Category Archives: Zinc

Zinc-Carnosine or Zinc Reduce IL-6 in Mouse Osteoblast-Like Cells

Abstract

Zinc suppresses IL-6 synthesis by prostaglandin F2alpha in osteoblasts: inhibition of phospholipase C and phospholipase D.

We previously reported that prostaglandin F2alpha (PGF2alpha) induces phosphoinositide hydrolysis by phospholipase C and phosphatidylcholine hydrolysis by phospholipase D through heterotrimeric GTP-binding protein, resulting in the activation of protein kinase C (PKC) in osteoblast-like MC3T3-E1 cells and that PGF2alpha stimulates the synthesis of interleukin-6 (IL-6) via PKC-dependent p44/p42 mitogen-activated protein (MAP) kinase activation. In the present study, we investigated whether zinc affects the PGF2alpha-induced IL-6 synthesis in these cells. Zinc complex of l-carnosine (l-CAZ) dose-dependently suppressed the PGF2alpha-stimulated IL-6 synthesis. In addition, zinc alone reduced the IL-6 synthesis. L-CAZ suppressed the PGF2alpha-induced p44/p42 MAP kinase phosphorylation. However, the p44/p42 MAP kinase phosphorylation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA), a direct activator of PKC, or NaF, a direct activator of GTP-binding protein, was not affected by l-CAZ. l-CAZ reduced the PGF2alpha-stimulated formation of inositol phosphates and choline. However, l-CAZ did not affect the formation of inositol phosphates or choline induced by NaF. These results strongly suggest that zinc reduces PGF2alpha-induced IL-6 synthesis via suppression of phosphoinositide-hydrolyzing phospholipase C and phosphatidylcholine-hydrolyzing phospholipase D in osteoblasts.

Hatakeyama D, Kozawa O, Otsuka T, Shibata T…
J. Cell. Biochem. 2002
PMID: 11968002

Osteoblasts secrete IL-6 to stimulate osteoclast formation. Reducing IL-6 should help reduce resorption.

Zinc-Carnosine Increases Osteoblast Differentiation in Mesenchymal Cells

Abstract

Effect of beta-alanyl-L-histidinato zinc on the differentiation of C2C12 cells.

Although beta-alanyl-L-histidinato zinc (AHZ) can promote osteoblast differentiation, the molecular mechanism responsible is not fully understood. The purpose of this study was to determine the effect of AHZ on undifferentiating mesenchymal cells. C2C12, a typical pluripotential mesenchymal cell line, was used. The cells were cultured in 5% serum-containing medium to induce differentiation, either with or without the addition of AHZ. Cell lineage was determined by immunostaining of type II myosin heavy chains, alkaline phosphatase (ALPase) activity, mRNA expression of cellular phenotype-specific markers using semi-quantitative reverse transcriptase-polymerase chain reaction, and core binding factor alpha1/runt-related transcription factor-2 (Cbfa1/Runx2) protein synthesis using Western blot analysis. C2C12 cells cultured in the presence of AHZ were strongly inhibited from developing into myoblasts, and showed high ALPase activity that was approximately double that in the vehicle. The expression of mRNA for Cbfa1/Runx2, ALPase, Sox9 and type X collagen was increased markedly by the AHZ-stimulated medium, whereas that of desmin and MyoD mRNA was drastically decreased. AHZ increased Cbfa1/Runx2 protein expression substantially. These results provide clear evidence that AHZ converts the differentiation pathway of C2C12 cells to the osteoblast and/or chondroblast lineage.

Takada T, Suzuki N, Ito-Kato E, Noguchi Y…
Life Sci. Dec 2004
PMID: 15556164

Review: Zinc Compounds in Osteoporosis

Abstract

Role of nutritional zinc in the prevention of osteoporosis.

