Kudzu (Pueraria lobata) vine ethanol extracts improve ovariectomy-induced bone loss in female mice

Ultrasonic effects on the degradation kinetics, structural characteristics and protective effects on hepatocyte lipotoxicity induced by palmitic acid of Pueraria Lobata polysaccharides

In this study, a high-molecular-weight Pueraria lobata polysaccharide (PLP) with a molecular weight of 273.54 kDa was degraded by ultrasound, and the ultrasonic degradation kinetics, structural characteristics and hepatoprotective activity of ultrasonic degraded PLP fractions (PLPs) were evaluated. The results showed that the ultrasonic treatment significantly reduced the Mw and particle size of PLP, and the kinetic equation of ultrasonic degradation of PLP followed to the midpoint fracture model (the fist-order model). The monosaccharide composition analysis, FT-IR, triple helix structure and XRD analysis all indicated that the ultrasound degradation did not destroy the primary structure of PLP, but the thermal stability of degraded fractions improved. Additionally, the scanning electron microscopy analysis demonstrated that the surface morphology of PLP was altered from smooth, flat, compact large flaky structure to a sparse rod-like structure with sparse crosslinking (PLP-7). The degraded PLP fractions (0.5 mg/mL) with lower Mw exhibited better antioxidant activities and protective effects against palmitic acid-induced hepatic lipotoxicity, which may be due to the increased exposure of active groups such as hydroxyl groups of PLP after ultrasound. Further investigation showed that PLPs not only increased Nrf2 phosphorylation and its nuclear translocation, thereby activating Nrf2/Keap1 signaling pathway, but also enhanced HO-1, NQO-1, γ-GCL gene expressions and promoted superoxide dismutase and catalase activities, which protected hepatocytes against PA-induced oxidative stress and lipotoxicity. Overall, our research might provide an in-depth insight into P. Lobata polysaccharide in ameliorating lipid metabolic disorders, and the results revealed that ultrasonic irradiation could be a promising degradation method to produce value-added polysaccharide for use in functional food.

Bioassay-Guided Characterization, Antioxidant, Anti-Melanogenic and Anti-Photoaging Activities of Pueraria thunbergiana L. Leaf Extracts in Human Epidermal Keratinocytes (HaCaT) Cells

Although the roots and flowers of P. thunbergiana are known to have various physiologically active effects, studies on the anti-melanin production and anti-photoaging effects of its leaf extracts and cellular mechanisms are still lacking. In this study, we evaluated the possibility of using Pueraria thunbergiana leaves as a natural material for skin whitening and anti-aging-related functional cosmetics. The 30% ethyl alcohol (EtOH) extract from P. thunbergiana leaves was fractionated using n-hexane, ethyl acetate (EtOAc), butanol, and aqueous solution to measure their whitening, and anti-aging effects. The EtOAc fraction contained a high content of phenolic and flavonoids and showed higher 1,1-diphenyl-2-picryhydrazyl (DPPH) and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activities than the other fractions. It was also confirmed that the EtOAc fraction markedly inhibited α-melanocyte stimulating hormone (α-MSH)-induced melanogenesis in B16F10 melanoma cells. In addition, the EtOAc fraction showed a protective effect against ultraviolet B (UVB) in HaCaT cells and increased the collagen synthesis that was decreased due to UVB exposure. Matrix metalloproteinase-1 (MMP-1) activity and MMP-1 protein expression were reduced in human epidermal keratinocytes (HaCaT) cells. These results indicate that the EtOAc fraction has superior antioxidant activity, anti-melanogenesis, and anti-photoaging effects compared to the other fractions. Therefore, in this study, we confirmed the potential of P. thunbergiana leaf extract as a functional cosmetic ingredient, and it can be used as basic data for the physiological activity of P. thunbergiana leaf extracts.

Isolation of Mirificin and Other Bioactive Isoflavone Glycosides from the Kudzu Root Lyophilisate Using Centrifugal Partition and Flash Chromatographic Techniques

Pueraria lobata (Willd.) Ohwi is a legume taxon native to Southeast Asia and widely used in traditional medicine systems of that region. The therapeutic applications of the underground parts of this species (known as kudzu root) are related to its high content of isoflavones, mainly the characteristic C-glycoside derivatives. Within this group, the most explored compound both phytochemically and pharmacologically is puerarin. However, current scientific findings document important anti-biodegenerative effects for some of the minor isoflavones from kudzu roots. Therefore, the main objective of the study was to develop an original preparative method that allowed the efficient isolation of closely related hydrophilic daidzein C-glycosides, including mirificin, from vacuum-dried aqueous-ethanolic extracts of kudzu roots. For this purpose, the combined centrifugal partition (CPC) and flash chromatographic (FC) techniques were elaborated and used. The optimized biphasic solvent system in CPC, with ethyl acetate, ethanol, water, and 0.5% (V/V) acetic acid as a mobile phase modifier, enabled the purification and separation of the polar fraction containing bioactive isoflavones and ultimately the isolation of mirificin, 3′-hydroxy- and 3′-methoxypuerarin, puerarin, and daidzin using FC. The identity of isoflavones was confirmed using spectroscopic (UV absorption and nuclear magnetic resonance) and mass spectrometric methods. The determined purity of isolated mirificin was 63%.

