• Title/Summary/Keyword: G Proteins

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Codon Optimization, Soluble Expression and Purification of PE_PGRS45 Gene from Mycobacterium tuberculosis and Preparation of Its Polyclonal Antibody Protein

  • Xu, Tao;Li, Minying;Wang, Chutong;Yuan, Meili;Chang, Xianyou;Qian, Zhongqing;Li, Baiqing;Sun, Meiqun;Wang, Hongtao
    • Journal of Microbiology and Biotechnology
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    • v.31 no.11
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    • pp.1583-1590
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    • 2021
  • Studies have demonstrated that PE_PGRS45 is constitutively expressed under various environmental conditions (such as nutrient depletion, hypoxia, and low pH) of the in vitro growth conditions examined, indicating that PE_PGRS45 protein is critical to the basic functions of Mycobacterium tuberculosis. However, there are few reports about the biochemical function and pathogenic mechanism of PE_PGRS45 protein. The fact that this M. tuberculosis gene is not easily expressed in E. coli may be mainly due to the high content of G+C and the use of unique codons. Fusion tags are indispensable tools used to improve the soluble expression of recombinant proteins and accelerate the characterization of protein structure and function. In the present study, His6, Trx, and His6-MBP were used as fusion tags, but only MBP-PE_PGRS45 was expressed solubly. The purification using His6-MBP tag-specific binding to the Ni column was easy to separate after the tag cleavage. We used the purified PE_PGRS45 to immunize New Zealand rabbits and obtained anti-PE_PGRS45 serum. We found that the titer of polyclonal antibodies against PE_PGR45 was higher than 1:256000. The result shows that purified PE_PGRS45 can induce New Zealand rabbits to produce high-titer antibodies. In conclusion, the recombinant protein PE_PGRS45 was successfully expressed in E. coli and specific antiserum was prepared, which will be followed by further evaluation of these specific antigens to develop highly sensitive and specific diagnostic tests for tuberculosis.

Visualization of the binding between gintonin, a Panax ginseng-derived LPA receptor ligand, and the LPA receptor subtypes and transactivation of the EGF receptor

  • Choi, Sun-Hye;Lee, Ra Mi;Cho, Han-Sung;Hwang, Sung Hee;Hwang, Hong-Ik;Rhim, Hyewhon;Kim, Hyoung-Chun;Kim, Do-Geun;Cho, Ik-Hyun;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • v.46 no.3
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    • pp.348-356
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    • 2022
  • Background: Gintonin is a ginseng-derived exogenous G-protein-coupled lysophosphatidic acid (LPA) receptor ligand. Gintonin exerts its neuronal and non-neuronal in vitro and in vivo effects through LPA receptor subtypes. However, it is unknown whether gintonin can bind to the plasma membrane of cells and can transactivate the epidermal growth factor (EGF) receptor. In the present study, we examined whether gintonin-biotin conjugates directly bound to LPA receptors and transactivated the EGF receptor. Methods: We designed gintonin-biotin conjugates through gintonin biotinylation and examined whether gintonin-biotin conjugate binding sites co-localized with the LPA receptor subtype binding sites. We further examined whether gintonin-biotin transactivated the EGF receptor via LPA receptor regulation via phosphor-EGF and cell migration assays. Results: Gintonin-biotin conjugates elicit [Ca2+]i transient similar to that observed with unbiotinylated gintonin in cultured PC3 cells, suggesting that biotinylation does not affect physiological activity of gintonin. We proved that gintonin-biotin conjugate binding sites co-localized with the LPA1/6 receptor binding sites. Gintonin-biotin binding to the LPA1 receptor transactivates the epidermal growth factor (EGF) receptor through phosphorylation, while the LPA1/3 receptor antagonist, Ki16425, blocked phosphorylation of the EGF receptor. Additionally, an EGF receptor inhibitor AG1478 blocked gintonin-biotin conjugate-mediated cell migration. Conclusions: We observed the binding between ginseng-derived gintonin and the plasma membrane target proteins corresponding to the LPA1/6 receptor subtypes. Moreover, gintonin transactivated EGF receptors via LPA receptor regulation. Our results suggest that gintonin directly binds to the LPA receptor subtypes and transactivates the EGF receptor. It may explain the molecular basis of ginseng physiology/pharmacology in biological systems.

