Simultaneous analysis and retention behavior of major isoflavonoids in Radix Puerariae lobatae and Radix Puerariae thomsonii by high performance liquid chromatography with cyclodextrins as a mobile phase modifier

Constituent isoflavones of Puerariae radix as a potential neuroprotector in cognitive impairment: Evidence from preclinical studies

With the increasing aging population worldwide, the incidence of senile cognitive impairment (CI) is increasing, posing a serious threat to the health of elderly persons. Despite developing new drugs aimed at improving CI, progress in this regard has been insufficient. Natural preparations derived from plants have become an unparalleled resource for developing new drugs. Puerariae radix (PR) has a long history as Chinese herbal medicine. PR is rich in various chemical components such as isoflavones, triterpenes, and saponins. The isoflavones (puerarin, daidzein, formononetin, and genistein) exhibit potential therapeutic effects on CI through multiple mechanisms. Relevant literature was organized from major scientific databases such as PubMed, Elsevier, SpringerLink, ScienceDirect, and Web of Science. Using "Puerariae radix," "Pueraria lobata," "isoflavones," "puerarin," "antioxidant," "daidzein," "formononetin," "genistein," "Alzheimer"s disease," and "vascular cognitive impairment" as keywords, the relevant literature was extracted from the databases mentioned above. We found that isoflavones from PR have neuroprotective effects on multiple models of CI via multiple targets and mechanisms. These isoflavones prevent Aβ aggregation, inhibit tau hyperphosphorylation, increase cholinergic neurotransmitter levels, reduce neuroinflammation and oxidative stress, improve synaptic plasticity, promote nerve regeneration, and prevent apoptosis. PR has been used as traditional Chinese herbal medicine for a long time, and its constituent isoflavones exert significant therapeutic effects on CI through various neuroprotective mechanisms. This review will contribute to the future development of isoflavones present in PR as novel drug candidates for the clinical treatment of CI.

The chemistry and activity-orientedcharacterization of isoflavones difference between roots of Pueraria lobata and P. thomsonii guided by feature-based molecular networking

Isoflavones are important chemical components in Pueraria species with various biological activities. This study proposed an integrated strategy combining feature-based molecular networking (FBMN), chemometrics and activity evaluation for isoflavone analysis in the roots of P. lobate (PLR) and P. thomsonii (PTR). Based on the strategy, a total of 68 isoflavones were annotated in the two Pueraria species, and 11 significant difference isoflavones between PLR and PTR were identified by chemometric methods. Additionally, the correlation coefficient between the characteristic isoflavones and hypoglycemic activity were calculated, and 7 isoflavones were further confirmed as bioactive marker compounds. This approach provided guidance for the discovery of active markers among different products.

Determination of Isoflavones in Radix puerariae from Different Origins by Ultra-High Performance Liquid Chromatography Based on Optimal Pretreatment Method

A new method for simultaneous determination of puerarin, daidzin, daidzein and genistein in Radix puerariae by ultra-high performance liquid chromatography was established. The target analytes were extracted from Radix puerariae by 70% ethylene glycol with the assistance of ultrasonication, purified by the absorption of N-propyl ethylenediamine (PSA), and separated on a Supersil ODS column (4.6 mm × 250 mm × 2.5 μm). Gradient elution in 12 min was performed with the mobile phase 0.1% formic acid(A)-acetonitrile(B). The column temperature was 25 °C and the flow rate was 1 mL/min. The detection wavelength of the four target analytes was 250 nm. The limits of detection (LODs) of puerarin, daidzin, daidzein and genistein were 0.086 mg/L, 0.020 mg/L, 0.027 mg/L and 0.037 mg/L, respectively, and limits of quantitation (LOQs) were 0.29 mg/L, 0.065 mg/L, 0.090 mg/L and 0.12 mg/L, respectively. The recovery of the four substances ranged from 90.5% to 109.6%, and the relative standard deviation (n = 6) was less than 7.7%. With the established methods, puerarin, daidzin, daidzein and genistein in Radix puerariae from 11 origins were determined. The contents of the four compounds varied with the origin and variety. It provides basic data and technical means for quality control and regulation of Radix puerariae.