Puerarin specifically disrupts osteoclast activation via blocking integrin-β3 Pyk2/Src/Cbl signaling pathway

Objective

Given the limitations of current anti-resorption agents for postmenopausal osteoporosis, there is a need for alternatives without impairing coupling crosstalk between bone resorption and bone formation ie. osteoclastogenesis. Puerarin, a unique C-glycoside isoflavonoid, was found to be able to prevent bone loss by inhibiting bone resorption, but the underlying mechanism was controversial. In this study, we investigated the effects of puerarin on osteoclastic differentiation, activation and bone resorption and its underlying molecular mechanism in vitro, and then evaluated the effects of puerarin on bone metabolism using an ovariectomized (OVX) rat model.

Methods

In vitro, the effect of puerarin on osteoclastic cytotoxicity, differentiation, apoptosis, activation and function were studied in raw 264.7 ​cells and mouse BMMs. Mechanistically, osteoclast-related makers were determined by RT-PCR, western blot, immunofluorescence, and kinase activity assay. In vivo, Micro-CT, histology, serum bone biomarker, and mechanical testing were used to evaluate the effects of puerarin on preventing osteoporosis.

Results

Puerarin significantly inhibited osteoclast activation and bone resorption, without affecting osteoclastogenesis or apoptosis. In terms of mechanism, the expressions of protein of integrin-β3 and phosphorylations of Src, Pyk2 and Cbl were lower in puerarin group than those in the control group. Oral administration of puerarin prevented OVX-induced trabecular bone loss and significantly improved bone strength in rats. Moreover, puerarin significantly decreased trap positive osteoclast numbers and serum TRAP-5b, CTx1, without affecting bone formation rate.

Conclusions

Collectively, puerarin prevented the bone loss in OVX rat through suppression of osteoclast activation and bone resorption, by inhibiting integrin-β3-Pyk2/Cbl/Src signaling pathway, without affecting osteoclasts formation or apoptosis.

Translational potential of this article

These results demonstrate the unique mechanism of puerarin on bone metabolism and provide a novel agent for prevention of postmenopausal osteoporosis.

Puerarin blocks the aging phenotype in human dermal fibroblasts

Dermal fibroblast aging contributes to aging-associated functional defects in the skin since dermal fibroblasts maintain skin homeostasis by interacting with the epidermis and extracellular matrix. Here, we found that puerarin, an isoflavone present in Pueraria lobata (Kudzu), can prevent the development of the aging-phenotype in human dermal fibroblasts. Normal human dermal fibroblasts (NHDFs) were subcultivated and high-passage cells were selected as senescent cells, whereas low-passage cells were selected as a young cell control. Puerarin treatment increased cell proliferation and decreased the proportion of senescence-associated beta-galactosidase-positive cells in a high-passage culture of NHDFs. Moreover, puerarin treatment reduced the number of smooth muscle actin (SMA)-positive myofibroblasts and the expression of a reticular fibroblast marker, calponin 1 (CNN1), which were induced in high-passage NHDFs. Fulvestrant, an estrogen receptor antagonist, blocked the puerarin-mediated downregulation of SMA and CNN1. Our results suggest that puerarin may be a useful functional food that alleviates aging-related functional defects in dermal fibroblasts.

Combined Extract of Leonurus japonicus Houtt, Eclipta prostrata L., and Pueraria lobata Ohwi Improved Hot Flashes and Depression in an Ovariectomized Rat Model of Menopause

Menopause leads to ovarian hormone loss, which causes symptoms such as weight gain, hot flashes, and depression. Exploring nutraceuticals is important for treating menopausal symptoms that extensively impact women's quality of life. We hypothesized that a combination of Leonurus japonicus Houtt, Eclipta prostrata L., and Pueraria lobata Ohwi (LEPE) would alleviate menopausal symptoms in an ovariectomized menopausal rat model. Bilateral ovariectomy was performed and animals were assigned to five groups: (1) Sham, (2) Vehicle, (-) Control, (3) LEPE (100 mg/kg bw), (4) LEPE (200 mg/kg bw), and (5) Estradiol (3 μg/kg bw). LEPE was orally administered daily for 12 weeks. LEPE supplementation did not affect growth performance (body weight and feed intake) or body composition (lean mass and fat in tissue). LEPE did not cause deviations in aspartate aminotransferase, alanine aminotransferase, estradiol, and follicle-stimulating hormone levels, indicating no hepatotoxicity or endocrine disturbance. LEPE decreased type I collagen (CTX-1) but did not affect bone mineral density or osteocalcin. LEPE decreased tail temperature and increased rectal temperature, improving menopause-related vasomotor symptoms. Furthermore, LEPE ameliorated depression-related behavior, including in forced swimming and tail suspension tests. Thus, LEPE may improve menopausal symptoms by enhancing vasomotor symptoms and depression in an ovariectomized rat menopause model.

