Ethel H. Alcantara

Andong National University, Antō, Gyeongsangbuk-do, South Korea

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Publications (7)24.95 Total impact

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    ABSTRACT: Background: The accelerated proliferation of vascular smooth muscle cells (VSMCs) is a contributor for atherosclerosis by thickening the vascular wall. Since zinc modulation of VSMC proliferation has not been clarified, this study investigated whether zinc affects VSMC proliferation. Methods and results: Both a rat aorta origin vascular smooth muscle cell line (A7r5 VSMCs) and primary VSMCs which were collected from rat aorta (pVSMCs) were cultured with zinc (0-50 μM Zn) for short- (≤12 d) and long-term (28 d) periods under normal non-calcifying (0 or 1 mM P) or calcifying (>2 mM P) P conditions. Mouse vascular endothelial cells (MS I cells) were also cultured (under 0-50 μM Zn and 10 mM P for 20 d) to compare with VSMC cultures. While during short-term culture of VSMCs, zinc deprivation decreased cell proliferation in a zinc-concentration manner both under non-calcifying and calcifying conditions in A7r5 and pVSMCs (P < 0.05), during long-term cultures (28 d), A7r5 VSMC proliferation was inversely related to medium zinc concentration under normal physiological P conditions (regression coefficient r(2) = -0.563, P = 0.012). The anti-cell proliferative effect of zinc supplementation (>50 μM) was VSMC-specific. Long-term (35 d), low zinc treatment down-regulated JNK expression and activation, while not affecting ERK1/2 MAPK signaling in A7r5 VSMCs. Conclusion: The results showed that chronic zinc deprivation accelerated VSMC proliferation, perhaps due to down-regulation of MAPK-JNK signaling, and that the anti-cell proliferative role of zinc is VSMC-specific. The findings suggested that zinc may have anti-VSMC proliferative properties in atherosclerosis.
    No preview · Article · Feb 2013 · Atherosclerosis
  • Mee-Young Shin · Ethel H. Alcantara · Youn-Moon Park · Soon-Tae Kwon · In-Sook Kwun
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    ABSTRACT: Yam extracts (Dioscorea batatas) have been reported to possess a variety of functions. However, studies on its osteogenic properties are limited. In this study, we investigated the effect of ethanol and water extracts on osteoblast proliferation and bone matrix protein synthesis, type I collagen and alkaline phosphatase (ALP), using osteoblastic MC3T3-E1 cell model. MC3T3-E1 cells were cultured with yam ethanol and water extracts (0̃30 mg/L) within 39 days of osteoblast differentiation period. Cell proliferation was measured by MTT assay. Bone matrix proteins were assessed by the accumulation of type I collagen and ALP activity by staining the cell layers for matrix staining. Also, the secreted (media) matrix protein concentration (type I collagen) and enzyme activity (ALP) were measured colorimetrically. Yam ethanol and water extracts stimulated cell proliferation within the range of 15̃30 mg/L at 15 day treatment. The accumulation of type I collagen in the extracellular matrix, as well as secreted collagen in the media, increased with increasing doses of yam ethanol (3̃15 mg/L) and water (3̃30 mg/L) extracts. ALP activity was not affected by yam ethanol extracts. Our results demonstrated that yam extracts stimulated osteoblast proliferation and enhanced the accumulation of the collagenous bone matrix protein type I collagen in the extracellular matrix. These results suggest that yam extracts may be a potential activator for bone formation by increasing osteoblast proliferation and increasing bone matrix protein type I collagen. Before confirming the osteogenic action of yam, further studies for clarifying how and whereby yam extracts can stimulate this ostegenesis action are required.
    No preview · Article · Dec 2011 · Journal of Food Science and Nutrition
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    ABSTRACT: Zinc is implicated as an activator for bone formation, however, its influence on bone calcification has not been reported. This study examined how zinc regulates the bone matrix calcification in osteoblasts. Two osteoblastic MC3T3-E1 cell subclones (SC 4 and SC 24 as high and low osteogenic differentiation, respectively) were cultured in normal osteogenic (OSM), Zinc deficient (Zn-, 1 μM), or adequate (Zn+, 15 μM) media up to 20 days. Cells (SC 4) were also supplemented with (50 μg/mL) or no ascorbic acid (AA) in combination with Zinc treatment. Zn- decreased collagen synthesis and matrix accumulation. Although AA is essential for collagen formation, its supplementation could not compensate for Zinc deficiency-induced detrimental effects on extracellular matrix mineralization. Zn- also decreased the medium and cell layer alkaline phosphatase ALP activity. This decreased ALP activity might cause the decrease of Pi accumulation in response to Zn-, as measured by von Kossa staining. Ca deposition in cell layers, measured by Alizarin red S staining, was also decreased by Zn(-) . Our findings suggest that zinc deprivation inhibits extracellular matrix calcification in osteoblasts by decreasing the synthesis and activity of matrix proteins, type I collagen and ALP, and decreasing Ca and Pi accumulation. Therefore zinc deficiency can be considered as risk factor for poor extracellular matrix calcification.