MHY2251, a New SIRT1 Inhibitor, Induces Apoptosis via JNK/p53 Pathway in HCT116 Human Colorectal Cancer Cells

  • Yong Jung Kang;Young Hoon Kwon;Jung Yoon Jang;Jun Ho Lee;Sanggwon Lee;Yujin Park;Hyung Ryong Moon;Hae Young Chung;Nam Deuk Kim
    • Biomolecules & Therapeutics
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    • v.31 no.1
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    • pp.73-81
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    • 2023
  • Sirtuins (SIRTs) belong to the nicotinamide adenine dinucleotide (NAD+)-dependent class III histone deacetylase family. They are key regulators of cellular and physiological processes, such as cell survival, senescence, differentiation, DNA damage and stress response, cellular metabolism, and aging. SIRTs also influence carcinogenesis, making them potential targets for anticancer therapeutic strategies. In this study, we investigated the anticancer properties and underlying molecular mechanisms of a novel SIRT1 inhibitor, MHY2251, in human colorectal cancer (CRC) cells. MHY2251 reduced the viability of various human CRC cell lines, especially those with wild-type TP53. MHY2251 inhibited SIRT1 activity and SIRT1/2 protein expression, while promoting p53 acetylation, which is a target of SIRT1 in HCT116 cells. MHY2251 treatment triggered apoptosis in HCT116 cells. It increased the percentage of late apoptotic cells and the sub-G1 fraction (as detected by flow cytometric analysis) and induced DNA fragmentation. In addition, MHY2251 upregulated the expression of FasL and Fas, altered the ratio of Bax/Bcl-2, downregulated the levels of pro-caspase-8, -9, and -3 proteins, and induced subsequent poly(ADP-ribose) polymerase cleavage. The induction of apoptosis by MHY2251 was related to the activation of the caspase cascade, which was significantly attenuated by pre-treatment with Z-VAD-FMK, a pan-caspase inhibitor. Furthermore, MHY2251 stimulated the phosphorylation of c-Jun N-terminal kinase (JNK), and MHY2251-triggered apoptosis was blocked by pre-treatment with SP600125, a JNK inhibitor. This finding indicated the specific involvement of JNK in MHY2251-induced apoptosis. MHY2251 shows considerable potential as a therapeutic agent for targeting human CRC via the inhibition of SIRT1 and activation of JNK/p53 pathway.

Effects of Dietary Caloric Restriction and Exercise on GLUT 2 in Liver and GLUT-4 and VAMP-2 in Muscle Tissue of Diabetic Rats

  • Jeong, Ilgyu;Oh, Myungjin;Jang, Moonnyeo;Koh, Yunsuk;Biggerstaff, Kyle D.;Nichols, David;Ben-Ezra, Vic
    • Korean Journal of Exercise Nutrition
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    • v.13 no.1
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    • pp.1-7
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    • 2009
  • It has been shown that both caloric restriction and exercise, enhances glucose uptake through translocation of GLUT-4 protein. It remains unclear how exercise and caloric restriction affect the changes in VAMP (vesicle-associated membrane protein) in skeletal muscle and GLUT-2 in liver. This study investigated the effects of exercise training and caloric restriction on the expressions of glucose transport relating proteins in muscle and liver tissues in diabetic rats. Forty male Sprague-Dawley rats (250±10 g; 8 week in age) were assigned equally to four different groups; control (C), exercise only (E), dietary restriction only (D) and dietary restriction and exercise (DE). Daily food consumption was monitored to establish baseline intake. Both C and E groups consumed baseline food intake while D and DE groups were provided with only 60% of baseline total food intake. Forty-eight hours after intraperitoneal injection of STZ (50 mg/kg), diabetes was confirmed (8-hr fasting blood glucose levels ≥300 mg/dl). Rats in the E and DE groups exercised on a motorized treadmill for 30 min/d, 5 days/week for 4 weeks (5 min running at 3 m/min, 0% grade; 8 m/min for the next 5min, and then 15 m/min for 20 min). Rats were sacrificed 48 hrs after the last bout of exercise. Soleus muscle and liver were extracted to analyze for GLUT-4, VAMP-2, and GLUT-2, respectively. All variables were analyzed using the Western Blotting technique. All values were expressed as optical volume measured by optical density. A Two-way ANOVA was used to examine the difference between groups and applied Duncan's test for post-hoc. No significant differences in GLUT-2 expression were found among groups. However, E (280133±13228 arbitrary units{AU}) and DE (268833±14424 AU) groups showed significantly higher (p<.001) levels of GLUT-4 as compared with C (34461±2099 AU) and D groups (27847±703 AU). VAMP-2 protein expression increased (p<.001) in E (184137±7803 AU) and DE (189800±10856 AU) groups as compared to C (74201±8296AU) and D (72967±863 AU) groups. These results suggest that either exercise with or without caloric restriction increases the up-regulation of GLUT-4 and VAMP-2 in skeletal muscle of diabetic rats. However, GLUT-2 protein in liver was not affected by either exercise or exercise with caloric restriction.