A fraction of Pueraria tuberosa extract, rich in antioxidant compounds, alleviates ovariectomized-induced osteoporosis in rats and inhibits growth of breast and ovarian cancer cells

Pueraria tuberosa (Roxb. ex Willd.) DC., known as Indian Kudzu belongs to family Fabaceae and it is solicited as “Rasayana” drugs in Ayurveda. In the present study, we analyzed the efficacy of an ethyl acetate fraction from the tuber extract of Pueraria tuberosa (fraction rich in antioxidant compounds, FRAC) against menopausal osteoporosis, and breast and ovarian cancer cells. The FRAC from Pueraria tuberosa was characterized for its phenolic composition (total phenolic and flavonoid amount). Antioxidant property (in vitro assays) of the FRAC was also carried out followed by the analysis of the FRAC for its antiosteoporotic and anticancer potentials. The antiosteoporotic activity of FRAC was investigated in ovariectomy-induced osteoporosis in rats. The cytotoxicity effect was determined in breast and ovarian cancer cells. Gas chromatography/mass spectrometry (GC/MS) analysis of the FRAC was performed to determine its various phytoconstituents. Docking analysis was performed to verify the interaction of bioactive molecules with estrogen receptors (ERs). The FRAC significantly improved various biomechanical and biochemical parameters in a dose-dependent manner in the ovariectomized rats. FRAC also controlled the increased body weight and decreased uterus weight following ovariectomy in rats. Histopathology of the femur demonstrated the restoration of typical bone structure and trabecular width in ovariectomized animals after treatment with FRAC and raloxifene. The FRAC also exhibited in vitro cytotoxicity in the breast (MCF-7 and MDA-MB-231) and ovarian (SKOV-3) cancer cells. Furthermore, genistein and daidzein exhibited a high affinity towards both estrogen receptors (α and β) in the docking study revealing the probable mechanism of the antiosteoporotic activity. GC/MS analysis confirmed the presence of other bioactive molecules such as stigmasterol, β-sitosterol, and stigmasta-3,5-dien-7-one. The FRAC from Pueraria tuberosa has potential for treatment of menopausal osteoporosis. Also, the FRAC possesses anticancer activity.

A fraction of Pueraria tuberosa extract, rich in antioxidant compounds, alleviates ovariectomized-induced osteoporosis in rats and inhibits growth of breast and ovarian cancer cells

Pueraria tuberosa (Roxb. ex Willd.) DC., known as Indian Kudzu belongs to family Fabaceae and it is solicited as "Rasayana" drugs in Ayurveda. In the present study, we analyzed the efficacy of an ethyl acetate fraction from the tuber extract of Pueraria tuberosa (fraction rich in antioxidant compounds, FRAC) against menopausal osteoporosis, and breast and ovarian cancer cells. The FRAC from Pueraria tuberosa was characterized for its phenolic composition (total phenolic and flavonoid amount). Antioxidant property (in vitro assays) of the FRAC was also carried out followed by the analysis of the FRAC for its antiosteoporotic and anticancer potentials. The antiosteoporotic activity of FRAC was investigated in ovariectomy-induced osteoporosis in rats. The cytotoxicity effect was determined in breast and ovarian cancer cells. Gas chromatography/mass spectrometry (GC/MS) analysis of the FRAC was performed to determine its various phytoconstituents. Docking analysis was performed to verify the interaction of bioactive molecules with estrogen receptors (ERs). The FRAC significantly improved various biomechanical and biochemical parameters in a dose-dependent manner in the ovariectomized rats. FRAC also controlled the increased body weight and decreased uterus weight following ovariectomy in rats. Histopathology of the femur demonstrated the restoration of typical bone structure and trabecular width in ovariectomized animals after treatment with FRAC and raloxifene. The FRAC also exhibited in vitro cytotoxicity in the breast (MCF-7 and MDA-MB-231) and ovarian (SKOV-3) cancer cells. Furthermore, genistein and daidzein exhibited a high affinity towards both estrogen receptors (α and β) in the docking study revealing the probable mechanism of the antiosteoporotic activity. GC/MS analysis confirmed the presence of other bioactive molecules such as stigmasterol, β-sitosterol, and stigmasta-3,5-dien-7-one. The FRAC from Pueraria tuberosa has potential for treatment of menopausal osteoporosis. Also, the FRAC possesses anticancer activity.

