Major isoflavonoid contents of the phytoestrogen rich-herb Pueraria mirifica in comparison with Pueraria lobata

Free and bound phenolic profiles of Radix Puerariae Thomsonii from different growing regions and their bioactivities

The free and bound phenolic profiles and their bioactivities of radix puerariae thomsonii (RPT) cultivars from 7 growing regions in China were investigated. Total phenolic and flavonoid contents were from 148.71 to 435.32 mg gallic acid equivalents /100 g dry weight and 561.93 to 826.11 mg catechin equivalents /100 g dry weight, respectively, with 20.64-38.28% and 32.77-47.29% contribution from bound fractions. Sixteen phenolic compounds were detected in RPTs. Bound fractions contributed 28.15-70.84% to the total antioxidant activities. The cultivars from Qiannan and Guangzhou showed much higher regulatory effects on carbohydrate hydrolyzing enzymes and alcohol metabolizing enzymes than the other cultivars. The bound fractions exhibited equivalent EC50 values for alcohol metabolizing enzymes and IC50 values for carbohydrate hydrolyzing enzymes to the free fractions in RPT cultivars. Therefore, bound phenolics significantly contributed to the potential health benefits of RPT. The results provided information for the utilization of RPT for health promoting purpose.

Therapeutic potential of puerarin against cerebral diseases: From bench to bedside

The incidence of cerebral diseases is rapidly increasing worldwide, and they have become an important challenge for modern medicine. Most of the available chemical drugs used in the treatment of cerebral diseases are highly toxic and single-targeted. Therefore, novel drugs from natural resources have attracted much attention for their potential to manage cerebral diseases. Puerarin is a natural isoflavone isolated from the roots of Pueraria species such as P. lobata (Willd) Ohwi, P. thomsonii, and P. mirifica. Several authors have reported the beneficial effects of puerarin in cerebral ischemic disease, intracerebral hemorrhage, vascular dementia, Alzheimer's disease, Parkinson's disease, depression, anxiety, and traumatic brain injury. This review summarizes the brain pharmacokinetics, brain drug delivery system, clinical use (in cerebral diseases), toxicity, and the adverse clinical reactions of puerarin. We have systematically presented the pharmacological actions and the molecular mechanisms of puerarin in various cerebral diseases to provide a direction for future research on the therapeutic use of puerarin in cerebral diseases.

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.

Cytoprotective Effect of Liposomal Puerarin on High Glucose-Induced Injury in Rat Mesangial Cells

In diabetic patients, high glucose and high oxidative states activate gene expression of transforming growth factor beta (TGF-β) and further translocate Smad proteins into the nucleus of renal cells. This signal pathway is characterized as the onset of diabetic nephropathy. Puerarin is an active ingredient extracted from Pueraria lobata as an anti-hyperglycemic and anti-oxidative agent. However, the poor oral availability and aqueous solubility limit its pharmaceutical applications. The present paper reports the liposomal puerarin and its protective effect on high glucose-injured rat mesangial cells (RMCs). The purity of puerarin extracted from the root of plant Pueraria lobata was 83.4% as determined by the high-performance liquid chromatography (HPLC) method. The liposomal puerarin was fabricated by membrane hydration followed by ultrasound dispersion and membrane extrusion (pore size of 200 nm). The fabricated liposomes were examined for the loading efficiency and contents of puerarin, the particle characterizations, the radical scavenge and the protective effect in rat mesangial cells, respectively. When the liposomes were subjected to 20 times of membrane extrusion, the particle size of liposomal puerarin can be reduced to less than 200 nm. When liposomal puerarin in RMCs in high glucose concentration (33 mM) was administered, the over-expression of TGF-β and the nuclear translocation of Smad 2/3 proteins was both inhibited. Therefore, this study successfully prepared the liposomal puerarin and showed the cytoprotective effect in RMCs under high glucose condition.

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.

