Quality Evaluation of Astragali Radix based on DPPH Radical Scavenging Activity and Chemical Analysis

Colour, chemical compounds, and antioxidant capacity of Astragali Radix based on untargeted metabolomics and targeted quantification

INTRODUCTION

Astragali Radix has been used for over 2000 years in traditional Chinese medicine. Its secondary xylem "Jinjing" and secondary phloem "Yulan" are important for evaluating the quality of the Daodi medicinal material in China. However, its systematic characterisation has not been conducted.

OBJECTIVE

This study aims to investigate the colour, chemical compounds, and antioxidant capacity of the secondary xylem and phloem of Astragali Radix on the basis of untargeted metabolomics, broadening the application scope of Astragali Radix in food and pharmaceutical industries.

METHODS

The L*, a*, and b* of the secondary xylem and phloem were measured by colorimetry, and the chemical compounds were identified and quantified by ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and high-performance liquid chromatography-diode array detector-evaporative light scattering detection. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays were conducted to evaluate their antioxidant capacity.

RESULTS

Thirty-one compounds were identified by UPLC-Q-TOF-MS. The secondary xylem exhibited high parameter b*, flavonoid content, and antioxidant capacity, while the secondary phloem was rich in astragalosides. The colour parameters of well-defined type A significantly varied from those of the other types. Well-defined type A also exhibited the highest antioxidant activity and flavonoid content, followed by middle type A-like, middle type B-like, and yellow shading type B.

CONCLUSION

The colour parameters, chemical compounds, and antioxidant capacity among the different transverse sections of secondary xylem and phloem varied. The yellow colour of secondary xylem was correlated to high flavonoid content and antioxidant activity, and well-defined type A of Astragali Radix had better quality than other types.

Probiotic Properties of Bacillus proteolyticus Isolated From Tibetan Yaks, China

Yaks (Bos grunniens) live primarily in high-altitude hypoxic conditions and have a unique intestinal micro-ecosystem, remarkable adaptability, and strong climatic resistance. Accumulating evidence revealed the importance of probiotics in host metabolism, gut microbiota, growth performance, and health. The goal of this study was to screen out probiotics with excellent probiotic potential for clinical application. In this study, four strains of Bacillus, i.e., Bacillus proteolyticus (named Z1 and Z2), Bacillus amyloliquefaciens (named J), and Bacillus subtilis (named K), were isolated and identified. Afterward, their probiotic potential was evaluated. Antioxidant activity tests revealed that Z1 had the highest DPPH and hydroxyl radical scavenging activity, whereas Z2 had higher reducing power and inhibited lipid peroxidation. Additionally, the antibacterial testing revealed that all strains were antagonistic to three indicator pathogens, Escherichia coli C83902, Staphylococcus aureus BNCC186335, and Salmonella enteritidis NTNC13349. These isolates also had a higher hydrophobicity, autoaggregation, and acid and bile tolerance, all of which helped to survive and keep dangerous bacteria out of the host intestine. Importantly, all strains could be considered safe in terms of antibiotic susceptibility and lack of hemolysis. In conclusion, this is the first study to show that B. proteolyticus and B. amyloliquefaciens isolated from yaks have probiotic potential, providing a better foundation for future clinical use.

Astragaloside IV inhibits excessive mesangial cell proliferation and renal fibrosis caused by diabetic nephropathy via modulation of the TGF-β1/Smad/miR-192 signaling pathway

Astragaloside IV (ASI) exhibits a wide variety of pharmacological effects in cardiovascular diseases, hepatitis and kidney disease and due to this, ASI has recently become an attractive research target. The present study aimed to determine the effect of ASI on renal fibrosis and the mechanisms underlying its therapeutic effects in diabetic nephropathy (DN). In vitro, ASI was added to rat mesangial cells (RMCs) and cultured with a high level of glucose (HG) to observe the effects exhibited on proliferation and fibrosis-related mRNA and protein expression. In vivo, a DN model was established using streptozotocin administration in rats, and renal injury was evaluated using renal histological examination. The expression levels of related mRNAs and proteins were analyzed using reverse transcription-quantitative PCR, western blot analysis and immunohistochemistry. ASI was demonstrated to downregulate miR-192 expression and inhibit excessive proliferation of RMCs, which was induced by HG, in a dose-dependent manner. Additionally, ASI exhibited a therapeutic effect on DN rats. ASI was also demonstrated to decrease the miR-192 expression and mRNA and protein expression of transforming growth factor-β1 (TGF-β1), Smad3, α-smooth muscle actin (α-SMA) and collagen type 1 (col1), and increase the mRNA and protein expression of Smad7 in vitro and in vivo. These results suggested that ASI exhibited a therapeutic effect on DN, possibly due to the inhibition of excessive mesangial proliferation and renal fibrosis via the TGF-β1/Smad/miR-192 signaling pathway.