A critical assessment of the potential of pharmacological modulation of aldehyde dehydrogenases to treat the diseases of bone loss

Chronic alcoholism (CA) decreases bone mass and increases the risk of hip fracture. Alcohol and its main metabolite, acetaldehyde impairs osteoblastogenesis by increasing oxidative stress. Aldehyde dehydrogenase (ALDH) is the rate-limiting enzyme in clearing acetaldehyde from the body. The clinical relevance of ALDH in skeletal function has been established by the discovery of single nucleotide polymorphism, SNP (rs671) in the ALDH2 gene giving rise to an inactive form of the enzyme (ALDH2*2) that causes increased serum acetaldehyde and osteoporosis in the affected individuals. Subsequent mouse genetics studies have replicated human phenotype in mice and confirmed the non-redundant role of ALDH2 in bone homeostasis. The activity of ALDH2 is amenable to pharmacological modulation. ALDH2 inhibition by disulfiram (DSF) and activation by alda-1 cause reduction and induction of bone formation, respectively. DSF also inhibits peak bone mass accrual in growing rats. On the other hand, DSF showed an anti-osteoclastogenic effect and protected mice from alcohol-induced osteopenia by inhibiting ALDH1a1 in bone marrow monocytes. Besides DSF, there are several classes of ALDH inhibitors with disparate skeletal effects. Alda-1, the ALDH2 activator induced osteoblast differentiation by increasing bone morphogenic protein 2 (BMP2) expression via ALDH2 activation. Alda-1 also restored ovariectomy-induced bone loss. The scope of structure-activity based studies with ALDH2 and the alda-1-like molecule could lead to the discovery of novel osteoanabolic molecules. This review will critically discuss the molecular mechanism of the ethanol and its principal metabolite, acetaldehyde in the context of ALDH2 in bone cells, and skeletal homeostasis.

Structural characterization of a homopolysaccharide with hypoglycemic activity from the roots of Pueraria lobata

A water-soluble neutral homopolysaccharide (PLP-1) was obtained from the roots of Pueraria lobata by DEAE cellulose and Sephadex G-200 gel chromatography purification. The average molecular weight of PLP-1 was 16.2 kDa. Monosaccharide composition analysis showed that PLP-1 was composed of glucose as a glucan. The structure of PLP-1 was characterized on the basis of extensive physical and chemical analysis, which indicated that the backbone of PLP-1 was mainly composed of →3)-α-d-Glcp(1→ and →4)-β-d-Glcp(1→ with a molar ratio of 7.0 : 1.0. Moreover, the hypoglycemic activity of PLP-1 was investigated by palmitic acid and high glucose induced insulin resistant HepG2 cells. The results elucidated that PLP-1 could decrease the glucose concentration by up-regulating the expression of PI3K and AKT, and down-regulating the expression of FoxO1, PCK2, and G6Pase in insulin resistant cells. Therefore, PLP-1 could serve as a dietary supplement to ameliorate insulin resistance for diabetic patients.

Neobavaisoflavone Inhibits Melanogenesis through the Regulation of Akt/GSK-3β and MEK/ERK Pathways in B16F10 Cells and a Reconstructed Human 3D Skin Model

Previous studies have confirmed the anti-melanogenic effect of the aerial part of Pueraria lobata, however, due to its inherent color, P. lobata has limited commercial use. In this study, an extract (GALM-DC) of the aerial part of P. lobata having improved color by the use of activated carbon was obtained. Furthermore, the active compound neobavaisoflavone (NBI) was identified from GALM-DC. The effect of NBI on melanogenesis, tyrosinase activity, α-glucosidase activity, and mechanism of action in melanocytes was investigated. Tyrosinase activity, melanin contents and the expression of melanin-related genes and proteins were determined in B16F10 cells. NBI reduced melanin synthesis and tyrosinase activity. Furthermore, NBI treatment reduced the mRNA and protein expression levels of MITF, TRP-1, and tyrosinase. NBI also works by phosphorylating and activating proteins that inhibit melanogenesis, such as GSK3β and ERK. Specific inhibitors of Akt/GSK-3β (LY294002) and MEK/ERK (PD98059) signaling prevented the inhibition of melanogenesis by NBI. NBI inhibited melanin production through the regulation of MEK/ERK and Akt/GSK-3β signaling pathways in α-MSH-stimulated B16F10 cells. NBI suppresses tyrosinase activity and melanogenesis through inhibition of α-glucosidase activity. Besides, NBI significantly reduced melanogenesis in a reconstructed human 3D skin model. In conclusion, these results suggest that NBI has potential as a skin-whitening agent for hyperpigmentation.

