• 생약학회지
• /
• 제26권2호
• /
• pp.139-147
• /
• 1995

Crinum asiaticum var. japonicum is a wild plant growing only in Jeju-island, Korea, and in Japan. The whole part of this plant has been known to have the pharmacological actions such as analgesic, anti-inflammatory, platelet-aggregation inhibitory, antitussive, and expectorant. With these assumed actions, the leaves (Crinum folium) of this plant has been used in the folk remedies for arthritis and arthralgia. There is, however, no scientific evidences for the pharmacological actions of Crinum asiaticum var. japonicum. In the present study, the analgesic, anti-inflammatory, and platelet-aggregation inhibitory actions of Crinium folium were evaluated using writhing test, tail-flick test, carrageenin antiedema test, in vitro thromboxane $B_2$ quantitation assay and in vitro platelet aggregation test. In order to obtain the partially purified fraction whose pharmacological action is excellent, the methanol extract of Crinium folium was fractionated consecutively into four biological fractions such as ether, ethyl acetate, butanol, and water fractions and their pharmacological actions of the fractions were investigated. Putting our results together, Crinium folium, especially ethyl acetate fraction was proven to have significant analgesic, anti-inflammatory and platelet-aggregation inhibitory actions by inhibition of prostanoids biosynthesis as one of its mechanism of action.

• E2M - 전기 전자와 첨단 소재
• /
• 제14권12호
• /
• pp.3-6
• /
• 2001

In common globular proteins, the native form is n its most stable state. However, the native form of inhibitory serpins (serine protease inhibitors) and some viral membrane fusion proteins is in a metastable state. Metastability in these proteins is critical to their biological functions. Our previous studies revealed that unusual interactions, such as side-chain overpacking, buried polar groups, surface hydrophobic pockets, ad internal cavities are the structural basis of the native metastability. To understand the mechanism by which these structural defects regulate protein functions, cavity-filling mutations of $\alpha$1-antitrypsin, a prototype serpin, were characterized. Increasing conformational stability is correlated with decreasing inhibitory activity. Moreover, the activity loss appears to correlate with the decrease in the rate of the conformational switch during complex formation with a target protease. We also increased the stability of $\alpha$1-antitrypsin greatly via combining various stabilizing single amino acid substitutions that were distributed throughout the molecule. The results showed that a substantial increase of stability, over 13 kcal/mol, affected the inhibitory activity with a correlation of 11% activity loss per kcal/mol. The results strongly suggest that the native metastability of proteins is indeed a structural design that regulates protein functions and that the native strain of $\alpha$1-antitrypsin distributed throughout the molecule regulates the inhibitory function in a concerted manner.

• 한방안이비인후피부과학회지
• /
• 제16권2호
• /
• pp.96-118
• /
• 2003

The effect of Glycyrrhizae Radix water extract, known as depigmenting agent, on melanin biosynthesis was investigated in cellular level by using B16 mouse melanoma cells. The inhibitory effect of Glycyrrhizae Radix water extract on melanogenesis was determined by mushroom tyrosinase assay traditionally using in vitro screening test. To determine whether Glycyrrhizae Radix water extract suppress melanin synthesis in cellular level, B16 mouse melanoma cells were cultured in the presence of different concentrations of Glycyrrhizae Radix water extract. Effects on cell proliferation, melanin biosynthesis, tyrosinase activity, DOPAchrome tautomerase activity, and expression level of mRNA for tyrosinase were examined. The maximum concentration of Glycyrrhizae Radix water extract that was not inhibitory to growth of the cells was 2 mgml. At that concentration, melanin synthesis was significantly inhibited without cytotoxicity after 5 days, compared with untreated cells. The treatment with Glycyrrhizae Radix water extract reduced tyrosinase and DOPAchrome tautomerase activity in a dose-dependent manner. However, the treatment with Glycyrrhizae Radix water extract did not affect significantly mRNA levels for tyrosinase. These results suggest that the inhibitory effect of Glycyrrhizae Radix water extract on melanogenesis is correlated with the suppression of tyrosinase and DOPAchrome tautomerase activity more than altering mRNA levels of tyrosinase.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집
• /
• pp.3-6
• /
• 2001