Isoflavones Suppress Cyp26b1 Expression in the Murine Colonic Lamina Propria

Isoflavones have many biological activities and are major bioactive components of kakkonto, a traditional Japanese herbal medicine. We previously reported that the combined therapy of oral immune therapy (OIT) and kakkonto downregulates the mRNA expression of Cyp26b1, a major retinoic acid (RA)-degrading enzyme, in the colon of food allergy mice and thereby ameliorates allergic symptoms. In this study, we evaluated the effects of various isoflavones on Cyp26b1 expression in primary cultured lamina propria (LP) cells isolated from the mouse colon. The mRNA expression of Cyp26b1 was extremely downregulated by all isoflavones tested in the LP cells except for puerarin. In particular, genistein and genistin markedly suppressed Cyp26b1 mRNA expression without affecting RA-synthesizing enzyme expression. Moreover, to evaluate the effects of isoflavones on allergic reactions, genistein and genistin were administered to ovalbumin (OVA)-induced food allergy mice. Oral administration of genistin suppressed the development of allergic symptoms. These results raise the possibility that isoflavones elevated the level of RA in the colon by inhibiting RA degradation and then the high concentration of RA in the colon might exert immunosuppressive and antiallergic effects on food allergy mice.

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.

The potential health benefits of the isoflavone glycoside genistin

Genistin is a type of isoflavone glycoside and has a broad range of health benefits. It is found in a variety of dietary plants, such as soybean, kudzu (Japanese arrowroot), and other plant-based products. Genistin has been described to have several beneficial health impacts, such as decreasing the risk of osteoporosis and post-menopausal symptoms, as well as anti-cancer, anti-oxidative, cardioprotective, anti-apoptotic, neuroprotective, hepatoprotective, and anti-microbial activities. It may also assist individuals with metabolic syndrome. This review summarizes some of the molecular impacts and prospective roles of genistin in maintaining and treatment of health disorders. The review could help to develop novel genistin medicine with significant health benefits for application in the nutraceutical and pharmaceutical fields.

Molecular Mechanisms of Anticancer Activities of Puerarin

Medicinal plants are a vital source of natural products (NPs) that can cure cancer through modulation of different pathways, including oxidative stress, extrinsic and intrinsic apoptosis, cell cycle, inflammation, NF-kB, PI3K/AKT/mTOR, AMPK (JNK), MEK/ERK (Raf)-MEK-ERK and autophagy. Puerarin (Pue), an important NP belonging to the isoflavone glycoside group, is derived from Pueraria lobata (Willd.) Ohwi, Pueraria thomsonii Benth, and Pueraria tuberosa (Willd.). This NP was approved by the Chinese Ministry of Health for the treatment of different diseases in 1993, but it was also later reported to exhibit anticancer activity. Pue causes cancer cells death through modulation of different mechanisms including oxidative stress, intrinsic and extrinsic, Survivin and XIAP, PI3K/AKT/mTOR, Ras-Raf-MEK-ERK, JNK, cell cycle, AMPK, NF-kB, inflammation and autophagy pathways. Therefore, this review compiles for the first time the studies about the anticancer mechanism of Pue and provides comprehensive information about the anticancer effects of Pue. This review may serve as a basis for future research and clinical treatment.

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.

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.

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).

Phytoestrogens and the Intestinal Microbiome

The microflora of the digestive tract is composed of a unique set of bacteria, yeasts, viruses and other microorganisms, generally known as the microbiome. The microbiome exhibits considerable inter-individual variability, with up to two-thirds of the microflora differing between individuals. Because of this, the variable intestinal microflora is responsible for many differences in metabolic, hormonal and immunological processes in humans and animals. Significant differences have been observed in the metabolism of phytoestrogens, naturally occurring substances that possess estrogenic or anti-estrogenic activity. These substances occur predominately in legumes, especially in soy and many soy products. Because of their effects, phytoestrogens are used as an alternative therapy for menopausal disorders and benign prostate hyperplasia. In connection with the worldwide expansion of soy products as part of healthy lifestyles including vegetarianism and veganism, phytoestrogens have become a regular part of everyday life. The activity of phytoestrogens is strongly dependent on the microbiome. Their metabolites have stronger estrogenic activity than the natural substances themselves, and because of the variability in microbiomes, there are large differences in the effects of phytoestrogens among individuals.

