Identification of deoxymiroestrol as the actual rejuvenating principle of "Kwao Keur", Pueraria mirifica. The known miroestrol may be an artifact

Isocyanide-based multicomponent reactions for the synthesis of benzopyran derivatives with biological scaffolds

Benzopyrans (BZPs) are among the most privileged and influential small O-heterocycles that form the core of many natural compounds, commercial drugs, biological compositions, agrochemicals, and functional materials. BZPs are divided into six general categories including coumarins, chromans, 2H-chromenes, 4H-chromenes, chromones, and 4-chromanones, each of which is abundant in many plants and foods. These oxygenated heterocyclic compounds are fascinating motifs and have extensive applications in biology and materials science. Hence, numerous efforts have been made to develop innovative approaches for their extraction and synthesis. However, most of them are step-by-step or multi-step strategies that suffer from waste material generation and a tedious extraction process. Isocyanide-based multicomponent reactions (I-MCRs) offer a highly efficient method for overcoming these problems. The I-MCR is a simple and environmentally friendly one-pot domino procedure that does not require intermediate isolation or workup and is generally more efficient in material usage. This review covers all research articles related to I-MCRs for synthesizing BZP derivatives from the beginning to the middle of the year 2023. This strategy will be useful for organic and pharmaceutical chemists to design new drugs and optimize the synthesis steps of biological compounds and commercial drugs with benzopyran cores.

Immunoaffinity separation of miroestrol and deoxymiroestrol from Pueraria candollei var. mirifica (Airy Shaw & Suvat.) Niyomdham using fragment antigen-binding antibody produced via Escherichia coli

INTRODUCTION

Miroestrol and deoxymiroestrol are potent phytoestrogens and are oestrogen markers of Pueraria candollei var. mirifica. However, purifying these compounds is difficult because they only exist in trace amounts.

OBJECTIVES

Active fragment antigen-binding (Fab) antibodies were produced via Escherichia coli SHuffle® T7 and used to selectively separate these compounds.

MATERIALS AND METHODS

Two immunoaffinity separation approaches were developed, namely the immunoaffinity column (IAC) and a cell-based method. Group-specific Fab antibodies against miroestrol and deoxymiroestrol (anti-MD Fab) were used as biological binding reagents for selective separation.

RESULTS

The Fab-based IAC effectively separated miroestrol and deoxymiroestrol (0.65 and 2.24 μg per 2 mL of resin, respectively) from P. mirifica root extract. When P. mirifica extract was added to E. coli cultures during Fab expression via a cell-based method, the target compound accumulated in intracellular compartments and, thus, were separated from E. coli cells after the removal of other compounds. A yield of 1.07 μg of miroestrol per gram of cell pellet weight was obtained. Miroestrol and deoxymiroestrol were successfully purified from P. mirifica extract using anti-MD Fab via the IAC and an intracellular cell-based method.

CONCLUSION

The proposed methods can simplify the miroestrol and deoxymiroestrol extraction process and provide a basis for applications utilising recombinant antibodies to separate target compounds.

Immunochromatographic assay for miroestrol and deoxymiroestrol, its cross-reactivity, and application in Pueraria mirifica (white Kwao Krua) analysis

INTRODUCTION

Miroestrol (Mi) and deoxymiroestrol (Dmi) are trace, yet potent, phytooestrogens found in white Kwao Krua [Pueraria candollei var. mirifica (Airy Shaw & Suvat.) Niyomdham, PM]. However, the analysis of these substances is difficult because of complex matrix effects and their various analogues. In addition, alteration in the cross-reactivity of a gold nanoparticle (AuNP)-based immunochromatographic assay (ICA) resulting from the electrostatic adsorption between antibodies and AuNPs has not yet been evaluated.

OBJECTIVES

This study aims to develop, characterise, and validate ICA with a monoclonal antibody exhibiting similar reactivity against Mi and Dmi (MD-mAb).

MATERIALS AND METHODS

The ICA performance was validated for cross-reactivity and performance in comparison with those of indirect competitive enzyme-linked immunosorbent assays (icELISAs) with MD-mAb and mAb exhibiting specificity against Mi (Mi-mAb).

RESULTS

The ICA showed a limit of detection (LOD) at 1 and 16 μg/mL for Mi and Dmi, respectively. The cross-reactivity of the ICA with Dmi was lower (6.25%) than that observed with the icELISA (120%). Cross-reactivity of ICA against other compounds of the PM was also correlated with those of icELISA; no false-positive/negative results were observed. The repeatability and reproducibility of the ICA were confirmed. The results obtained using ICA in samples of PM are correlated with the concentrations determined through icELISAs.

CONCLUSION

An ICA with MD-mAb was constructed and validated. However, direct conjugation via the electrostatic adsorption of mAb-AuNPs was expected to alter the cross-reactivity of ICA, especially that of the analyte analogue Dmi.

UHPLC-QTOF-MS Metabolic Profiling of Marchantia polymorpha and Evaluation of Its Hepatoprotective Activity Using Paracetamol-Induced Liver Injury in Mice

Marchantia species were traditionally used to treat liver failure. Marchantia polymorpha chloroform extract showed a marked hepatoprotective activity in a dose-dependent manner in paracetamol-induced extensive liver damage in mice. At a dose of 500 mg/kg (MP-500), it resulted in a reduction in aspartate transaminase by 49.44%, alanine transaminase by 44.11%, and alkaline phosphatase by 24.4% with significant elevation in total proteins by 58.69% with respect to the diseased group. It showed significant reductions in total bilirubin, total cholesterol, triglycerides, low density lipoprotein (LDL), very LDL, total lipids, and to high density lipoprotein ratio (CH/HDL) by 53.42, 30.14, 35.02, 45.79, 34.74, 41.45, and 49.52%, respectively, together with a 37.69% increase in HDL with respect to the diseased group. It also showed an elevation of superoxide dismutase by 28.09% and in glutathione peroxidase by 81.83% in addition to the reduction of lipid peroxidation by 17.95% as compared to the paracetamol only treated group. This was further supported by histopathological examination that showed normal liver architecture and a normal sinusoidal gap. Metabolic profiling by ultrahigh performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometer (UHPLC-QTOF/MS) led to the tentative identification of 28 compounds belonging to phenols, quinolones, phenylpropanoid, acylaminosugars, terpenoids, lipids, and fatty acids to which the activity was attributed. Four compounds were detected in the negative ionization mode which are neoacrimarine J, marchantin A, chitobiose, and phellodensin F, while the rest were detected in the positive mode. Thus, it can be concluded that this plant could serve as a valuable choice for the treatment of hepatotoxicity that further consolidated its traditional use.