Zinc is known as an essential nutritional factor in the growth of the human and animals. Bone growth retardation is a common finding in various conditions associated with dietary zinc deficiency. Bone zinc content has been shown to decrease in aging, skeletal unloading, and postmenopausal conditions, suggesting its role in bone disorder. Zinc has been demonstrated to have a stimulatory effect on osteoblastic bone formation and mineralization; the metal directly activates aminoacyl-tRNA synthetase, a rate-limiting enzyme at translational process of protein synthesis, in the cells, and it stimulates cellular protein synthesis. Zinc has been shown to stimulate gene expression of the transcription factors runt-related transcription factor 2 (Runx2) that is related to differentiation into osteoblastic cells. Moreover, zinc has been shown to inhibit osteoclastic bone resorption due to inhibiting osteoclast-like cell formation from bone marrow cells and stimulating apoptotic cell death of mature osteoclasts. Zinc has a suppressive effect on the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-induced osteoclastogenesis. Zinc transporter has been shown to express in osteoblastic and osteoclastic cells. Zinc protein is involved in transcription. The intake of dietary zinc causes an increase in bone mass. beta-Alanyl-L: -histidinato zinc (AHZ) is a zinc compound, in which zinc is chelated to beta-alanyl-L: -histidine. The stimulatory effect of AHZ on bone formation is more intensive than that of zinc sulfate. Zinc acexamate has also been shown to have a potent-anabolic effect on bone. The oral administration of AHZ or zinc acexamate has the restorative effect on bone loss under various pathophysiologic conditions including aging, skeletal unloading, aluminum bone toxicity, calcium- and vitamin D-deficiency, adjuvant arthritis, estrogen deficiency, diabetes, and fracture healing. Zinc compounds may be designed as new supplementation factor in the prevention and therapy of osteoporosis.

Yamaguchi M
Mol. Cell. Biochem. May 2010
PMID: 20035439

Zinc-Carnosine > Zinc at Stimulating Mouse Osteoblasts In Vitro

Abstract

Effect of beta-alanyl-L-histidinato zinc on differentiation of osteoblastic MC3T3-E1 cells: increases in alkaline phosphatase activity and protein concentration.

The effect of beta-alanyl-L-histidinato zinc (AHZ) on bone cell function was investigated in osteoblastic MC3T3-E1 cells. Cells were cultured for 3 days at 37 degrees C in a CO2 incubator in plastic dishes containing alpha-modified minimum essential medium supplemented with 10% fetal bovine serum. After the cultures, the medium was exchanged for that containing 0.1% bovine serum albumin plus AHZ (10(-7)-10(-5) M) or other reagents, and the cells were cultured further for appropriate periods of time. The presence of AHZ (10(-7)-10(-5) M) produced a remarkable increase of alkaline phosphatase activity and protein concentration in osteoblastic cells. Thus increase were seen with the prolonged cultivation (12-21 days). With the culture of 1, 3 and 12 days, the effect of AHZ (10(-6) M) to increase alkaline phosphatase activity and protein concentration was more intensive than the effect of zinc sulfate (10(-6) M). The AHZ effects were completely abolished by the presence of cycloheximide (10(-6) M), indicating that AHZ stimulates protein synthesis in the cells. The present study suggests that AHZ has a stimulatory effect on cell differentiation, and that this effect is partly involved on protein synthesis in osteoblastic cells.

Hashizume M, Yamaguchi M
Mol. Cell. Biochem. Feb 1994
PMID: 8047061

Zinc-Carnosine > Zinc at Increasing Alkaline Phosphatase in Rat Tissue

Abstract

Comparison of the effect of beta-alanyl-L-histidinato zinc and its zinc-chelating ligand on bone metabolism in tissue culture.

The present investigation was undertaken to compare the effects of beta-alanyl-L-histidinato zinc (AHZ) and its zinc-chelating ligands on bone metabolism in tissue culture. Calvaria were removed from 3-week-old male rats and cultured for up to 72 h in Dulbecco’s modified eagle medium containing zinc sulfate, AHZ, di(N-acetyl-beta-alanyl-L-histidinato)zinc (AAHZ), and di(histidino)zinc (HZ). The bone calcium content and alkaline phosphatase activity were significantly increased in the presence of AHZ or AAHZ (10(-8)-10(-5) M). Those increases were seen at 10(-7) to 10(-5) M zinc sulfate and HZ. The bone deoxyribonucleic acid (DNA) content was significantly increased by AHZ or AAHZ with 10(-7) to 10(-5) M, while 10(-7) M zinc sulfate and HZ had no effect. Thus, AHZ and AAHZ had more potent effect than that of zinc sulfate and HZ. The effect of AHZ, AAHZ and HZ (10(-5) M) increasing bone alkaline phosphatase activity was abolished by the presence of 10(-4) M dipicolinate, a chelator of zinc. Moreover, the effect of these zinc compounds on bone metabolic indices was not seen in the presence of 10(-6) M cycloheximide. The present results suggest that the effect of AHZ and AAHZ on bone metabolism is more potent than that of zinc sulfate and HZ.

