The semi-refined polysaccharide of Pseudostellaria heterophylla is a complex polysaccharide that exhibits significantly hypoglycemic activities. A novel homogeneous polysaccharide, named as H-1-2, was isolated from the semi-refined polysaccharide. The mean molecular weight of H-1-2 was 1.4 × 10⁴ Da and it was only composed of d-glucose monosaccharide. Structure elucidation indicated that H-1-2 contains pyranride, and has the characteristics of the α-iso-head configuration, a non-reducing end (T-), 4-, 1,6-, and 1,4,6-connection, in all four ways to connect glucose. H-1-2 was a type of glucan, where chemical combination exists in the main chain between 1→4 linked glucose, and contains a small amount of 1,6-linked glucose, which was in the branched chain. In vitro HepG2, 3T3-L1, and L6 cells were used to assess cellular glucose consumption and cellular glucose uptake by glucose oxidase, and the transport of 2-NBDG fluorescence probe results showed that H-1-2 could clearly increase glucose uptake and utilization in muscle and adipose cells, which is beneficial to screen for in the discovery of anti-diabetes lead compounds. H-1-2 was labeled with radioisotopes (^99mTc-pertechnetate). ^99mTc-labeled-H-1-2 was performed by SPECT/CT analysis images after oral administration in rats. At 4 h post ingestion, about 50% of the radioactivity was observed in the intestine. No significant radioactivity was found in the heart, liver, and kidney, conjecturing that absorption of ^99mTc-labeled H-1-2 might, via intestinal mucosa, be absorbed into systemic circulation. This problem, as to whether the polysaccharide is absorbed orally, will need further examination. Full article

The complexity of traditional Chinese medicines (TCMs) is related to their multi-component system. TCM aqueous decoction is a common clinical oral formulation. Between molecules in solution, there exist intermolecular strong interactions to form chemical bonds or weak non-bonding interactions such as hydrogen bonds and Van der Waals forces, which hold molecules together to form “molecular aggregates”. Taking the TCM Puerariae lobatae Radix (Gegen) as an example, we explored four Gegen decoctions of different concentration of 0.019, 0.038, 0.075, and 0.30 g/mL, named G-1, G-2, G-3, and G-4. In order of molecular aggregate size (diameter) the four kinds of solution were ranked G-1 < G-2 < G-3 < G-4 by Flow Cell 200S IPAC image analysis. A rabbit vertebrobasilar artery insufficiency (VBI) model was set up and they were given Gegen decoction (GGD) at a clinical dosage of 0.82 g/kg (achieved by adjusting the gastric perfusion volume depending on the concentration). The HPLC fingerprint of rabbit plasma showed that the chemical component absorption into blood in order of peak area values was G-1 < G-2 > G-3 > G-4. Puerarin and daidzin are the major constituents of Gegen, and the pharmacokinetics of G-1 and G-2 puerarin conformed with the two compartment open model, while for G-3 and G-4, they conformed to a one compartment open model. For all four GGDs the pharmacokinetics of daidzin complied with a one compartment open model. FQ-PCR assays of rabbits’ vertebrobasilar arterial tissue were performed to determine the pharmacodynamic profiles of the four GGDs. GGD markedly lowered the level of AT₁R mRNA, while the AT₂R mRNA level was increased significantly vs. the VBI model, and G-2 was the most effective. In theory the dosage was equal to the blood drug concentration and should be consistent; however, the formation of molecular aggregates affects drug absorption and metabolism, and therefore influences drugs’ effects. Our data provided references for the rational use of Chinese medicines in the clinic, such as the best oral preparation and decoction concentration. Full article