Comparative stability and analytical performance of anti-miroestrol recombinant antibody in different cassettes

Immunoassays are efficient for the phytochemical analysis of various matrices. However, producing an appropriate recombinant antibody for small molecules is challenging, resulting in costly analyses. In this study, we aimed to develop recombinant fragment antigen-binding (Fab) antibodies against miroestrol, a potent phytoestrogen marker of Pueraria candollei. Two expression cassettes of Fab were established for the production of active Fab antibodies using SHuffle^® T7 Escherichia coli cells. The orientation of variable fragment heavy chain (VH) and variable fragment light chain (VL) in the expression vector constructs influences the reactivity, stability, and binding specificity of the resultant Fab. Stability testing of antibodies demonstrated that Fab is a more stable form of recombinant antibody than a single-chain variable fragment (ScFv) antibody in all conditions. Based on the obtained Fab, the ELISA specifically detected miroestrol in the range of 39.06-625.00 ng/mL. The intra- and inter-assay precisions were 0.74-2.98% and 6.57-9.76%, respectively. The recovery of authentic miroestrol spiked into samples was 106.70-110.14%, and the limit of detection was 11.07 ng/mL. The results for P. candollei roots and products determined using our developed ELISA with Fab antibody and an ELISA with anti-miroestrol monoclonal antibody (mAb) were consistent (R² = 0.9758). The developed ELISA can be applied for the quality control of miroestrol derived from P. candollei. Therefore, the appropriate expression platform of Fab resulted in the stable binding specificity of the recombinant antibody and was applicable for immunoassays.Key points• ELISAs with Fab has higher sensitivity than that with ScFv.• Fab is more stable than ScFv.• Fab-based ELISA can be used for miroestrol determination of Pueraria candollei.

Daidzein Hydroxylation by CYP81E63 Is Involved in the Biosynthesis of Miroestrol in Pueraria mirifica

White Kwao Krua (Pueraria candollei var. mirifica), a Thai medicinal plant, is a rich source of phytoestrogens, especially isoflavonoids and chromenes. These phytoestrogens are well known; however, their biosynthetic genes remain largely uncharacterized. Cytochrome P450 (P450) is a large protein family that plays a crucial role in the biosynthesis of various compounds in plants, including phytoestrogens. Thus, we focused on P450s involved in the isoflavone hydroxylation that potentially participates in the biosynthesis of miroestrol. Three candidate P450s were isolated from the transcriptome libraries by considering the phylogenetic and expression data of each tissue of P. mirifica. The candidate P450s were functionally characterized both in vitro and in planta. Accordingly, the yeast microsome harboring PmCYP81E63 regiospecifically exhibited either 2' or 3' daidzein hydroxylation and genistein hydroxylation. Based on in silico calculation, PmCYP81E63 had higher binding energy with daidzein than with genistein, which supported the in vitro result of the isoflavone specificity. To confirm in planta function, the candidate P450s were then transiently co-expressed with isoflavone-related genes in Nicotiana benthamiana. Despite no daidzein in the infiltrated N. benthamiana leaves, genistein and hydroxygenistein biosynthesis were detectable by liquid Chromatography with tandem mass spectrometry (LC-MS/MS). Additionally, we demonstrated that PmCYP81E63 interacted with several enzymes related to isoflavone biosynthesis using bimolecular fluorescence complementation studies and a yeast two-hybrid analysis, suggesting a scheme of metabolon formation in the pathway. Our findings provide compelling evidence regarding the involvement of PmCYP81E63 in the early step of the proposed miroestrol biosynthesis in P. mirifica.

Inhibition of LPS-Induced Microglial Activation by the Ethyl Acetate Extract of Pueraria mirifica

Microglial activation has been found to play a crucial role in various neurological disorders. Proinflammatory substances overproduced by activated microglia, such as cytokines, chemokines, reactive oxygen species, and nitric oxide (NO), can result in neuroinflammation that further exacerbates the course of the diseases. This study aimed to explore the anti-inflammatory effect of the ethyl acetate extract of Pueraria mirifica on microglial activation. Lipopolysaccharide (LPS)-induced inflammation was used as a model to investigate the effects of P. mirifica on HAPI (highly aggressive proliferating immortalized), a rat microglial cell line. Administration of ethyl acetate extract from the tuberous roots of P. mirifica to HAPI cells dose-dependently reduced NO production and iNOS expression induced by LPS. Attenuation of IRF-1 (interferon regulatory factor-1) induction, one of the transcription factors governing iNOS expression, suggested that the inhibitory effect on NO production by the plant extract was at least partially mediated through this transcription factor. In addition, LPS-stimulated mRNA expression of MCP-1 (monocyte chemoattractant protein-1), IL-6 (interleukin-6), and TNF-α (tumor necrosis factor-α) was also suppressed with P. mirifica extract pretreatment. This study indicates that the ethyl acetate extract of P. mirifica could potentially serve as an anti-inflammatory mediator and may be useful in relieving the severity of neurological diseases where microglia play a role.

