Comparison of Wild and Cultivated Paeoniae Radix Rubra Based on Traditional Quality Evaluation / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo compare wild and cultivated Paeoniae Radix Rubra（PRR） in three aspects， including character， microscope， determination of primary and secondary metabolites. MethodSeventeen batches of wild and nine batches of cultivated PRR were collected，their character data were measured by vernier caliper and scales， and their paraffin sections were made by safranin-fixed green dyeing for the observation of microscopic features. The content of ethanol-soluble extracts and total tannin from wild and cultivated PRR was determined by the method of general principle 2201 and 2202 in the 2020 edition of Chinese Pharmacopoeia， the content of polysaccharides was determined by phenol-sulfuric acid method. Anthrone colorimetry was used to determine the content of starch， and Van Soest method of washing fiber was used to determine the content of fiber. The contents of fructose， glucose and sucrose in wild and cultivated PRR were determined by ultra-high performance liquid chromatography evaporative light scattering detection（UPLC-ELSD）， and the secondary metabolites（gallic acid， methyl gallate， catechin， oxypaeoniflorin， albiflorin， paeoniflorin， ellagic acid， 1，3，4，6-tetragalloylglucose， galloylpaeoniflorin， 1，2，3，4，6-O-pentagalloylglucose， naringenin， benzoylpaeoniflorin and benzoylalbiflorin） were determined by UPLC. Principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） were used to analyze the data of wild and cultivated PRR， the contribution of different factors to the difference was determined according to the variable importance in the projection（VIP） value>1 and P<0.05. ResultIn term of characters， wild PRR showed the traditional characteristic of Zaopi Fencha， its outer skin was loose and easy to fall off， its surface had longitudinal furrow and wrinkle， but the outer skin of cultivated PRR was not easy to fall off， and its surface was relatively smooth. The radial texture of xylem of wild PRR cross-section was more obvious， showing radial striations， vacuoles and more cracks， while the radial texture of xylem of cultivated PRR cross-section was not obvious， dense and some had cracks. Microscopically， the number of radial vessels arranged in the xylem of wild PRR was more than that of cultivated PRR， the number of calcium oxalate clusters in the phloem and xylem of wild PRR was more than that of cultivated PRR， while the number of starch grains was significantly higher in cultivated PRR. In terms of the content of primary chemical constituents， the contents of polysaccharides and starch of cultivated PRR were significantly higher than those of wild PRR（P<0.05）， while the contents of cellulose， lignin， fructose and glucose of wild PRR were significantly higher than those of cultivated PRR（P<0.05）. The results of determination of 13 secondary metabolites showed that the contents of paeoniflorin， methyl gallate， catechin and oxypaeoniflorin in wild PRR were significantly higher than those in cultivated PRR（P<0.05）， while the contents of albiflorin， gallic acid， ellagic acid， naringenin， benzoylpaeoniflorin and benzoylalbiflorin were significantly lower than those of cultivated PRR（P<0.05）. A total of 10 variables contributing to the differentiation between wild and cultivated PRR were screened， including albiflorin， cellulose， benzoylpaeoniflorin， oxypaeoniflorin， naringenin， ellagic acid， starch， lignin， paeoniflorin and total tannins. ConclusionThere are significant differences between wild and cultivated PRR in characters， microscopic characteristics， contents of primary and secondary metabolites. It is suggested that the content ratio of paeoniflorin and albiflorin， the contents of oxypaeoniflorin and cellulose can be used as indicators to characterize production methods of PRR so as to improve the quality standard of PRR. This study can provide reference for the improvement of quality standard of PRR and the guidance of high quality production of PRR.