Chemical Constituents from Berchemia polyphylla var. Leioclada.

One previously undescribed naphthoquinone-benzisochromanquinone dimer berpolydiquinone A (1), along with two previously undescribed naphthoquinone-anthraquinone dimers berpolydiquinones B and C (2-3), and one previously undescribed dimeric naphthalene berpolydinaphthalene A (4), were isolated from the stems and leaves of Berchemia polyphylla var. leioclada. The chemical structures of these compounds were determined using high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS), spectroscopic data, the exciton chirality method (ECM), and quantum chemical calculation. Notably, compounds (1-2 and 5) are dimeric quinones that share the same naphthoquinone moiety, specifically identified as 2-methoxystypandron. Compound (4) is a derivative of dimeric naphthalene with a symmetrical structure, which is a new structure type isolated from B. polyphylla var. leioclada for the first time. These findings suggest that B. polyphylla var. leioclada serves as a significant reservoir of structurally diverse phenolic compounds. This study provides a scientific foundation for regarding B. polyphylla var. leioclada as a potential source of "Tiebaojin".

Anthraquinone-benzisochromanquinone dimers from the stems and leaves of Berchemia polyphylla.

Three new anthraquinone-benzisochromanquinone dimers polyphylldiquinones A-C (1-3), along with three known analogs floribundiquinone A-B (4-5) and 7-dehydroxyventiloquinone H (6), were isolated from the stems and leaves of Berchemia polyphylla. The chemical structures and absolute configurations of these compounds were determined using HR-ESI-MS, spectroscopic data, and electronic circular dichroism. Notably, compounds (1-5) are dimeric quinones that share the same benzisochromanquinone moiety, specifically identified as 7-dehydroxyventiloquinone H (6), which was the first time to report as a natural product. Compounds 1-2 and compounds 4-5 are two pairs of atropisomers respectively.

Daidzein stimulates osteogenesis facilitating proliferation, differentiation, and antiapoptosis in human osteoblast-like MG-63 cells via estrogen receptor-dependent MEK/ERK and PI3K/Akt activation.

Daidzein, a natural soy isoflavone, has a structure similar to estradiol and exhibiting bone-sparing effects against osteoporosis. However, the molecular mechanisms of osteogenesis remain unclear. We hypothesized that daidzein stimulates osteogenesis through estrogen receptor (ER)-dependent signal pathways. To test this hypothesis, we investigated the effects of daidzein compared with 17ß-estradiol on proliferation, differentiation, and cisplatin-induced apoptosis in human osteoblast-like MG-63 cells containing 2 ER isoforms. The results showed that daidzein stimulated cell proliferation by altering cell cycle distribution, promoted cell differentiation by increasing the alkaline phosphatase activity and collagen content, and reduced cell apoptosis associated by up-regulating the expression of Bcl-xL. The above actions of daidzein were prevented by cotreatment with the ER antagonist ICI 182780. Using small interfering RNA technology, we further demonstrated that the effects of daidzein on alkaline phosphatase activity, collagen content, and cell apoptosis are mediated by both ERα and ERß, whereas the effects on cell proliferation are primarily mediated by ERα. However, the effects of 17ß-estradiol on osteoblastic proliferation and survival are mediated by both ER isotypes, and the effects on osteoblastic differentiation are primarily mediated by ERα. The use of specific inhibitors indicated that activation of the mitogen-activated protein kinase kinase/extracellular regulated kinase (MEK/ERK) and phosphoinositide 3-kinase/protein kinase B or PKB (PI3K/Akt) signaling pathway at least partially accounts for these effects of daidzein. Taken together, the results indicate that daidzein stimulates osteogenesis through facilitating proliferation, differentiation, and antiapoptosis in human osteoblast-like MG-63 cells via activation of MEK/ERK and PI3K/Akt in an ER-dependent manner.

Expression of the NLRP3 Inflammasome in Carotid Atherosclerosis.

BACKGROUND: The aim of the present study was to investigate NLRP3 inflammasome expression in human carotid atherosclerotic plaques and its relationship to plaque vulnerability. METHODS: Carotid atherosclerotic plaques collected from 30 patients scheduled for carotid endarterectomy (CEA) were subjected to immunohistochemical, mRNA, and protein expression studies. Ten mesenteric arteries from intestinal cancer patients served as controls for the immunohistochemical studies. Twenty individuals who had no carotid stenosis or coronary artery stenosis served as controls for analyzing atherosclerotic risk factors and for enzyme-linked immunosorbent assay (ELISA) studies. Serum samples were collected from all patients to determine interleukin-1ß (IL-1ß) and IL-18 levels. RESULTS: The NLRP3 inflammasome signaling pathway components NLRP3, ASC, caspase-1, IL-1ß, and IL-18 were strongly expressed in carotid atherosclerotic plaques, but not in healthy mesenteric arteries. Immunohistochemical, mRNA, and protein expression studies revealed higher expression levels of NLRP3, ASC, caspase-1, IL-1ß, and IL-18 in unstable compared to stable plaques. The NLRP3 inflammasome was localized in the cytoplasm of macrophages and foam cells and was associated with cholesterol crystal clefts inside and outside of cells. ELISA showed that the serum levels of the cytokines IL-1ß and IL-18 were higher in the CEA group compared to controls. CONCLUSIONS: These results demonstrated for the first time the close relationship between the expression of NLRP3 signaling pathway and human carotid atherosclerotic plaques. NLRP3, ASC, caspase-1, IL-1ß, and IL-18 were associated with plaque vulnerability and atherogenesis. The serum levels of IL-1ß and IL-18 may be useful predictors of atherosclerosis.