Bioimprinting as a Receptor for Detection of Kwakhurin

Bioimprinting was performed against ovalbumin (OVA) to confer its binding cavities for kwakhurin (Kwa), an isoflavonoid, produced solely by Pueraria candollei var. mirifica (P. candollei). The characterization of bioimprinted-OVA (biOVA), evaluated by an enzyme-linked immunosorbent assay (ELISA), revealed that it functioned as a specific receptor for Kwa. Using biOVA, two systems, i.e., an indirect competitive ELISA (icELISA) and the even simpler and more rapid competitive enzyme-linked bioimprinted-protein assay (cELBIA), were developed as novel techniques for the quantitative analysis of Kwa in P. candollei and its related products. The two analysis methods were found to have limits of detection (LOD) of 4.0 and 2.5 µg/mL, respectively. The high reliability of the developed icELISA and cELBIA using biOVA was also demonstrated by various validation analyses. Subsequently, bioimprinting was performed using eight other proteins to investigate them as candidate scaffolds for the generation of binding cavities for Kwa. Interestingly, two bioimprinted-IgG monoclonal antibodies (biMAbs) recognized Kwa, but their original binding affinity to hapten was lost. That is, the MAbs obtained a new binding ability to Kwa in exchange for their original binding affinity, raising the possibility that biMAb could be alternatively used as a probe for the quantitative analysis of Kwa as well as biOVA. This is the first report of small molecules recognition by MAbs used as proteins for bioimprinting.

Improvement in the binding specificity of anti-isomiroestrol antibodies by expression as fragments under oxidizing conditions inside the SHuffle T7 E. coli cytoplasm

Sensitive and specific analysis of isomiroestrol (Iso) is required for the quality control of Pueraria candollei, an herb used to treat menopausal disorders. The anti-isomiroestrol monoclonal antibody (Iso-mAb) exhibits cross-reactivity with miroestrol and deoxymiroestrol, which impacts the analytical results. Here, the active and soluble forms of the single-chain variable fragment (Iso-scFv) and fragment antigen-binding (Iso-Fab) against Iso were expressed using Escherichia coli SHuffle® T7 to alter the binding specificity. The Iso-scFv format exhibited a higher binding activity than the Iso-Fab format. The reactivity of Iso-scFv towards Iso was comparable to that of the parental Iso-mAb. Remarkably, the binding specificity of the scFv structure was improved and cross-reactivity against analogs was reduced from 13.3-21.0% to less than 1%. The structure of recombinant antibodies affects the binding characteristics. Therefore, the immunoassays should improve specificity; these findings can be useful in agricultural processes and for quality monitoring of P. candollei-related materials.

Permeation, stability and acute dermal irritation of miroestrol and deoxymiroestrol from Pueraria candollei var. mirifica crude extract loaded transdermal gels

In this study, permeation behaviors and chemical stability of miroestrol and deoxymiroestrol from Pueraria candollei var. mirifica (PM), Thai traditional medicine, crude extract containing transdermal gels were firstly evaluated. Three different PM extract containing gels were formulated, including hydroalcoholic and microemulsion gels using carbomer, and silicone gel using silicone elastomer. In vitro permeation through porcine ear skin demonstrated that the flux and 24 h cumulative permeation of miroestrol and deoxymiroestrol were in the order of hydroalcoholic > silicone > microemulsion gels. Hydroalcoholic gel provided the highest partition coefficient from gel onto skin, and thus the skin permeability coefficient. After 24 h permeation, no miroestrol and deoxymiroestrol remained deposited in the skin. Accelerated study using heating-cooling revealed insignificant difference between the remaining percentages of miroestrol and deoxymiroestrol in aqueous and non-aqueous based gels. Long-term stability study showed that miroestrol contents remained constant for 90 d and 30 d under 5 ± 3 °C and 30 ± 2 °C, 75 ± 5%RH, respectively; whereas the percentage of deoxymiroestrol decreased significantly after 30 d storage, irrespective of storage conditions. Acute dermal irritation test on New Zealand White rabbits showed that PM hydroalcoholic gels were non-irritant, with no signs of erythema or oedema.[Figure: see text].

Fragment antigen-binding (Fab) antibody-based lateral flow immunoassay for rapid and sensitive detection of potent phytoestrogen, deoxymiroestrol

Pueraria candollei is an ingredient of Thai herbal medicine, dietary supplements, and cosmetics. The in vitro and in vivo studies of this plant supported anti-osteoporotic activity and used for hormone replacement therapy. Deoxymiroestrol shows the most potent phytoconstituent in tuberous root of P. candollei with estrogenic activity. The quality controls are important for good agricultural practice (GAP) and good manufacturing practice (GMP) of plant-derived raw materials. The rapid detection of lateral flow immunoassay (LFIA) using colloidal gold is simply method, easy visualize detection and produce less waste than conventional chromatographic detection. In this study, LFIA for qualitative detection of deoxymiroestrol using antigen-binding fragment antibody (Fab) was developed. The result showed that the developed LFIA displays specific detection of deoxymiroestrol. Cross reactivity of this method was analyzed with miroestrol, isomiroestrol and methylisomiroestrol which showed 39.97%, 7.71% and 5.72%, respectively. After optimal condition, limit of detection (LOD) for deoxymiroestrol is 250 ng/ml. Plant samples were applied to strip test compare with indirect competitive ELISA using polyclonal antibody to confirm the application of LFIA. The results of LFIA method were comparable with those from ELISA. This developed lateral flow immunoassay can apply to detect deoxymiroestrol for the rapid testing. The developed method can use for quality control in plant samples as deoxymiroestrol is biomarker compound in P. candollei.