Yamaguchi M, Kishi S
Biol. Pharm. Bull. Apr 1994
PMID: 8069261

Zinc-Carnosine Stimulates Alkaline Phosphatase in Rat Bone Cells

Abstract

Stimulatory effect of beta-alanyl-L-histidinato zinc on alkaline phosphatase activity in bone tissues from elderly rats: comparison with zinc sulfate action.

The capability of beta-alanyl-L-histidinato zinc (AHZ) to increase alkaline phosphatase activity in the femoral diaphysis from elderly rats was investigated. The femoral-diaphyseal tissues were removed from weanling (3-week-old) and elderly (10-month-old) female rats. Bone tissues were cultured in Dulbecco’s modified Eagle medium (high glucose, 4.5%) supplemented with antibiotics and bovine serum albumin. Among various other bone-stimulating factors (AHZ; 10(-5) M, zinc sulfate; 10(-4) M, sodium fluoride; 10(-3) M, insulin; 10(-8) M, and beta-estradiol; 10(-9) M), AHZ had a potent effect on increasing alkaline phosphatase activity in the diaphyseal tissues from both rat groups. In the bone tissues from elderly rats, the effect was concentration dependent (10(-7) – 10(-5) M). At 10(-5) M the effect of AHZ was seen for a longer time during 72-h culture, although the zinc sulfate (10(-5) M) effect was no longer. The effect of AHZ to increase bone alkaline phosphatase activity was completely abolished by the presence of cycloheximide (10(-6) M). AHZ thus appears able to directly stimulate alkaline phosphatase activity dependent on protein synthesis in the bone tissues from elderly rats.

Kisi S, Yamaguchi M
Biol. Pharm. Bull. Feb 1994
PMID: 8205136

Zinc-Carnosine Can Prevent Bone Loss in Ovariectomized Rats

Abstract

Histomorphological confirmation of the preventive effect of beta-alanyl-L-histidinato zinc on bone loss in ovariectomized rats.

The effect of beta-alanyl-L-histidinato zinc (AHZ), in which zinc is chelated to beta-alanyl-L-histidine, on bone loss was investigated in the femur of ovariectomized rats. AHZ (10, 30 and 100 mg/kg/d) was orally administered to ovariectomized rats for 3 months. Ovariectomy significantly decreased the estradiol concentration in the serum as compared with that from sham-operated rats. This decrease was not altered by the dose of AHZ. The bone ash weight and mineral density in the femur of ovariectomized rats significantly decreased in comparison with those from sham-operated rats. Moreover, the trabecular bone at the femoral metaphysis was clearly decreased by ovariectomy. The decreases in the femoral ash content and mineral density and the metaphyseal trabecular bone were clearly prevented by the tested doses of AHZ (10, 30 and 100 mg/kg/d). The present finding with histomorphological study further supports the view that the administration of AHZ can prevent bone loss by ovariectomy.

Kishi S, Segawa Y, Yamaguchi M
Biol. Pharm. Bull. Jun 1994
PMID: 7951157

Zinc-Carnosine Prevents Bone Loss in Ovariectomized Rats

Abstract

Prolonged administration of beta-alanyl-L-histidinato zinc prevents bone loss in ovariectomized rats.

The effect of beta-alanyl-L-histidinato zinc (AHZ), in which zinc is chelated to beta-alanyl-L-histidine, on bone metabolism was investigated in the femoral diaphysis of ovariectomized rats. AHZ (10, 30 and 100 mg/kg body weight/day) was orally administered to ovariectomized rats for 3 months. Ovariectomy significantly decreased the estradiol concentration in the serum as compared with that from sham-operated rats. This decrease was not altered by the dose of AHZ. The bone volume and dry weight in the femur of ovariectomized rats significantly decreased in comparison with those from sham-operated rats. Moreover, alkaline phosphatase activity, deoxyribonucleic acid (DNA) and calcium contents in the femoral diaphysis were significantly decreased by ovariectomy. The decreases of the femoral volume and dry weight, the femoral-diaphyseal alkaline phosphatase activity, DNA and calcium contents by ovariectomy were completely prevented by the tested doses of AHZ (10, 30 and 100 mg/kg/day). AHZ in the dose range of 10-100 mg/kg/day caused a significant increase in zinc content in the femoral diaphysis of ovariectomized rats. The present study suggests that the prolonged administration of AHZ can prevent bone loss by ovariectomy.