Effects of polysaccharide from Pueraria lobata on gut microbiota in mice

Polysaccharide was derived from Pueraria lobata (PPL) which was considered as one of the traditional Chinese medicinal and edible herbs. In the present study, PPL was administered in equal doses (12.5 mg/kg) to both normal mice and antibiotic-associated diarrhea (AAD) mice for two weeks, and was evaluated in terms of body weight, organ indices, gut structure, gut microbiota and short chain fatty acids. The results showed that normal mice treated with PPL not only reduced the isovaleric acid concentration (P < 0.05), but also significantly increased the abundance of beneficial bacteria, involving Oscillospira and Anaerotruncus (P < 0.05). In addition, PPL could relieve colonic pathological changes and gut microbiota dysbiosis caused by AAD. It indicated that PPL was a potential functional food ingredient by modulating gut microbiota.

Lobatamunsolides A-C, Norlignans from the Roots of Pueraria lobata and their Nitric Oxide Inhibitory Activities in Macrophages

Phytochemical investigation of the methanol (MeOH) extract of Pueraria lobata roots, known as “kudzu”, combined with liquid chromatography/mass spectrometry (LC/MS)-based analysis, resulted in the identification of four norlignans (1–4), including three new norlignans, lobatamunsolides A–C (1–3), and five known isoflavonoids (5–9). The structures of the new compounds were elucidated by a combination of spectroscopic methods, including 1D and 2D nuclear magnetic resonance (NMR) and high resolution (HR)-electrospray ionization mass spectrometry (ESIMS), and their absolute configurations were determined by chemical reaction and quantum chemical electronic circular dichroism (ECD) calculations. The isolated compounds (1–9) were evaluated for their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Compound 9 displayed the strongest NO inhibitory effect and compound 2 showed a weak effect. The potential mechanism of the effect of compound 9 was investigated by analysis of its molecular docking on the active site of inducible nitric oxide synthase (iNOS), which showed the potential interactions of compound 9 with key amino acid residues and the heme cofactor of iNOS. The mechanism as the inhibition of transcriptional iNOS protein expression was confirmed by western blotting experiments.

Comparison among Activities and Isoflavonoids from Pueraria thunbergiana Aerial Parts and Root

Kudzu (Pueraria thunbergiana Benth.) has long been used as a food and medicine for many centuries. The root is the most commonly used portion of the plant, but the aerial parts are occasionally used as well. In this study, we investigated the constituent compounds and biological activities of the aerial parts, leaves, stems, and sprouts, and compared their constituents and activities with those of roots. Leaf extract showed a significantly higher TPC level at 59 ± 1.6 mg/g and lower free radical scavenging (FRS) values under 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS), and NO inhibition at 437 ± 11, 121 ± 6.6 μg/mL and 107 ± 4.9 μg/mL, respectively, than those of sprout, stem, and root extract. Leaf extract also significantly suppressed lipopolysaccharide (LPS)-mediated gene expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). The main components of leaf extract were found to be genistin and daidzin. This study suggests that the leaves of kudzu are a good source of biological activities and isoflavones that can be used in functional or medicinal foods and cosmetics for the prevention or treatment of diseases related to inflammation and oxidative stress.

Support Vector Regression Approach to Predict the Design Space for the Extraction Process of Pueraria lobata

A support vector regression (SVR) method was introduced to improve the robustness and predictability of the design space in the implementation of quality by design (QbD), taking the extraction process of Pueraria lobata as a case study. In this paper, extraction time, number of extraction cycles, and liquid–solid ratio were identified as critical process parameters (CPPs), and the yield of puerarin, total isoflavonoids, and extracta sicca were the critical quality attributes (CQAs). Models between CQAs and CPPs were constructed using both a conventional quadratic polynomial model (QPM) and the SVR algorithm. The results of the two models indicated that the SVR model had better performance, with a higher R² and lower root-mean-square error (RMSE) and mean absolute deviation (MAD) than those of the QPM. Furthermore, the design space was predicted using a grid search technique. The operational range was extraction time, 24–51 min; number of extraction cycles, 3; and liquid–solid ratio, 14–18 mL/g. This study is the first reported work optimizing the design space of the extraction process of P. lobata based on an SVR model. SVR modeling, with its better prediction accuracy and generalization ability, could be a reliable tool for predicting the design space and shows great potential for the quality control of QbD.

Investigation of inulins from the roots of Morinda officinalis for potential therapeutic application as anti-osteoporosis agent

SCOPE

In China, the root of M. officinalis has been widely used over thousands of years against a wide range of bone disease such as lumbago, limb-ache, sciatica and rheumatic arthralgia, and has tremendous medicinal value. But the bioactive constituents responsible for the osteoprotective effects in M. officinalis remain unknown.

