Medical applications of phytoestrogens from the Thai herb Pueraria mirifica

The isolation, characterization and biological activities of the non-glucan polysaccharides from the high-starch-content plant Pueraria mirifica

The dried root of Pueraria mirifica (P. mirifica) is an edible foodstuff widely used in Asian countries. P. mirifica is known for its high starch content. The isolation of polysaccharides from high-starch plant parts is challenging due to the interference of starch. Therefore, this study aimed to develop a technique for isolating and investigating the structure and activity of non-glucan polysaccharides from P. mirifica (PMP). An effective starch removal process was developed using α-amylase hydrolysis and thorough membrane dialysis. Four non-glucan polysaccharides were isolated, and PMP-2 was subjected to structural elucidation. The results indicated that PMP-2 has a molecular weight of 124.4 kDa and that arabinose and galactose are the main components, accounting for 27.8 % and 58.5 %, respectively. Methylation and NMR analysis suggested that PMP-2 is an Arabinogalactan composed of 1,6-linked Galp and 1,4-linked Galp as the main chain, with arabinan and rhamnose as side chains. Furthermore, PMP-C and PMP-2 exhibited concentration-dependent antioxidant activities against DPPH, ABTS, and hydroxyl radicals and certain immunomodulatory activities related to the release of NO, TNF-α and IL-6. These findings suggest that PMP-2 has potential therapeutically active ingredient in functional foods. The developed method successfully removed starch and isolated non-glucan polysaccharides from the high-starch content plant P. mirifica and can be applied to other high-starch plants.

Puerarin alleviates sleep disorders in aged mice related to repairing intestinal mucosal barrier

More and more evidence suggests that puerarin, a potential remedy for gut inflammation, may have an ameliorative effect on sleep disturbances. However, the relationship between puerarin and sleep disruption has not been extensively researched. This study aims to explore the role and mechanisms of puerarin in improving sleep disorders. We established a light-induced sleep disorder model in mice and assessed the effects of puerarin on cognitive behavior using open field and water maze tests. Pathological detection demonstrated that sleep disturbances resulted in observable damage to the liver, lung, and kidney. Puerarin reversed multi-organ damage and inflammation. Further, puerarin activated paneth cells, resulting in increased lysozyme and TGF-β production, and stimulating intestinal stem cell proliferation. Puerarin also effectively inhibited the expression of F4/80, iNOS, TNF-α, and IL-1β in the small intestine, while it increased Chil3, CD206, and Arg-1 levels. Moreover, puerarin treatment significantly decreased P-P65, TLR4, Bcl-xl, and cleaved caspase-3 protein levels while increasing barrier protein levels, including ZO-1, Occludin, Claudin 1 and E-cadherin suggesting a reduction in inflammation and apoptosis in the gut. Overall, puerarin diminished systemic inflammation, particularly intestinal inflammation, and enhanced intestinal barrier integrity in mice with sleep disorders. Our findings suggest a potential new therapeutic pathway for sleep disorders.

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.

The Prevalence of Dietary Supplements That Claim Estrogen-like Effects in Japanese Women

Recently, adverse events, such as irregular vaginal bleeding and menstrual disorders, associated with the use of dietary supplements containing Pueraria mirifica, have been reported in Japan. P. mirifica contains phytoestrogens, such as deoxymiroestrol and miroestrol. Therefore, we investigated the use of supplements that claim to have estrogen-like effects (i.e., estrogen-like supplements) in Japanese women aged from 15 to 69 years old in an online survey. The prevalence of estrogen-like supplement use was 5%, accounting for approximately 15% of the sample, including ex-users. The majority of the users were in their 40s and 50s, mainly using these supplements for the treatment of menopausal symptoms. In contrast, the younger generation mainly used them for beauty purposes, such as weight loss, mastogenic effects, and skin care. Many of them visited a clinic or took medicines for menstrual-related troubles. In all age groups, soybeans/isoflavones were the most commonly used, followed by equol and placenta. Participants in their teens and 20s also used P. mirifica. Among them, 16.2% had experienced adverse events, including irregular vaginal bleeding, breast swelling and pain, and heavy menstruation. In conclusion, estrogen-like supplement use is associated with adverse events; thus, it is necessary to pay attention to the use of these supplement. Furthermore, because the purpose of use differs depending on generation, caution according to each generation is necessary.

