phytoestrogens and puerarin

Contemporary pharmacological research has demonstrated that puerarin, the most important phytoestrogen extracted from Pueraria lobata(Willd.) Ohwi, has protecting functions on the cardiovascular system, nervous system, osteoporosis, liver injury, and inflammation in vivo and in vitro. Most of these research studies focused on inhibiting oxidative stress and apoptosis through regulating various bioactivators and signal pathways. Among these, superoxide dismutase (SOD), endothelial nitric oxide synthase (eNOS) and malondialdehyde (MDA), and PI3K/Akt, MAPK, and NF-κB are of great importance. The data cited in this review were mainly obtained from articles listed in PubMed and Elsevier SDOL published from 1959 to 2013, and the search term used was "puerarin".

Topics: Anti-Inflammatory Agents; Antioxidants; Apoptosis; Cardiovascular Diseases; Humans; Isoflavones; Liver Diseases; Neuroprotective Agents; Oxidative Stress; Phytoestrogens; Phytotherapy; Plant Extracts; Pueraria

Pueraria candollei var. mirifica is a medicinal plant that is promoted as a "Champion Product" by the Government of Thailand. This plant has been reported to relieve postmenopausal symptoms, prevent and reverse bone loss, inhibit the growth of breast cancer, and alleviate cardiovascular diseases in preclinical and clinical studies. However, there is little information on the oral bioavailability and tissue distribution of puerarin with respect to its pharmacodynamic activities. Therefore, the aim of this study was to determine the pharmacokinetics of puerarin, including absorption, distribution, metabolism, and elimination, in rats. Moreover, this is the first study to examine the tissue distribution of puerarin in the hippocampus, femur, tibia, and mammary gland.. Adult female rats were administered puerarin at 1 mg/kg intravenously or 5 and 10 mg/kg orally. Blood, tissue, urine, and feces were collected and analyzed by liquid chromatography-tandem mass spectrometry.. Puerarin reached a maximum concentration in the blood of 140-230 μg/L within 1 h of oral dosing, and had an absolute oral bioavailability of approximately 7%. Following intravenous administration, puerarin was widely distributed in several tissues, including the hippocampus, heart, lung, stomach, liver, mammary gland, kidney, spleen, femur, and tibia. Approximately 50% of the intravenous dose was excreted as glucuronide metabolites via the urinary route.. The absolute oral bioavailability of puerarin was approximately 7% at doses of 5 and 10 mg/kg. Puerarin was widely distributed to several organs related to the diseases of aging, including the hippocampus, femur, tibia, and mammary gland. Glucuronides were the major metabolites of puerarin and were mainly excreted in the urine. These results are useful for the development of puerarin and Pueraria candollei var. mirifica as phytopharmaceutical products.

Topics: Administration, Oral; Animals; Biological Availability; Female; Isoflavones; Kinetics; Phytoestrogens; Rats, Sprague-Dawley; Tissue Distribution

Although it has been clearly shown that Pueraria mirifica and its phytoestrogens can mimic estrogen in preventing bone loss, as osteoporosis is an asymptomatic disease, the therapeutic effects of P. mirifica should be acknowledged. In this study, 6-month-old female rats were ovariectomized, kept for 4 weeks to induce bone loss, divided into five groups, and treated with P. mirifica at doses of 0, 5, 25, and 50 mg/kg BW/day (PM0, PM5, PM25, and PM50 groups, respectively) or 7 mg/kg BW/day of puerarin (PU group) for 12 weeks. Only the trabecular bone mineral densities (BMDs) of tibia metaphysis (at the 12th, 14th, and 16th week) and total and trabecular BMDs of L4 (at the 16th week) of the PM50 group were significantly higher than those of the PM0 group. However, the BMDs of tibia metaphysis and L4 at the 16th week of the study period were kept significantly lower than those of the 0 week, and the BMD was also significantly lower than that of the 4th week for tibia metaphysis. The trabecular bone area (BV/TV), trabecular number (Tb.N), and osteoblast surface (Ob.S/BS) were significantly higher, and trabecular space (Tb.Sp) was significantly lower in the PM50 group, as compared with those of the PM0 group. This study indicates that P. mirifica could be used as an anti-osteoporotic agent for postmenopausal women. Since P. mirifica could mainly retain bone mass at the levels before bone loss is initiated, the use of other anabolic agents in combination with P. mirifica is recommended for osteoporotic patients.

