• Journal of Periodontal and Implant Science
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• v.33 no.4
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• pp.585-597
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• 2003

Porphyromonas gingivalis has been implicated as an important periodontophathic bacterium in the etiology and progression of periodontal diseases. It has been reported that P.gingivalis may mediate periodontal destruction not only directly through its virulence factors, but also indirectly by including complex host mediated inflammatory reponses. The purpose of this study was t o evaluate the effects of P.gingivalis on the bone formation and resorption by osteoblasts. For this purpose, after determining the concentration below which sonicated P.gingivalis extracts (SPEs) have no cytotoxicity on mouse calvarial primary osteoblastic (POB) cells, we investigated the effects of SPEs on the alkaline phosphatase (ALP) activity, matrix metalloproteinase (MMP) expression (MMP-2, -9, 13), and prostaglandin $E_2$ ($PGE_2$) release in POB cells by treatment with SPEs below that concentration. The results were as follows; 1. SPEs showed no cytotoxic effect on POB cells up to a concentration of 1 ${\mu}m$/ml. 2. The treatment with SPEs reduced ALP activity in a dose-dependent manner in POB cells, In addition, when we investigated the effect of SPEs (1 ${\mu}m$/ml) on ALP activity for different exposure periods, statistically significant inhibition of ALP activity was shown at 2 days of exposure, and further significant inhibition occurred by extending the periods of exposure. 3. The treatment with SPEs stimulated the gene expression of MMP-9 in POB cells. 4. The pre-treatment with SPEs increased the amount of $PGE_2$ released in POB cells. In summary, the present study shows that P.gingivalis could inhibit osteogenesis and stimulate bone resorption not only by reducing ALP activity but also by increasing MMP-9 mRNA expression in osteoblasts, possibly through an endogenous $PGE_2$ pathway. In addition, our results suggest that if P.gingivalis affects osteoblasts in early differentiation stage, such effects by P. gingivalis could be irreversible.

• Journal of Life Science
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• v.25 no.1
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• pp.113-120
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• 2015

Osteoporosis is a major bone disorder defined as having bone mineral density (BMD) of 2.5 standard deviations or more below the peak bone mass. Osteoporosis will increasingly be a major disorder that faces the aging mankind. It is the result of an imbalance in the bone remodeling system, where bone constantly undergoes a cycle of resorption by osteoclasts and formation by osteoblasts. Estrogen deficiency in women following menopause is identified as the predominant reason that causes disparity in this system. Current medical treatments for osteoporosis include hormone replacement therapy (HRT), biphosphonates, and teriparatide, but have various side effects that raise questions concerning their medical safety and practicality. Alternative treatments involving natural product sources are under study to find a safer therapy. Many natural sources including lactoferrin and isoflavones and numerous traditional herbal medicines exhibit anti-resorptive or anabolic effects on bone and thus show promises to provide therapeutic agents in treating osteoporosis. Unfortunately, the majority of natural product treatments are still in its preliminary stages to prove their efficacy even though the development pace of treatment for osteoporosis is astounding in the past few decades. Further progress in pre-clinical studies and the subsequent clinical studies will someday lead to a breakthrough that takes us another step forward in science.

• Journal of Life Science
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• v.20 no.8
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• pp.1268-1275
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• 2010

This study was carried out to investigate the anti-proliferative activity of solid-state fermented medicinal herbs which include Phellinus baumii. Methanol extracts were prepared from 36 different medicinal herbs and their fermented counterparts. These extracts were used to treat human colorectal HCT116 cell, human embryonic kidney cell HEK-293, pre-adipocyte cell 3T3-L1, and pre-osteoblast cell MC3T3-E1 for 24 hr. At a concentration of 100 ${\mu}g/ml$, the extracts of Amomum villosum, Cnidium officinale Makino, Dendrobium moniliforme, Dictamnus dasycarpus, Diospyros kaki Thunb, Eucommia ulmoides Oliv, Ginkgo biloba L, Magnolia denudata Desrousseaux, Orostachys japonicus, Panax notoginseng, Pharbitis nil Choisy, Polygala tenuifolia and Trichosanthes kirilowii (seed) led to a < 50% decrease in cell proliferation, and mycelium of P. baumii showed a 46.3% decrease in cell proliferation. Meanwhile, the extracts of the 25 fermented herbs showed similar anti-proliferative activities compared to those of individual non-fermented herbs. However, the extracts of the fermented Drynaria fortunei Kunze (1), Lycium chinense Mill (2), Fritillaria thunbergii Miquel (3) and Prunus persica showed increased anti-proliferative activity. The $IC_{50}s$ of (1), (2) and (3) were especially decreased to 28, 85 and 80 ${\mu}g/ml$ from 394, 917 and 149 ${\mu}g/ml$, respectively. Furthermore, the cytotoxicity of the extracts of fermented (1), (2) and (3) against HEK-293, 3T3-L1, and MC3T3-E1was negligible up to 200 ${\mu}g/ml$. These results suggest that solid-state fermentation using the mycellium of P. baumiiproduce potential anti-cancer agents or strengthen the bioactivity of medicinal herbs.