Effects of puerarin on estrogen-regulated gene expression in gonadotropin-releasing hormone pulse generator of ovariectomized rats

Effects of puerarin on the hypothalamic gonadotropin-releasing hormone (GnRH) pulse generator function is investigated, for the first time, in ovariectomized rats at the level of mRNA expression of estrogen-responsive genes, e.g., estrogen receptor (ER), GnRH and its receptor (GnRHR). Rats were treated orally for 90 days either with a soy-free diet containing two different doses of puerarin (low dose of 600 mg/kg and high dose of 3000 mg/kg) or estradiol benzoate (E2B) at either low dose (4.3 mg/kg) or high dose (17.3 mg/kg). Levels of mRNA expression in the medial preoptic area/anterior hypothalamus (MPOA/AH), mediobasal hypothalamus/median eminence (MBH/ME) and adenohypophysis were measured by quantitative TaqMan® real-time RT-PCR. Plasma levels of luteinizing hormone (LH) and prolactin (PRL) were measured by radioimmunoassay. In the MPOA/AH, both puerarin and E2B decreased ERα mRNA levels without any significant changes in ERβ and GnRH mRNA levels. Both puerarin and E2B did not significantly alter the expression levels of ERα, ERβ and GnRHR in the MBH/ME. E2B exerted significant effects on the down-regulation of adenohypophyseal GnRHR mRNA transcripts and serum LH levels. Puerarin did not cause significant changes in pituitary GnRHR mRNA transcripts and serum LH and PRL levels. This is the first study to demonstrate that in ovariectomized rat models of ovarian hormone deprivation, puerarin acted as a weak estrogen-active compound in the hypothalamic GnRH pulse generator through the downregulation of MPOA/AH ERα mRNA expression.

A New Highly Selective and Specific Anti-puerarin polyclonal Antibody for Determination of Puerarin Using a Mannich Reaction Hapten Conjugate

Background

Puerarin (PUE) is a phytoestrogen found in Pueraria candollei and Pueraria lobata. These plants are substantial for traditional medicine in various Asian countries. PUE is a key marker that can be found only in the Pueraria species.

Objective

To establish the method for determination of PUE content which is required for quality control of pharmaceutical products.

Materials and Methods

PUE-cationized bovine serum albumin conjugate was created via Mannich reaction. After the rabbit immunization, the obtain anti-PUE polyclonal antibody (PAb) was used to develop an enzyme-linked immunosorbent assay (ELISA).

Results

An anti-PUE PAb possess a great sensitivity and specificity. The cross-reactivity analysis shows no cross-reaction of an established antibody against other substances. In addition, we successfully developed an indirect competitive ELISA (icELISA) for the quantitative analysis of PUE. The result of method validation conforms to acceptance criteria and correlates with high-performance liquid chromatography, the reference method. The icELISA was applied to determine PUE content in Pueraria spp. plant samples and its derived pharmaceutical products.

Conclusion

This highly specific immunogen was created from the Mannich reaction. An icELISA can also be applied to other research propose in the further studies.

SUMMARY

The new immunogen conjugated (puerarin-cBSA) via Mannich reaction was successfully in rising of antibody against puerarin (PUE)The obtained anti-PUE polyclonal antibody (PAb) was high sensitivity and specificity to PUEAn indirect competitive enzyme-linked immunosorbent assay (icELISA) was developed and validated using anti-PUE PAbThe established icELISA was applied to determine PUE content in various tuberous root of Pueraria sppMoreover, icELISA method can be applicable in Pueraria spp. derived products. Abbreviations used: PUE: Puerarin; PAb: Polyclonal antibody; ELISA: Enzyme-linked immunosorbent assay; icELISA: Indirect competitive ELISA; cBSA: Cationized bovine serum albumin.

The Effects and Possible Mechanisms of Puerarin to Treat Uterine Fibrosis Induced by Ischemia-Reperfusion Injury in Rats

Background

Tissues fibrosis is caused by ischemia-reperfusion injury (IRI) and results in organ dysfunction. In this study, we aimed to investigate whether fibrosis occurs after uterine ischemia-reperfusion injury, and to investigate the effects of puerarin (Pur) on the fibrosis process in rats.

Material/Methods

Twenty-four female Wistar rats were randomly divided into three groups (8 in each group): the control group rats only received operation without uterine ischemic, the IRI group and the IRI + Pur group rats received 30-minutes ischemia and 2-weeks of reperfusion. Pur was orally administered at the onset of reperfusion. Picrosirius red staining was used to assess uterine fibrosis. Immunohistochemistry was used to detect the expression levels of transforming growth factor (TGF)-β and α-smooth muscle actin (α-SMA). Western blotting was used to evaluate the expression of chymase, TGF-β, α-SMA, and the activity of the Wnt/β-catenin pathway.