Topics: Animals; Bone Density; Bone Density Conservation Agents; Estrogens; Female; Humans; Isoflavones; Osteoblasts; Osteoporosis; Phytoestrogens; Phytotherapy; Plant Extracts; Pueraria; Rats; Rats, Sprague-Dawley; Tibia

Puerarin is a phytoestrogen that shows osteogenic effects. Meanwhile, zinc stimulates bone formation and inhibits bone resorption. The study aims to investigate the effects of coadministration of puerarin (low dose) and zinc on bone formation in ovariectomized rats.. Co-administration or use alone of puerarin (low dose) and/or zinc were gavaged in OVX rats. The estrogen-like effects were detected by the uterus weight, the histologic observation and the IGF-1 protein expression. The osteogenic effects were determined by bone histomorphometric and mechanical parameters, osteogenic and adipogenic blood markers, and so on.. The results showed that oral administration of puerarin (low dose) plus zinc didn't significantly increase uterus weight. The glandular epithelial of endometrium had no proliferation and no protein expression of IGF-1. Moreover, co-administration attenuated bone loss and biomechanical decrease more than single use of puerarin or zinc (p<0.05). Next, combined administration of puerarin and zinc promoted the serological level of osteocalcin, bone marrow stromal cell (BMSC) proliferation, and the expression of alkaline phosphatase (ALP), and suppressed the serological level of adiponectin and adiposity in bone marrow (BM).. In conclusion, co-administrated puerarin (low dose) and zinc can partially reverse OVX-induced bone loss and suppress the adiposity of BM in rats, which shed light on the potential use of puerarin and zinc in the treatment of osteoporosis.

Topics: Adipogenesis; Adiponectin; Adiposity; Animals; Biomechanical Phenomena; Bone Marrow; Cells, Cultured; Female; Insulin-Like Growth Factor I; Isoflavones; Osteocalcin; Osteoporosis; Ovariectomy; Phytoestrogens; Rats, Sprague-Dawley; Tibia; Zinc

Several studies demonstrate that estradiol can prevent arterial calcification. However, little is known regarding the effect of puerarin, a phytoestrogen extracted from Radix Puerariae, on arterial calcification. The aim of the present study was to determine whether puerarin reduced osteoblastic differentiation of calcifying vascular smooth muscle cells (CVSMCs). The CVSMCs were isolated from mice aorta and treated with different concentrations of puerarin. The alkaline phosphatase (ALP) activity, osteocalcin secretion and Runx2 expression were determined. To examine whether estrogen receptors (ERs) PI3K and Akt play a role in this effect, ICI182789, phosphoinositide 3-kinase (PI3K) inhibitor, LY294002, or the Akt inhibitor, 1L-6-hydroxymethyl-chiro-inositol 2-(R)-2-O-methyl-3-O-octadecylcarbonate (HIMO) was used. Our results showed puerarin could inhibit ALP activity, osteocalcin secretion and Runx2 expression in CVSMCs. Puerarin could induce the activation of Akt. Furthermore, pretreatment of ICI182780, LY294002, HIMO could abolish the effect of puerarin on ALP activity in CVSMCs. Our experiment demonstrated that puerain could attenuate the osteoblastic differentiation of VSMCs through the ER/PI3K-Akt signal pathway.

Topics: Alkaline Phosphatase; Animals; Aorta; Cell Differentiation; Cells, Cultured; Core Binding Factor Alpha 1 Subunit; Endoplasmic Reticulum Stress; Isoflavones; Mice; Muscle, Smooth, Vascular; Osteoblasts; Osteocalcin; Phosphatidylinositol 3-Kinases; Phytoestrogens; Phytotherapy; Plant Roots; Proto-Oncogene Proteins c-akt; Pueraria; Signal Transduction; Vascular Calcification