Quantitative fingerprint and quality control analysis of Compound Liquorice Tablet combined with antioxidant activities and chemometrics methods

BACKGROUND

Herbal medicine (HM), as a complex system, is difficult to investigate their quality consistency effectively by chromatographic fingerprinting obtained in a single detection method. Moreover, active compound discovery affords no information about pharmacological activity until late in the discovery process, and the interaction between HMs in vitro is not yet clear, which requires sufficient practice to prove their effectiveness.

PURPOSE

Therefore, the purpose of this study was to improve the quality control methods of Compound Liquorice Tablet (CLT) using multi-wavelength fusion fingerprinting, explore the possible antioxidant components and assess the interaction between herbs combined with bioactivity evaluation.

METHODS AND DESIGN

Once the theoretical standard preparation obtained in combination of multi-wavelength fusion fingerprinting and hierarchical clustering analysis, averagely linear quantified fingerprint method could rapidly calculate the composition similarities and efficiently quantify the multiple components of CLTs without any chemical standard. Furthermore, the fingerprint-efficacy relationship was investigated by integrating high performance liquid chromatography fingerprints with antioxidant activity assessment using the partial least squares model, which was capable of directly discovering the bioactive ingredients. Hereafter, combination index value was introduced to evaluate the correlation between the two antioxidant herbs in CLT formula.

RESULTS

The results showed that CLT samples were effectively identified and quantified, and their quality was accurately distinguished. By analyzing the antioxidant evaluation results, it was found that CLT had strong antioxidant activity, and through the study on PLS model and antioxidant activity assay of individual compounds, it was found that the order of chemical constituents responsible for antioxidant activity in CLT was as follows: flavonoids > saponins > alkaloids. Finally, it was determined that the CI value of GE-PPCE was in the range of 1.20-1.61, indicating that the interaction of the GE-PPCE pair was a slight antagonism.

CONCLUSION

Thus, this study provided a preferred way for monitoring the quality consistency of HM, exploring possible bioactive components of HMs and assessing the interaction between herbs.

Cytoprotective effects of the medicinal herb Astragalus membranaceus on lipopolysaccharide‑exposed cells

Astragalus membranaceus (AM) is a traditional Chinese medicinal herb, whose cytoprotective effects remain largely unknown. Here, the bacterial endotoxin lipopolysaccharide (LPS) was applied to a human pulmonary type II-like epithelial lung adenocarcinoma cell line, a human umbilical vein endothelial cell line, and a human bladder carcinoma cell line to construct in vitro models of intracellular oxidative stress. The authors assayed the cellular and mitochondrial cytoprotective effects of varying doses of AM root extract upon these cell lines. The cell lines were cultured as follows: LPS-only group, four LPS+AM groups treated with various AM concentrations plus LPS, and an untreated control group. Flow cytometry was used to assess apoptosis and cell cycle progression. A 2′,7′-dichlorofluorescein-diacetate assay was used to quantitate reactive oxygen species (ROS) generation. Mitochondrial membrane potential (Δψ_mit) was analyzed by Rhodamine 123 assay. Western blotting was performed to detect cleaved caspase-3, p53, and B cell lymphoma (Bcl)-2 levels. Across all cell lines, LPS significantly elevated apoptosis rates, shifted cells to S/G2 phase, increased ROS production, reduced Δψ_mit, upregulated cleaved caspase-3, upregulated p53, and downregulated Bcl-2 relative to controls (all P<0.05). As a general trend, increasing AM concentrations produced progressively greater reductions in the apoptosis rate, greater reductions in S/G2 phase %, greater reductions in ROS production, greater increases in Δψ_mit, greater reductions in cleaved caspase-3 and p53 expression, and greater increases in Bcl-2 expression. AM treatment protects human pulmonary and bladder epithelial cells, in addition to human endothelial cells, from LPS-induced apoptosis, in a dose-dependent manner.