METHODS AND RESULTS

M. officinalis polysaccharides were extracted, isolated and purified via DEAE-cellulose 52 and Sephacryl S-100HR column to obtain two saccharides (MOP70-1 and MOP70-2). The results of osteogenic activity assays revealed that MOP70-1 and MOP70-2 significantly promoted the proliferation, differentiation and mineralization of MC3T3-E1 cells. Furthermore, MOP70-2 also upregulated gene expression of runt-related transcription factor 2, osterix, osteocalcin, osteopontin, bone sialoprotein and osteoprotegerin, which implied that MOP70-2 stimulated osteoblastic differentiation by up-regulating osteogenic differentiation-related marker genes. In addition, structural analysis indicated that MOP70-2 contained (2 → 1)-linked-β-D-Fruf residues and terminated with a glucose residue. Morphological and conformational analyses indicated that MOP70-2 exhibited spherical structure of conglomeration and had no triple helix structure.

CONCLUSION

Our studies reported the osteogenic inulins obtained from root of M. officinalis for the first time. The systematical investigation including extraction, purification, biological activities and structural characterization provide a strong evidence for future therapeutic applications as anti-osteoporosis agent.

Isolation, purification, characterization and bioactivities of a glucan from the root of Pueraria lobata

The root of Pueraria lobata is considered to be a medicinal and edible herb for the treatment of diabetes, and it has a long history of application in China.

Puerarin Suppresses Macrophage Activation via Antioxidant Mechanisms in a CaPO4-Induced Mouse Model of Aneurysm

Aneurysm is characterized by balloon-like expansion of the arterial wall and eventual rupture of the aorta. The pathogenesis of aneurysm is associated with the degradation of matrix proteins by matrix metalloproteinases (MMPs) produced by activated macrophages. Although aneurysm is associated with significant mortality and morbidity, surgical intervention is the only proven treatment strategy. Therefore, development of therapeutic agents for aneurysm is greatly anticipated. Here, we demonstrated the protective effects of the major isoflavone puerarin, which is found in kudzu roots and vines. Aneurysms were surgically induced in ten-wk-old male mice using CaPO₄. Subsequently, animals were intraperitoneally injected daily with puerarin at 2.5 mg/kg body weight or with vehicle alone for 2 wk. CaPO₄-induced aneurysm was significantly suppressed by puerarin administration. In subsequent macrophage activation assays using Tumor necrosis factor (TNFα) and CaPO₄ crystals in vitro, puerarin decreased Mmp9 mRNA expression and secreted protein levels. Moreover, induction of IκB, ERK, and p38 phosphorylation by TNFα and CaPO₄ in macrophages was suppressed by puerarin treatments. Finally, puerarin attenuated reactive oxygen species production, following induction by TNFα and CaPO₄. Taken together, the present data demonstrate that puerarin suppresses macrophage activation by inhibiting IκB, ERK, and p38 activity and reactive oxygen species production in a CaPO₄-induced mouse model of aneurysm.

Anti-Hyperglycemic Effect of a Kudzu (Pueraria lobata) Vine Extract in Ovariectomized Mice

Postmenopausal diabetes is exacerbated by estrogen deficiency. Ovariectomized (OVX) animal models can be used to develop strategies for preventing or treating postmenopausal symptoms. We previously found that a diet containing kudzu (Pueraria lobata) vine ethanol extract (PVEE) suppressed weight gain in OVX mice. Therefore, this study further elucidated how PVEE affected OVX mice. Ten-week-old OVX or sham-operated mice were fed diets containing either no PVEE (control) or 20 mg•kg^-1•d^-1 PVEE for 8 wk, 5 mg•kg^-1•d^-1 PVEE for 24 wk, or 20 mg•kg^-1•d^-1 puerarin (daidzein-8-C-glucoside), a major isoflavone present in PVEE, for 10 wk. The effects of puerarin on glucose tolerance were also tested in OVX mice. The experimental diets were not associated with any abnormalities in any mice tested in the present study. Weight gain and serum glucose levels were increased in OVX mice and these effects were significantly attenuated in OVX mice that consumed PVEE (5 or 20 mg•kg^-1•d^-1) or puerarin. Puerarin-treated OVX mice also showed reduced serum glucose levels following administration of 1,000 mg•kg^-1 glucose. These results suggested that puerarin contributed to PVEE-mediated improvements in glucose metabolism in OVX mice. Although further studies are needed to clarify the molecular mechanism underlying these observations, PVEE and puerarin could provide effective approaches to the amelioration of postmenopausal diabetes.

Protective activity of kudzu (Pueraria thunbergiana) vine on chemically-induced hepatotoxicity: in vitro and in vivo studies

Background

Kudzu (Pueraria thunbergiana) root has long been used in Traditional Chinese Medicine. However, the vine of the kudzu plant has been considered waste material. This study aimed to investigate the hepatoprotective properties of the kudzu vine.