Osteoblasts are key functional cells in the process of bone metabolic balance. Phytoestrogens have an important influence on the proliferation and differentiation of osteoblasts. Puerarin, a plant estrogen, has a wide range concentration in vitro on the function of osteoblasts. The current study investigates the effect of the phytoestrogen puerarin on the proliferation, differentiation, and mineralization of osteoblasts in vitro.. The calvaria bone of eight-ten Wistar rats which were born within 24 h were obtained in aseptic condition. After enzyme digestion, isolation, purified osteoblasts of rats were cultured for further study. The cells of the first to third generation were divided into a control group and a puerarin-treated group with 10(-3)-10(-10) mol·L(-1) puerarin. The cells were exposed to the medium containing a low level of carbohydrates, 10% (V/V) FBS for 24 h. After 1 to 4 days of culture, the OD values on the proliferation of osteoblasts in each group were determined by microplate reader. The cells were cultured in the medium containing 50 μg·mL(-1) vitamin C, 10(-2) mol·L(-1) sodium glycerophosphate, 10% FBS and the medium was changed every 3 to 4 days. After 2 to 8 days of culture, expression of alkaline phosphatase were tested and compared by microplate reader. The mineral nodes of osteoblasts were dyed using alizarin red or improved Von Kossa way after four weeks.. Compared with those in the 10(-5)-10(-9) mol·L(-1) puerarin, the proliferation of osteoblasts, the expression of alkaline phosphatase, and the number of mineral nodes of osteoblasts were significantly decreased in the control group. The increase was the fastest in the third day, while on the fourth day it was decreased, and arrived at statistical significance compared with the alkaline phosphatase activities and control group. The 10(-6) mol·L(-1) group was the most distinct, and formed the most mineralized nodule. Compared with the 10(-3) mol·L(-1) puerarin group, those changes were markedly increased in the control group.. Puerarin has proliferation, differentiation, and mineralization effects on osteoblasts in a dose-dependent manner, and has a double-way effect on the osteoblasts in vitro. A low-dose showed positive effects on the development of osteoblasts, and high-dose puerarin could inhibit the formation of bone.

Topics: Alkaline Phosphatase; Animals; Bone and Bones; Bone Density; Calcification, Physiologic; Cell Differentiation; Cell Proliferation; Cells, Cultured; Dose-Response Relationship, Drug; Female; In Vitro Techniques; Isoflavones; Osteoblasts; Phytoestrogens; Rats, Wistar

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.

Topics: Alkaline Phosphatase; Animals; Cell Proliferation; Cells, Cultured; Collagen Type I; Female; Isoflavones; Osteoblasts; Papio; Phytoestrogens; Plant Extracts; Primary Cell Culture; Pueraria; Receptors, Estrogen

Oxidative stress plays an essential role in the pathogenesis of cardiovascular diseases and osteoporosis resulting from oestrogen deficiency in the postmenopausal period. In this report, we observed a dynamic change of oxidative stress and DNA damage after ovariectomy in female rats. We then compared phytoestrogen puerarin and 17β-oestradiol (E₂) in their effects on oestrogen deficiency-induced oxidative stress and DNA damage. Serum total antioxidant capacity (TAC), malondialdehyde (MDA) and lymphocytes DNA damage (comet%) were measured. There was a gradual increase in oxidative stress in the ovariectomized (OVX) rats over time after ovariectomy, as compared to rats receiving sham operation. OVX rats that were on puerarin and E₂ showed increased TAC and decreased MDA in the serum, as well as decreased lymphocytes comet%. Puerarin appeared to have a more powerful protective effect on DNA oxidative damage than E₂. The study indicates that postmenopausal women may benefit from phytoestrogen puerarin.

Topics: Animals; Antioxidants; Comet Assay; DNA Damage; Estradiol; Estrogens; Female; Isoflavones; Lymphocytes; Malondialdehyde; Ovariectomy; Oxidative Stress; Phytoestrogens; Rats; Rats, Sprague-Dawley

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.

