• Journal of Life Science
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• v.27 no.5
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• pp.545-552
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• 2017

Julbernardia globiflora, a tropical African tree widespread in Miombo woodland, has been used in folk medicine for the treatment of depression and stomach problems. However, the antioxidative and anticancer activities of J. globiflora remain unclear. The objective of this study is to evaluate the antioxidative and anticancer effects of methanol extract of J. globiflora (MEJG) and the molecular mechanism of its anticancer activity in human colon carcinoma HT29 cells. MEJG exhibited significant antioxidative effect with an $IC_{50}$ (concentration at 50% inhibition) value of $1.23{\mu}g/ml$ measuring by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and inhibited cell proliferation in a dose-dependent manner in HT29 cells. We found that MEJG induced apoptosis of HT29 cells with the increase of apoptotic cells and apoptotic bodies using Annexin V staining and 4,6-diamidino-2-phenylindole (DAPI) staining, respectively. The MEJG treatment showed the increase of Fas, a death receptor, and Bax, a pro-apoptotic protein, and the decrease of Bcl-2, an anti-apoptotic protein, resulting in the release of cytochrome c from the mitochondria into the cytosol and activation of caspase-3, -8 and -9. The apoptotic effects of MEJG were confirmed by cleavage of poly (ADP-ribose) polymerase (PARP). Collectively, these results suggest that MEJG may exert the anticancer effect in HT29 cells by inducing apoptosis via both the intrinsic and extrinsic pathways.

• Journal of Pharmaceutical Investigation
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• v.25 no.4
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• pp.299-305
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• 1995

Cloning the gene encoding a dipeptide transporter is necessary for understanding the absorption mechanism of peptides and peptide-like drugs in the gastrointestinal tract. Functional expression of a dipeptide transporter after microinjection into Xenopus laevis oocytes was performed using the mRNA purified from human intestinal HT-29 cells. Fifty nanoliters of purified mRNA (1 mg/mL) were microinjected into healthy oocytes followed by incubation for 4 days in order to express a dipeptide transporter. Functional expression was determined by a uptake assay using 10 Ci/mL $[^3H]-glycylsarcosine$, a dipeptide substate of the transporter. Seasonal variability and batch-to-batch variability were greater in summer. The usage of beveled micropipettes improves viability of oocytes at 4 days after microinjection. Expression of a dipeptide transporter in oocytes after microinjection of mRNA obtained from HT-29 cells was significantly larger than those after microinjection of water or mRNA obtained from the rabbit intestine.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.2
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• pp.93-101
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• 2022

Hizikia fusiforme, a type of brown algae, is widely used in Asian cuisine. It has been reported to have various pharmacological effects. In this study, the effects of the ethanol extract from H. fusiforme (EAHF) on the proliferation of human colon carcinoma cells were investigated. The effect on the survival of human hepatocarcinoma and colon carcinoma cells was examined, and results revealed that the anti-proliferative effects of EAHF were higher in colon carcinoma cells than in hepatocarcinoma cells. The inhibition of proliferation of HT29 colon carcinoma cells by EAHF treatment was closely related to the induction of apoptosis. EAHF treatment also increased caspase activity and poly(ADP-ribose) polymerase degradation, induced mitochondrial dysfunction, altered Bcl-2 family protein expression, and increased the rate of cytochrome c released from the mitochondria into the cytoplasm. Furthermore, the production of reactive oxygen species (ROS) was markedly stimulated by EAHF treatment, and when ROS production was blocked, EAHF-induced cytotoxicity was significantly attenuated. These results indicate that the anticancer activity of EAHF in HT29 colon carcinoma cells was induced by ROS-dependent mitochondrial impairment. While EAHF exhibited potent anticancer activity in colon carcinoma cells in this study, further studies on the active components of EAHF and their efficacy should be performed.