    No preview · Article · Oct 2011 · Molecular Nutrition & Food Research
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    ABSTRACT: Diosgenin, a steroid saponin extracted from the root of wild yam (Dioscorea villossa) is claimed to have osteogenic property. However, detailed studies providing evidence to this claim have not been fully undertaken. In this study, we investigated the effect of diosgenin on the osteogenesis of murine MC3T3-E1 osteoblastic cells. Cells were cultured with varying levels of diosgenin (0-10 μM) within 25 days of bone formation period. Diosgenin was found to stimulate proliferation within the range of 0.01-5 μM using MTT assay. The medium and cellular levels of Type 1 collagen and alkaline phosphatase (ALP), both of which are major bone matrix proteins, increased within the low range of diosgenin concentration (>0-3 μM), and this pattern was further confirmed by collagen and ALP staining of the extracellular matrix (ECM). The cellular protein expression of ALP and collagen Type 1 was also increased at 0.1-1 μM diosgenin treatment as analyzed by Western blot. Calcium deposition within the ECM also showed the same pattern as assessed by Alizarin Red S and Von Kossa staining. Bone-specific transcription factor runt-related transcription factor 2 (Runx2) and Runx2-regulated osteopontin protein expressions were induced at low concentration (0.1-1 μM) and again decreased with high diosgenin concentrations. Based on our findings, our study suggests that diosgenin can enhance bone formation by stimulating the synthesis and secretion of Type 1 collagen and ALP and bone marker proteins Runx2 and osteopontin expression. The increased levels of these marker proteins, in turn, can increase the formation of calcium deposits within the ECM thereby increasing bone formation.
    No preview · Article · Feb 2011 · The Journal of nutritional biochemistry
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    ABSTRACT: Red yeast (Monascus purpureus) is used as a traditional hypocholesterolemic dietary food component in Asia due to its bioactive component, lovastatin. Recently, new evidence suggesting that the statins in red yeast enhance bone formation has been reported, but more research is still needed in order to support these claims of osteogenic effects. Therefore, in this study, we hypothesized that red yeast rice (in which red yeast is fermented) can improve osteogenic function through osteoblast cell proliferation and differentiation. We studied the effect of methanol extract of red yeast rice powder (RYRP) on osteoblast proliferation and differentiation by measuring mitochondrial enzyme activity and bone marker alkaline phosphatase (ALP) activity, respectively. Osteoblast-like MC3T3-E1 cells were cultured in various concentrations of RYRP methanol extract (0.001-1 mg/mL) during the osteoblast differentiation period (1, 5, 10, and 15 days). As measured by 3-[4,5-dimethylthiazol-2-y]-2,5-diphenyltetrazolium bromide assay, RYRP extracts stimulated cell proliferation during a 24-hour period, compared to cooked white rice powder extract. The most pronounced effect was observed at the concentration range between 0.075 and 0.1 mg/mL. This RYRP stimulatory effect for cell proliferation was observed during the whole osteogenic period. Cellular (synthesized) ALP activity was increased at a RYRP extract concentration of 0.075 mg/mL during 15 days of culture, but the medium (secreted) ALP activity did not show any significant change. This cellular ALP activity stimulation by RYRP extract was confirmed by the staining of ALP activity on cell matrix layers for matrix calcification. The results imply that RYRP extract may increase osteogenic effect by stimulating cell proliferation and ALP activity in osteoblastic cells.
    Full-text · Article · Jul 2010 · Nutrition research
  • Md. Jahangir Alam · Young-Eun Cho · Ethel H. Alcantara · Hyun-Ju Seo · In-Sook kwun

    No preview · Article · Jan 2009 · The FASEB Journal
  • Ethel H. Alcantara · Young-Eun Cho · Md. Jahangir Alam · In-Sook kwun

    No preview · Article · Jan 2009 · The FASEB Journal