Topics: Animals; Biomarkers; Cell Differentiation; Cell Line; Cell Proliferation; Drug Evaluation, Preclinical; Estradiol; Genistein; Humans; Isoflavones; Osteoblasts; Osteoporosis, Postmenopausal; Phytoestrogens; Plant Extracts; Pueraria; Rats; Receptors, Estrogen; RNA, Messenger; Up-Regulation

Estrogen deficiency results in loss of bone mass. Phytoestrogens are plant-derived non-steroidal compounds with estrogen-like activity that bind to estrogen receptors. The main aim of this study was to investigate the effect of the phytoestrogen puerarin on adult mouse osteoblasts.. Osteoblast cells were harvested from 8-month old female imprinting control region (ICR) mice. The effects of puerarin stimulation on the proliferation, differentiation and maturation of osteoblasts were examined. The production of nitric oxide (NO) and the expression of bone morphogenetic protein-2 (BMP-2), SMAD4, mitogen-activated protein kinases (MAPK), core binding factor α1/ runt-related transcription factor 2 (Cbfa1/Runx2), osteoprotegerin (OPG), and receptor activator of NF-κB ligand (RANKL) genes were analyzed. The activation of signal pathways was further confirmed by specific pathway inhibitors.. The osteoblast viability reached its maximum at 10(-8) mol/L puerarin. At this concentration, puerarin increases the proliferation and matrix mineralization of osteoblasts and promotes NO synthesis. With 10(-8) mol/L puerarin treatment, BMP-2, SMAD4, Cbfa1/Runx2, and OPG gene expression were up-regulated, while the RANKL gene expression is down-regulated. Concurrent treatment involving the (bone morphogenetic protein) BMP antagonist Noggin or the NOS inhibitor L-NAME diminishes puerarin induced cell proliferation, Alkaline phosphatase (ALP) activity, NO production, as well as the BMP-2, SMAD4, Cbfa1/Runx2, OPG, and RANKL gene expression.. In this in vitro study, we demonstrate that puerarin is a bone anabolic agent that exerts its osteogenic effects through the induction of BMP-2 and NO synthesis, subsequently regulating Cbfa1/Runx2, OPG, and RANKL gene expression. This effect may contribute to its induction of osteoblast proliferation and differentiation, resulting in bone formation.

Topics: Animals; Bone Morphogenetic Protein 2; Cell Differentiation; Cell Survival; Cells, Cultured; Female; Isoflavones; MAP Kinase Signaling System; Mice; Mice, Inbred ICR; Nitric Oxide; Osteoblasts; Osteogenesis; Phytoestrogens; RANK Ligand

Adverse drug reactions (ADR), especially intravenous hemolysis, have largely limited the application of puerarin injections in clinics. This study investigated the underlying mechanisms of puerarin-induced hemolysis. Our results show that puerarin induced concentration-dependent and time-dependent hemolysis when human erythrocytes were incubated in saline solution with more than 2mM puerarin for over 2h. However, incubation in PBS or addition of 1mM of lidocaine to the saline solution completely abolished the hemolysis. Providing materials that could start ATP synthesis did not reverse the hemolysis, and puerarin did not affect Na(+)-K(+)-ATPase activity. In addition, puerarin (0.1-2mM) did not cause calcium influx or exhibited pro-oxidant activity in erythrocytes. Puerarin exhibited different influences on the membrane microviscosity of erythrocytes in saline and PBS. Moreover, 1mM lidocaine inhibited 8mM puerarin-induced reduction of membrane microviscosity in saline solution. SDS-PAGE analysis of membrane proteins revealed that 2mM puerarin treatment induced the appearance of several new protein bands but attenuated the expression of protein bands 2.1, 3, 4.1, 4.2 and 5. These results suggest that high concentrations of puerarin-induced hemolysis were associated with the changes of membrane lipids and of the composition of erythrocytes membrane proteins but not with ATP depletion, pro-oxidation and calcium influx. These changes could be related to the intercalation of amphiphilic puerarin at high concentration into the erythrocyte membrane in certain media, resulting in membrane disorganization and, eventually, cytolysis. Hence, in clinics, determining the optimal dose of puerarin is critical to avoid overdosing and ADR.

