Hui-Hui Xiao

Flavonoids from Herba epimedii selectively activate estrogen receptor alpha (ERα) and stimulate ER-dependent osteoblastic functions in UMR-106 cells.

Total flavonoids in Herba epimedii (HEP) have been demonstrated to protect against bone loss and bone deterioration associated with estrogen deficiency without exerting any uterotrophic effects. However, it is unclear how flavonoids in HEP exert their protective effects on bone and if different flavonoids exert estrogenic actions in bone cells via similar mechanism of actions. The present study aims to investigate the bone anabolic effects of four major flavonoids isolated from HEP, namely icariin, baohuoside-I, epimedin B and sagittatoside A as well as the mechanism involved in mediating their estrogenic actions in rat osteoblastic-like UMR-106 cells. All tested compounds significantly stimulated the cell proliferation rate, alkaline phosphate (ALP) activity and osteoprotegerin (OPG)/receptor activator of nuclear factor κ-B ligand (RANKL) mRNA expression in UMR-106 cells and their effects could be abolished by co-incubation with 10(-6)M ICI 182,780. None of the flavonoids exhibited binding affinities toward ERα and ERβ. However, sagittatoside A selectively activated estrogen response element (ERE)-luciferase activity via ERα. In addition, icariin and sagittatoside A induced ERα phosphorylation at serine 118 residue. Taken together, our results indicated that all four flavonoids from HEP stimulated ER-dependent osteoblastic functions in UMR-106 cells, but only two of them appeared to exert their actions by ligand-independent activation of ERα. Our study provides evidence to support the hypothesis that the estrogen-like protective effects on bone by flavonoids are mediated via mechanisms that are distinct from the classical actions of estrogen.

Doxorubicin-loaded biodegradable self-assembly zein nanoparticle and its anti-cancer effect: Preparation, in vitro evaluation, and cellular uptake.

Cancer is one top leading cause of the deaths worldwide. Various anticancer drugs, which can effectively kill cancer cells, have been developed in the last decade. However, the problem is still about the low therapeutic index of the drugs, which means that the effective dose of drugs will cause cytotoxicity to normal cells. A strategy based on drug nano-encapsulation is applied to achieve an effective anti-cancer therapy. In this study, we use zein, which is an amphiphilic protein, to make the anti-cancer drug nano-encapsulation. Doxorubicin (DOX), a popular anti-cancer drug, is selected as the core drug. The results show that DOX could be successfully encapsulated into zein to form spherical nanoparticles. The encapsulation efficiency and loading efficiency could reach as high as 90.06% and 15.01 mg/g, respectively. The cumulative release result showed a desired pH-responsible release behavior: DOX could be released faster in acidic buffer solutions (pH 5.0 and 6.5) than neutral one (pH 7.4). The effects of the nano-encapsulation on the anti-proliferation of HeLa cells were also examined. It indicated that, compared with free DOX, the DOX-loaded zein nanoparticles (DOX-zein-NPs) had a better effect on cancer cell killing at low DOX concentrations. We also investigated the cellular uptake of DOX-zein-NPs using confocal laser scanning microscopy (CLSM), flow cytometry, and transmission electron microscopy (TEM). And the endocytosis mechanism of DOX-zein-NPs entering into HeLa cells was studied using various endocytosis pathway inhibitors.

New lignans from the bioactive fraction of Sambucus williamsii Hance and proliferation activities on osteoblastic-like UMR106 cells

Four new lignans (1, 7-9), together with nine known ones, were isolated from the anti-osteoporosis fraction of the extract of Sambucus williamsii Hance which was eluted by 50% and 95% aqueous ethanol over D101 macroporous resin column. Their structures were elucidated by NMR spectroscopic analyses, and the absolute configurations of all compounds were determined by application of circular dichroism method. All the compounds were reported for the first time from the Sambucus genus and firstly studied for their proliferation effects on osteoblastic-like UMR 106 cell. The data showed that compounds 2-9 significantly promoted cell proliferation in some dose, especially compounds 2, 3, 4, 5, and 7 increased osteoblastic cell numbers by 31.3%, 28.3%, 25.6%, 25.1% and 26.0% at 10(-10) M, 10(-10) M, 10(-7) M, 10(-10) M and 10(-10) M, respectively, which suggested that lignans were the components accounting for the bone protective effects of SWH.

Vanillic acid exerts oestrogen-like activities in osteoblast-like UMR 106 cells through MAP kinase (MEK/ERK)-mediated ER signaling pathway