Miroestrol Quantification in Pueraria mirifica Crude Drugs and Products by Single-Reference UPLC/PDA/MS Using Relative Molar Sensitivities to Kwakhurin

Owing to occasional health damages caused by health food products derived from Pueraria mirifica (PM), the Japanese government has designated PM as an "ingredient calling for special attention." Miroestrol is a specific isoflavone isolated from PM and possesses very strong estrogenic activity enough to induce side effects in small amount. Therefore, routine analyses for miroestrol quantification is recommended to control the safety and quality of PM products. However, miroestrol content in PM is quite low, and commercial reagent for its detection is rarely available. In this study, we developed a quantitative analysis method for miroestrol in PM without using its analytical standard by using the relative molar sensitivity (RMS) of miroestrol to kwakhurin, another PM-specific isoflavone, as a reference standard. The RMS value was obtained by an offline combination of ¹H-quantitative NMR spectroscopy and a LC/photo diode array (PDA) and miroestrol content was determined by single-reference LC/PDA using RMS. Furthermore, we investigated miroestrol content in commercially available PM crude drugs and products, and the RMS method was compared with the conventional calibration curve method in terms of performance. The rate of concordance of miroestrol contents determined by two method was 89-101%. The results revealed that our developed LC/PDA/MS method with RMS using kwakhurin as a reference standard was accurate for routine monitoring of miroestrol content in PM crude drugs and products to control their quality.

Transformation of Pueraria candollei var. mirifica phytoestrogens using immobilized and free β-glucosidase, a technique for enhancing estrogenic activity

Pueraria candollei var. mirifica (PM) has a significant beneficial effect on postmenopausal symptoms associated with estrogen deficiency. However, the estrogenic activity and intestinal absorption of isoflavonoid glycosides derived from PM, such as daidzin and genistin, are significantly lower than those of their aglycones. To enhance the estrogenic activity of the PM extract, we developed β-glucosidase and its immobilized form to increase the PM aglycone content (daidzein and genistein). The enzyme immobilization was done by alginate beads, and the resulting β-glucosidase alginate beads have a diameter of about 0.20 cm. Response surface methodology (RSM) was used to optimize certain parameters, such as the pH, temperature, and ethanol concentration. The optimal conditions of β-glucosidase for daidzein and genistein production were pH of 4.8–4.9, a temperature in the range 46.3–49.1 °C, and ethanol concentration of 10.0–11.0%. The ANOVA results indicated that the design experiment involving free and immobilized β-glucosidase was the best fit by quadratic models, which had adjusted R² values between 0.8625 and 0.9318. Immobilized β-glucosidase can be reused up to nine times and maintained efficacy of greater than 90%. Treatment of the PM extract with β-glucosidase increased the estrogenic activity of the PM extract by 8.71- to 23.2-fold compared to that of the untreated extract. Thus, β-glucosidase has a high potential for enhancing the estrogenic activity of PM constituents, and it can be applied on an industrial scale to increase the utility of these natural products.

Transformation of Pueraria candollei var. mirifica phytoestrogens by β-glucosidase increases estrogenic activity.

Quantification of methylisomiroestrol, a phytoestrogen of Pueraria candollei, by enzyme-linked immunosorbent assay in comparison with high-performance liquid chromatography

Pueraria candollei is a phytoestrogen-rich herb used to treat estrogen deficiency disorders; however, quality control of P. candollei-related health products is required for consistency of clinical outcomes. Estrogenically active (+)-7-O-methylisomiroestrol could be a potential chemical marker that facilitates the prediction of the overall estrogenic activity of P. candollei. The analytical performance of ELISA using newly produced monoclonal antibodies against methylisomiroestrol was compared with HPLC analysis. The developed indirect competitive ELISA (icELISA) was highly sensitive to methylisomiroestrol for detection, with an LOQ of 2.9 ng/mL, whereas the LOQ was 1.15 μg/mL by HPLC. The results from method validation indicated acceptable precision (1.71-6.37 % and 0.13-2.40 %) and accuracy (99.23-102.54 % and 96.84-101.88 %) of the methylisomiroestrol analysis using icELISA and HPLC. These methods were effectively applied for the determination of the methylisomiroestrol content in P. candollei samples. Apart from the plant tubers, the stem was observed as a source of methylisomiroestrol. The developed ELISA was more effective than HPLC in detecting a small quantity of methylisomiroestrol in the plant samples [0.23 × 10^-3% (w/w) to 0.628 × 10^-3% (w/w) dry weight]. Therefore, the ELISA could be a useful tool for the standardization of P. candollei, which is the crucial step to improve the quality of plant-derived products.

Daily White kwao krua dietary supplement alleviates LDL oxidative susceptibility, plasma LDL level and improves vasculature in a hypercholesterolemia rabbit model

BACKGROUND AND AIM

White kwao krua is an edible plant that grows in Southeast Asia. It is very rich in natural phytoestrogens. Previous clinical studies revealed that the use of White kwao krua as a hormone replacement therapy has beneficial effects on the lipid profile of menopause women. In this present study, we utilized the hypercholesterolemia rabbit model to demonstrate the effect of White kwao krua on the daily intake of high-fat diet.

EXPERIMENTAL PROCEDURE

We induced hypercholesterolemia in rabbits by feeding with high-fat diet (1% cholesterol-containing diet). The animals were maintained 12 weeks for the experimentation. The White kwao krua supplement was administered 100 mg/kg/day, and the effects were monitored comparing with Statins and turmeric. Blood was collected periodically to monitor the plasma cholesterol level and the oxidative susceptibility of isolated LDL-cholesterol. At the end of the experiment, the aorta was collected from the animal and performed endothelial-dependent relaxation and endothelial-independent relaxation assays. The relative ratio of intima to media layer was microscopically evaluated from hematoxylin/eosin-stained tissues.

RESULTS AND CONCLUSION

We showed that the White kwao krua supplement reduced LDL-cholesterol about 40% compared with high-fat diet consumption alone. Administration of White kwao krua had significantly prolonged the susceptibility of LDL-cholesterol to oxidation. Besides, it led to the improvement of vascular function by recovering endothelium-dependent relaxation and alleviating vascular structure impairment induced by high-fat dietary intake. Together, we suggest that White kwao krua should be used as a dietary supplement to reduce the atherogenesis in high-fat dietary consumption.