In common globular proteins, the native form is in its most stable state. However, the native form of inhibitory serpins (serine protease inhibitors) and some viral membrane fusion proteins is in a metastable state. Metastability in these Proteins is critical to their biological functions. Our previous studies revealed that unusual interactions, such as side-chain overpacking, buried polar groups, surface hydrophobic pockets, and internal cavities are the structural basis of the native metastability. To understand the mechanism by which these structural defects regulate protein functions, cavity-filling mutations of ${\alpha}$1-antitrypsin, a prototype serpin, were characterized. Increasing conformational stability is correlated with decreasing inhibitory activity. Moreover, the activity loss appears to correlate with the decrease in the rate of the conformational switch during complex formation with a target protease. We also increased the stability of ${\alpha}$1-antitrypsin greatly via combining various stabilizing single amino acid substitutions that were distributed throughout the molecule. The results showed that a substantial increase of stability, over 13 kcal/mol, affected the inhibitory activity with a correlation of 11% activity loss per kcal/mol. The results strongly suggest that the native metastability of proteins is indeed a structural design that regulates protein functions and that the native strain of e 1-antitrypsin distributed throughout the molecule regulates the inhibitory function in a concerted manner.

• Corrosion Science and Technology
• /
• 제22권1호
• /
• pp.1-9
• /
• 2023

This work studied the inhibitory effect of the combination of benzoate-intercalated hydrotalcite (HT-BZ) and Ce³⁺-loaded clay (Clay-Ce) on carbon steel (CS). HT-BZ was prepared by the co-precipitation method and Clay-Ce was fabricated by a cation exchange reaction. HT-BZ and Clay-Ce were assessed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) coupled with zeta potential measurement. Electrochemical measurements coupled with scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) were used for studying the inhibitory action of the mixture of HT-BZ and Clay-Ce on steel electrodes immersed in 0.1 M NaCl. For comparison, the inhibitory effect of HT-BZ or Clay-Ce alone was also evaluated. The results showed that HT-BZ combined with Clay-Ce provided synergistic inhibition of the CS substrate. The mixture of 0.5 g/L HT-BZ + 0.5 g/L Clay-Ce provided 93.5% inhibition efficiency. The protective mechanism of the HT-BZ + Clay-Ce mixture consisted of the reaction of released BZ and Ce³⁺ and the deposition of HT-BZ and Clay-Ce structures on the CS substrate.

• 한국약용작물학회:학술대회논문집
• /
• 한국약용작물학회 2007년도 추계학술발표회
• /
• pp.293.2-293.2
• /
• 2007

• Biomolecules & Therapeutics
• /
• 제18권4호
• /
• pp.442-447
• /
• 2010

This study was conducted to determine whether treatment with the anti-inflammatory eupatilin influences intestinal smooth muscle contraction stimulated by carbachol and, if so, to investigate the related mechanism. Denuded ileal or colonic muscles from Sprague-Dawley rats were used for the study and measurements of isometric contractions were obtained using a computerized data acquisition system; this data was also combined with results from molecular experiments. Eupatilin from Artemisia asiatica Nakai significantly decreased carbachol-induced contractions in both ileal and colonic muscles. Interestingly, eupatilin decreased carbachol-induced phosphorylation of ERK1/2 more significantly than that of MYPT1 at Thr855 in ileal and colonic muscles. However, eupatilin significantly decreased phosphorylation of MYPT1 at Thr855, but only in ileal muscle. Therefore, thin filament regulation, including MEK inactivation and related phospho-ERK1/2 decrease, is mainly involved in the eupatilin-induced decrease of intestinal contraction induced by carbachol. In conclusion, this study provides the evidence and a possible related mechanism concerning the inhibitory effect of the flavonoid as an antispasmodic on the agonist-induced contractions in rat ileum and colonic muscles.

