ETHNIC PHARMACOLOGICAL RELEVANCE: "Cyathula officinalis Kuan (COK)" has the effect of "guiding the drug downward" and can enhance the efficacy of formula, e.g., Shentong Zhuyu Decoction (STZYD). However, there is currently no scientific basis on COK to guide drugs to target organs in STZYD.
Aim of the study: The main objective of this study was to unclose the scientific connotations of Yin-Jing medicinal properties of COK using molecular biology and modern chemical methods.
Materials and methods: A rat model of adjuvant arthritis was established. The optimal dose of STZYD was determined by observing a series of indicators, and the therapeutic effects of STZYD and [STZYD - COK] were compared. The water decoction of COK was divided into five fragments (i.e., Fr. A-E) by macroporous adsorption resin and alcohol deposition methods. The Fr. A-E were further characterized by a combination of multiple chromatographic and spectral techniques. The potentiating therapeutic effects, guidance and targetability tests were used to evaluate "Yin-Jing" function by compatible combination of other drugs using pharmacological indicators, pharmacokinetics, high-performance liquid chromatography (HPLC) and small animal live imaging (SALI) techniques.
Results: The optimal dose of STZYD was confirmed to be 1× dose and COK increased the efficacy of [STZYD-COK]. The results of chemical characterization showed that the main components of Fr. A-E were polysaccharide, fructooligosaccharide and small Mw fructan, saponins and flavonoid glycosides, steroidal ketones, organic acids esters, respectively. Pharmacological experiments showed that Fr. A, Fr. B and Fr. E were attributed to potentiating therapeutic effects. Guidance assays showed that Fr. B enhanced drug distribution and uptake in the kidneys, joints and cells. Targetability assays further confirmed that Fr. B had apparent targetability toward the joints and kidneys rather than other organs and tissues.
Conclusions: This study for the first time combined potentiating therapeutic effects, guidance and targeting evaluation system, and identified Fr. B as the pharmacodynamic material basis of COK's Yin-Jing medicinal properties.