Topics: Adenosine Triphosphate; Antioxidants; Cell Membrane; Erythrocytes; Hemolysis; Hemolytic Agents; Humans; Isoflavones; Membrane Proteins; Phytoestrogens; Sodium-Potassium-Exchanging ATPase

Phytoestrogens, which have a weak estrogenic effect, bind to estrogen receptors (ERs), thereby competing with estradiol, have an antiestrogenic effect on women of reproductive age with high estrogenic level. Herein, we examined the ability of the phytoestrogen Puerarin to treat endometriosis in rat models of endometriosis. In total, 75 adult, mature female Sprague-Dawley rats in which endometriotic implants were successfully induced by transplanting autologous endometrial tissue to ectopic sites were used in this study. Oral gavage of Puerarin (at doses of 600, 200, or 60 mg/kg per day) or Danazol (80 mg/kg per day) started 4 weeks after implantation. Control model rats received vehicle alone. After administration for 4 weeks, the weight of the ectopic implants, estradiol concentration, as well as ER-α and Aromatase P450 (P450arom) expression in different groups of rat tissues were evaluated after treatment. The endometriotic tissue weight and serum estrogen levels were significantly lower in high, medium, low dose of Puerarin and Danazol treatment groups than that in control group (P < .05 or P < .01). Low-dose Puerarin inhibited P450arom expression and significantly reduced estrogen levels in endometriotic tissue (P < .01). Three doses of Puerarin had no adverse effects on liver, kidney, and ovary, whereas high-dose Puerarin administration caused thinner bone trabecula with distortion and breakage and Danazol administration caused mild or moderate hepatic cell damage. These data demonstrate that Puerarin was able to effectively suppress the growth and development of ectopic endometrium in the rat endometriosis model, even at low doses, suggesting it may be an effective treatment for endometriosis.

Topics: Animals; Endometriosis; Estradiol; Estrogen Receptor alpha; Estrogen Receptor beta; Female; Isoflavones; Phytoestrogens; Random Allocation; Rats; Rats, Sprague-Dawley

Whether urinary incontinence in the postmenopause can be prevented or delayed by estrogens is currently controversially debated. Ovariectomized (ovx) rats have been successfully used as models in the past years but plant derived substances with estrogenic effects in the lower urinary tract have not been studied so far. Therefore we compared the effects of a 3 months lasting oral administration of estradiol 17beta (E2) with those of the phytoestrogens equol, genistein and puerarin. They were ovariectomized, fed with test substance containing food and then anaesthetized and catheterized with a biluminal catheter having one outlet in the bladder and another in the urethra at the level of the urethral sphincter. Urethral and bladder pressure were recorded during a 240s period of retrograde bladder filling (2 x 0.5 ml within 30s with 1 min filling intermission). Bladder and urethra pressures were highest in the E2>puerarin>equol>genistein treated animals. Phytoestrogen and E2 treatment resulted in consistently higher urethral than the bladder pressures during the filling period and in the filled status whereas bladder often exceeded urethral pressures in ovx controls. In summary, we demonstrate significant improvement of urethral closure mechanism under E2 and phytoestrogen administration that can be assumed to be beneficial for prevention or therapy of postmenopausal urge incontinence.

Topics: Aging; Animals; Equol; Estradiol; Female; Genistein; Isoflavones; Ovariectomy; Phytoestrogens; Pressure; Rats; Rats, Sprague-Dawley; Urethra; Urinary Bladder; Urinary Incontinence; Urodynamics

Elevated levels of β-amyloid (Aβ) in the brains being a hallmark of Alzheimer's disease have been believed to play a critical role in the cognitive dysfunction that occurs in Alzheimer's disease. Recent evidence suggests that Aβ induces neuronal apoptosis in the brain and in primary neuronal cultures. In this study, we investigated the effects of puerarin, a phytoestrogen isolated from Pueraria lobata, on cognitive function and neuronal apoptosis in the intrahippocampal injection of Aβ rats and its mechanism of action. The results show the intrahippocampal injection of Aβ induced a spatial memory deficit, apoptosis, and caspase-9 activation in hippocampal neurons. Puerarin treatment ameliorated Aβ(1-42)-induced cognitive impairment and reversed the increase of apoptosis in the hippocampus. The attenuation is associated with the activation of Akt and phosphorylation of Bad. These results suggest that puerarin may be an anti-Alzheimer's disease candidate drug to suppress both Alzheimer's disease-related neuronal cell apoptosis and dysfunction of the memory system.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Apoptosis; Apoptosis Regulatory Proteins; Cells, Cultured; Cognition Disorders; Dose-Response Relationship, Drug; Enzyme Activation; Gene Expression Regulation; Hippocampus; Isoflavones; Male; Maze Learning; Memory Disorders; Nerve Tissue Proteins; Neurons; Neuroprotective Agents; Phosphorylation; Phytoestrogens; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; RNA, Messenger

