Tankeu Sidonie, Vermaak Ilze, Chen Weiyang, Sandasi Maxleene, Viljoen Alvaro
Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
Department of Pharmaceutical Sciences, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa; SAMRC Herbal Drugs Research Unit, Faculty of Science, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa.
Phytochemistry. 2016 Feb;122:213-222. doi: 10.1016/j.phytochem.2015.11.008. Epub 2015 Nov 26.
Stephania tetrandra ("hang fang ji") and Aristolochia fangchi ("guang fang ji") are two different plant species used in Traditional Chinese Medicine (TCM). Both are commonly referred to as "fang ji" and S. tetrandra is mistakenly substituted and adulterated with the nephrotoxic A. fangchi as they have several morphological similarities. A. fangchi contains aristolochic acid, a carcinogen that causes urothelial carcinoma as well as aristolochic acid nephropathy (AAN). In Belgium, 128 cases of AAN was reported while in China, a further 116 cases with end-stage renal disease were noted. Toxicity issues associated with species substitution and adulteration necessitate the development of reliable methods for the quality assessment of herbal medicines. Hyperspectral imaging in combination with partial least squares discriminant analysis (PLS-DA) is suggested as an effective method to distinguish between S. tetrandra and A. fangchi root powder. Hyperspectral images were obtained in the wavelength region of 920-2514nm. Reduction of the dimensionality of the data was done by selecting the discrimination information range (964-1774nm). A discrimination model with a coefficient of determination (R(2)) of 0.9 and a root mean square error of prediction (RMSEP) of 0.23 was created. The constructed model successfully identified A. fangchi and S. tetrandra samples inserted into the model as an external validation set. In addition, adulteration detection was investigated by preparing incremental adulteration mixtures of S. tetrandra with A. fangchi (10-90%). Hyperspectral imaging showed the ability to accurately predict adulteration as low as 10%. It is evident that hyperspectral imaging has tremendous potential in the development of visual quality control methods which may prevent cases of aristolochic acid nephropathy in the future.
防己（“汉防己”）和广防己是两种用于传统中医（TCM）的不同植物物种。两者通常都被称为“防己”，由于它们在形态上有一些相似之处，汉防己常被错误地用具有肾毒性的广防己替代和掺假。广防己含有马兜铃酸，一种可导致尿路上皮癌以及马兜铃酸肾病（AAN）的致癌物。在比利时，报告了128例马兜铃酸肾病病例，而在中国，又发现了116例终末期肾病病例。与物种替代和掺假相关的毒性问题使得开发可靠的草药质量评估方法成为必要。建议将高光谱成像与偏最小二乘判别分析（PLS-DA）相结合，作为区分汉防己和广防己根粉的有效方法。在920 - 2514nm波长区域获取了高光谱图像。通过选择判别信息范围（964 - 1774nm）对数据进行降维。创建了一个判定系数（R²）为0.9且预测均方根误差（RMSEP）为0.23的判别模型。构建的模型成功识别了作为外部验证集插入模型中的广防己和汉防己样本。此外，通过制备汉防己与广防己的增量掺假混合物（10 - 90%）来研究掺假检测。高光谱成像显示能够准确预测低至10%的掺假情况。显然，高光谱成像在开发视觉质量控制方法方面具有巨大潜力，这可能在未来预防马兜铃酸肾病病例的发生。