Discovering the Anti-cancer Effects of Ligusticum Chuanxiong through Network-based Pharmacology Analysis and Molecular Docking: An Inquiry into Natural Products (네트워크 기반 약리학 분석 및 분자 도킹을 통한 천궁의 항암 효과 예측: 천연물에 대한 탐구)

  • Do Kyung Han;Jee Won Shon;Eui Suk Sung;Youn Sook Kim;Won G. An
    • Journal of Life Science
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    • v.33 no.11
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    • pp.876-886
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    • 2023
  • In some cases of head and neck cancers (HNC), surgical interventions may result in the loss of organs and/or changes to their functions, thereby significantly affecting the patient's quality of life. As a result, the surgical treatment of HNC patients is often limited to specific cases, and alternative treatment modalities, such as chemotherapy, are considered. However, serious adverse effects caused by chemotherapy, such as severe nausea and vomiting, necessitate the need for the development of adjunctive methods to minimize patient suffering. Chuanxiong, Ligusticum chuanxiong (L. chuanxiong), is a natural herb used in Eastern medicine to treat cerebrovascular disorders and headaches. This study aimed to predict the effect and potential of L. chuanxiong as an auxiliary anticancer drug through network-based pharmacology and molecular docking analysis. The study results showed that 40 out of 41 genes of L. chuanxiong shared common targets of HNC and their proteins could be used to target HNC cells to prevent cancer progression. The results of the functional enrichment analysis confirmed that L. chuanxiong is associated with the neuroactive-ligand metabolism and neurotransmitter pathways, indicating its potential medicinal value as an adjuvant in HNC treatment. Lastly, our findings demonstrated that the active ingredient of L. chuanxiong, (Z)-Ligustilide, has the ATP binding site of heat shock protein 90, a protein known to promote the activation of cancer cells. These results suggest that L. chuanxiong is a promising candidate for developing auxiliary anticancer drugs, and further research could potentially lead to the discovery of newer and safer anti-cancer agents.

Microbiological Studies of Korean Native Soy-sauce Fermentation -A Study on the Microflora Changes during Korean Native Soy-sauce Fermentation- (한국재래식(韓國在來式) 간장의 발효미생물(醱酵微生物)에 관(關)한 연구(硏究)(제2보(第二報)) -한국재래식(韓國在來式) 간장의 담금중(中)에 있어서의 발효미생물군(醱酵微生物群)의 소장(消長)에 관(關)한 연구(硏究)-)