Phytoestrogens are polyphenolic non-steroidal plant compounds with estrogen-like biological activity. The phytoestrogen puerarin, the main isoflavone glycoside found in the root of Pueraria lobata, has been used for various medicinal purposes in traditional Chinese medicines for thousands of years. Recent studies have indicated that the estrogen receptor (ER), through interaction with p85, regulates phosphoinositide 3-kinase (PI3K) activity, revealing a physiologic, non-nuclear function of ER that may be relevant in cytoprotection. In this study, we demonstrate that the phytoestrogen puerarin inhibits tert-butyl hydroperoxide (t-BHP)-induced oxidative injury via an ER-dependent Gbeta1/PI3K/Akt and heme oxygenase-1 (HO-1) pathway. Pretreatment of Hepa1c1c7 and HepG2 cells with puerarin significantly reduced t-BHP-induced caspase-3 activation and subsequent cell death. Also, puerarin up-regulated HO-1 expression and this expression conferred cytoprotection against oxidative injury induced by t-BHP. Moreover, puerarin induced Nrf2 nuclear translocation, which is upstream of puerarin-induced HO-1 expression, and PI3K activation, a pathway that is involved in induced Nrf2 nuclear translocation, HO-1 expression and cytoprotection. Puerarin-induced up-regulation of HO-1 and cytoprotection against t-BHP were abolished by silencing Nrf2 expression with specific siRNA. Also, puerarin-mediated increases in PI3K activation and HO-1 induction were reversed by co-treatment with ICI 182,780 and pertussis toxin. Taken together, these results suggest that puerarin augments cellular antioxidant defense capacity through ER-dependent HO-1 induction via the Gbeta1/PI3K/Akt-Nrf2 signaling pathway, thereby protecting cells from oxidative stress.

Topics: Animals; Apoptosis; Blotting, Western; Caspase 3; Cell Line, Tumor; Cell Nucleus; Cell Survival; Cytoprotection; Cytosol; Electrophoretic Mobility Shift Assay; Heme Oxygenase-1; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Isoflavones; Mice; NF-E2-Related Factor 2; Oxidative Stress; Phosphatidylinositol 3-Kinases; Phytoestrogens; Proto-Oncogene Proteins c-akt; Receptors, Estrogen; Reverse Transcriptase Polymerase Chain Reaction; RNA; tert-Butylhydroperoxide; Up-Regulation

Topics: Drugs, Chinese Herbal; Endometriosis; Female; Humans; Isoflavones; Phytoestrogens

The aim of this study was to evaluate the estrogenic activity of tuberous samples of wild, phytoestrogen-rich Pueraria mirifica collected from 28 out of 76 provinces of Thailand by MCF-7 proliferation assay. The plant extracts were administered to MCF-7, ER alpha positive human mammary adenocarcinoma cell cultures, for 3 days at dosages of 0.1, 1, 10, 100 and 1,000 microg/ml and were compared with 17 beta-estradiol at concentrations of 10(-12)-10(-6) M. The mean P. mirifica population at 1 mug/ml exhibited significant proliferation. Two plant samples exhibited levels of proliferation in MCF-7 that were similar to 17beta-estradiol. The mean P. mirifica populations at 100 and 1,000 microg/ml exhibited significant cytotoxicity in MCF-7. Analysis of the estrogenic activity of puerarin, representative of major isoflavonoids in P. mirifica tubers, revealed proliferation in MCF-7 only at the highest dose (10(-6) M) that was 10(2)-10(5) times less active than 17 beta-estradiol. Puerarin and 17 beta-estradiol at concentration of 10(-12)-10(-6) M exhibited no cytotoxicity in MCF-7.

