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Yulong Zheng,Eun-Hye Lee,Ji-Hyun Lee,So-Yeon Lee,Ga-Ryeong Kim,Il-Jun Kang 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10
Previous studies have shown that Morus alba L. root 30% ethanol extract (MAR) can inhibit the accumulation and release of melanin in B16F10 melanoma cells. This study aimed to explore the mechanism of MAR involving the MAPK pathway to inhibit melanogenesis in B16F10 melanoma cells. We treated MAR with different concentrations and times in melanocytes and investigated the expression and phosphorylation of MAPK pathway-related proteins. Moreover, we have identified several potential anti-melanogenic active compounds in MAR by LC-MS/MS. MAR prevents the transient activation of ERK induced by melanogenesis in melanocytes within 2 h, but it does not affect JNK and p38 MAPK. However, MAR significantly reduced the phosphorylation of ERK, JNK, and p38 MAPK at 72 h. These results indicate that the anti-melanogenesis effects of MAR mainly involve the rapid suppression of the ERK signaling pathway in a short period, followed by inhibiting JNK and p38 MAPK in the MAPK pathway and finally down-regulating the expression level of MITF. In addition, several active compounds wtith anti-melanogenic effects have been identified in MAR, such as mulberroside A and oxyresveratrol.
Yulong Zheng,이재선,이은혜,인교,김종한,이미향,이옥환,강일준 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.3
Anti-obesity activities of Korean red ginseng saponin fraction (RGS) and/or Glycyrrhiza glabra L. extract (GG) were investigated in 3T3-L1 adipocytes and high-fat diet-induced C57BL/6J obese mice. RGS and GG extracts were mixed at a mass ratio of 3:1 (SG31), 1:1 (SG11), or 1:3 (SG13). SG31 showed the highest anti-obesity activity among the three different mass ratios of RGS and GG extracts. SG31 showed higher inhibition efficiency on triglyceride (TG) accumulation than either single extract in 3T3-L1 adipocytes and without any cytotoxicity. It also decreases the expression of adipogenic and lipogenic genes such as C/EBPα and SREBP-1c (sterol regulatory element-binding protein 1c). In the obese induced mouse model, SG31 significantly reduced white adipose tissue weight and body weight, attenuated dyslipidemia, and decreased serum TG levels. In some indices, the activity of SG31 was even higher compared with Garcinia Cambogia water extract, a positive control. The possible mechanism by which SG31 causes the above results was by activating the AMP-activated protein kinase (AMPK) pathway and stimulating the secretion of adiponectin in adipose tissue to regulate energy metabolism balance, inhibit TG formation, and promote β-oxidation of fatty acids. Therefore, SG31 may have efficacy as an anti-obesity functional food or raw material if the results can be confirmed in human studies.
Yulong Zheng,Sanghee Um,Il Jun Kang 건강기능식품미래포럼 2024 건강기능식품미래포럼 학술지 Vol.4 No.2
We treated extracts from Abelmoschus manihot flower (AME) and Aristotelia chilensis fruit (ACE) with Lactobacillus plantarum or Bacillus subtilis since probiotic fermentation is known to modify or enhance the bioactivity of natural compounds. From this process, we derived a total of 10 fermented products: AMEL and ACEL (fermented with L. plantarum) and AMEB and ACEB (fermented with B. subtilis), along with 6 blends of these products in various proportions. Our study revealed significant findings regarding these fermented products. Firstly, all fermented products exhibited 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. Particularly, AMEL, ACEB, and the 2:1 blend showed the highest scavenging activity. Secondly, at a concentration of 5%, they notably suppressed the production of nitric oxide in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells without adversely affecting cell viability. Notably, AMEL, ACEB, and a 2:1 blend of AMEL and ACEB exhibited the highest suppression. Consequently, only these 3 products were further tested in subsequent experiments. Thirdly, these selected products inhibited the secretion of tumor necrosis factor-α and interleukin-6 from LPS-stimulated RAW 264.7 cells. Fourthly, they demonstrated inhibitory effects on collagenase activity, with the 2:1 blend showing the highest inhibition, comparable to adenosine, a known enzyme inhibitor. Lastly, these products promoted collagen release and inhibited matrix metalloproteinase-1 release from human fibroblast Hs68 cells, with the 2:1 blend exhibiting the highest activity. These in vitro findings indicate that AMEL, ACEB, and their 2:1 blend possess anti-inflammatory properties, suggesting their potential for preventing skin aging and wrinkle formation.