  • Lee, Woo-Jin;Cho, Duck-Hiyon
    • Applied Biological Chemistry
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    • v.14 no.2
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    • pp.137-148
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    • 1971
  • Studies were carried out to investigate the main fermentation microorganisms and their flora changes during Korean native soy-sauce fermentation. Korean native Maeju loaves collected from 5 Do's were separated into surface and inner parts. Four different soy-sauces-the surface part Maeju fermented soy-sauce, the inner part, the surface and inner part combined Maeju fermented soy-sauce, and the semi-Japanese type soy-sauce were fermented and the changes of fermentation microorganism flora and the various chemical components during the period of their fermentations were studied. Besides, 14 home-made soy-sauces collected from 14 different places all over Korea were examined in comparison with the laboratory soy-sauces and to determine the characteristics of Korean native soy-sauce. The results were as follows: 1. The main microorganisms in Korean native soy-sauce fermentation were determined as; Aerobic bacteria: Bacillus subtilis, Bacillus pumilus Lactic acid bacteria: Pediococcus halophilus, Leuconostoc mesenteroides Yeasts: Torulopsis datila, Saccharomyces rouxii 2. Microflora changes during Korean native soy-sauce fermentation were as follows; Aerobic bacteria increased until the 2nd week of fermentation and then gradually decreased. The lactic acid bacteria increased until the 3rd week, after which decreased. When the lactic acid fermentation lowered the pH value to below the 5.4, yeasts were able to grow and participate the fermentation. As the production of organic acids amounted, to a certain height, the growth of all microorganisms lead to the period of decline or death at about the 2nd month of fermentation. After boiling of soy-sauce most microorganisms except a few of Bacillus sp. disappeared. Occosionally yeasts and lactic acid bacteria survived depending upon the composition of soy-sauce. 3. Changes of general chemical components influencing the microflora were investigated for the period of Korean native soy-sauce fermentation. Tetal acidity, salt concentration and total nitrogen were increasing steadily over the entire period of fermentation. pH values were dropping to a certain degree of about 4.5. Salt concentration and pH value seemed to be the important factors influencing the microflora. 4. The microflora were influenced by chemical components of soy-sauce. Aerobic bacteria were able to survive in all soy-sauce as they made spores. Growth of lactic acid bacteria was inhited at 23-26% of salt concentration and pH 4.8. Soy-sauce yeasts started to grow only at pH below 5.4 and seemed to be inhibited at around 26% of salt concentration under pH 4.5-4.7. 5. The open kettle boiling of soy-sauce, the characteristic process of Korean native soy-sauce manufacturing, was effective to sterilize microorganisms, increase the salt concentration, and coagulate proteins. 6. The average viable cell counts of microorganism found in collected samples of home-made Korean native soy-sauces were; Aerobic bacteria: $53{\times}10^2\;cell/ml$ Lactic acid bacteria: 34 cell/ml Yeasts: 14 cell/ml The average values of chemical compositions of samples of home-made Korean native soy-sauce were; Salt concentration: 28.9% pH value: 4.79 Total acidity(lactic acid): 0.91g/100ml Total nitrogen: 1.09g/100ml

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The Effect of 1,25-Dihydroxyvitamin D3 on the Viability of Periodontal Ligament Cells and the Experimental Tooth Movement in Rats (1,25-Dihydroxyvitamin D3가 치주인대세포활성 및 실험적 치아이동에 미치는 영향에 관한 연구)

