We studied virus-inhibiting activity of Baikal skullcap (Scutellaria baicalensis) flavonoids against tick-borne encephalitis virus using various model schemes. The half-maximum cytotoxic concentration (CC50) for the plant extract was found (363.9±58.6 μg/ml). Based on the CC50 and IC50, selective index (SI) was calculated for viricidal (53.4), preventive (50.5), and direct antiviral actions (39.1) and for-intracellular replication of the virus (40.4). Suppression of virus reproduction ≥2.0 lg TCID50 was observed at extract concentration ≥5 μg/ml (viricidal effect), ≥11.2 μg/ml (preventive and direct antiviral effects), and ≥9 μg/ml (intracellular replication). Flavonoids of Baikal skullcap extract produced an in vitro inhibitory effect on tick-borne encephalitis virus due to their direct viricidal activity and direct inhibition of adsorption and intracellular replication of tick-borne encephalitis virus, which determines their value as highly effective antiviral drugs.

中文翻译：

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黄芩黄酮类化合物对蜱传脑炎病毒的抑制作用

我们使用各种模型方案研究了贝加尔黄芩（Scutellaria baicalensis）黄酮类化合物对蜱传脑炎病毒的病毒抑制活性。发现植物提取物的半数最大细胞毒性浓度 (CC50) (363.9±58.6 μg/ml)。基于 CC50 和 IC50，计算了杀病毒 (53.4)、预防 (50.5) 和直接抗病毒作用 (39.1) 以及病毒细胞内复制 (40.4) 的选择指数 (SI)。在提取物浓度≥5 μg/ml（杀病毒作用）、≥11.2 μg/ml（预防和直接抗病毒作用）和≥9 μg/ml（细胞内复制）时观察到病毒繁殖抑制≥2.0 lg TCID50。