Effect of Yakae-Prajamduen-Jamod Traditional Thai Remedy on Cognitive Impairment in an Ovariectomized Mouse Model and Its Mechanism of Action

Cognitive impairment is a neurological symptom caused by reduced estrogen levels in menopausal women. The Thai traditional medicine, Yakae-Prajamduen-Jamod (YPJ), is a formula consisting of 23 medicinal herbs and has long been used to treat menopausal symptoms in Thailand. In the present study, we investigated the effects of YPJ on cognitive deficits and its underlying mechanisms of action in ovariectomized (OVX) mice, an animal model of menopause. OVX mice showed cognitive deficits in the Y-maze, the novel object recognition test, and the Morris water maze. The serum corticosterone (CORT) level was significantly increased in OVX mice. Superoxide dismutase and catalase activities were reduced, while the mRNA expression of IL-1β, IL-6, and TNF-α inflammatory cytokines were up-regulated in the frontal cortex and hippocampus of OVX mice. These alterations were attenuated by daily treatment with either YPJ or 17β-estradiol. HPLC analysis revealed that YPJ contained antioxidant and phytoestrogen constituents including gallic acid, myricetin, quercetin, luteolin, genistein, and coumestrol. These results suggest that YPJ exerts its ameliorative effects on OVX-induced cognitive deficits in part by mitigating HPA axis overactivation, neuroinflammation, and oxidative brain damage. Therefore, YPJ may be a novel alternative therapeutic medicine suitable for the treatment of cognitive deficits during the menopausal transition.

Comparison of neuroprotective effects of dihydrotestosterone, 17β-estradiol, and Pueraria mirifica herb extract on cognitive impairment in androgen deficient male rats

This study investigated the neuroprotective effects of dihydrotestosterone (DHT), 17β-estradiol (E₂), and Pueraria mirifica herb extract (PME; an alternative source of natural estrogens) on the (i) learning and memory in androgen-deficient male rats, and on the hippocampus expression levels of (ii) mRNA of genes associated with synaptic transmission and structure, neurofibrillary tangles, and amyloid plaques, and (iii) total and phosphorylated tau proteins. The four-month-old male rats were sham-operated or orchidectomized (ODX). The ODX rats were divided into four groups, and orally treated for 2 months with either 1 mL/d of distilled water or 100 mg/kg/d of PME; or subcutaneously injected with 1 mg/kg/d of DHT or 80 μg/kg/d of E₂. The impairment of spatial learning behavior and memory capacity in the ODX rats was prevented by DHT, E_2, and PME. Recovery of the orchidectomy-induced deterioration of the synaptic plasticity in the hippocampus of rats was ranked as E₂ ≥ PME > DHT. Both DHT and PME mitigated the increased Tau3 and Tau4 mRNA levels, and Tau-5 and P-Tau Ser³⁹⁶ protein levels more than E₂ (DHT ≥ PME > E₂). Only DHT tended to decrease App mRNA expression level. In conclusion, DHT showed a stronger efficacy for mitigation of the impaired spatial learning behavior and memory capacity in androgen-deficient male rats compared to E₂ and PME, and their mechanisms of action are slightly different.

Pueraria mirifica, an estrogenic tropical herb, unveiled the severity of Type 1 LQTS caused by KCNQ1-T587M

After taking an estrogen-containing supplement derived from a tropical plant Pueraria mirifica, a 24-year-old woman presented marked QT prolongation and repetitive torsade de pointes. The patient was found to carry a heterozygous KCNQ1-T587M mutation. This is the first report on Pueraria mirifica-related acquired long QT syndrome.

