METHODS: Aqueous extract of S. baicalensis was prepared by microwave energy steam evaporation method (MEGHE™), and the anti-dengue virus replication activity was evaluated using the foci forming unit reduction assay (FFURA) in Vero cells. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was used to determine the actual dengue virus RNA copy number. The presence of baicalein, a flavonoid known to inhibit dengue virus replication was determined by mass spectrometry.
RESULTS: The IC(50) values for the S. baicalensis extract on Vero cells following DENV adsorption ranged from 86.59 to 95.19 μg/mL for the different DENV serotypes. The IC(50) values decreased to 56.02 to 77.41 μg/mL when cells were treated with the extract at the time of virus adsorption for the different DENV serotypes. The extract showed potent direct virucidal activity against extracellular infectious virus particles with IC(50) that ranged from 74.33 to 95.83 μg/mL for all DENV serotypes. Weak prophylactic effects with IC(50) values that ranged from 269.9 to 369.8 μg/mL were noticed when the cells were pre-treated 2 hours prior to virus inoculation. The concentration of baicalein in the S. baicalensis extract was ~1% (1.03 μg/gm dried extract).
CONCLUSIONS: Our study demonstrates the in vitro anti-dengue virus replication property of S. baicalensis against all the four DENV serotypes investigated. The extract reduced DENV infectivity and replication in Vero cells. The extract was rich in baicalein, and could be considered for potential development of anti-DENV therapeutics.
METHODS: A retrospective review of consecutive HCV patients treated with PegIFN/RBV in 2004 to 2012.
RESULTS: A total of 273 patients received treatment. The mean age was 44.16 ± 10.5 years and 76% were male. The top 2 self-reported risks were blood or blood product transfusion before 1994 and injection drug use, found in 57.1% of patients. The predominant HCV genotype (GT) was 3 at 60.6%, second was GT1 at 36.1% and other GTs were uncommon at about 1% or less. About half of our patients have high baseline viral load (>800,000 iu/ml), 18.3% had liver cirrhosis and 22.3% had HIV co-infection. Co-morbid illness was found in 42.9%, hypertension and type 2 diabetes were the two most common. The overall sustained virological response (SVR) by intention-to-treat analysis were 54.9% (n=150/273), 41.2% (40/97) for GT1, 100% (5/5) for GT2 and 62% (101/163) for GT3. Subgroup analysis for HCV monoinfected, treatment naïve showed SVR of 49.2% (31/63) for GT1, 100% (5/5) for GT2 and 67% (69/103) for GT3. In HCV mono-infected and treatment experienced (n=29), the SVR was 28.6% (4/14) for GT1, 21.4% (69/103) for GT3. In the HIV/HCV co-infected, treatment naïve (n=56), the SVR was 28.6% (4/14) for GT1 and 64.3% (27/42) for GT3. Treatment naïve GT3 mono-infected patients had a statistically significant higher SVR compared to treatment experienced patients (P=0.001). In GT3 patients who achieved rapid virological response, the SVR was significantly higher at 85.2% (P< 0.001). The SVR for cirrhotics were low especially for GT1 at 21% (4/19) and 31% (4/13) based on all patients and treatment naïve HCV monoinfected respectively. In GT3 cirrhotics the corresponding SVR were 57.1% (16/28) and 60.9% (14/23). Premature discontinuation rate was 21.2% with the majority due to intolerable adverse events at 12.1%.
CONCLUSIONS: In our routine clinical practice, the HCV patients we treated were young, predominantly of GT3 and many had difficult-to-treat clinical characteristics. The SVR of our patients were below those reported in Asian clinical trials but in keeping with some "real world" data.