Potential therapeutic interventions of plant-derived isoflavones against acute lung injury

Acute lung injury (ALI) is a life-threatening syndrome that possibly leads to high morbidity and mortality as no therapy exists. Several natural ingredients with negligible adverse effects have recently been investigated to possibly inhibit the inflammatory pathways associated with ALI at the molecular level. Isoflavones, as phytoestrogenic compounds, are naturally occurring bioactive compounds that represent the most abundant category of plant polyphenols (Leguminosae family). A broad range of therapeutic activities of isoflavones, including antioxidants, chemopreventive, anti-inflammatory, antiallergic and antibacterial potentials, have been extensively documented in the literature. Our review exclusively focuses on the possible anti-inflammatory, antioxidant role of botanicals'-derived isoflavones against ALI and their immunomodulatory effect in experimentally induced ALI. Despite the limited scope covering their molecular mechanisms, isoflavones substantially contributed to protecting from ALI via inhibiting toll-like receptor 4 (TLR4)/Myd88/NF-κB pathway and subsequent cytokines, chemokines, and adherent proteins. Nonetheless, future research is suggested to fill the gap in elucidating the protective roles of isoflavones to alleviate ALI concerning antioxidant potentials, inhibition of the inflammatory pathways, and associated molecular mechanisms.

Isoflavones derived from plant raw materials: bioavailability, anti-cancer, anti-aging potentials, and microbiome modulation

Isoflavones are secondary metabolites that represent the most abundant category of plant polyphenols. Dietary soy, kudzu, and red clover contain primarily genistein, daidzein, glycitein, puerarin, formononetin, and biochanin A. The structural similarity of these compounds to β-estradiol has demonstrated protection against age-related and hormone-dependent diseases in both genders. Demonstrative shreds of evidence confirmed the fundamental health benefits of the consumption of these isoflavones. These relevant activities are complex and largely driven by the source, active ingredients, dose, and administration period of the bioactive compounds. However, the preclinical and clinical studies of these compounds are greatly variable, controversial, and still with no consensus due to the non-standardized research protocols. In addition, absorption, distribution, metabolism, and excretion studies, and the safety profile of isoflavones have been far limited. This highlights a major gap in understanding the potentially critical role of these isoflavones as prospective replacement therapy. Our general review exclusively focuses attention on the crucial role of isoflavones derived from these plant materials and critically highlights their bioavailability, possible anticancer, antiaging potentials, and microbiome modulation. Despite their fundamental health benefits, plant isoflavones reveal prospective therapeutic effects that worth further standardized analysis.

In silico production of relative correction factor for the quantitative analysis of multi-components by single marker method

INTRODUCTION

Traditional methods to derive experimentally-generated relative correction factors (RCFs) for the quantitative analysis of herbal multi-components by single marker (QAMS) method require reference standards and multiple validations with different instruments and columns, which hampers high throughput implementation.

OBJECTIVES

To effectively reduce the application amounts of raw material and provide higher and more stable accuracy, this study aimed to develop a method to computationally generate RCFs of herbal components.

MATERIALS AND METHODS

This strategy included the published data collection, calibration curves screening, computer algorithm-based RCFs generation and accuracy validation.

RESULTS

Using the in silico approach, we have successfully produced 133 RCFs for the multi-component quantitative analysis of 63 widely used herbs.

CONCLUSION

Compared with conventional RCFs, this in silico method would be a low cost and highly efficient way to produce practical RCFs for the QAMS method.