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.

Effects of Pueraria candollei var mirifica (Airy Shaw and Suvat.) Niyomdham on Ovariectomy-Induced Cognitive Impairment and Oxidative Stress in the Mouse Brain

The effects of the phytoestrogen-enriched plant Pueraria mirifica (PM) extract on ovari-ectomy (OVX)-induced cognitive impairment and hippocampal oxidative stress in mice were investigated. Daily treatment with PM and 17β-estradiol (E2) significantly elevated cognitive behavior as evaluated by using the Y maze test, the novel object recognition test (NORT), and the Morris water maze test (MWM), attenuated atrophic changes in the uterus and decreased serum 17β-estradiol levels. The treatments significantly ameliorated ovariectomy-induced oxidative stress in the hippocampus and serum by a decrease in malondialdehyde (MDA), an enhancement of superoxide dismutase, and catalase activity, including significantly down-regulated expression of IL-1β, IL-6 and TNF-α proinflammatory cytokines, while up-regulating expression of PI3K. The present results suggest that PM extract suppresses oxidative brain damage and dysfunctions in the hippocampal antioxidant system, including the neuroinflammatory system in OVX animals, thereby preventing OVX-induced cognitive impairment. The present results indicate that PM exerts beneficial effects on cognitive deficits for which menopause/ovariectomy have been implicated as risk factors.

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.

Kwakhurin-magnetic particles conjugates enable fast enzyme immunoassay for the detection of kwakhurin in Pueraria candollei

INTRODUCTION

Kwakhurin (Kwa) is one of the unique isoflavonoids produced in Pueraria candollei var. mirifica (P. candollei), which has long been used as folk medicine for rejuvenation in Thailand. Recently, the use of P. candollei-derived products has widely spread among Japanese women for cosmetic purposes. Correspondingly, there has been an increase in the number of reports regarding possible health hazards caused by estrogenic activity inherent to the plant; thus, the need for a detailed evaluation of the phytoestrogen content of P. candollei-derived products has gained a sense of urgency in recent years.

OBJECTIVE

This study aims to develop a rapid enzyme immunoassay that can be applied to the quantitative analysis of Kwa in P. candollei and its derived products.

MATERIAL AND METHOD

A rapid and sensitive immunoassay was developed with a combination of Kwa-specific monoclonal antibody (MAb 11F) and Kwa-magnetic particles (MPs) conjugates, which increased the surface area of the solid phase, resulting in a decrease in the immunoreaction time.

RESULT

This novel MPs-based enzyme immunoassay (MPs-EIA) was used to determine Kwa concentration in the range from 2.44 to 78.1 ng/mL with a limit of detection of 1.90 ng/mL. Validation analyses revealed that the proposed MPs-EIA protocol was sufficiently precise and accurate for effective quantitative analysis of Kwa in P. candollei and its derived products.

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.

Potential Thai medicinal plants for neurodegenerative diseases: A review focusing on the anti-glutamate toxicity effect

Neurodegenerative diseases (NDD) are a range of debilitating conditions of the brain involving progressive loss of neurons, many of which are still currently incurable despite enormous efforts on drug discovery and development in the past decade. As NDD is closely linked to old age, the rapid worldwide growth in the aging population contributes to an increasing number of people with one of these incurable diseases and therefore it is considered a significant global health issue. There is an urgent need for novel effective treatments for NDD, and many new research strategies are centered on traditional medicine as an alternative or complementary solution. Several previous findings have suggested that glutamate toxicity drives neurodegeneration in many NDD, and the medicinal plants with anti-glutamate toxicity properties can be potentially used for their treatment. In order to obtain data relating to natural products against glutamate toxicity, six candidate plant species of Thailand were identified. Studies utilizing these herbs were searched for using the herb name (Latin and common names) along with the term "glutamate" in the following databases across all available years: PubMed, Scopus, and Google Scholar. This review emphasizes the importance of glutamate toxicity in NDD and summarizes individual plants and their active constituents with the mechanism of action against glutamate toxicity-mediated neuronal cell death that could be a promising resource for future NDD therapy.