Topics: Cell Line, Tumor; Cell Proliferation; Estradiol; Geography; Humans; Isoflavones; Phytoestrogens; Plant Extracts; Plant Tubers; Pueraria; Thailand

There is evidence that metabolic activation can increase the estrogenic activity of the phytoestrogen-rich herb in tests with HepG2 cells. Variation in both plant genetics and harvest season may also influence estrogenic activity of the plant materials. We evaluated the influence of in vitro metabolic activation by S9 mixture on the estrogenic activity of tuberous samples of different cultivars of the phytoestrogen-rich herb, Pueraria mirifica, harvested in different seasons.. Plant extracts were derived from the tubers of five plant cultivars collected during summer, rainy season and winter and administered to MCF-7 cultures, an ERalpha-positive human mammary adenocarcinoma cell line for 3 days at dosages of 0.1, 1, 10, 100 and 1000microg/ml. These data were compared with the major plant isoflavonoids puerarin, daidzin, genistin, daidzein and genistein and with 17beta-estradiol, at concentrations of 10(-12) to 10(-6)M. The test system was done in the absence and presence of the S9 mixture.. The major plant isoflavonoids and the plant extracts exhibited variable degrees of estrogenic activities as evaluated by altered proliferation of the MCF-7 cell line which were significantly enhanced in the presence of the S9 mixture.. Metabolic activation of plant isoflavonoids at least in vitro by S9 mixture plays a significant role in amplification of the estrogenic activity of the phytoestrogen-rich plant. In addition, the estrogenic activities of the plant samples were potentially influenced by both seasonal changes and plant genetics.

Topics: Adenocarcinoma; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Estradiol; Female; Genistein; Humans; Isoflavones; Phytoestrogens; Plant Extracts; Pueraria; Seasons

Pueraria mirifica tubers collected from 28 out of 76 provinces of Thailand and Pueraria lobata tubers collected from Guangzhou province, China were submitted to HPLC analysis with the established gradient system comprising 1.5% acetic acid and acetonitrile. Five major isoflavonoids, including puerarin, daidzin, genistin, daidzein and genistein, were adopted as authentic standards. P. mirifica tubers showed intra- as well as inter-provincial differences in isoflavonoid and total isoflavonoid contents. The difference in both cases should be mostly influenced by genetic and environmental factors. In comparison with P. lobata, P. mirifica population exhibited differences only with a lower amount of daidzein.

Topics: Calibration; China; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Genistein; Isoflavones; Molecular Structure; Phytoestrogens; Plant Tubers; Pueraria; Quality Control; Seasons; Thailand

The effects of puerarin on behaviour and brain neuronal activity in animal studies have been described previously. However, molecule mechanisms underlying these effects were poorly understood. Here, we examined the regulation of puerarin on the Ca(2+) signals in primary rat hippocampal neurons using Fura-2 based calcium imaging techniques. Application of puerarin had no effect on the basal intracellular calcium concentration ([Ca(2+)](i)), but potentiated the KCl-evoked [Ca(2+)](i) transient in 87% of recorded neurons. Dantrolene or ruthenium red, the inhibitors of ryanodine receptors, completely blocked this potentiation induced by puerarin. Moreover, in Ca(2+)-free solution, pre-application of puerarin significantly augmented the elevation of [Ca(2+)](i) evoked by caffeine (3 mM), which is a specific agent to activate the ryanodine receptors. In contrast, nifedipine failed to prevent the potentiation induced by puerarin. Similarly, in the experiments of whole-cell patch-clamp recording, puerarin did not show any effect on calcium currents generated by depolarization pulses. These data demonstrated that the potentiation induced by puerarin was attributed to the facilitation of Ca(2+)-induced Ca(2+) release (CICR) via ryanodine receptors, rather than extracellular Ca(2+) influx. Using estrogen receptor antagonist ICI 182780 and tamoxifen, we further demonstrated that the potentiation induced by puerarin was mediated by the estrogen receptor. Furthermore, the membrane-permeant inhibitor of protein kinase A (PKA) H89 completely inhibited this potentiation. However, U-73122, the inhibitor of phospholipase C (PLC) had no effect, indicating that the cyclic AMP/PKA signaling pathway was involved in the activation of CICR by puerarin.