• Archives of Pharmacal Research
• /
• 제12권3호
• /
• pp.207-213
• /
• 1989

This study was performed to investigate the mechanism of in vitro cytotosic actions of polyacetylenes which are panaxydol, panaxynol and panaxytriol isolated from Panax ginseng C. A. Meyer. DNA synthesis of L1210 cells was significantly inhibited with dose dependent pattern when L1210 cells were treated for 1 hour with over 5 .mu.g/ml of polyacetylenes. Panaxydol which had the most potent cytotoxicity among three polyacetylenes showed also the strongest inhibitory effect on DNA synthesis. Intracellular cyclic AMP levels of L1210 cells treated with 2.5 $\mu$g/ml of panaxydol or panaxytriol were significantly elevated on the incubation duration. The elevation of cyclic AMP levels by panaxytriol was higher than that by panaxydol, but no significant increase in cyclic AMP by panaxynol was observed. All three polyacetylenes had no effect on glycolysis of L1210 cells. Electron microscopic observations revealed that polyacetylenes caused damage to plasma membranes of L1210 cells in proportion to their cytotoxicities at each $ED_{50}$ value (panaxydol > panaxynol> panaxytriol). These results suggest that cytotoxicities of polyacetylenes against L1210 cells might be mediated by elevated cyclic AMP level, even though the relationship among their cytotoxicities, inhibitory effect on DNA synthesis and ability to elevation of cyclic AMP level are not fully agreed, and might be also related to membrane damage.

• International Journal of Oral Biology
• /
• 제33권4호
• /
• pp.137-141
• /
• 2008

The present study reports the protective properties of a total methanol extract of B. platyphylla var. japonica against ultraviolet (UV)-C irradiation. Pretreatment of Chinese hamster fibroblast (V79-4) cells with a total methanol extract significantly increased cell survival following $300\;J/m^2$ of UV-C irradiation. The total methanol extract was further fractionated into 5 fractions: n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these fractions, B. platyphylla var. japonica ethylacetate, butanol and water fractions showed significant protective effects against the cellular damage induced by UV-C irradiation. In order to elucidate the mechanism underlying this protective effect, DPPH (Editor note: abbreviations should be spelled out at first use.) radical scavenging and lipid peroxidation inhibitory activity were measured. Significant radical scavenging and lipid peroxidation inhibitory activities were observed for the ethylacetate fraction. In summary, the present data demonstrate that an extract of B. platyphylla var. japonica has a significant protective effect against UV-C irradiation. The underlying mechanism of this protective effect may involve radical scavenging and inhibition of lipid peroxidation by the B. platyphylla var. japonica extract.

• 대한한의학회지
• /
• 제18권1호
• /
• pp.218-237
• /
• 1997

In order to investigate the antihypertentive effects and its mechanism of the Siegesbeckia pubescens aqua-acupuncture treatment, experiments were performed on immediate and continuous antihypertensive effects, vasodilatation-autonomic nerve block, diuretic activity, and angiotensin converting enzyme inhibitory activity. The results were as follows; 1. Acupuncture treatment group showed significantly immediate antihypertensive effects in 4 hours after treatment. Normal saline aqua-acupuncture treatment group showed significantly immediate antihypertensive effects in 2, 4 and 6 hours after treatment. Siegesbeckia pubescens aqua-acupuncture treatment group showed significantly immediate antihypertensive effects in 30 minutes, 1, 2, 4 and 6 hours after treatment. 2. Siegesbeckia pubescens aqua-acupuncture treatment group showed significantly continuous antihypertensive effects in 6, 8, 9 and 10 days after treatment. 3. Siegesbeckia pubescens aqua-acupuncture extract solution showed significantly vasodilatatory and sympathetic nerve block effects with concentration of $10^{-6},\;10^{-5},\;10^{-4},\;10^{-3}g/m{\ell}$. 4. Oral administration group of the Siegesbeckia pubescens aqua-acupuncture extract solution didn't show no significantly diuretic effects. 5. Siegesbeckia pubescens aqua-acupuncture extract solution showed 28.8% angiotensin converting enzyme inhibitory activity.