基于神经氨酸酶活性检测的板蓝根品质的生物评价

采用流感病毒神经氨酸酶 (NA) 体外活性荧光检测法测定板蓝根的NA抑制生物活性, 并建立板蓝根抗病毒生物效价检测方法。研究表明板蓝根具有抑制NA的活性, IC₅₀ = (0.90 ± 0.20) mg·mL^-1 (相当于生药), 其量效曲线形状与阳性对照药磷酸奥司他韦相似, 提示二者对NA的抑制可能具有相同的作用方式。采用“质反应平行线”法设计和优化的板蓝根抗病毒生物效价检测方法, 重复性较好 (RSD = 5.78%), 实际样品检测结果均能通过可靠检验 (偏离直线P > 0.05、偏离平行P > 0.05)。研究结果表明, 所建立的生物效价检测方法可以作为板蓝根品质生物评价的方法之一。

Biological evaluation of Radix Isatidis based on neuraminidase activity assay

Radix Isatidis (Banlangen in Chinese) is a traditional Chinese medicinal (TCM) herb, and is   frequently used for treating influenza.  However, the current quality control method for Radix Isatidis should be developed since it has little correlation to the pharmacodynamic action.  In this paper, the in vitro inhibitory  action of Radix Isatidis on neuraminidase (NA) was investigated by fluorometric assay with 4-methylumbelliferyl- D-N-acetylneuraminate (FL-MU-NANA) method.  Based on the method, the experimental condition was    optimized and a bioassay statistic method was established according to the reaction type and the regularity of “parallel lines of qualitative effect”.  Then the bioassay method of Radix Isatidis was established.  This study indicated that Radix Isatidis had obvious in vitro inhibitory activity on NA with IC₅₀ = (0.90 ± 0.20) mg·mL^-1 (herb).  The correlation between logarithmic dose and reaction rate showed an “S” shape —— is quite similar to Tamiflu’s reaction curve, which hinted that Radix Isatidis had the same inhibitory function on NA as Tamiflu.  The established bioassay method of “parallel lines of qualitative effect” had a good reproducibility (RSD = 5.78%).  The results of potency determination of Radix Isatidis were reliable (reliability test: deviation from straight line P > 0.05, deviation from parallel line P > 0.05) and well regular.  As a conclusion, this bioassay method is suitable to control and evaluate the quality of Radix Isatidis.