Methods

We created 0 %, 30 %, 70 %, and 95 % ethanolic kudzu vine extracts. The isoflavone contents of kudzu vine extract were quantified by high-performance liquid chromatography. Tertiary-butylhydroperoxide (t-BHP) was added to human liver-derived HepG2 cells, and the production of reactive oxygen species was measured in the presence and absence of kudzu vine extract. Antioxidant activity was evaluated in all kudzu vine extracts using a hydroxyradical scavenging assay. Thirty-five male Sprague–Dawley rats were divided into seven groups (n = 5); two groups were not given any extract or drug, one group was treated with 50 mg/kg silymarin orally for 5 days, and the remaining four groups were respectively treated with 100 mg/kg of 0 %, 30 %, 70 %, or 95 % ethanolic extract of kudzu vine orally once daily for 5 days. On day 5 the treatment groups and one untreated group were fed 0.75 ml/kg carbon tetrachloride (CCl₄) to induce liver damage. Blood and liver tissue samples were collected 24 h after CCl₄ administration for measurement of plasma alanine aminotransferase and aspartate aminotransferase, and concentration of malondialdehyde and glutathione in liver tissue.

Results

Puerarin was the most abundant isoflavone in kudzu vine extract. Kudzu vine extract significantly reduced the cytotoxicity and production of reactive oxygen species induced by t-BHP in a dose-dependent manner. Treatment with 0 % and 30 % ethanolic extracts of kudzu vine significantly lowered the plasma levels of alanine aminotransferase and aspartate aminotransferase in a CCl₄-induced hepatotoxicity rat model (P < 0.05). Glutathione was significantly elevated in the 30 % ethanolic extract-treated group (P < 0.05), while the malondialdehyde level in liver tissue was significantly decreased in the 0 % and 30 % ethanolic extract-treated groups (P < 0.05).

Conclusions

The kudzu vine is potentially highly beneficial in treating liver damage, as it scavenges reactive free radicals and boosts the endogenous antioxidant system.

Phosphorylated Peptides from Antarctic Krill (Euphausia superba) Prevent Estrogen Deficiency Induced Osteoporosis by Inhibiting Bone Resorption in Ovariectomized Rats

In the current study, we investigated the improvement of phosphorylated peptides from Antarctic krill Euphausia superba (PP-AKP) on osteoporosis in ovariectomized rats. PP-AKP was supplemented to ovariectomized Sprague-Dawley rats for 90 days. The results showed that PP-AKP treatment remarkably prevented the reduction of bone mass and improved cancellous bone structure and biochemical properties. PP-AKP also significantly decreased serum contents of tartrate-resistant acid phosphatase (TRACP), cathepsin K (Cath-k), matrix metalloproteinases-9 (MMP-9), deoxypyridinoline (DPD), C-terminal telopeptide of collagen I (CTX-1), Ca, and P. Mechanism investigation revealed that PP-AKP significantly increased the osteoprotegerin (OPG)/receptor activator of nuclear factor κB ligand (RANKL) ratio in mRNA expression, protein expression, and serum content. Further research suggested that NF-κB signaling pathways were inhibited by suppressing the mRNA and protein expressions of nuclear factor of activated T-cells (NFATc1) and tumor necrosis factor receptor-associated factor 6 (TRAF6), diminishing the mRNA expression and phosphorylation of nuclear factor κB p65 (NF-κB p65), three key transcription factors in NF-κB pathways. These results suggest that PP-AKP can improve osteoporosis by inhibiting bone resorption via suppressing the activation of osteoclastogenesis related NF-κB pathways.

Puerarin concurrently stimulates osteoprotegerin and inhibits receptor activator of NF-κB ligand (RANKL) and interleukin-6 production in human osteoblastic MG-63 cells

Puerarin, a daidzein-8-C-glucoside, is the major isoflavone glycoside found in the Chinese herb radix of Pueraria lobata (Willd.) Ohwi, and has received increasing attention because of its possible role in the prevention of osteoporosis. In our previous studies, puerarin reduced the bone resorption of osteoclasts and promoted long bone growth in fetal mouse in vitro. Further study confirmed that puerarin stimulated proliferation and differentiation of osteoblasts in rat. However, the mechanisms underlying its actions on human bone cells have remained largely unknown. Here we show that puerarin concurrently stimulates osteoprotegerin (OPG) and inhibits receptor activator of nuclear factor-κB ligand (RANKL) and Interleukin-6 (IL-6) production by human osteoblastic MG-63 cells containing two estrogen receptor (ER) isotypes. Treatment with the ER antagonist ICI 182,780 abrogates the above actions of puerarin on osteoblast-derived cells. Using small interfering double-stranded RNAs technology, we further demonstrate that the effects of puerarin on OPG and RANKL expression are mediated by both ERα and ERβ but those on IL-6 production primarily by ERα. Moreover, we demonstrate that puerarin may promote activation of the classic estrogen response element (ERE) pathway through increasing ERα, ERβ and steroid hormone receptor coactivator (SRC)-1 expression. Therefore, puerarin will be a promising agent that prevents or retards osteoporosis.

