• The Journal of Internal Korean Medicine
• /
• v.21 no.1
• /
• pp.13-22
• /
• 2000

목적 : 본(本) 연구(硏究)는 배기음(排氣飮)이 인간(人間)의 장관내(腸管內)에서 산화물(酸化物)에 의해 유발(誘發)된 세포(細胞)의 사망(死亡) 및 DNA의 손상(損傷)을 방지할수 있는지를 검증(檢證)하기 위한 실험(實驗)이다. 방법 : 배양(培養)된 인체장관(人體腸管) 세포계열(細胞系列)인 Caco-2 세포(細胞)에서 세포(細胞)의 사망(死亡)은 trypan bile의 소실정도에 의해서 평가했으며, DNA의 손상(損傷)은 double stranded DNA의 파괴정도를 측정하여 평가하였다. $H_2O_2$는 표본(標本) 산화제(酸化劑)로 사용되었다. 결과 : $H_2O_2$에 노출된 세포들의 세포사망(細胞死亡) 정도는 노출시간과 용량에 비례하여 증가하는 양상을 보였다. 배기음(排氣飮)은 $H_2O_2$에 의해 유발(誘發)되는 세포방지를 방지하였고, 0.05-1%의 농도범위에 걸쳐서는 그 효과가 용량에 비례하여 증가하는 양상을 보였다. $H_2O_2$에 의해 유발(誘發)된 세포손상(細胞損傷)은 catalase(hydrogen peroxide scavenger enzyme)와 deferoxamine(iron chelator)에 의해 억제되었다. 그러나 강력한 항산화제(抗酸化劑)인 DPPD는 $H_2O_2$에 의해 유발(誘發)되는 세포손상(細胞損傷)에는 영향을 주지 못했다. $H_2O_2$에 의해 유발(誘發)된 지질(脂質)의 과산화(過酸化)는 배기음(排氣飮)과 DPPD에 의해 억제되었다. $H_2O_2$에 의해 유발(誘發)된 DNA의 손상(損傷)은 배기음(排氣飮)에 의해 방지되었으며 용량에 의존하는 양상을 보였다. $H_2O_2$에 의해 유발(誘發)된 DNA의 손상은 catalase와 deferoxamine에 의해 억제되었지만 DPPD는 억제시키지 못했다. 배기음(排氣飮)은 $H_2O_2$에 의해 유발(誘發)된 ATP의 소실을 회복시켰다. 이러한 실험결과 $H_2O_2$에 의해 유발(誘發)된 세포(細胞)의 손상(損傷)은 지질(脂質)의 과산화(過酸化)와는 다른 독립적인 기전에 의해 일어남을 나타낸다. 결론 : 이러한 결과들로 볼 때 Caco-2 세포(細胞)에서 배기음(排氣飮)이 항산화작용(亢酸化作用)보다는 다른 기전을 통하여 Caco-2 세포안에서 산화제(酸化劑)에 의해 유발(誘發)된 세포(細胞)의 사망(死亡)와 DNA의 손상(損傷)을 방지할 수 있다는 것을 가리킨다. 따라서 본 연구(硏究)는 배기음(排氣飮)이 반응성산소기(反應性酸素基)에 의해 매개된 인체(人體) 위장관질환(胃腸管疾患)의 치료(治療)에 사용할 수 있을 가능성(可能性)이 있음을 제시하고 있다.

• Journal of Pharmaceutical Investigation
• /
• v.25 no.2
• /
• pp.137-143
• /
• 1995

The peptide transporter can be utilized for improving the bioavailability of compounds that are poorly absorbed. Characterization of the dipeptide uptake into the human intestinal epithelial cells, HT-29 was investigated. The uptake of tritiated glycylsarcosine $([^3H]-Gly-Sar,\;0.1\;{\mu}Ci/ml)$ was measured in confluent or subconfluent HT-29, Caco-2, and Cos-7 cells. Uptake medium was the Dulbecco's Modified Eagle's Media (DMEM) adjusted to pH 6.0. Both HT-29 and Caco-2 cells expressed the dipeptide transporter significantly (p<0.005) but Cos-7 did not. Certain portions of passive uptake were observed in all three cell lines. Uptake of Gly-Sar was largest at 7 days after plating HT-29 cells with significant inhibition with 25 mM cold Gly-Sar (p<0.05). but expression ratio of the dipeptide transporter was 0.7, suggesting lower expression. The effect of pH on Gly-Sar uptake was not significant in the range of pH 6 to 8. Gly-Sar uptake was also inhibited with 50 mM carnosine, 25 mM Gly-Sar, and 35 mM cephalexin significantly (p<0.05). From above results the dipeptide transporter was expressed well in HT-29 cells and was similar to that in the small intestine, suggesting that large amounts of mRNA of the transporter from the cells can be obtained.

