z. multiflora.