Results

Uterine fibrosis in the IRI+Pur group was significantly decreased compared with the IRI group. In addition, immunohistochemistry reveals that TGF-β and α-SMA were decreased in the IRI+Pur group compared with the IRI group. Western blotting results showed that Pur significantly suppresses the increase in chymase, α-SMA, TGF-β, and β-catenin expression levels induced by IRI.

Conclusions

The results indicated that IRI could induce uterine fibrosis and that Pur had an improvement effect on IRI-induced uterine fibrosis by downregulating the activity of mast cell chymase, TGF-β, α-SMA, and the Wnt/β-catenin pathway.

The antioxidant, cytotoxic, and antigenotoxic effects of galangin, puerarin, and ursolic acid in mammalian cells

Phenolic compounds not only contribute to the sensory qualities of fruits and vegetables but also exhibit several health protective properties. Galangin, puerarin, and ursolic acid are commonly used plant phenolics in folk medicine. In this study, the antioxidant capacities of galangin, puerarin, and ursolic acid by the trolox equivalent antioxidant capacity (TEAC) assay and the cytotoxic effects by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in V79 cells were investigated. The genotoxic potentials of galangin, puerarin, and ursolic acid were evaluated by micronucleus (MN) and alkaline COMET assays in human lymphocytes and in V79 cells. Galangin, puerarin, and ursolic acid (10, 100, 500, 1000, 2000, 5000, 10 000, and 20 000 μM) were found to have antioxidant activities at the studied concentrations. IC50 values of galangin, puerarin, and ursolic acid in V79 cells were found to be 275.48 μM, 2503.712 μM, and 224.85 μM, respectively. Galangin, puerarin, and ursolic acid, at the all concentrations, have not exerted genotoxic effects and galangin, puerarin, and ursolic acid revealed a reduction in the frequency of MN and DNA damage induced by H2O2.

Evaluation of in vivo estrogenic potency of natural estrogen-active chemical, puerarin, on pituitary function in gonadectomized female rats

AIMS

Previous research has revealed that puerarin, the major phytoestrogen in tuberous roots of Pueraria lobata and Pueraria mirifica, acts as a selective estrogen receptor modulator that displays predominantly estrogenic potential for health benefit. However, little is known about the estrogenic potency of puerarin in pituitary, especially in the rat model of postmenopausal females.

MAIN METHODS

Plasma prolactin and growth hormone levels as well as mRNA expression levels of pituitary estrogen-regulated genes, such as estrogen receptor (ER) subtypes alpha (ERα) and beta (ERβ), truncated ER product-1 (TERP-1) and -2 (TERP-2) and gonadotropin alpha subunit, were examined using radioimmunoassay and TaqMan® real-time PCR, respectively. The effects were compared with the potent ER agonist, 17β-estradiol-3-benzoate (E2B), and both substances were supplemented at low and high doses, i.e., 0.6 or 3g puerarin and 0.0043 or 0.0173g E2B per kilogram of phytoestrogens-free rat chow, and applied to ovariectomized rats (five groups; 11-12 rats per group) for 12weeks.

KEY FINDINGS

Puerarin possessed weak E2B-like activities on pituitary function by acting as ERβ and TERP-1/-2 agonists, which resulted in the downregulation and upregulation of ERβ and TERP-1/-2 mRNA expressions, respectively, and elevation of growth hormone levels. There were trends of decreased levels of alpha subunit mRNA transcripts and increased levels of prolactin in puerarin-treated rats as observed in E2B-treated animals.

SIGNIFICANCE

This is the first report in ovariectomized rats the effects of puerarin on somatotropes and pituitary estrogen-responsive mRNA expressions, which are very weakly estrogenic by acting through ERβ- and TERP-1/-2 mediated pathways.

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.

A Root-Based Combination Supplement Containing Pueraria lobata and Rehmannia glutinosa and Exercise Preserve Bone Mass in Ovariectomized Rats Fed a High-Fat Diet