SECTION

Dietary therapy/nutrients supplements.

TAXONOMY

Inflammation, Disease.

Facile Synthesis of Kwakhurin, a Marker Compound of Pueraria mirifica and Its Quantitative NMR Analysis for Standardization as a Reagent

The side effects of kwao keur dietary supplements (obtained from the tuberous root of Pueraria mirifica) have recently been reported by the Ministry of Health, Labour and Welfare, Japan. To control the quality of kwao keur products, its ingredients need to be maintained by characteristic marker compounds, such as miroestrol, deoxymiroestrol, and kwakhurin (KWA). In this study, we described the facile synthesis of KWA, a marker compound of P. mirifica. Our revised synthetic method produced KWA with shorter steps and higher yield than the reported method. Furthermore, the absolute purity of KWA was determined by quantitative NMR analysis for standardization as a reagent, and its purity was 92.62 ± 0.12%.

(+)-7-O-Methylisomiroestrol, a new chromene phytoestrogen from the Pueraria candollei var. mirifica root

(+)-7-O-Methylisomiroestrol (MeI), a novel chromene, was discovered as a phytoestrogen in the Pueraria candollei var. mirifica (Airy Shaw & Suvat.) Niyomdham (PM) root having been used as an active agent against oestrogen depletion disorders. The identification of PM phytochemicals is crucial for the development of standardised botanical drugs of PM. MeI was purified from the root cortex of PM, and its structure was elucidated using NMR and mass spectrometry. The content of MeI in the root bark of the PM root was 2.1-6.5 × 10^-3% (w/w). The oestrogenic potency of MeI was stronger than that of isomiroestrol but less than that of deoxymiroestrol and miroestrol. Therefore, MeI is a new oestrogenic biomarker for the effective chemical standardisation of the PM extract for health product development.

β-C(sp2)–H alkylation of enamides using xanthate chemistry

Access to the γ-amino-β,γ-unsaturated acyl scaffold was established by applying xanthate chemistry to enamides.

Preparation of a highly specific single chain variable fragment antibody targeting miroestrol and its application in quality control of Pueraria candollei by enzyme-linked immunosorbent assay

INTRODUCTION

Miroestrol is the potent phytoestrogen isolated from White Kwao Krua (Pueraria candollei var. mirifica (Airy Shaw & Suvat.) Niyomdham, a Thai traditional medicinal plant. Nowadays, various health supplementary products featuring White Kwao Krua are available worldwide. A sensitive and rapid analytical method for quantification of miroestrol is necessary for quality control of these products.

OBJECTIVES

To prepare a single-chain variable fragment (scFv) antibody specific to miroestrol and develop a scFv-based enzyme-linked immunosorbent assay (ELISA) for quantitative analysis of miroestrol in plant materials and health supplementary products.

METHODS

A gene encoding anti-miroestrol scFv antibody was constructed and expressed in Escherichia coli SHuffle T7 strain. Anti-miroestrol scFv antibody was characterised and applied to ELISA. The developed scFv-based ELISA method was validated for its sensitivity, specificity, accuracy and precision.

RESULTS

Anti-miroestrol scFv antibody was highly specific to miroestrol. The scFv-based ELISA was applied to determine miroestrol in the range 0.06-7.81 μg/mL, with the limit of quantification of 0.06 μg/mL miroestrol. The accuracy of the assay was validated by its 95.08-103.99% recovery from the spiked miroestrol recovery experiment and in good correlation with the results from the monoclonal antibody-based ELISA. The relative standard deviation of the intra- and inter-assay were less than 6.0%.

CONCLUSION

The developed scFv-based ELISA was sensitive, specific, accurate, and precise for determination of miroestrol and useful for quality control of P. candollei plant raw materials and supplementary products.

Development of a simple and rapid method for the detection of isomiroestrol in Pueraria candollei by an immunochromatographic strip test

Pueraria candollei (P. candollei) is a traditional Thai herb widely used for estrogen replacement therapy because it contains many unique chromenes that possess potent estrogenic activity, one of which is known as isomiroestrol. Since isomiroestrol is a promising compound that is solely present in P. candollei, it can be used as an identifying marker for standardization of P. candollei. Here, we developed a lateral-flow immunochromatographic strip (ICS) test using a colloidal gold nanoparticle-conjugated anti-isomiroestrol monoclonal antibody (12C1-mAb) for the detection of isomiroestrol in plant samples and products of P. candollei. The advantages of the developed ICS over an enzyme-linked immunosorbent assay are its simplicity and rapidity, as the ICS test can be completed 15 min after dipping the strip into the analyte solution. The detectable concentration of isomiroestrol was 7.0 µg/mL. Considering the demand for the standardization of P. candollei due to concerns regarding its quality, our ICS test using isomiroestrol as an identifying marker would be effective and useful to assess the presence of isomiroestrol.

The effects of Pueraria mirifica extract, diadzein and genistein in testosterone-induced prostate hyperplasia in male Sprague Dawley rats