TAXONOMY CLASSIFICATION BY EVISE

Alzheimer's disease, Neurodegenerative diseases, Cell culture, Molecular Biology, Traditional herbal medicine, Oxidative stress, Glutamate neurotransmitter.

(+)-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.

Transcriptome analysis of Pueraria candollei var. mirifica for gene discovery in the biosyntheses of isoflavones and miroestrol

BACKGROUND

Pueraria candollei var. mirifica, a Thai medicinal plant used traditionally as a rejuvenating herb, is known as a rich source of phytoestrogens, including isoflavonoids and the highly estrogenic miroestrol and deoxymiroestrol. Although these active constituents in P. candollei var. mirifica have been known for some time, actual knowledge regarding their biosynthetic genes remains unknown.

RESULTS

Miroestrol biosynthesis was reconsidered and the most plausible mechanism starting from the isoflavonoid daidzein was proposed. A de novo transcriptome analysis was conducted using combined P. candollei var. mirifica tissues of young leaves, mature leaves, tuberous cortices, and cortex-excised tubers. A total of 166,923 contigs was assembled for functional annotation using protein databases and as a library for identification of genes that are potentially involved in the biosynthesis of isoflavonoids and miroestrol. Twenty-one differentially expressed genes from four separate libraries were identified as candidates involved in these biosynthetic pathways, and their respective expressions were validated by quantitative real-time reverse transcription polymerase chain reaction. Notably, isoflavonoid and miroestrol profiling generated by LC-MS/MS was positively correlated with expression levels of isoflavonoid biosynthetic genes across the four types of tissues. Moreover, we identified R2R3 MYB transcription factors that may be involved in the regulation of isoflavonoid biosynthesis in P. candollei var. mirifica. To confirm the function of a key-isoflavone biosynthetic gene, P. candollei var. mirifica isoflavone synthase identified in our library was transiently co-expressed with an Arabidopsis MYB12 transcription factor (AtMYB12) in Nicotiana benthamiana leaves. Remarkably, the combined expression of these proteins led to the production of the isoflavone genistein.

CONCLUSIONS

Our results provide compelling evidence regarding the integration of transcriptome and metabolome as a powerful tool for identifying biosynthetic genes and transcription factors possibly involved in the isoflavonoid and miroestrol biosyntheses in P. candollei var. mirifica.

Effects of Puerarin on the Ovariectomy-Induced Depressive-Like Behavior in ICR Mice and Its Possible Mechanism of Action

Daily treatment of ovariectomized (OVX) ICR mice with puerarin, a glycosyl isoflavone isolated from the root bark of Pueraria candollei var. mirifica, and 17β-estradiol attenuated ovariectomy-induced depression-like behavior, as indicated by a decrease in immobility times in the tail suspension test (TST) and the forced swimming test (FST), an increase in the uterine weight and volume, a decrease in serum corticosterone levels, and dose-dependently normalized the downregulated transcription of the brain-derived neurotrophic factor (BDNF) and estrogen receptor (Erβ and Erα) mRNAs. Like 17β-estradiol, puerarin also inhibited ovariectomy-induced suppression of neurogenesis in the dentate gyrus of the hippocampus (increased the number of doublecortin (DCX)-immunosuppressive cells). These results suggest that puerarin exerts antidepressant-like effects in OVX animals, possibly by attenuating the OVX-induced hyperactivation of the HPA axis and/or normalizing the downregulated transcription of BDNF and ER mRNA in the brain.

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.