  • Kim, Sung-Woo;Park, Dong-Kwon;Kim, Sang-Cheol
    • The korean journal of orthodontics
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    • v.27 no.2
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    • pp.335-347
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    • 1997
  • Vitamin D is known to exert its action by activating DNA and RBA within target cells to produce proteins and enzymes that can be used in bone resorption process. Particularly, the active form of vitmain D, 1,25-dihydroxycholecalciferol $[1,25-(OH)_2D_3]$, is considered to be one of the most potent stimulators of osteoclatic acitivity in vitro. The purpose of this study was to evaluate the effect of 1,25-Dihydroxyvitamin $D_3$ on the avtivity of periodotal ligament cells and, the experimental tooth movement. Human periodontal ligament cells were collected from the first premolar tooth extracted for the orthodontic treatment, and were incubated in the environment of $37^{\circ}C$, 5% $CO_2$ and 95% humidity. Microtitration(MIT) assay was done at 10, 25, 50 and 100ng/ml of 1,25-Dihydroxyvitamin $D_3$. 21 Sprague-Daft rats were divided into a control gmup(3), and experimental groups(18) where 100g of force from helical spring was applied across the maxillary incisors 1,25-Dihydroxyvitamin $D_3$ was injected into periodontal ligament at the mesial or distal surface of maxillary incisors so that we can compare the control side and the experimental side. Expreimental groups were sac rifled at 12, 24, 36, 48, 72hours and 7 days after force application, respectively. And the obtained tissues were evaluated histologically. The observed results were as follows. 1. The activity of periodontal ligament cells in l0ng/ml or 25ng/ml of 1,25-Dihydroxyvitamin $D_3$ 1,25-Dihydroxyvitamin $D_3$ was not significantly different to the control at the cultivation of 1, 2 and 3 days. 2. The activity of periodontal ligament cells was significantly increased at 3 days in 50 ng/ml of 1,25-Dihydroxyvitamin $D_3$ and 2, 3 days in 100g/ml of 1,25-Dihydroxyvitamin $D_3$. 3. Up to 7 days after force application, there was no difference in osteoblastic activity, tearing of periodontal ligament and proliferation of capillary at tension side between 1,25-Dihydroxyvitamin $D_3$ injection side and the control side. 4. The osteoclastic activity and the resorption of alveolar bone was greater in 1,25-Dihydroxyvitamin $D_3$ injection side than the control side at 36 hours after force application.

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Allium hookeri Extract Improves Type 2 Diabetes Mellitus in C57BL/KSJ Db/db Obese Mouse via Regulation of Hepatic Lipogenesis and Glucose Metabolism (삼채 추출물의 인슐린 저항성 개선 효과 및 기전 탐색)

  • Kim, Ji-Soo;Heo, Jin-Sun;Choi, Jong-Won;Kim, Gun-Do;Sohn, Kie-Ho
    • Journal of Life Science
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    • v.25 no.10
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    • pp.1081-1090
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    • 2015
  • Diabetes has been one of major health risks in industrialized countries. Allium hookeri is a wild herb distributed in India and Myanmar. The root of the plant has been used as food and medicine in Southeast Asia. We investigated Allium hookeri extract improves type 2 diabetes mellitus in C57BL/KSJ db/db obese mouse. C57BL/KSJ db/db obese mouse arise out of Type 2 diabetes and we treated Allium hookeri methanol extract 400 mg/kg (AH 400), 800 mg/kg (AH 800), positive control group (thiazolidinedine;TZDs) were administered orally for 8weeks. AH treated group normalized lipid enzyme system (triglyceride, total cholesterol, HDL-cholesterol and LDL-cholesterol) and serum glucose, HbA1c and plasma insulin level. AH treated group recovered β-cell damage by hyperglycemia and fatty liver disease. AH treated group significantly up regulated expression of Peroxisome proliferator-activated receptor gamma (PPAR-γ), pyruvate dehydrogenase kinase4 (PDK4), Sterol regulatory element-binding protein 1c (SREBP 1) and fork head box O1 (FOX 01) proteins in C57BL/KSJ db/db obese mouse liver. And we found that AH treated group decreased hepatic malondialdehyde formation in C57BL/KSJ db/db obese mouse liver. These results indicate that Allium hookeri methanol extract might be a potential anti-diabetic agent and could be useful in the treatment of type 2 diabetes mellitus.

Studies on the Development of Food Resources from Waste Seeds IV. Chemical Composition of Red Pepper Seed (폐기종실(廢棄種實)의 식량자원화(食糧資源化)에 관(關)하여 제(第) 4 보(報) : 고추씨의 화학적(化學的) 조성(組成))