Pueraria mirifica (PM) is a medicinal plant native to Thailand contained high amount of phytoestrogen and possesses anticancer activity. This study reports the effect of P. mirifica extract, phytoestrogen of diadzein and genistein for its benign prostate hyperplasia properties in testosterone-induced prostate hyperplasia in male Sprague Dawley rats. The P. mirifica extract was evaluated for its total phenols, flavonoid and antioxidant activity using DPPH, FRAP and metal chelating assay. The assessment of P. mirifica, diadzein and genistein against benign prostate hyperplasia was determined in testosterone-induced prostate hyperplasia in male Sprague Dawley rats. The total phenol was higher than flavonoid but showed low antioxidant activity of DPPH, FRAP and metal chelating. The aqueous PM extract at 1000 mg/kg significantly increased testosterone levels in testosterone-induced rats by 13% while diadzein and genistein increased it by 11% and 17% respectively. However, levels of FSH, LH, triglyceride and HDL are not affected by the oral administration of PM, diadzein and genistein to the rats. Similarly, total protein, albumin, globulin, total bilirubin, conjugated bilirubin, alkaline phosphatase, alanine aminotransferase, AST, and G-glutamyltransferase showed no significant difference as compared with negative control rats. The body weight of the rats, testis, kidney and liver showed no toxic effect. The zinc content increased significantly and the zinc transporter gen of ZnT4 and ZIP4 highly expressed suggesting that the PM, diadzein and genistein plays essential role in modulating prostate zinc homeostasis. Similarly, the expression of IL-6, AR and ER was significantly reduced indicating functioning in regulation of prostate growth and acts as anti-inflammatory role in preventing BPH. In conclusion, the results indicated that PM reduced BPH and contributed to the regulation in the zinc transport expression of the prostate cells in the benign prostate hyperplasia (BPH).

Pueraria mirifica inhibits 17β-estradiol-induced cell proliferation of human endometrial mesenchymal stem cells

OBJECTIVE

The notion that the human endometrium may contain a population of stem cells has recently been proposed. The mesenchymal stem cells (MSCs) in the endometrium are believed to be responsible for the remarkable regenerative ability of endometrial cells. Estrogens influence the physiological and pathological processes of several hormone-dependent tissues, such as the endometrium. Pueraria mirifica (PM) is a herbal plant that contains several phytoestrogens, including isoflavones, lignans, and coumestans, and is known to exert an estrogenic effect on animal models. The present study investigated the effects of PM on the proliferation of human endometrial MSCs (hEN-MSCs).

MATERIALS AND METHODS

The hEN-MSCs were isolated from human endometrial tissue. The surface markers of these hEN-MSCs were identified through reverse transcription-polymerase chain reaction analysis. The proliferation potential of hEN-MSCs was measured through a cell proliferation assay. Multilineage differentiation ability was confirmed through Oil red O and von Kossa staining.

RESULTS

This study demonstrated that 17β-estradiol-responsive MSCs with Oct-4, CD90, and CD105 gene expression can be derived from the human endometrium and that PM exerts biological effects on hEN-MSCs, specifically, enhanced cell growth rate, through the estrogen receptor. Furthermore, PM at 1500 and 2000 μg/mL significantly increased cell proliferation compared with the vehicle control, and PM concentration at 1000 μg/mL significantly inhibited the enhanced cell growth rate induced by 17β-estradiol in hEN-MSCs.

CONCLUSION

This study provides new insights into the possible biological effects of PM on the proliferation of hEN-MSCs.

Efficacy and safety of Pueraria candollei var. mirifica (Airy Shaw & Suvat.) Niyomdham for menopausal women: A systematic review of clinical trials and the way forward

ETHNOPHARMACOLOGICAL RELEVANCE

Pueraria candollei var. mirifica (Airy Shaw & Suvat.) Niyomdham (commonly termed P. mirifica, PM) growing in upland Thailand has a long history as a postmenopausal rejuvenant therapy for indigenants. Its amelioration of menopause symptoms in clinical trials was assessed.

MATERIALS AND METHODS

International and Thai databases were searched from inception to February 2017. Clinical trials investigating effects of PM menopausal or postmenopausal women were included. Outcomes were self-reported menopausal symptoms, serum reproductive hormones, urino-genital tract function, and bone surrogates. Methodological quality was assessed by Cochrane risk-of-bias v2.0, and a 22-parameter quality score based on the CONSORT checklist for herbal medicines.

RESULTS

Eight studies (9 articles) used data from 309 menopausal patients. Five-studies demonstrated that PM was associated with climacteric scores reduced by ~50% compared to baseline. Other PM studies using limited numbers of placebo participants suggested improved vaginal and other urogenital tract symptoms. Bone alkaline phosphatase halved (suggesting lowered bone turnover). Variable serum reproductive hormone levels suggested menopausal status differed between studies. PM active ingredients and sources were not defined. Adverse event rates (mastodynia, vaginal spotting, dizziness) were similar in all groups (PM, conjugated equine estrogen, and placebos) but serum C-reactive protein doubled. These studies had design and reporting deficiencies, high risks of biases, and low quality scores.

CONCLUSIONS

The efficacy of PM on menopausal symptoms remains inconclusive because of methodological short-comings especially placebo effects inherent in self-assessment/recall questionnaires and no PM standardization. PM efficacy and safety need a fundamental re-appraisal by: (i) cohort (retro- and prospective) studies on current users to define its traditional use for rejuvenation; (ii) tightly coupling long-term efficacy to safety of well-defined PM and multiple end-points; (iii) using study design related to current understanding of menopause progression and estrogen pharmacology (iv) robust pharmacovigilance.

A pilot pharmacokinetic study of miroestrol and deoxymiroestrol on rabbit sera using polyclonal antibody-based icELISA analysis

Miroestrol (ME) and deoxymiroestrol (DME) are the most potent phytoestrogens and bioactive markers in Pueraria candollei var. mirifica tuberous roots. To understand their pharmacokinetic profiles, a pharmacokinetic study of ME and DME, at 0.43 and 0.21 mg per kg body weight, respectively, in three rabbits was performed after orally administering a single dose of P. candollei var. mirifica enriched fraction extract. Two established polyclonal antibody-based indirect competitive enzyme-linked immunosorbent assays were validated to determine ME and DME in rabbit sera. In rabbits, the area under the 0- to 48-hr concentration-time curve of ME and DME were 854.92 and 1,692.84 ng·h/ml, respectively. The maximum concentration of ME was measured 1 hr after administration as 69.62 ± 8.28 ng/ml, and the maximum concentration of DME was measured at 3 hr as 81.8 ± 5.43 ng/ml. These results provide an initial approach for designing and studying the relationship between the ME and DME levels and their therapeutic effects based on their pharmacokinetic profiles.