Sambucus williamsii Hance (SWH) has been used for treatment of bone and joint disease in China for thousands of years. Our previous study showed that SWH extract and its bioactive fraction could effectively prevent oestrogen-deficiency induced bone loss in ovariectomized mice. The present study aimed to study the bone protective effects of vanillic acid (VA), a phenolic acid isolated from the bioactive fraction of SWH, and to characterize the signaling pathways that mediated its actions in rat osteoblast-like UMR 106 cells. VA significantly stimulated proliferation, alkaline phosphatase (ALP) activities as well as significantly altered the mRNA expression of genes involved in osteoblast functions and osteoclastogenesis in UMR 106 cells. Co-treatment of UMR 106 cells with 10(-6)M ICI182,780 (a specific oestrogen receptor (ER) antagonist) abolished the stimulatory effects of VA on osteoblast proliferation and ALP activities, suggesting the role of ER in mediating its actions. However, VA (10(-12) to 10(-6)M) failed to bind to ERα or ERβ and did not activate oestrogen response element (ERE)-luciferase activities via ERα or ERβ in UMR 106 cells. In contrast, 10(-10) and 10(-8)M of VA induced the phosphorylation of MEK 1/2, ERK1/2 and ERα at Ser118 residue in UMR 106 cells, suggesting that MAP kinase-mediated pathway is involved in mediating its actions. Taken together, our results indicated that VA is a bioactive compound in SWH that exerts stimulatory effects in osteoblast-like cells via non-genomic, but not classical, ER signaling pathway.

Neuroprotective effects of total flavonoid fraction of the Epimedium koreanum Nakai extract on dopaminergic neurons: In vivo and in vitro

Flavonoids, the active components of Epimedii Genus, have been demonstrated to protect against osteoporosis, cardiovascular diseases and rheumatoid arthritis. The present study aimed to investigate the neuroprotective effects of total flavonoid (TF) fraction of Epimedium koreanum Nakai on dopaminergic neurons in the cellular and mice models of Parkinsons disease (PD). TF pretreatment could ameliorate the decrease of striatal dopamine (DA) content and the loss of tyrosine hydroxylase (TH)-immunoreactive neurons in the substantia nigra pars compacta (SNpc) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). TF treatment could reverse the changes of Bcl-2 and Bax protein expressions in the striatum of PD mice. 1-Methyl-4-phenylpyridinium ion (MPP+) significantly decreased the cell viability and mitochondrial membrane potential in MES23.5 cells. These effects could be reversed by TF treatment. In addition, MPP+-induced changes of Bcl-2 and Bax mRNA and protein expressions were also reversed by TF pretreatment. These data demonstrated that TF of E. koreanum Nakai could protect against MPTP-induced dopaminergic neuronal death in mice and MPP+-induced neurotoxicity in dopaminergic MES23.5 cells. Anti-apoptosis might be involved in this process.

Differential response of bone and kidney to ACEI in db/db mice: A potential effect of captopril on accelerating bone loss

The components of renin-angiotensin system (RAS) are expressed in the kidney and bone. Kidney disease and bone injury are common complications associated with diabetes. This study aimed to investigate the effects of an angiotensin-converting enzyme inhibitor, captopril, on the kidney and bone of db/db mice. The db/db mice were orally administered by gavage with captopril for 8weeks with db/+ mice as the non-diabetic control. Serum and urine biochemistries were determined by standard colorimetric methods or ELISA. Histological measurements were performed on the kidney by periodic acid-schiff staining and on the tibial proximal metaphysis by safranin O and masson-trichrome staining. Trabecular bone mass and bone quality were analyzed by microcomputed tomography. Quantitative polymerase chain reaction and immunoblotting were applied for molecular analysis on mRNA and protein expression. Captopril significantly improved albuminuria and glomerulosclerosis in db/db mice, and these effects might be attributed to the down-regulation of angiotensin II expression and the expression of its down-stream profibrotic factors in the kidney, like connective tissue growth factor and vascular endothelial growth factor. Urinary excretion of calcium and phosphorus markedly increased in db/db mice in response to captopril. Treatment with captopril induced a decrease in bone mineral density and deterioration of trabecular bone at proximal metaphysis of tibia in db/db mice, as shown in the histological and reconstructed 3-dimensional images. Even though captopril effectively reversed the diabetes-induced changes in calcium-binding protein 28-k and vitamin D receptor expression in the kidney as well as the expression of RAS components and bradykinin receptor-2 in bone tissue, treatment with captopril increased the osteoclast-covered bone surface, reduced the osteoblast-covered bone surface, down-regulated the expression of type 1 collagen and transcription factor runt-related transcription factor 2 (markers for osteoblastic functions), and up-regulated the expression of carbonic anhydrase II (marker for bone resorption). Captopril exerted therapeutic effects on renal injuries associated with type 2 diabetes but worsened the deteriorations of trabecular bone in db/db mice; the latter of which was at least in part due to the stimulation of osteoclastogenesis and the suppression of osteogenesis by captopril.

Two new phenylpropanoids and one new sesquiterpenoid from the bioactive fraction of Sambucus williamsii

Two new phenylpropanoids, samwirin (1) and samwiphenol (2), and a new sesquiterpenoid, 2β,4β,10α-trihydroxy-1αH,5βH-guaia-6-ene (3), together with six known compounds were isolated from the bioactive fraction of Sambucus williamsii Hance. Their structures including the absolute configurations were characterized on the basis of extensive 1D, 2D-NMR, MS, and CD spectral data. In vitro proliferation effects of all compounds on osteoblast-like UMR 106 cells were examined. Compounds 1, 4–9 significantly promoted cell proliferation. Compounds 5, 6, and 8 increased osteoblastic cell numbers separately by 24.3%, 25.2%, and 29.1% at 10–10 M, 10–10 M, and 10–8 M, respectively.