• Archives of Pharmacal Research
• /
• v.28 no.8
• /
• pp.988-994
• /
• 2005

The purpose of the present study was to prepare multivesicular liposomes with a high drug loading capacity and to investigate its potential applicability in the oral delivery of a peptide, human epidermal growth factor (rhEGF). The multivesicular liposomes containing rhEGF was prepared by a two-step water-in-oil-in-water double emulsification process. The loading efficiency was increased as rhEGF concentration increased from 1 to 5mg/mL, reaching approximately $60\%$ at 5 mg/mL. Approximately $47\%$ and $35\%$ of rhEGF was released from the multivesicular liposomes within 6 h in simulated intra-gastric fluid (pH 1.2) and intra-intestinal fluid (pH 7.4), respectively. rhEGF-loaded multivesicular liposomes markedly suppressed the enzymatic degradation of the peptide in an incubation with the Caco-2 cell homogenate. However, the transport of rhEGF from the multivesicular liposomes to the basolateral side of Caco­2 cells was two times lower than that of the rhEGF in aqueous solution. The gastric ulcer healing effect of rhEGF-loaded multivesicular liposomes was significantly enhanced compared with that of rhEGF in aqueous solution; the healing effect of the liposomes was comparable to that of the cimetidine in rats. Collectively, these results indicate that rhEGF-loaded multivesicular liposomes may be used as a new strategy for the development of an oral delivery system in the treatment of peptic ulcer diseases.

• Archives of Pharmacal Research
• /
• v.24 no.6
• /
• pp.584-589
• /
• 2001

Isopropryl 2-(1-3-dithiethane-2-ylidene)-2 [N-(4-methyl-thiazole-2-yl) carbamoyl] acetate (YH439) is currently under phase ll clinical trials by the Yuhan Research Center for use as a hepatoprotective agent. Unfortunately, the oral bioavailbility of YH439, which is sparingly soluble in water (i.e., $0.3{\;}\mu\textrm{g}/ml{\;}or{\;}0.91{$\mu}M$ at room temperature), reportedly, is negligibleregardless of the dose administered to rats in the 10-300 mg/kg range. The bioavailability of the compound increased up to 24%, when administered in the form of a micellar solution ($700{\;}\mu\textrm{g}/ml$or 2.1 mM for YH439) at a dose of 10 mg/kg, suggesting that its limited solubility is associated with its negligible bioavailability. In order to obtain additional informmation concerning the bioavailability of YH439, the mechanism(s) involved in gastrointestinal (Gl) absorption were investigated in the present study. For this purpose, the transport of YH430 across a Caco-2 cell monolayer was measured in a $Transwell^{\circledR}$. A permeability of $4.07{\times}10^{-5}{\;}cm/s$ was obtained for the absorptive (i.e., apical to basolateral direction) transport of $0.42{\mu}M$ YH439, implicating that the in vivo Cl absorption is nearly complete. The absorptive transport exhibited a slight concentration-dependency with an intrinsic clearance ($CL_{i}$) of $0.38{\mu}L/{\textrm{cm}^2}/sec$, which accounted for 28.1% of the total intrinsic clearance (i.e., $CL_i$ plus the intrinsic clearance for the linear component) of the transport. Thus, saturation of the absorption process appears to be a minor factor in limiting the bioavailability of the compound. The apparent permeability of YH439 from the basolateral to the apical direction (i.e., efflux, $6.67{\times}10^{-5}{\;}cm/s$) was comparable to that for absorptive transport, but, interestingly, a more distinct concentration-dependency was observed for this transport. However, the efflux does not appear to influence the bioavailability of the compound, as evidenced by the sufficiently high permeability in the absorption direction. Rather, a reportedly extensive first-pass hepatic metabolism appears to be a principal factor in limiting the bioavailability. In this respect, reducing the first-pass metabolism by some means would lead to a higher bioavailability of the compound. Thus, elevation of the absorption rate of YH439 becomes a necessity. From a practical point of view, increasing the concentration of YH439 in the Cl fluid appears to be a feasible way to increase the absorption rate, because the compound is primarily absorbed via a linear mechanism. In summary, the solubilization of YH439, as previously demonstrated for a micellar solution of the compound, appears to be a practical way to increase the oral bioavailability of YH439.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.2
• /
• pp.288-298
• /
• 2016

Resveratrol acts as a free radical scavenger and a potent antioxidant in the inhibition of numerous reactive oxygen species (ROS). The function of resveratrol and resveratrol-loaded nanoparticles in protecting human lung cancer cells (A549) against hydrogen peroxide was investigated in this study. The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay was performed to evaluate the antioxidant properties. Resveratrol had substantially high antioxidant capacity (trolox equivalent antioxidant capacity value) compared to trolox and vitamin E since the concentration of resveratrol was more than $50{\mu}M$. Nanoparticles prepared from ${\beta}$-lactoglobulin (${\beta}$-lg) were successfully developed. The ${\beta}$-lg nanoparticle showed 60 to 146 nm diameter in size with negatively charged surface. Non-cytotoxicity was observed in Caco-2 cells treated with ${\beta}$-lg nanoparticles. Fluorescein isothiocynate-conjugated ${\beta}$-lg nanoparticles were identified into the cell membrane of Caco-2 cells, indicating that nanoparticles can be used as a delivery system. Hydrogen peroxide caused accumulation of ROS in a dose- and time-dependent manner. Resveratrol-loaded nanoparticles restored $H_2O_2$-induced ROS levels by induction of cellular uptake of resveratrol in A549 cells. Furthermore, resveratrol activated nuclear factor erythroid 2-related factor 2-Kelch ECH associating protein 1 (Nrf2-Keap1) signaling in A549 cells, thereby accumulation of Nrf2 abundance, as demonstrated by western blotting approach. Overall, these results may have implications for improvement of oxidative stress in treatment with nanoparticles as a biodegradable and non-toxic delivery carrier of bioactive compounds.