The Deoxymiroestrol and Isoflavonoid Production and Their Elicitation of Cell Suspension Cultures of Pueraria candollei var. mirifica: from Shake Flask to Bioreactor

To address the high demand for Pueraria candollei var. mirifica (PM) used as the active ingredient in health products and its difficulty to cultivate in the field, the growth and production of deoxymiroestrol (DME) and isoflavonoid (ISF) phytoestrogens in PM cell suspensions were studied. In a 125-mL shake flask, the cell suspension produced DME [78.7 ± 8.79-116 ± 18.2 μg/g dry weight (DW)] and ISF (140 ± 6.83-548 ± 18.5 μg/g DW), which are the predominant ISF glycosides. While ISF aglycones accumulated in the PM cell suspension cultured in the airlift bioreactor. The DME content was increased to 976 ± 79.6 μg/g DW when the PM cell suspension was cultured in the 5-L scale bioreactor. The production of DME and ISF was enhanced by elicitors including methyl jasmonate (MJ), yeast extract (YE), and chitosan (CHI). MJ produced the highest induction of DME accumulation, while ISF accumulation was the highest with YE treatment. Analysis of catalase activity implied that the elicitors enhanced ROS production, which resulted in the enhancement of DME and ISF production and accumulation in PM cell suspension cultures. PM cell suspension culture is a promising source of beneficial PM phytoestrogens that exhibit bioactivity that may useful for the treatment of menopausal symptoms.

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.

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.

Estrogenic Potentials of Traditional Chinese Medicine

Estrogen, a steroid hormone, is associated with several human activities, including environmental, industrial, agricultural, pharmaceutical and medical fields. In this review paper, estrogenic activity associated with traditional Chinese medicines (TCMs) is discussed first by focusing on the assays needed to detect estrogenic activity (animal test, cell assay, ligand-binding assay, protein assay, reporter-gene assay, transcription assay and yeast two-hybrid assay), and then, their sources, the nature of activities (estrogenic or anti-estrogenic, or other types), and pathways/functions, along with the assay used to detect the activity, which is followed by a summary of effective chemicals found in or associated with TCM. Applications of estrogens in TCM are then discussed by a comprehensive search of the literature, which include basic study/pathway analysis, cell functions, diseases/symptoms and medicine/supplements. Discrepancies and conflicting cases about estrogenicity of TCM among assays or between TCM and their effective chemicals, are focused on to enlarge estrogenic potentials of TCM by referring to omic knowledge such as transcriptome, proteome, glycome, chemome, cellome, ligandome, interactome and effectome.

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.

Pueraria mirifica alleviates cortical bone loss in naturally menopausal monkeys

Since the in vitro and in vivo anti-osteoporotic effects of Pueraria mirifica (PM) in rodents have been verified, its activity in menopausal monkeys was evaluated as required before it can be applicable for human use. In this study, postmenopausal osteoporotic monkeys were divided into two groups (five per group), and fed daily with standard diet alone (PMP0 group) or diet mixed with 1000 mg/kg body weight (BW) of PM powder (PMP1000 group) for 16 months. Every 2 months, the bone mineral density (BMD), bone mineral content (BMC) and bone geometry parameters (cortical area and thickness and periosteal and endosteal circumference) at the distal radius and proximal tibia were determined using peripheral quantitative computed tomography together with plasma and urinary bone markers. Compared with the baseline (month 0) values, the cortical, but not trabecular, BMDs and BMCs and the cortical area and thickness at the metaphysis and diaphysis of the radius and tibia of the PMP0 group continuously decreased during the 16-month study period. In contrast, PMP1000 treatment ameliorated the bone loss mainly at the cortical diaphysis by decreasing bone turnover, as indicated by the lowered plasma bone-specific alkaline phosphatase and osteocalcin levels. Generally, changes in the cortical bone geometry were in the opposite direction to the cortical bone mass after PMP1000 treatment. This study indicated that postmenopausal monkeys continuously lose their cortical bone compartment, and they have a higher possibility for long bone fractures. Oral PMP treatment could improve both the bone quantity (BMC and BMD) and quality (bone geometry).