Inhibitory effects of the leaves of loquat (Eriobotrya japonica) on bone mineral density loss in ovariectomized mice and osteoclast differentiation

The loquat, Eriobotrya japonica Lindl. (Rosaceae), is a small tree native to Japan and China that is widely cultivated for its succulent fruit. Its leaves are used as an ingredient of a tasty tea called "Biwa cha" in Japanese. The anti-osteoporosis effects of the leaves of loquat in vitro and in vivo have been investigated. After 15 days of feeding normal diet or diet supplemented with 5% loquat leaves, the body weight, viscera weights, and bone mineral density (BMD) of both groups of eight ovariectomized (OVX) mice were compared. The result showed that the loss of BMD in loquat-fed mice was significantly prevented in three parts of the body, especially in the trabecular bone of the head (P < 0.05), abdomen (P < 0.01), and lumbar (P < 0.05) compared to the control group. No hypertrophy in the uterus by the loquat leaves diet was observed. The effect of the extract (447.25 g) prepared from the dried leaves of loquat (2.36 kg) was further studied on RANKL-induced osteoclast differentiation and cell viability. The extract suppressed the differentiation of osteoclasts under 50, 125, 250, and 500 μg/mL. Through bioactivity-guided fractionation, ursolic acid (1) was isolated and inhibited osteoclast differentiation under 4 and 10 μg/mL. It was concluded that loquat leaves possess the potential to suppress ovariectomy-induced bone mineral density deterioration.

Puerarin attenuates pressure overload-induced cardiac hypertrophy

BACKGROUND

Puerarin is the most abundant isoflavonoid in kudzu root. It has been used to treat angina pectoris and myocardial infarction clinically. However, little is known about the effect of puerarin on cardiac hypertrophy.

METHODS

Aortic banding (AB) was performed to induce cardiac hypertrophy in mice. Puerarin premixed in diets was administered to mice after one week of AB. Echocardiography and catheter-based measurements of hemodynamic parameters were performed at 7 weeks after starting puerarin treatment (8 weeks post-surgery). The extent of cardiac hypertrophy was also evaluated by pathological and molecular analyses of heart samples. Cardiomyocyte apoptosis was assessed by measuring Bax and Bcl-2 protein expression and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. In addition, the inhibitory effect of puerarin (1 μM, 5 μM, 10 μM, 20 μM, 40 μM) on mRNA expression of atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) in Ang II (1 μM)-stimulated H9c2 cells was investigated using quantitative real-time reverse transcription-polymerase chain reaction.

RESULTS

Echocardiography and catheter-based measurements of hemodynamic parameters at 7 weeks revealed the amelioration of systolic and diastolic abnormalities. Puerarin also decreased cardiac fibrosis in AB mice. Moreover, the beneficial effect of puerarin was associated with the normalization in gene expression of hypertrophic and fibrotic markers. Further studies showed that pressure overload significantly induced the activation of phosphoinositide 3-kinase (PI3K)/Akt signaling and c-Jun N-terminal kinase (JNK) signaling, which was blocked by puerarin treatment. Cardiomyocyte apoptosis and induction of Bax in response to AB were suppressed by puerarin. Furthermore, the increased mRNA expression of ANP and BNP induced by Ang II (1 μM) was restrained to a different extent by different concentrations of puerarin.

CONCLUSION

Puerarin may have an ability to retard the progression of cardiac hypertrophy and apoptosis which is probably mediated by the blockade of PI3K/Akt and JNK signaling pathways.

Puerarin stimulates proliferation and differentiation and protects against cell death in human osteoblastic MG-63 cells via ER-dependent MEK/ERK and PI3K/Akt activation

Puerarin, the main isoflavone glycoside found in the Chinese herb radix of Pueraria lobata (Willd.) Ohwi, has received increasing attention because of its possible role in the prevention of osteoporosis. Previously, we showed that puerarin could inhibit the bone absorption of osteoclasts and promote long bone growth in fetal mouse in vitro. Further study confirmed that puerarin stimulated proliferation and differentiation of osteoblasts in rat. However, the mechanisms underlying its actions on human bone cells have not been well defined. Here we show that puerarin increases proliferation and differentiation and opposes cisplatin-induced apoptosis in human osteoblastic MG-63 cells containing two estrogen receptor (ER) isoforms. Puerarin promotes proliferation by altering cell cycle distribution whereas puerarin-mediated survival may be associated with up-regulation of Bcl-xL expression. Treatment with the ER antagonist ICI 182,780 abolishes the above actions of puerarin on osteoblast-derived cells. Using small interfering double-stranded RNA technology, we further demonstrate that the effects of puerarin on proliferation, differentiation and survival are mediated by both ERα and ERβ. Moreover, we also demonstrate that puerarin functions at least partially through activation of MEK/ERK and PI3K/Akt signaling. This agent also shows much weaker effect on breast epithelial cell growth than that of estrogen. Therefore, puerarin will be a promising agent that prevents or retards osteoporosis.