• Journal of Nutrition and Health
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• v.33 no.6
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• pp.660-667
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• 2000

Previous studies on the effect of age on intestinal taurine transport in animals have invariably shown a decline in the activity of the transport system with increasing age. In the present study changes in taurine transporter activity were observed during cell differentiation in the human colon carcinoma cell line HT-29 This cell line exhibits various enterocytic characteristics when differentiated and therefore has frequently been used to study the characteristcs and regulation of nutrient and drug absorption in the small intestine at the cellular level. Pre-treatment of the cells with $\beta$-alanine(10mM) reduced the taurine transport activity to 33% of the value for the control cells(p<0.05) which implies that taurine and $\beta$-alanine share a common $\beta$-amino acid transport system for their celluar uptake in the HI-29 was continued until 21 days post seeding. Kinetic studies of the taurine transporter were conducted in the HT-29 cell line with varying taurine concentration(5-60$\mu$M) in the uptake medium Both Vmax and the Michaelis-Menten constant(Km) of taurine transporter were decreased as differentiation of the HT-29 cell line was progressed ; Vmax of the taurine transporter in cells incubated for 4, 14 and 21 days post seeding was 2.79$\pm$3.4m 16.89$\pm$1.74, and 0.85$\pm$0.08 and 0.32$\pm$0.01nmol.mg protein-1 .30min-1 respectively(p<0.001) and Km was 42.3$\pm$3.4, 16.89$\pm$1.74, and 11.2$\pm$3.0$\mu$M respectively (p<0.01) These results indicate that the activity of sodium dependent active taurine transport system in the HT-29 cell line is decreased as confluent cells are differentiated. This phenomenon in cell culture system corresponds well with the earlier observation of lower intestinal taurine transport activity in suckling rats compared to that in adult animals although direct relationship of cell differentiation with in vivo aging process needs further verification.

• Journal of Life Science
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• v.16 no.4
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• pp.659-663
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• 2006

The extracts of Plocamium telfairiae using several solvents with different polarities were prepared and their growth inhibitory effects were examined on the human cancer cells. We investigated the cytotoxic effects of P. telfairiae extracts on HT-29 cells by the MTT reduction assay and examining the morphological change under the inverted microscope. Among three extracts, the methanol extract showed the strongest inhibitory effect on the growth of HT-29 cells. The methanol extract was further fractionated sequentially with n-hexane, diethyl ether, ethyl acetate, and aqueous for purifying crude methanol extract. The n-hexane layer among the fractioned layers showed remarkable inhibitory activity on the growth of HT-29 cells. Moreover n-hexane layer showed the notable growth inhibition effects with a dose-dependent manner against SW620, HeLa, and MCF-7 cells as well as HT-29 cells. These results indicated that P. telfairiae extracts may be contained bioactive materials with inhibitory effect on the growth of human cancer cells.

• The Korean Journal of Food And Nutrition
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• v.35 no.3
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• pp.204-212
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• 2022

The purpose of this study was to investigate the biological activity of fucoidan, a sulfur-containing polysaccharide, on cytotoxicity and apoptosis in the human HT-29 colorectal cancer cell line using cell viability, Flow cytometry, Western blot, and RT-PCR analyses. Fucoidan inhibited the proliferation of HT-29 cells by 39.6% at a concentration of 100 ㎍/mL for 72 h. The inhibition was dose-dependent and accompanied by apoptosis. Flow cytometric analysis showed that fucoidan increased early apoptosis and late apoptosis by 65.84% and 72.09% at concentrations of 25 and 100 ㎍/mL, respectively. Analysis of the mechanism of these events indicated that fucoidan-treated cells exhibited increases in the activation of caspase-3, caspase-8, and PARP in a dose-dependent manner. These results suggest that fucoidan may inhibit the growth of human colorectal cancer cells by various apoptosis-promoting effects, as well as by apoptosis itself.

• Molecular & Cellular Toxicology
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• v.4 no.2
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• pp.144-149
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• 2008