Simultaneous analysis of five triterpenes in Centella asiatica by high performance liquid chromatography with cyclodextrins as the mobile phase additives

Triterpenes are considered the major active components in Centella asiatica (L.) Urb. (C. asiatica), such as asiatic acid, madecassic acid, asiaticoside, madecassoside and asiaticoside B. It is difficult to simultaneously determine five triterpenes because of madecassoside isomers (madecassoside and asiaticoside B), and the great polarity difference between triterpene acid and triterpene glycoside. In this study, a simple high performance liquid chromatography method with isocratic elution employing cyclodextrins (CDs) as the mobile phase additives was developed to determine five triterpenes in C. asiatica. Various factors affecting triterpenes retention in the C18 column, such as the nature of CDs, γ-CD concentration, acetonitrile percentage and temperature, were studied. Experimental results showed that γ-CD, as an effective mobile phase additive, could markedly reduce the retention of triterpenes (especially asiatic acid and madecassic acid), and improve the separation for madecassoside and asiaticoside B. The elution of five triterpenes could be achieved on an ODS C18 column within 30 min using the acetonitrile-0.2% phosphoric acid contained 4.0 mM γ-CD (20:80, v/v) mixture as the mobile phase. The retention modification of triterpenes may be attributed to the formation of the triterpenes-γ-CD inclusion complexes. The optimized method was successfully applied for simultaneous determination of five triterpenes in C. asiatica.

Selectivity of Current Extraction Techniques for Flavonoids from Plant Materials

Flavonoids have a broad spectrum of established positive effects on human and animal health. They find an application in medicine for disease therapy and chemoprevention, whence the interest in flavonoids increases. In addition, they are used in food and cosmetic industries as pigments and biopreservatives. Plants are an inexhaustible source of flavonoids. The most important step of plant raw material processing is extraction and isolation of target compounds. The quality of an extract and efficiency of a procedure are influenced by several factors: Plant material and pre-extracting sample preparation, type of solvent, extraction technique, physicochemical conditions, etc. The present overview discusses the common problems and key challenges of the extraction procedures and the different mechanisms for selective extraction of flavonoids from different plant sources. In summary, there is no universal extraction method and each optimized procedure is individual for the respective plants. For an extraction technique to be selective, it must combine an optimal solvent or mixture of solvents with an appropriate technique. Last but not least, its optimization is important for a variety of applications. Moreover, when the selected method needs to be standardized, it must achieve acceptable degree of repeatability and reproducibility.

Extraction Methods for the Isolation of Isoflavonoids from Plant Material

The purpose of this review is to describe and compare selected traditional and modern extraction methods employed in the isolation of isoflavonoids from plants. Conventional methods such as maceration, percolation, or Soxhlet extraction are still frequently used in phytochemical analysis. Despite their flexibility, traditional extraction techniques have significant drawbacks, including the need for a significant investment of time, energy, and starting material, and a requirement for large amounts of potentially toxic solvents. Moreover, these techniques are difficult to automate, produce considerable amount of waste and pose a risk of degradation of thermolabile compounds. Modern extraction methods, such as: ultrasound-assisted extraction, microwave-assisted extraction, accelerated solvent extraction, supercritical fluid extraction, and negative pressure cavitation extraction, can be regarded as remedies for the aforementioned problems. This manuscript discusses the use of the most relevant extraction techniques in the process of isolation of isoflavonoids, secondary metabolites that have been found to have a plethora of biological and pharmacological activities.

Colloidal gold-based indirect competitive immunochromatographic assay for rapid detection of bioactive isoflavone glycosides daidzin and genistin in soy products

Daidzin (DZ) and genistin (GEN) are two major soy isoflavone glycosides isolated from soybeans. Soy products containing isoflavones have recently been widely accepted for commercial use. However, the Japanese Government has suggested that soy isoflavone intake should be limited because of their estrogenic effects due to their interactions with estrogen receptors. In this study, we established a one-step indirect competitive immunochromatographic assay (ICA) for rapid and sensitive detection of total isoflavone glycosides (DZ and GEN) using gold nanoparticles conjugated with a monoclonal antibody against DZ. This assay was able to be completed in 15min following the immersion of a test strip in an analyte solution. Furthermore, the limit of detection for the total amount of isoflavone glycosides was ∼125ngmL(-1). Considering that the major soy isoflavone glycosides found in soy products are DZ and GEN, this study demonstrates the potential use of ICA for the assessments of over consumption of isoflavones in soy supplements and foods, which would increase the safe dietary intake of soy products.