Topics: Animals; Caffeine; Calcium; Cells, Cultured; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Hippocampus; Isoflavones; Neurons; Phytoestrogens; Potassium Chloride; Rats; Rats, Sprague-Dawley; Ryanodine Receptor Calcium Release Channel

Pueraria mirifica is a tuberous plant enriched with active phytoestrogens. There is no established information about the factors influencing isoflavonoid storage in the tubers. We investigated the tuberous storage of the major isoflavonoids of 1-year-old plants. Four cultivars of P. mirifica were cultivated in the same field trial during the same period to establish a unique plant age and differentiation under the same environment and soil conditions. The tubers collected from the 1-year-old plants in the summer, rainy season and winter were submitted to an HPLC analysis with a gradient system comprising 0.1% acetic acid and acetonitrile. Five major isoflavonoids, puerarin, daidzin, genistin, daidzein and genistein, were adopted as standards. P. mirifica tubers of different cultivars collected in the same season exhibited significant differences in individual and total isoflavonoid contents, showing chemovariety. P. mirifica tubers of the same cultivar collected from different seasons also exhibited significant differences in individual and total isoflavonoid contents, showing the influence of season. In conclusion, the tuberous storage of major isoflavonoids in 1-year-cultivated plants was greatly diverse and was strongly influenced by the season and plant genetics.

Topics: Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Genistein; Isoflavones; Models, Biological; Molecular Structure; Phytoestrogens; Plant Tubers; Pueraria; Rain; Seasons; Time Factors

To understand the relationship between the metabolites and estrogenic activity of the main isoflavones puerarin and daidzin of the rhizome of Pueraria thunbergiana (PT, family Leguminosae), PT and its isoflavones were transformed by human intestinal bacteria and their estrogenic effects were investigated. All human fecal specimens hydrolyzed puerarin and daidzin to daidzein, but their hydrolyzing activities varied depending on the individuals. All intestinal bacteria isolated from human also hydrolyzed daidzin to daidzein, but a few bacteria transformed puerarin to daidzein. When the estrogenic effect of PT, puerarin and daidzin was compared with those of their metabolites, the metabolites more potently increased proliferation of MCF-7 cells than PT, puerarin and daidzin. The metabolite daidzein also potently increased estrogen-response c-fos mRNA and PR protein expressions. These findings suggest that intestinal bacteria, which can hydrolyze puerarin and/or daidzin, may activate a potent estrogenic activity of PT.

Topics: Bacteria; Bacterial Physiological Phenomena; Base Sequence; Cell Line; DNA Primers; Humans; Intestines; Isoflavones; Phytoestrogens; Pueraria; Reverse Transcriptase Polymerase Chain Reaction

The protective effect of puerarin on the Parkinson disease (PD) mice with decreased estrogen level was investigated in order to develop a new potential medicine as a substitute for estrogen for preventing and treating PD. By using immunohistochemical method of avidinbiotin peroxidase complex (ABC), the distribution of the cells positive for tyrosine hydroxylase (TH) and fibres in the substantia nigra of the mouse were observed. These mice were divided into three groups randomly: group A, normal-female-mouse models; group B containing three subgroups, B1 (normal saline), B2 (estrogen), B3 (puerarin); group C containing three sub groups, C1 (normal saline), C2 (estrogen), C3 (puerarin). By using TUNEL the numbers of apoptosis cells in every visual field was counted and the difference between the experimental group and control group was compared. The results showed the numbers of the cells positive for TH were more and the numbers of apoptosis cells were less in the normal-female-mouse models group than in the group of model made after ovariosteresis and the group of model made before ovariosteresis (P < 0.05), respectively. However, there was no significant difference, between the group given estrogen/puerarin and the controls, and between the group given estrogen and given puerarin. (P > 0.05). It was suggested that puerarin may have protective effect on the nigral neurons to PD. Moreover, the protective effect might serve as a surrogate of estrogen and be associated with the apoptosis.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Apoptosis; Estrogens; Female; Isoflavones; Mice; Mice, Inbred BALB C; Ovariectomy; Parkinson Disease; Phytoestrogens; Plant Preparations; Random Allocation; Substantia Nigra; Tyrosine 3-Monooxygenase; Vasodilator Agents