Quality evaluation for Radix Astragali based on fingerprint, indicative components selection and QAMS

Radix Astragali (RA) is one of the most widely used Chinese herbs prescribed in many Chinese formulas to reinforce 'Qi' and treat vital energy deficiency. This study combined fingerprinting with quantitative analysis multi-components by a single marker (QAMS) to improve the quality control standard for RA on the basis of existing quality control methods of traditional Chinese medicinal materials. UPLC-ESI-TOF-MS technique was used to evaluate the quality of RA by fingerprinting and QAMS. Using the anti-inflammatory, anti-oxidation and anti-anoxic activities to screen characteristic components of RA, the calycosin-7-O-β-d-glucoside (CG), ononin, astragaloside IV, astragaloside II, calycosin and astrageloside I significantly inhibited ear edema in mice, the calycosin and CG had good antioxidant activity and the astragaloside I had a significant anti-hypoxia activity. Astragaloside I, astragaloside II, astragaloside IV, ononin, calycosin and CG had significant pharmacological actions. These components were comprehensively used as the indicative components for the quality control of RA. Astragaloside I was used as the internal standard of the relative correction factors of CG (13.45), ononin (0.51), calycosin (12.08), astragaloside IV (0.73) and astragaloside II (0.81). Astragaloside I and CG were used as internal standards of the relative correction factors of the flavonoids and saponins of ononin (1.11), calycosin (0.04), astragaloside IV (0.73) and astragaloside II (0.81). The study combined fingerprinting with QAMS to improve the quality control standard for RA.

The Extracts and Major Compounds Derived from Astragali Radix Alter Mitochondrial Bioenergetics in Cultured Cardiomyocytes: Comparison of Various Polar Solvents and Compounds

Astragali Radix (AR) is a widely used "Qi-invigorating" herb in China for its tonic effects in strengthening biological tissues. The extract of AR contains abundant antioxidants, including astragalosides and isoflavonoids. However, very few reports have systematically measured the effects of the major components of AR on cell mitochondrial bioenergetics. Here, a systemic approach employing an extracellular flux analyzer was developed to evaluate mitochondrial respiration in cultured cardiomyocyte cells H9C2. The effects of different polar extractives, as well as of the major compounds of AR, were compared. The contents of astragaloside IV, calycosin, formononetin, and genistein in the AR extracts obtained by using water, 50% ethanol, and 90% ethanol were measured by liquid chromatograph-mass spectrometer (LC⁻MS). The antioxidant activities of the AR extracts, as well as of their major compounds, were determined by measuring the free radical scavenging activity and protective effects in tert-butyl hydroperoxide (tBHP)-treated H9C2 cells. By monitoring the real-time oxygen consumption rate (OCR) in tBHP-treated cardiomyocytes with a Seahorse extracellular flux analyzer, the tonic effects of the AR extracts and of their main compounds on mitochondrial bioenergetics were evaluated. AR water extracts possessed the strongest antioxidant activity and protective effects in cardiomyocytes exposed to oxidative stress. The protection was proposed to be mediated via increasing the spare respiratory capacity and mitochondrial ATP production in the stressed cells. The major compounds of AR, astragaloside IV and genistein, showed opposite effects in regulating mitochondrial bioenergetics. These results demonstrate that highly polar extracts of AR, especially astragaloside-enriched extracts, possess better tonic effects on mitochondrial bioenergetics of cultured cardiomyocytes than extracts with a lower polarity.

Identification of chemical components in Baidianling Capsule based on gas chromatography-mass spectrometry and high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry

Baidianling Capsule, which is made from 16 Chinese herbs, has been widely used for treating vitiligo clinically. In this study, the sensitive and rapid method has been developed for the analysis of chemical components in Baidianling Capsule by gas chromatography-mass spectrometry in combination with retention indices and high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Firstly, a total of 110 potential volatile compounds obtained from different extraction procedures including alkanes, alkenes, alkynes, ketones, ethers, aldehydes, alcohols, phenols, organic acids, esters, furans, pyrrole, acid amides, heterocycles, and oxides were detected from Baidianling Capsule by gas chromatography-mass spectrometry, of which 75 were identified by mass spectrometry in combination with the retention index. Then, a total of 124 components were tentatively identified by high-performance liquid chromatography combined with Fourier transform ion cyclotron resonance mass spectrometry. Fifteen constituents from Baidianling Capsule were accurately identified by comparing the retention times with those of reference compounds, others were identified by comparing the retention times and mass spectrometry data, as well as retrieving the reference literature. This study provides a practical strategy for rapidly screening and identifying the multiple constituents of a complex traditional Chinese medicine.