  • Yoon, Hyung Sik;Kwon, Joong Ho;Bae, Man Jong;Hwang, Joo Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.12 no.1
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    • pp.46-50
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    • 1983
  • In order to find out the possibility of utilizing red pepper seed as food resources of fats and proteins, a series of studies were conducted. The red pepper seed contained 27.6% of crude fat and 22.2% of crude protein. The lipid fractions obtained by silicic acid column chromatography were mainly composed of 95.4% neutral lipid, where as compound lipid were 4.6%. Among the neutral lipid separated by thin layer chromatography, triglyceride was 85.6%, sterol ester 4.9%, free fatty acids 3.4%, diglyceride 2.5%, sterol 2.2% and monoglyceride 1.1%, respectively. The predominant fatty acids of red pepper seed oil were linoleic acid (57.1-75.4%), palmitic acid (13.9-21.3%) and oleic acid (8.0-15.1%), especially glycolipid contained 1.7% of linolenic acid and small amount of myristic acid and arachidic acid. The salt soluble protein of red pepper seed was highly dispersible in 0.02M sodium phosphate buffer containing 1.0M $MgSO_4$, and the extractability of seed protein was about 25.0%. Glutamic acid and arginine were major amino acids of red pepper seed protein. The electrophoretic analysis showed 6 bands in seed protein, and the collection rate of the main protein fraction purified by sephadex G-100 and G-200 was about 62.2%. Glutamic acid (19.9%) was major amino acid of the main protein, followed by glycine and alanine. The molecular weight of the main protein was estimated to be 93,000.

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Antioxidant and Anti-Adipogenic Activities of Bread Containing Corn Silk, Job's Tears, Lentinus edodes, and Apple Peel in 3T3-L1 Preadipocytes (옥수수수염, 율무, 표고버섯 그리고 사과껍질을 함유한 빵의 항산화 및 3T3-L1 지방 전구세포 분화 억제 활성)

  • Lee, Chang Won;Park, Yong Il;Kim, Soo-Hyun;Lim, Heekyung;Chung, Mi Ja
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.5
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    • pp.651-663
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    • 2016
  • Corn silk, Job's tears, Lentinus edodes, and apple peel 70% ethanol extracts (CS, JT, LE, and AP) were studied for their antioxidant activities. CS among all extracts showed the highest antioxidant activities based on total polyphenol and flavonoid contents, 2,2-diphenyl-${\beta}$-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical scavenging activity, and reducing power. Adipocyte differentiation was investigated by Oil Red O staining assay using CS, JT, LE, AP, and extract of developed bread containing corn silk, Job's tears, Lentinus edodes, and apple peel (DB) treated to 3T3-L1 adipocytes. DB1 and DB2 showed anti-adipogenic and antioxidant effects. Triglyceride (TG) accumulation in 3T3-L1 cells was measured, and among the samples tested (CS, JT, LE, and AP), CS was found to have the highest inhibitory activity against TG accumulation of differentiated 3T3-L1 adipocytes and regulated factors associated with adipogenesis. CS suppressed lipid droplet formation and adipocyte differentiation in 3T3-L1 cells in a dose-dependent manner. We examined the effects of CS on the levels of CCAAT-enhancer-binding protein ${\beta}(C/EBP{\beta})$, peroxisome proliferator activated receptor ${\gamma}(PPAR{\gamma})$, and adipocyte-specific lipid binding protein (aP2) mRNA as well as protein levels in 3T3-L1 cells treated with CS at various concentrations (0, 10, 50, and $100{\mu}g/mL$) during adipocyte differentiation and treatment with CS in 3T3-L1 adipocytes down-regulated expression of $PPAR{\gamma}$ and aP2 mRNA. CS also significantly inhibited up-regulation of $C/EBP{\beta}$, $PPAR{\gamma}$, and aP2 proteins during adipocyte differentiation. These data indicate that DBs have anti-adipogenic activity induced by CS in 3T3-L1 preadipocytes, and CS exerts anti-adipogenic activity by inhibiting expression of $C/EBP{\beta}$, $PPAR{\gamma}$, and aP2 signaling pathway in 3T3-L1 adipocytes. JT, LE, and AP had no inhibitory effects on differentiation of 3T3-L1 preadipocytes but displayed strong antioxidant effects. These results suggest that the developed bread may be a health beneficial food that can prevent or treat obesity and diseases induced by oxidative stress.