ZM-66, a new podophyllotoxin derivative inhibits proliferation and induces apoptosis in K562/ADM cells.

OBJECTIVE: To investigate the anti-tumor effect of ZM-66 on multidrug-resistant leukemic cell line K562/ADM. METHODS: The K562/ADM cells were treated with varying concentrations (0, 1, 2, 4 × 10⁻³ mmol/L) of ZM-66 or etoposide for 24 hours. The proliferation was detected by Sulforhodamine B Sodium Salt (SRB) assay and apoptosis was detected by flow cytometry analysis and fluorescent staining. In addition, the expression levels of p53 and bax genes in K562/ADM cells were detected by RT-PCR analysis. The level of P-glycoprotein (P-gp), P53 and Bax protein in K562/ADM cells were detected by Western blot assay. RESULTS: SRB assay demonstrated that etoposide had little inhibitory effect on K562/ADM cells, whereas ZM-66 (1, 2, 4 × 10⁻³ mmol/L) had significantly inhibitory effect on K562/ADM cells (all P<0.01). The acridine orange/propidium iodide dual staining showed that there were typical condensation of chromatin and nuclear fragmentation nuclei with red color in ZM-66 treated cells. Flow cytometric analysis showed that there was a significantly increase of apoptotic cells in K562/ADM cells after treated with ZM-66. RT-PCR showed that the p53 and bax mRNA expression levels in K562/ADM cells treated with ZM-66 at 1, 2, 4 × 10⁻³ mmol/L were higher than those in the cell without treatment. Western blot showed that the P53 and Bax protein expression levels in K562/ADM cells treated with ZM-66 at 2, 4 × 10⁻³ mmol/L were higher than those in the cell without treatment. But the P-gp protein expression level in K562/ADM cells treated with ZM-66 at 2, 4 × 10⁻³ mmol/L was gradually lower than those in the cell without treatment. CONCLUSION: ZM-66 is able to induce cell death by apoptosis in vitro, as a result of the reverse of the apoptosis resistance in drug-resistant K562/ADM cells by modulating expression of key factors associated with apoptosis induction.

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 ERß 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, ERß and steroid hormone receptor coactivator (SRC)-1 expression. Therefore, puerarin will be a promising agent that prevents or retards osteoporosis.

CXCR7 upregulation is required for early endothelial progenitor cell-mediated endothelial repair in patients with hypertension.

Dysfunction of early endothelial progenitor cells (EPCs) is responsible for impaired endothelial repair capacity after arterial injury in patients with hypertension. Here, we hypothesized that diminished signaling of CXC chemokine receptor 7 (CXCR7) contributes to the reduced EPC functions, and enhanced CXCR7 expression restores the capacities of EPCs from hypertensive patients. CXCR7 expression of EPCs from hypertensive patients was significantly reduced when compared with that from healthy subjects. Meanwhile, the phosphorylation of p38 mitogen-activated protein kinase, a downstream signaling of CXCR7, was elevated, which increased cleaved caspase-3 level of EPCs. CXCR7 gene transfer augmented CXCR7 expression and decreased the phosphorylation of p38 mitogen-activated protein kinase, which was paralleled to EPC functional upregulation of in vitro adhesion, antiapoptosis activities, and in vivo re-endothelialization capacity in a nude mouse model of carotid artery injury. The enhanced in vitro and in vivo functions of EPCs were markedly inhibited by neutralizing monoclonal antibody against CXCR7, which was blocked by p38 mitogen-activated protein kinase inhibitor SB203580. Downregulation of cleaved caspase-3 level induced by CXCR7 gene transfer or SB203580 pretreatment improved EPC functions. Furthermore, we found that lercanidipine, a dihydropyridine calcium channel antagonist, enhanced CXCR7 expression and facilitated in vitro and in vivo functions of EPCs. Our study demonstrated for the first time that diminished CXCR7 signal at least partially contributes to the reduced in vitro functions and in vivo re-endothelialization capacity of EPCs from hypertensive patients. Upregulation of CXCR7 expression induced by gene transfer or lercanidipine treatment may be a novel therapeutic target for increased endothelial repair capacity in hypertension.

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 ERß. 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.

[Effect of geniposide on serum IL-1beta and TNF-alpha of rheumatoid arthritis rats].

OBJECTIVE: To study the effect of geniposide on serum IL-1beta and TNF-alpha levels of rheumatoid arthritis rats, as well as the mechanism of this drug. METHOD: To establish an experimental rat model of type II collagen-induced arthritic (CIA). The inhibitory effects on paw edema were observed, and serum IL-1beta and TNF-alpha levels were determined in experimental rats. RESULT: Compared with the model, geniposide delayed the starting time of right paw edema significantly, and the levels of serum IL-1beta and TNF-alpha were significantly decreased by geniposide at high dose or medium dose (P < 0.01). CONCLUSION: Geniposide can lower serum IL-1beta and TNF-alpha levels in rheumatoid arthritis rats. The effect may be close related to inhibitory development of rheumatoid arthritis by the agent.