• Journal of Life Science
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• v.28 no.12
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• pp.1448-1454
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• 2018

Insects have been investigated as a novel source of food and biomaterial in several recent studies. However, their osteoblastogenic cell activity has not been sufficiently researched and so, to investigate the potential of this natural material for promoting osteoblastogenesis, we studied the activity of Locusta migratoria ethanol extract (LME) on MG-63 pre-osteoblast cells. The cytotoxicity and proliferation effects of LME on MG-63 cells were measured by MTS assay, and there was no cytotoxicity up to $1,000{\mu}g/ml$. With LME treatment of 500 and $1,000{\mu}g/ml$ for 48 hr, cell proliferation increased to 105% and 116% versus control, respectively. The osteoblastogenic activity of the LME was measured through alkaline phosphatase (ALP) staining at three and five days. As a result, both 500 and $1,000{\mu}g/ml$ LME concentrations were seen to increase ALP activity by more than three times compared with control at three and five days. In addition, the expression level of the osteogenic markers ALP and RUNX2 was markedly increased after LME treatment. These results demonstrate that Locusta migratoria ethanol extract promotes osteoblastogenesis as evidenced by the increased osteogenic markers and suggest that LME may be a potential agent for bone formation and osteoporosis prevention.

• Journal of Life Science
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• v.20 no.4
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• pp.607-613
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• 2010

Osteoporosis is a disease involving a decrease in bone mineral density and an increased risk of fractures. The MC3T3-E1 pre-osteoblastic cell line is a well-accepted model of osteogenesis in vitro. Pine needles have long been used as a traditional health-promoting medicinal food in Korea. In this study, MTT assay, the alkaline phosphatase (ALP) activity and collagen synthesis of osteoblast cells were investigated to determine the effects of pine needle extracts on cell proliferation and differentiation. Pine needle extracts were prepared using hexane, ethanol and water. The effects of the pine needle extracts were examined by comparing the results with those of commercial agents, such as proanthocyanidin. The MC3T3-E1 cells exposed to proanthocyanidin showed increased proliferation in a concentration-dependent manner. The cells exposed to the hexane extract showed a similar increase in proliferation to that observed with proanthocyanidin. The hexane extract showed the highest ALP activity. Moreover, a supplement of pine needle extracts induced collagen synthesis in MC3T3-E1 cells. The pine needle extract produced the highest level of collagen synthesis at concentrations of $10{\sim}50\;{\mu}g/ml$. These results indicate that pine needle extracts have an anabolic effect on bone by promoting osteoblastic differentiation, and may be used in the treatment of common metabolic bone diseases.

• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.169-183
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• 2003

Tooth movement by orthodontic force effects great tissue changes within the periodontium, especially by shifting the blood flow in the pressure side and resulting in a hypoxic state of low oxygen tension. The aim of this study is to elucidate the possible mechanism of apoptosis in response to hypoxia in MC3T3El osteoblasts, the main cells in bone remodeling during orthodontic tooth movement. MC3T3El osteoblasts under hypoxic conditions ($2\%$ orygen) resulted in apoptosis in a time-dependent manner as estimated by DNA fragmentation assay and nuclear morphology stained with fluorescent dye, Hoechst 33258. Pretreatment with Z-VAD-FMK, a pancaspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, completely suppressed the DNA ladder in response to hypoxia. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-1 activity (YVADase) was detected. To confirm what caspases are involved in apoptosis, Western blot analysis was performed using anti-caspase-3 or -6 antibodies. The 10-kDa protein, corresponding to the active products of caspase-3, and the 10-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged cells in which the processing of the full length form of caspase-3 and -6 was evident. While a time course similar to this caspase-3 and -6 activation was evident, hypoxic stress caused the cleavage of lamin A, which was typical of caspase-6 activity. In addition, the stress elicited the release of cytochrome c into the cytosol during apoptosis. Furthermore, we observed that pre-treatment with SB203580, a selective p38 mitogen activated protein kinase inhibitor, attenuated the hypoxia-induced apoptosis. The addition of SB203S80 suppressed caspase-3 and -6-like protease activity by hypoxia up to $50\%$. In contrast, PD98059 had no effect on the hypoxia-induced apoptosis. To confirm the involvement of MAP kinase, JNK/SAPK, ERK, or p38 kinase assay was performed. Although p38 MAPK was activated in response to hypoxic treatment, the other MAPK -JNK/SAPK or ERK- was either only modestly activated or not at all. These results suggest that p38 MAPK is involved in hypoxia-induced apoptosis in MC3T3El osteoblasts.