The multi-component system of traditional Chinese medicine (TCM) is very complicated. The clusters are dynamic aggregates whose molecules are held together by hydrogen-bonded, Van der Waals forces or the opposite charges of particles attract each other. In this paper, field emission scanning electron microscopy proved that molecules form clusters in Pueraria thomsonii Benth (Fenge) water decoction. Four kinds of Fenge water decoction, 0.07 g∙mL⁻¹ (F-1), 0.1 g∙mL⁻¹ (F-2), 0.17 g∙mL⁻¹ (F-3), 0.35 g∙mL⁻¹ (F-4); F-1, average diameter of molecular was about 120 nm; F-2, 195 nm; F-3, 256 nm; and F-4, 480 nm. The molecular size was shown to depend on concentration. Rabbits were given equal does of 2.8 g∙kg⁻¹, to perfuse F-1, F-2, F-3, F-4 in volume of 80 mL, 56 mL, 33 mL, 17 mL, respectively. At 0–180 min to collect 2 mL blood from the rabbit ears middle arteries for metabolism fingerprints, the results show the particle size of molecular is smaller, the absorption of drugs is better instead. The acute blood stasis model rats were treatment with Fenge decoction of 1.5 g∙kg⁻¹ for 14 days, the concentrations of Ang II in plasma were significantly lower in F-1 and F-2 groups than those in model group (p < 0.01 or p < 0.05), but there were no significantly difference in F-3 and F-4 groups than those in model group (p > 0.05). Despite the molecular aggregation is a common physical phenomenon, it influence on the kind and amount of molecule per unit volume. Molecules morphology influence on the absorption behavior of drugs in vivo therefore is to have an impact on pharmacological function. Full article

A label-free split G-quadruplex and graphene oxide (GO)-based fluorescence platform has been designed to distinguish Pseudostellaria heterophylla (PH) from its adulterants based on the differences in their nrDNA ITS sequences. Herein, GO has been first introduced to capture G-rich probes with 2:2 split mode and then decrease the background signal. As T-DNA exists, the probes leave the GO surface to form double-stranded structures followed by the formation of the overhanging G-rich sequence into a G-quadruplex structure, which combines quinaldine red specifically to produce a strong fluorescence signal. In addition, this strategy allows detection of T-DNA in a wide range of concentrations from 1.0 × 10⁻⁸ to 2.0 × 10⁻⁶ mol·L⁻¹ with a detection limit of 7.8 × 10⁻⁹ mol·L⁻¹. We hope that the split G-quadruplex/GO platform can be utilized to further develop gene identification sensors in Traditional Chinese Medicine or other analysis areas. Full article

With an internal transcribed spacer of 18 S, 5.8 S and 26 S nuclear ribosomal DNA (nrDNA ITS) as DNA marker, we report a colorimetric approach for authentication of Pseudostellaria heterophylla (PH) and its counterfeit species based on the differentiation of the nrDNA ITS sequence. The assay possesses an unlabelled G-quadruplex DNAzyme molecular beacon (MB) probe, employing complementary sequence as biorecognition element and 1:1:1:1 split G-quadruplex halves as reporter. In the absence of target DNA (T-DNA), the probe can shape intermolecular G-quadruplex structures capable of binding hemin to form G-quadruplex-hemin DNAzyme and catalyze the oxidation of ABTS²⁻ to blue-green ABTS^•− by H₂O₂. In the presence of T-DNA, T-DNA can hybridize with the complementary sequence to form a duplex structure, hindering the formation of the G-quadruplex structure and resulting in the loss of the catalytic activity. Consequently, a UV-Vis absorption signal decrease is observed in the ABTS²⁻-H₂O₂ system. The “turn-off” assay allows the detection of T-DNA from 1.0 × 10⁻⁹ to 3.0 × 10⁻⁷ mol·L⁻¹ (R² = 0.9906), with a low detection limit of 3.1 × 10⁻¹⁰ mol·L⁻¹. The present study provides a sensitive and selective method and may serve as a foundation of utilizing the DNAzyme MB sensor for identifying traditional Chinese medicines. Full article

Pseudostellaria heterophylla (Miq.) Pax is one of the most widespread herbal and healthcare products in China. Extensive clinical use has shown that it has functions which “strengthens qi and generates saliva, moistens the lung and relieves cough”. The ethyl acetate fraction extracted from the roots of the plant Pseudostellaria heterophylla exhibited a dose-dependent antitussive effect between 100 to 500 mg/kg. At a dose of 400 mg/kg, the ethyl acetate fraction treatment markedly prolonged the cough latent period and reduced the number of coughs in a guinea pig model induced by citric acid. Fall lung airway resistance, rise in dynamic lung compliance, decreased serum levels of IL-8, GM-CSF, TNF-α, and ET-1 in rat model of stable phase chronic obstructive pulmonary disease induced by cigarette smoke exposure were also observed. These results suggest that ethyl acetate fraction has antitussive activity related to its improvement in lung function via attenuation of airway inflammation by adjustment of multi-cytokine levels. Full article