Neurotherapeutic Effects of Pueraria mirifica Extract in Early- and Late-Stage Cognitive Impaired Rats

We determined the neurotherapeutic effects of Pueraria mirifica extract (PME) and pure puerarin (PU) in comparison with 17β-estradiol (E2 ) in early- and late-stage cognitive impaired rats. Rats were ovariectomized (OVX), kept for 2 and 4 months to induce early- and late-stage cognitive impairment, respectively, and divided into four groups that were treated daily with (i) distilled water, (ii) 100 mg/kg of PME, (iii) 7 mg/kg of PU, and (iv) 80 µg/kg of E2 for 4 months. The estrogen deficiency symptoms of OVX rats were abrogated by treatment with E2 or PME, but not by treatment with PU. The mRNA level of genes associated with amyloid production (App and Bace1) and hyperphosphorylated Tau (Tau4) were upregulated together with the level of impaired cognition in the 2- and 4-month OVX rats. Treatment with E2 reduced the level of cognitive impairment more than that with PME and PU, and 2-month OVX rats were more responsive than 4-month OVX rats. All treatments down-regulated the Bace1 mRNA level in 2-month OVX rats, while PU and PME also decreased the App mRNA level in 2- and 4-month OVX rats, respectively. Only PU suppressed Tau4 expression in 2-month OVX rats. Thus, PME and PU elicit neurotherapeutic effects in different pathways, and earlier treatment is optimal. Copyright © 2016 John Wiley & Sons, Ltd.

Isoflavones in food supplements: chemical profile, label accordance and permeability study in Caco-2 cells

Consumers nowadays are playing an active role in their health-care. A special case is the increasing number of women, who are reluctant to use exogenous hormone therapy for the treatment of menopausal symptoms and are looking for complementary therapies. However, food supplements are not clearly regulated in Europe. The EFSA has only recently begun to address the issues of botanical safety and purity regulation, leading to a variability of content, standardization, dosage, and purity of available products. In this study, isoflavones (puerarin, daidzin, genistin, daidzein, glycitein, genistein, formononetin, prunetin, and biochanin A) from food supplements (n = 15) for menopausal symptoms relief are evaluated and compared with the labelled information. Only four supplements complied with the recommendations made by the EC on the tolerable thresholds. The intestinal bioavailability of these compounds was investigated using Caco-2 cells. The apparent permeability coefficients of the selected isoflavonoids across the Caco-2 cells were affected by the isoflavone concentration and product matrix.

Pueraria mirifica extract and puerarin enhance proliferation and expression of alkaline phosphatase and type I collagen in primary baboon osteoblasts

Phytoestrogen-rich Pueraria mirifica (PM) tuberous extract is a promising candidate for the development of anti-osteoporosis drugs for postmenopausal women, but its action has never been validated in humans or in non-human primates, which are more closely related to humans than rodents. In vitro study of non-human primate osteoblasts is thus fundamental to prepare for in vivo studies of phytoestrogen effects on primate bone. This study aimed to establish a culture system of baboon primary osteoblasts and to investigate the effects of PM extract and its phytoestrogens on these cells. Primary osteoblasts from adult baboon fibulae exhibited osteoblast characteristics in regard to proliferation, differentiation, mineralization, and estrogen receptor expression. They responded to 17β-estradiol by increased proliferation rate and mRNA levels of alkaline phosphatase (ALP), type I collagen, and osteocalcin. After being exposed for 48 h to 100 μg/ml PM extract, 1000 nM genistein, or 1000 nM puerarin, primary baboon osteoblasts markedly increased the rate of proliferation and mRNA levels of ALP and type I collagen without changes in Runx2, osterix, or osteocalcin expression. PM extract, genistein, and puerarin also decreased the RANKL/OPG ratio, suggesting that they could decrease osteoclast-mediated bone resorption. However, neither PM extract nor its phytoestrogens altered calcium deposition in osteoblast culture. In conclusion, we have established baboon primary osteoblast culture, which is a new tool for bone research and drug discovery. Furthermore, the present results provide substantial support for the potential of PM extract and its phytoestrogens to be developed as therapeutic agents against bone fragility.