Yamaguchi M, Kishi S
Jpn. J. Pharmacol. Oct 1993
PMID: 8283831 | Free Full Text

Zinc Restores Protein Synthesis in Unloaded Rats

Abstract

Zinc stimulates protein synthesis in the femoral-metaphyseal tissues of normal and skeletally unloaded rats.

The effect of zinc on protein synthesis in the femoral-metaphyseal tissues of normal and skeletally unloaded rats was investigated. Skeletal unloading was designed using the model of hindlimb suspension in rats. Animals were fed for 2 or 4 days during the unloading. [3H]Leucine was added to the reaction mixture containing the 5500 g supernatant fraction of the homogenate prepared from the femoral-metaphyseal tissues. In vitro protein synthesis was significantly decreased in the bone tissues from the rats which had undergone unloading for 2 or 4 days. When the metaphyseal tissues were cultured for 24 h in the presence of zinc sulfate (10(-5) M) or beta-alanyl-L-histidinato zinc (AHZ, 10(-5) M), zinc compounds clearly stimulated protein synthesis in the metaphyseal tissues from the 4-day unloaded rats. The zinc effect was also seen in the metaphyseal tissues from normal rats. The addition of zinc sulfate (10(-5) M) or AHZ (10(-7) to 10(-5) M) into the reaction mixture containing the 5500 g supernatant fraction of metaphyseal homogenate from normal or unloaded rats produced a significant increase in protein synthesis. This increase was clearly inhibited in the presence of cycloheximide (10(-7) M). The present result demonstrates that protein synthesis is impaired in the femoral-metaphyseal tissues of rats with skeletal unloading, and that this impairment is clearly restored by zinc supplementation.

Ehara Y, Yamaguchi M
Res Exp Med (Berl) 1997
PMID: 9089885

Zinc-Carnosine Has Proliferative Effect on Mouse Osteoblasts In Vitro

Abstract

Stimulatory effect of beta-alanyl-L-histidinato zinc on cell proliferation is dependent on protein synthesis in osteoblastic MC3T3-E1 cells.

The effect of beta-alanyl-L-histidinato zinc (AHZ) on bone metabolism was investigated in osteoblastic MC3T3-E1 cells. Cells were cultured for 3 days at 37 degrees C in a CO2 incubator in plastic dishes containing alpha-modified minimum essential medium supplemented with 10% fetal bovine serum. After the cultures, the medium was exchanged for that containing 0.1% bovine serum albumin plus various concentrations of AHZ or other reagents, and the cells were cultured further for appropriate periods of time. The presence of AHZ (10(-7)-10(-5) M) stimulated the proliferation of cells. AHZ (10(-6) and 10(-5) M) increased deoxyribonucleic acid (DNA) content in the cells with 48 hr-culture. This increase was completely blocked by the presence of cycloheximide (10(-6) M) or hydroxyurea (10(-3) M). Also, the presence of cycloheximide (10(-6) M) completely inhibited the AHZ (10(-5) M)-induced increase in the proliferation of cells. Meanwhile, parathyroid hormone (10(-7) M), estrogen (10(-9) M) and insulin (10(-8) M) significantly increased cellular DNA content. However, these hormonal effects clearly lowered in comparison with that of AHZ (10(-5) M). Dibutyryl cyclic AMP (10(-4) M) and zinc sulfate (10(-5) M) did not cause a significant increase in cellular DNA content. The present results support the view that AHZ has a direct specific proliferative effect on osteoblastic cells in vitro and that this effect is dependent on protein synthesis.

Hashizume M, Yamaguchi M
Mol. Cell. Biochem. May 1993
PMID: 8350864