Determination of Miroestrol and Isomiroestrol From Pueraria mirifica (White Kwao Krua) in Dietary Supplements by LC-MS-MS and LC-Q-Orbitrap/MS

The purpose of this study is to develop LC-MS-MS and LC-Q-Orbitrap/MS method for the analysis of the components of Pueraria mirifica, which are illegal additives in dietary supplements. Blank samples and samples spiked with miroestrol and isomiroestrol were used for the initial development and validation studies. Specificity, linearity, limit of quantification (LOQ), limit of detection (LOD), accuracy, precision, recovery and stability were employed as the validation parameters. The LODs of miroestrol and isomiroestrol were found to be 4.17 and 0.84 ng/mL, respectively, whereas their LOQs were 12.50 and 2.52 ng/mL, respectively. The determination coefficient was over 0.999, intra- and inter-day precisions were 0.8-6.9 and 1.9-9.8%, respectively, and intra and inter-day accuracies were 82.1-103.7 and 85.0-109.7%, respectively. The mean recoveries of the targeted compounds from the dietary supplements ranged from 86.9 to 108.9%. The relative standard deviations (RSDs) for recovery were <5.8%. On the other hand, the RSD of stability was <11.0%. Eight dietary supplements were tested using the newly developed and validated method, out of which six were found to be adulterated samples.

RhII -Catalyzed β-C(sp2 )-H Alkylation of Enol Ethers, Enamides and Enecarbamates with α-Diazo Dicarbonyl Compounds

A Rh^II -catalyzed method for intermolecular alkylation of the β-C(sp² )-H bond of enol ethers, enamides, and enecarbamates with α-diazo-1,3-dicarbonyl compounds is reported. The products are formed in up to 99 % yield and can be readily derivatized under a variety of conditions. By utilizing a combination of experimental and computational studies, the presumptive addition-elimination reaction mechanism was investigated and found to proceed under thermodynamic control at higher temperature. The acquired fundamental knowledge was translated into a strategic reaction design and yielded the first example of the β-C-H functionalizations of acyclic enol ethers using α-diazo-1,3-dicarbonyl compounds.

Pueraria mirifica Exerts Estrogenic Effects in the Mammary Gland and Uterus and Promotes Mammary Carcinogenesis in Donryu Rats

Pueraria mirifica (PM), a plant whose dried and powdered tuberous roots are now widely used in rejuvenating preparations to promote youthfulness in both men and women, may have major estrogenic influence. In this study, we investigated modifying effects of PM at various doses on mammary and endometrial carcinogenesis in female Donryu rats. Firstly, PM administered to ovariectomized animals at doses of 0.03%, 0.3%, and 3% in a phytoestrogen-low diet for 2 weeks caused significant increase in uterus weight. Secondly, a 4 week PM application to non-operated rats at a dose of 3% after 7,12-dimethylbenz[a]anthracene (DMBA) initiation resulted in significant elevation of cell proliferation in the mammary glands. In a third experiment, postpubertal administration of 0.3% (200 mg/kg body weight (b.w.)/day) PM to 5-week-old non-operated animals for 36 weeks following initiation of mammary and endometrial carcinogenesis with DMBA and N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG), respectively, resulted in significant increase of mammary adenocarcinoma incidence. A significant increase of endometrial atypical hyperplasia multiplicity was also observed. Furthermore, PM at doses of 0.3%, and more pronouncedly, at 1% induced dilatation, hemorrhage and inflammation of the uterine wall. In conclusion, postpubertal long-term PM administration to Donryu rats exerts estrogenic effects in the mammary gland and uterus, and at a dose of 200 mg/kg b.w./day was found to promote mammary carcinogenesis initiated by DMBA.

Preparation and application of a monoclonal antibody against the isoflavone glycoside daidzin using a mannich reaction-derived hapten conjugate

INTRODUCTION

Daidzin and its aglycone daidzein are major pharmacologically active compounds of soybean (Glycine max), kudzu (Pueraria lobata), and kwao kruea khao (P. mirifica). Pharmacological activities of daidzin are mediated by its more potent metabolites daidzein and equol; however, daidzin is the predominant compound found in these medicinal plants, and the efficacy and safety of equol depend on the amount of daidzin consumed.

OBJECTIVE

To develop a specific monoclonal antibody (MAb)-based indirect competitive enzyme-linked immunosorbent assay (icELISA) for standardisation of daidzin content in herbal medicines or nutraceuticals.

METHODOLOGY

The Mannich reaction was used for the synthesis of a highly immunogenic conjugate between daidzin and a cationised carrier protein. Splenocytes of hyperimmunised mice were fused with myeloma cells to generate a hybridoma secreting antibody against daidzin.

RESULTS

The icELISA showed high selectivity and acceptable sensitivity for daidzin determination (1.56-100 ng/mL) with high reproducibility (coefficients of variation were < 5%). The icELISA was a reliable analytical method for daidzin in Glycine max, Pueraria lobata and P. mirifica, for which daidzin recoveries from spiked samples were 98.99-104.94%. Daidzin content of these plant-derived products determined using the icELISA were in close agreement with those determined by a HPLC-UV method.

CONCLUSION

The icELISA is useful for specific daidzin determination because of its reliability, low cost, speed and high throughput.

Anti-miroestrol polyclonal antibodies: a comparison of immunogen preparations used to obtain desired antibody properties

Immunogen quality is one important factor that contributes to desirable antibody characteristics. Highly specific antibodies against miroestrol can be used to develop a quality control immunoassay for Pueraria candollei products. In this study, we investigated how various immunogen preparations affect antibody properties. The results show that immunogen prepared using the Mannich reaction provides antibodies with higher specificity and sensitivity against miroestrol than immunogen prepared with the periodate reaction. The results suggest the Mannich reaction maintains the original structure of miroestrol and generates useful antibodies for developing immunoassays.