An evidence-based systematic review of kudzu (Pueraria lobata) by the Natural Standard Research Collaboration

An evidence-based systematic review of kudzu (Pueraria lobata) by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

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.

Improvements of vaginal atrophy without systemic side effects after topical application of Pueraria mirifica, a phytoestrogen-rich herb, in postmenopausal cynomolgus macaques

The estrogenic efficacy of topical vaginal application of Pueraria mirifica extract (PM) on the restoration of vaginal atrophy, and the presence of any systemic side effects, were investigated in postmenopausal cynomolgus macaques. Twelve postmenopausal cynomolgus macaques, with complete cessation of menstruation for at least 5 years before start of this experiment, were divided into three groups. They received a topical vaginal application daily of 0.1 or 1% (w/w) PM cream or a conjugated equine estrogen (CEE) cream (a mixture of estrone, equilin, 17β-dihydroequilin, 17α-estradiol and 17α-dihydroequilin at 0.625 mg total estrogen/g cream) for 28 days. Estrogenic efficacy was assessed weekly by vaginal cytology assay and vaginal pH measurement, whilst the plasma luteinizing hormone (LH) and sex skin coloration levels were determined at the end of each treatment period to evaluate the systemic side effects. PM significantly increased the proportion of superficial cells in a dose-dependent manner, with a similar efficacy between 1% (w/w) PM and CEE. Together with increased vaginal maturation, PM decreased the vaginal pH to acidic levels, as observed in the CEE group. PM induced no detected systemic side effects, whilst CEE decreased the plasma LH level and increased the reddish color of the sex skin during the posttreatment period. Topical vaginal treatment with PM stimulated the maturation of the vaginal epithelium without causing systemic side effects in postmenopausal monkeys. The implication is that PM could be a safer alternative to treat vaginal atrophy in postmenopausal women.

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.

Upregulation of osteoblastic differentiation marker mRNA expression in osteoblast-like UMR106 cells by puerarin and phytoestrogens from Pueraria mirifica

Phytoestrogens have attracted attention for their potential in the prevention of postmenopausal osteoporosis. Recently, phytoestrogen-rich herb Pueraria mirifica has been demonstrated to possess an osteogenic effect on bone in ovariectomized rats, but its underlying cellular mechanism was not known. Here, we investigated the effects of P. mirifica extract and its major isoflavone compound, puerarin, on cell viability, cell proliferation and the expression of differentiation markers in rat osteoblast-like UMR106 cells. After exposure to 17β-estradiol (E2), genistein, P. mirifica extract and puerarin, proliferation but not viability of UMR106 cells was markedly decreased. Quantitative real-time PCR revealed that P. mirifica extract and puerarin significantly increased the mRNA expression of alkaline phosphatase (ALP) and osteoprotegerin, but not Runx2, osterix or osteocalcin. Puerarin also decreased the mRNA expression of receptor activator of nuclear factor-κB ligand, an osteoclastogenic factor, suggesting that it could induce bone gain by enhancing osteoblast differentiation and suppressing osteoclast function. Furthermore, after an exposure to high affinity estrogen receptor (ER) antagonist (ICI182780), the E2-, genistein-, P. mirifica extract- and puerarin-induced upregulation of ALP expressions were completely abolished. It could be concluded that P. mirifica extract and puerarin induced osteoblast differentiation rather than osteoblast proliferation in an ER-dependent manner. The present findings, therefore, corroborated the potential benefit of P. mirifica extract and puerarin in the prevention and treatment of postmenopausal osteoporosis.