Despite versatile activity (cancericidal, antimicrobial, hypoxia inducible factor (HIF) inhibition, immune deactivation of DNA bis-intercalation agent, echinomycin, its specific mechanism has been elusive. Of these novel mechanisms, we reported that using human colon cancer cells (HT-29), apoptotic machinery induced by echinomycin might be dependent of caspase-3 pathway. Despite a partial enlightenment of prototypic signal path triggered by echinomycin, the role of Bcl-2 in this signaling pathway is unclear. To address this issue, we explored whether or not echinomycin would overcome the anti-apoptotic impact of Bcl-2 in HT-29 cells by the controlled Bcl-2 overexpression. Prior to this proof, we confirmed that echinomycin induces mitochondrial depolarization, then triggering the mitochondrial pathway of apoptosis with an involvement of upstream cas-pases-3. Transiently transfection with inactive Bax-DNA failed to prevent echinomycin-induced apoptosis in HT-29 cells. To dissect the role of Bcl-2 in echinomycin-induced apoptosis, HT-29 cells were transiently transfected with Bcl-2 DNA for overexpression and then treated with echinomycin for 24h. Combined analyses of DNA fragmentation and flow cytometric analysis clearly verified that echinomycin-induced apoptosis was drastically attenuated by Bcl-2 overexpression, whereas a control vector rarely affected echinomycin-induced apoptosis. Collectively, these data verify that Bcl-2 regulates echinomycin-induced apoptosis in HT-29 cells. To my knowledge, this is the first evidence that of diverse, structured minor groove binders (MGB), the prototypic echinomycin might control the apoptotic signaling via Bcl-2-mitochondrial pathway.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.314-319
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• 2001

In the present study, effects of $\beta$-alanine, a known taurine antagonist for its structural similarity, on the adaptive regulation and kinetic behavior of the taurine transporter were investigated in the HT-29, human colon carcinoma cell line. Pretreatment of the cell with $\beta$-alanine(10mM) for varying periods from 3 to 30 hrs significantly reduced the taurine uptake compared to the value for control cells. This decrease in the taurine transporter activity was dependent on the incubation time with $\beta$-alanine, and the maximal down-regulation of the transporter activity was observed in cells pretreated with $\beta$-alanine for 24 hrs (25% of the control value, p<0.01). The taurine transporter appears to bind exclusively with $\beta$-alanine in the HT-29 cells since the same concentration of $\alpha$-alanine added in the culture medium for 24 hrs did not influence the taurine uptake. Kinetic analyses of the taurine transporter activity was performed in the HT-29 cell line with varying taurine concentration (5~60$\mu$M) in the uptake medium. Active taurine uptake was significantly lower in $\beta$-alanine pretreated cells compared to the value for control cells in the range of taurine concentration used in the experiment (p<0.001). The cells pretreated with $\beta$-alanine showed a 50% lower maximal velocity (Vmax, 1.7$\pm$2.0 nmole.mg $protein^{-1}$.$30min^{-1}$), and a 99% higher Michaelis constant (Km, 40.3$\pm$7.6$\mu$M) than the control values (3.3$\pm$1.9 nmole.mg $protein^{-1}$.$30min^{-1}$, and 20.3$\pm$2.1$\mu$M, respectively). These results on kinetic data suggest that $\beta$-alanine induced down-regulation of the taurine transporter activity was associated with decreases in both maximal velocity and affinity of the transporter.

• Korean Journal of Food Science and Technology
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• v.23 no.3
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• pp.370-374
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• 1991

The inhibitory effects of garlic on the mutagenicity in Salmonella assay system and on the growth of HT-29 human colon carcinoma cells were studied. Methanol extract of garlic inhibited the mutagenicities induced by aflatoxin $B_1(AFB_1)$and N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) in Salmonella typhimurium TA100. The inhibition rate increased significantly when the concentration of the methanol extract from garlic increased in both strains of Salmonella typhimurium TA98 and TA100. The chloroform fraction from the methanol extract exhibited strong antimutagenicity against $AFB_1$. The chloroform fraction also inhibited greatly the growth of human HT-29 colon carcinoma cells in fetal bovine serum concentrations of 1% and 5%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1115-1120
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• 2006

The effect of cinnamon ethanol extract (CN) on HT-29 cancer cell line has been examined. CN inhibited the growth of HT-29 colon cancer cells in a concentration and time dependent manner but not the growth of CCD-112CoN normal colon cells. And CN markedly inhibited the production of $PGE_2$ and cGMP as well as the mRNA expression of COX-2. These data suggest that non toxic concentration of CN has a significant inhibition effect on the growth of HT-29 cells, probably through the inhibition of $PGE_2$ production via COX-2 inhibition, and may have value as a safe chemopreventive agent for colon cancer.