The aim of this study was to evaluate the effects of a supplement containing Pueraria lobata/Rehmannia glutinosa (PR) root extracts on bone turnover in ovariectomized (OVX) rats (a model for postmenopausal osteoporosis). Female Sprague-Dawley rats (8 weeks old) were randomized into eight groups: sham-operated rats with low-fat control diet + vehicle, OVX rats with low-fat control diet + vehicle, OVX rats with high-fat diet (HFD) + vehicle, OVX rats with HFD + vehicle + exercise, OVX rats with HFD + PR (400 mg/kg body weight/day p.o.), OVX rats with HFD + PR + exercise, OVX rats with HFD + 17β-estradiol (0.5 mg/kg body weight/day p.o.), OVX rats with HFD + 17β-estradiol + exercise. Bone microarchitecture, bone turnover markers (e.g., plasma alkaline phosphatase and osteocalcin), expressions of osteogenic and resorptive gene markers in the bone were measured. Eight weeks of PR and/or aerobic exercise improved cortical microarchitecture of the femur and decreased markers of bone turnover and expression of skeletal osteoclastogenic genes in the femur. PR supplementation combined with exercise preserved bone loss induced by estrogen deficiency and should be investigated further as an alternative to hormone replacement therapy for preventing osteoporosis in postmenopausal women.

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

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

Bio-refinery of orange peels waste: a new concept based on integrated green and solvent free extraction processes using ultrasound and microwave techniques to obtain essential oil, polyphenols and pectin

In this study, extraction of essential oil, polyphenols and pectin from orange peel has been optimized using microwave and ultrasound technology without adding any solvent but only "in situ" water which was recycled and used as solvent. The essential oil extraction performed by Microwave Hydrodiffusion and Gravity (MHG) was optimized and compared to steam distillation extraction (SD). No significant changes in yield were noticed: 4.22 ± 0.03% and 4.16 ± 0.05% for MHG and SD, respectively. After extraction of essential oil, residual water of plant obtained after MHG extraction was used as solvent for polyphenols and pectin extraction from MHG residues. Polyphenols extraction was performed by ultrasound-assisted extraction (UAE) and conventional extraction (CE). Response surface methodology (RSM) using central composite designs (CCD) approach was launched to investigate the influence of process variables on the ultrasound-assisted extraction (UAE). The statistical analysis revealed that the optimized conditions of ultrasound power and temperature were 0.956 W/cm(2) and 59.83°C giving a polyphenol yield of 50.02 mgGA/100 g dm. Compared with the conventional extraction (CE), the UAE gave an increase of 30% in TPC yield. Pectin was extracted by conventional and microwave assisted extraction. This technique gives a maximal yield of 24.2% for microwave power of 500 W in only 3 min whereas conventional extraction gives 18.32% in 120 min. Combination of microwave, ultrasound and the recycled "in situ" water of citrus peels allow us to obtain high added values compounds in shorter time and managed to make a closed loop using only natural resources provided by the plant which makes the whole process intensified in term of time and energy saving, cleanliness and reduced waste water.

Transcriptomic landscape of Pueraria lobata demonstrates potential for phytochemical study

Pueraria lobata (Willd.) Ohwi has a long and broad application in the treatment of disease. However, in the US and EU, it is treated as a notorious weed. The information to be gained from decoding the deep transcriptome profile would facilitate further research on P. lobata. In this study, more than 93 million fastq format reads were generated by Illumina's next-generation sequencing approach using five types of P. lobata tissue, followed by CLC de novo assembly methods, ultimately yielding about 83,041 contigs in total. Then BLASTx similarity searches against the NCBI NR database and UniProtKB database were conducted. Once the duplicates among BLASTx hits were eliminated, ID mapping against the UniProt database was conducted online to retrieve Gene Ontology information. In search of the putative genes relevant to essential biosynthesis pathways, all 1,348 unique enzyme commission numbers were used to map pathways against the Kyoto Encyclopedia of Genes and Genomes. Enzymes related to the isoflavonoid and flavonoid biosynthesis pathways were focused for detailed investigation and subsequently, quantitative real-time reverse transcription polymerase chain reaction was conducted for biological validation. Metabolites of interest, puerarin and daidzin were studied by HPLC. The findings in this report may serve as a footstone for further research into this promising medicinal plant.

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.

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.

Suppression of BSEP and MRP2 in mouse liver by miroestrol and deoxymiroestrol isolated from Pueraria candollei

Miroestrol and deoxymiroestrol are highly active phytoestrogens isolated from the tuberous root of Pueraria candollei var. mirifica (Leguminosae). Modulatory effects of miroestrol and deoxymiroestrol on the mRNAs of BSEP and MRP2 genes involved in bile salt transportation, in C57BL/6 mice were investigated. In contrast to estradiol, miroestrol and deoxymiroestrol suppressed the expression of BSEP and MRP2 mRNA in both male and female mice. The results suggest for the first time that the use of miroestrol and deoxymiroestrol-containing products as alternative medicines or health supplements should be concerned according to their effects on key genes that regulate the bile salt export pump, which could result in the risk of hepatotoxicity and intrahepatic cholestasis.