A Metabolomics Study on the Bone Protective Effects of a Lignan-Rich Fraction From Sambucus Williamsii Ramulus in Aged Rats

The lignan-rich fraction (SWR) of Sambucus Williamsii Ramulus, a folk herbal medicine in China for treatment of bone diseases, has previously reported to exert protective effects on bone without exerting uterotrophic effects in ovariectomized (OVX) mice. The aim of the present study was to identify the potential metabolites and the associated metabolic pathways that contribute to the beneficial effects of SWR on bone in vivo. Aged female Sprague Dawley rats (9 months old) were either sham-operated or ovariectomized for 12 weeks, before receiving treatment for another 12 weeks with the following treatment groups (n = 12 each): vehicle (Sham), vehicle (OVX), Premarin (130 μg/kg) or low (57 mg/kg), medium (114 mg/kg), and high (228 mg/kg) doses of SWR. The results showed that SWRH significantly suppressed bone loss, improved bone micro-architecture and increased bone strength on tibia without stimulating uterus weight gain in OVX rats. Premarin exerted similar bone protective effects as SWRH but elicited uterotrophic effects in OVX rats. The metabolic profiles of serum samples were analyzed by using ultra-performance liquid chromatography quadrupole time-of flight mass spectrometry and gas chromatography time-of flight mass spectrometry, and the metabolites that were significantly altered were identified by multivariate statistical analysis. Our study indicated that SWRH effectively restored the changes of 26 metabolites induced by estrogen-deficiency in OVX rats, which related to lipids, amino acids, tryptophan metabolisms, and anti-oxidative system. A subsequent validation showed that the serum level of superoxide dismutase and catalase were indeed up-regulated, while the serotonin level in a tryptophan hydroxylase 1 (TPH1) high expressing cells (rats RBL-2H3 cells) was down regulated after treatment with SWR. The results also suggested that the gut-microbiota may play an important role on the bone protective effects of SWR. The current study provides insight for understanding the unique mechanism of actions of SWR that might be involved in achieving bone protective effects in vivo.

Bone Protective Effects of Danggui Buxue Tang Alone and in Combination With Tamoxifen or Raloxifene in vivo and in vitro

Danggui Buxue Tang (DBT), a traditional Chinese Medicine decoction containing Astragali Radix (AR) and Angelicae Sinensis Radix (ASR), is commonly prescribed for women in China as a remedy for menopausal symptoms. Previous study indicated that DBT stimulated cell growth and differentiation of human osteosarcoma MG-63 cells and exhibited estrogenic properties via estrogen receptors (ERs). The present study aimed to study the bone protective effects of DBT and its potential interactions with selective estrogen receptor modulators (SERMs, tamoxifen and raloxifene) in both in vivo and in vitro models as they act via similar ERs. Six-month-old Sprague-Dawley rats were randomly assigned to the following treatments for 12 weeks: (1) sham-operated control group with vehicle (sham), (2) ovariectomized group with vehicle (OVX), (3) OVX with 17β-estradiol (E2, 2.0 mg/kg day), (4) OVX with tamoxifen (Tamo, 1.0 mg/kg day), (5) OVX with raloxifene (Ralo, 3.0 mg/kg day), (6) OVX with DBT (DBT, 3.0 g/kg day), (7) OVX with DBT+Tamoxifen (DBT+Tamo), and (8) OVX with DBT+Raloxifene (DBT+Ralo). Effects of DBT and potential interactions between DBT and SERMs were also evaluated in MG-63 cells. DBT, tamoxifen, raloxifene, and their combinations significantly increased bone mineral density (BMD) and improved trabecular bone properties, including bone surface (BS), trabecular bone number (Tb.N), and trabecular bone separation (Tb.Sp), as well as restored changes in bone turnover biomarkers and mRNA expression of genes involved in bone metabolism in OVX rats. Furthermore, DBT, SERMs, and their combinations significantly increased serum estradiol and suppressed follicle stimulating hormone and luteinizing hormone in OVX rats, suggesting the possible involvement of the hypothalamus–pituitary–gonadal axis in mediating their bone protective effects. However, SERMs, but not DBT, significantly increased uterus index in OVX rats. DBT significantly induced ALP activity and estrogen response element-dependent transcription in MG-63 cells. Our study demonstrated that DBT alone and in combinations with SERMs could exert bone protective effects in vitro and in vivo.

A Lignan-Rich Bioactive Fraction of Sambucus williamsii Hance Exerts Oestrogen-Like Bone Protective Effects in Aged Ovariectomized Rats and Osteoblastic Cells

Sambucus williamsii Hance as a folk medicine has been used for the treatment of bone and joint diseases for thousands of years in China. The present study aims to examine the effects of the bioactive fraction (SWC) of S. williamsii on bone in aged OVX rats, identify the major bioactive components in SWC and circulation post-ingestion, and investigate the mechanism involved in its bone protective effects. The results indicated that the lignan-rich fraction SWC is effective in protection against ovariectomy induced bone loss in aged rats and its actions might be mediated by the direct oestrogen-like action of lignan on osteoblasts.