• Food Science and Biotechnology
• /
• v.18 no.3
• /
• pp.706-711
• /
• 2009

Lysozyme was treated with digestive enzymes and the production of interleukin 8 (IL-8) was measured in Caco-2 cell with the peptides from lysozyme upon stimulating with lipopolysaccharide (LPS) to investigate the overall anti-inflammatory activity of lysozyme when it is in digestive tracts. Lysozyme reduced IL-8 production, and the peptides from pepsin hydrolysis of lysozyme had the similar effect. The products of trypsin digestion of lysozyme had no effect on the reduction of IL-8 production while those of pepsin-trypsin hydrolysis did. The effectiveness of lowering IL-8 production was not different by time of the peptide addition. When Caco-2 cells were pre-incubated with peptides for 24 hr, the reduction effects were observed from the peptides from pepsin hydrolysis, indicating that some of the peptides are still remaining in the cells. Therefore, it can be concluded that the IL-8 reduction effect of lysozyme against LPS still remained even after the pepsin and trypsin hydrolysis.

• Nutrition Research and Practice
• /
• v.3 no.1
• /
• pp.9-14
• /
• 2009

Aloe products are one of the top selling health-functional foods in Korea, however the adequate level of intake to achieve desirable effects are not well understood. The objective of this study was to determine the intestinal uptake and metabolism of physiologically active aloe components using in vitro intestinal absorption model. The Caco-2 cell monolayer and the everted gut sac were incubated with $5-50{\mu}M$ of aloin, aloe-emodin, and aloesin. The basolateral appearance of test compounds and their glucuronosyl or sulfated forms were quantified using HPLC. The % absorption of aloin, aloe-emodin, and aloesin was ranged from 5.51% to 6.60%, 6.60% to 11.32%, and 7.61% to 13.64%, respectively. Up to 18.15%, 18.18%, and 38.86% of aloin, aloe-emodin, and aloesin, respectively, was absorbed as glucuronidated or sulfated form. These results suggest that a significant amount is transformed during absorption. The absorption rate of test compounds except aloesin was similar in two models; more aloesin was absorbed in the everted gut sac than in the Caco-2 monolayer. These results provide information to establish adequate intake level of aloe supplements to maintain effective plasma level.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2005.09a
• /
• pp.45-45
• /
• 2005

• Proceedings of the PSK Conference
• /
• 2000.10a
• /
• pp.266.1-266.1
• /
• 2000

• Journal of Veterinary Science
• /
• v.23 no.5
• /
• pp.74.1-74.16
• /
• 2022

Background: Previous studies have presented evidence to support the significant association between red meat intake and colon cancer, suggesting that heme iron plays a key role in colon carcinogenesis. Epigallocatechin-3-gallate (EGCG), the major constituent of green tea, exhibits anti-oxidative and anti-cancer effects. However, the effect of EGCG on red meat-associated colon carcinogenesis is not well understood. Objectives: We aimed to investigate the regulatory effects of hemin and EGCG on colon carcinogenesis and the underlying mechanism of action. Methods: Hemin and EGCG were treated in Caco2 cells to perform the water-soluble tetrazolium salt-1 assay, lactate dehydrogenase release assay, reactive oxygen species (ROS) detection assay, real-time quantitative polymerase chain reaction and western blot. We investigated the regulatory effects of hemin and EGCG on an azoxymethane (AOM) and dextran sodium sulfate (DSS)-induced colon carcinogenesis mouse model. Results: In Caco2 cells, hemin increased cell proliferation and the expression of cell cycle regulatory proteins, and ROS levels. EGCG suppressed hemin-induced cell proliferation and cell cycle regulatory protein expression as well as mitochondrial ROS accumulation. Hemin increased nuclear factor erythroid-2-related factor 2 (Nrf2) expression, but decreased Keap1 expression. EGCG enhanced hemin-induced Nrf2 and antioxidant gene expression. Nrf2 inhibitor reversed EGCG reduced cell proliferation and cell cycle regulatory protein expression. In AOM/DSS mice, hemin treatment induced hyperplastic changes in colon tissues, inhibited by EGCG supplementation. EGCG reduced the hemin-induced numbers of total aberrant crypts and malondialdehyde concentration in the AOM/DSS model. Conclusions: We demonstrated that EGCG reduced hemin-induced proliferation and colon carcinogenesis through Nrf2-inhibited mitochondrial ROS accumulation.