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.

Optimisation of ultrasound-assisted extraction of puerarin and total isoflavones from Puerariae Lobatae Radix (Pueraria lobata (Wild.) Ohwi) with response surface methodology

INTRODUCTION

Isoflavones, particularly puerarin, are a group of important components from Puerariae Lobatae Radix (PLR) which show diverse pharmacological activities, therefore giving rise to the development of various extraction methods. Ultrasound-assisted extraction (UAE) has been explored for isoflavone extraction from PLR as it provides higher extraction efficiency compared with traditional methods.

OBJECTIVE

To optimise the UAE conditions for puerarin and total isoflavone extraction from PLR using response surface methodology (RSM).

METHODOLOGY

Samples were prepared by use of ultrasound-assisted extraction, and then subjected to HPLC analysis. Box-Behnken Design (BBD), a widely used form of RSM, was used for the optimisation of the UAE process.

RESULTS

The effects of ethanol concentration, extraction time and the solvent-to-material ratio on the yields of puerarin and total isoflavones were investigated. The Box-Behnken experimental results demonstrate that optimal extraction was obtained with an ethanol concentration of 71.35%, an extraction time of 49.08 min and a solvent-to-material ratio of 21.72 for puerarin, and an ethanol concentration of 80.00%, an extraction time of 55.00 min and a solvent-to-material ratio of 12.81 for total isoflavones. The yields of puerarin and total isoflavones were 41 ± 0.63 mg/g and 128 ± 0.82 mg/g, respectively, under the optimised extraction conditions, which are in agreement with the values predicted by the RSM.

CONCLUSION

The RSM allows for optimising the extraction parameters such that maximum extraction of puerarin and total isoflavones was achieved experimentally.

Puerarin inhibits the retinal pericyte apoptosis induced by advanced glycation end products in vitro and in vivo by inhibiting NADPH oxidase-related oxidative stress

Retinal pericyte loss is one of the histopathological hallmarks of early diabetic retinopathy. Puerarin (4'-7-dihydroxy-8-beta-d-glucosylisoflavone), which is an isoflavone-C-glucoside, causes various pharmacological effects that include antihyperglycemic and anti-inflammatory activities. In the present study, we determined the efficacy and possible mechanism of puerarin on the advanced glycation end product (AGE)-modified bovine serum albumin (BSA)-induced apoptosis of cultured bovine retinal pericytes and rat retinal pericytes in intravitreally AGE-modified rat serum albumin (RSA)-injected eyes. Puerarin significantly inhibited pericyte apoptosis, the generation of reactive oxygen species (ROS), and NADPH oxidase activity by inhibiting the phosphorylation of p47phox and Rac1 which were induced by the AGE-BSA treatment. The puerarin treatment markedly suppressed the activation of nuclear factor-kappaB (NF-κB). In addition, the in vivo apoptosis of the retinal pericyte of rats that was stimulated by the intravitreal injection of AGE-RSA was evidently attenuated by the puerarin treatment. These results demonstrate that puerarin may exert inhibitory effects on AGE-induced pericyte apoptosis by interfering with the NADPH oxidase-related ROS pathways and blocking NF-κB activation, thereby ameliorating retinal microvascular dysfunction.

Medical applications of phytoestrogens from the Thai herb Pueraria mirifica

Pueraria mirifica Airy Shaw et Suvatabandhu is a medicinal plant endemic to Thailand. It has been used in Thai folklore medicine for its rejuvenating qualities in aged women and men for nearly one hundred years. Indeed, it has been claimed that P. mirifica contains active phytoestrogens (plant substances with estrogen-like activity). Using high performance liquid chromatography, at least 17 phytoestrogens, mainly isoflavones, have been isolated. Thus, fairly considerable scientific researches, both in vitro in cell lines and in vivo in various species of animals including humans, have been conducted to date to address its estrogenic activity on the reproductive organs, bones, cardiovascular diseases and other climacteric related symptoms. The antioxidative capacity and antiproliferative effect on tumor cell lines have also been assessed. In general, P. mirifica could be applicable for preventing, or as a therapeutic for, the symptoms related to estrogen deficiency in menopausal women as well as in andropausal men. However, the optimal doses for each desirable effect and the balance to avoid undesired side effects need to be calculated before use.