Effect of miroestrol on ovariectomy-induced cognitive impairment and lipid peroxidation in mouse brain

Miroestrol (MR) is a phytoestrogen isolated from Pueraria candollei var. mirifica (KwaoKrueaKhao), a Thai medicinal plant used for rejuvenation. We examined the effects of MR on cognitive function, oxidative brain damage, and the expression of genes encoding brain-derived neurotrophic factor (BDNF) and cyclic AMP-responsive element-binding protein (CREB), factors implicated in neurogenesis and synaptic plasticity, in ovariectomized (OVX) mice. OVX decreased serum 17β-estradiol level and uterine weight. OVX also impaired object recognition performance in the novel object recognition test and spatial cognitive performance in the Y-maze test and the water maze test. Daily treatment of MR dose-dependently attenuated OVX-induced cognitive dysfunction. Moreover, OVX mice had a significantly increased level of thiobarbituric acid-reactive substances, and down-regulated expression levels of BDNF and CREB mRNAs in the hippocampus and frontal cortex. MR treatment as well as hormone replacement therapy with 17β-estradiol significantly reversed these neurochemical alterations caused by OVX. These results suggest that MR ameliorates cognitive deficits in OVX animals via attenuation of OVX-induced oxidative stress and down-regulation of BDNF and CREB mRNA transcription in the brain. Our findings raise the possibility that MR and Pueraria candollei var. mirifica, the plant of origin of MR, may have a beneficial effect on cognitive deficits like AD in which menopause/ovariectomy are implicated as risk factors.

Pueraria mirifica leaves, an alternative potential isoflavonoid source

We investigated the major leaf isoflavonoid contents of Pueraria mirifica from three different cultivars (PM-III, PM-IV, and PM-V) using reverse RP-HPLC analysis. The proportions and net levels of puerarin, daidzin, genistin, and daidzein in P. mirifica leaves were found to depend on the plant cultivar and to correlate with cultivation temperature and rainfall amount. The crude leaf-extracts were tested using the Yeast Estrogen Screen (YES) assay with both human estrogen receptors (hERα and hERβ). Their estrogenic activity was higher when determined by the YES system containing hERβ than that with hERα and was also higher when the Δsnq2 than the wildtype yeast was employed. The results open the possibility of selecting and cultivating certain P. mirifica cultivars at a farm scale to produce a sufficient supply of leaf material to act as a starting source for the commercial scale extraction of these major isoflavonoids.

Characteristic chemical components of the essential oil from white kwao krua (Pueraria mirifica)

The components of the essential oil from the roots of Pueraria mirifica were analyzed by capillary gas chromatography-mass spectrometry (GC-MS). Eighty-two components, representing 88.5% of the total oil, were identified by GC-MS. The main component of the oil was 2-pentylfuran, followed by hexanal and hexadecanol. With regard to the odor components from the essential oil of P. mirifica as determined by gas chromatography-olfactometry and aroma extract dilution analysis, it was revealed that phenylacetaldehyde and (2E)-nonenal imparted the green odor of the oil, and geraniol contributed to the sweet odor.

The Use of Cycleave PCR for the Differentiation of the Rejuvenating Herb Species Pueraria candollei (White Kwao Khruea), Butea superba (Red Kwao Khruea), and Mucuna macrocarpa (Black Kwao Khruea), and the Simultaneous Detection of Multiple DNA Targets in a DNA Admixture

Kwao Khruea, the tuberous roots of Pueraria candollei Graham ex Benth. (White Kwao Khruea), Butea superba Roxb. (Red Kwao Khruea), and Mucuna macrocarpa Wall. (Black Kwao Khruea), are used as rejuvenating herbs in traditional medicine in many tropical countries. Although Kwao Khruea has attracted strong interest because of its rejuvenation properties, each species is used for specific purposes and effects. P. candollei shows estrogenic effects in females. In contrast, B. superba and M. macrocarpa show androgenic effects in males. The potential misidentification of dried tuberous roots of various Kwao Khruea species might cause problems in the drug market, especially when they are reduced into powders. A cycleave PCR, which is based on the sequence of chloroplast matK gene, was developed to differentiate P. candollei, B. superba, and M. macrocarpa. The results showed that cycleave PCR is able to identify specific Kwao Khruea species. A multiplex cycleave PCR was optimized for the simultaneous detection of two different DNA targets in a DNA admixture. The specificity of this technique was confirmed by its ability to distinguish M. macrocarpa from five related Mucuna species. Cycleave PCR can be a specific, sensitive, and rapid method for the identification of medicinal plants and crude plant samples.

Simple, sensitive and reliable in vivo assays to evaluate the estrogenic activity of endocrine disruptors

Purpose

We compared three in vivo assays, determining changes of body weight, and uterotropic and vaginal cytology assays, for the evaluation of estrogenic activity of an estrogen disrupting compound, Pueraria mirifica (PM), in comparison with 17β-estradiol (E).

Methods

Female rats were ovariectomized and gavaged with distilled water, 0.01, 0.1, 1, 10 and 20 mg/kg BW/day of E and 100 and 1,000 mg/kg BW/day of PM for 14 days. Body weights were measured weekly, and vaginal epithelium cells were monitored daily. The uterus was dissected at the end of the treatment period, weighed and examined for histomorphometry.

Results

There were a decrease in body weight and an increase in uterine weight, uterine, endometrium and myometrium areas, uterine gland numbers, and percent of cornified cell which were dependent on doses of E and PM treatments.

Conclusions

Of the three assays proposed, although all are reliable and had critical read-out, measurements of body and uterine weights is likely convenient and simple, but the uterotropic assay needs to kill the animals. Vaginal cytology assay appears most promising for sensitivity and shortening the duration of the assay. Compared to those of E, the estrogenic activity of PM at concentrations of 100 and 1,000 mg/kg BW was in the range of 14 to >20 mg/kg BW.