Dynamics of phytoestrogen, isoflavonoids, and its isolation from stems of Pueraria lobata (Willd.) Ohwi growing in Democratic People's Republic of Korea

Four isoflavonoids were isolated from stems of Pueraria lobata (Willd.) Ohwi growing in Democratic People’s Republic of Korea and identified as daidzein (1), genistin (2), daidzin (3), and puerarin (4), structures, which were elucidated by means of spectroscopic analysis. Isoflavonoids were isolated using silica gel chromatography and purified with organic solvents. Isoflavonoid contents in P. lobata were determined using reliable high-performance liquid chromatography. The results indicated that the contents of puerarin and genistin in the roots are higher than those in the stems (6.19% and 0.04% vs. 1.15% and 0.02%), whereas the stems have higher contents of daidzin and daidzein than the roots (3.17% and 0.06% vs. 1.72% and 0.05%). Accordingly, the root part of the plant is useful for the isolation of puerarin and the stem part for daidzin. This study suggests that the stem of P. lobata is useful as an alternative source of puerarin, daidzin, genistin, and daidzein. In addition, collection of the stem will not sacrifice the plant and thus is beneficial to the natural ecosystems.

Simultaneous determination of soy isoflavone glycosides, daidzin and genistin by monoclonal antibody-based highly sensitive indirect competitive enzyme-linked immunosorbent assay

Soy isoflavones are known as major bioactive compounds in soybean (Glycine max), which is an indispensable food. Despite their utility, the consumption of isoflavones has recently been limited because they exhibit oestrogenic and topoisomerase II inhibitory effects. To assess their intake limitation, accurate, sensitive, and effective quantitative analyses are necessary. In this study, we produced the monoclonal antibody (MAb) against daidzin (DZ) and applied it to an indirect competitive enzyme-linked immunosorbent assay (icELISA) for the simultaneous determination of DZ and genistin (GEN), which are known as two major soy isoflavone glycosides in soy products. Using the DZ-MAb, we developed a sensitive icELISA method, where the limit of detection for DZ and GEN was 1.95ng/ml. Several validation analyses revealed that the icELISA is sufficiently accurate and sensitive to be used to assess the overconsumption of soy isoflavones, which would lead to the safe dietary intake of soy products.

LC-MS/MS determination and pharmacokinetics study of puerarin and daidzein in rat plasma after oral administration of Gegenqinlian decoction and Radix Puerariae extract

Background:

Gegenqinlian decoction (GQD) is a famous traditional medicine recipe. It is composed of four herbs including Radix Puerariae (GG), Radix Scutellariae (HQ), Rhizoma Coptidis (HL) and Radix Glycyrrhizae (GC), which is widely used for treating gastro-intestinal disorders in the clinical practice of Traditional Chinese medicine (TCM). The aim of this study was to compare the pharmacokinetics of puerarin and daidzein in rats following oral administration of Gegenqinlian Decoction and Radix Puerariae extract. Thus, a sensitive and selective liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous determination of puerarin and daidzein in rat plasma following oral administration of Gegenqinlian Decoction and Radix Puerariae extract.

Materials and Methods:

Chromatographic separation was performed on a Shiseido CAPCELL PAK C₁₈ analytical column (100 mm × 2.0 mm i.d., 5 μm) by linear gradient elution, with water (0.1% formic acid)-acetonitrile (0.1% formic acid) as mobile phase. Detection was carried out by multiple reaction monitoring (MRM) mode using electrospray ionization in the positive ion mode.

Results:

The calibration curves were linear over a range of 7.80-1560 ng/mL for puerarin and 6.30-1260 ng/mL for daidzein. The intra- and inter-day precision values were less than 13.6% and their average recoveries was in the range of 77.8% and 88.6% for puerarin and was between 76.3 and 86.8% for daidzein, respectively.

Conclusion:

The validated method was applied to the comparative pharmacokinetic studies of puerarin and daidzein after oral administration of Gegenqinlian Decoction and Radix Puerariae extract. The pharmacokinetic parameters showed that puerarin and daidzein from Gegenqinlian Decoction were absorbed more effectively with slower elimination in rat plasma than that from Radix Puerariae extract. These results revealed that as far as the Radix Puerariae extract was concerned, it is very valuable to be used as a clinical directions of Gegenqinlian Decoction.