Yulong Zhang,Changzhong Li,Wenhui Zhang,Xiangqin Zheng,Xiujuan Chen 한국식품영양과학회 2020 Journal of medicinal food Vol.23 No.4
Myo-inositol supplementation may reduce insulin resistance (IR) with few serious side effects in patients with polycystic ovary syndrome (PCOS). To explore the mechanism of this action in an animal model, a PCOS-IR rat model was generated. Enzyme-linked immunosorbent assay was used to assess changes in ovulation function during treatment with a myo-inositol supplement, and Western blotting, real-time polymerase chain reaction, and immunohistochemistry were performed to investigate the underlying molecular mechanisms. The results showed that the myo-inositol supplement decreased the homeostatic model assessment of insulin resistance (HOMA-IR) index and significantly decreased the serum levels of luteinizing hormone (LH), LH/follicle-stimulating hormone ratio, and testosterone, while increasing the serum level of estradiol. Upregulation of interleukin 6 (IL-6), phospho-STAT3 (p-STAT3), Mir-21, and Mir-155 and significant downregulation of PPAR-γ and GLUT4 were detected in the untreated PCOS-IR rat model. However, downregulation of IL-6, p-STAT3, miR-21, and miR-155 and significant upregulation of PPAR-γ and GLUT4 were detected with myo-inositol supplementation. Thus, myo-inositol supplementation may reduce Mir-21 and Mir-155 levels by downregulating IL-6 and p-STAT3 and, subsequently, reverse the expression of PPAR-γ and GLUT4, leading to a decreased HOMA-IR index. In conclusion, the identification of an IL-6/p-STAT3/Mir-155/Mir-21/PPAR-γ/GLUT4 system in the PCOS-IR rat model provides insight into the pathogenesis of PCOS and may indicate a possible therapeutic strategy. Amelioration of the basal serum glucose levels and of the HOMA/HOMA-IR index may be achieved by the reversal of the expression of PPAR-γ and GLUT4 through the downregulation of IL-6, p-STAT3, miR-21, and miR-155 with myo-inositol supplementation.
Hongpeng Zheng,Yulong Lei,Pengxiang Song 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.3
Hydraulic retarders are auxiliary braking devices that reduce the velocity of a vehicle, particularly when a vehicle is driven downhill. Such velocity reduction could reduce the potential risk caused by brake failure caused by the service brake working for a long time and the temperature of the brake shoe becomes extremely high. This paper introduces the construction of the hydraulic retarder and proposes two mathematical models for the hydraulic retarder. The first mathematical model is deduced by using fluid mechanics, which is used to analyze the mechanism of how braking torque is produced and the key factors that can influence the value of the braking torque. The second mathematical model is deduced by using thermodynamics, which is used to quantify the heat produced by the hydraulic retarder. This research emphasizes that the flow rate and the average velocity of the working fluid in the working chamber mainly determine the braking torque of the hydraulic retarder. The flow rate into and out of the working chamber determines the temperature rise of the working fluid. Computational fluid dynamics (CFD) simulations are conducted with the Reynolds-averaged Navier-Stokes (RANS) and Shear Stress Transport (SST) turbulent models. Experiments are carried out to justify the two mathematical models and the CFD simulations. The results show that the mathematical models are capable of describing the force analysis and energy conversion of the hydraulic retarder and SST is more accurate for CFD simulation and the error is within 6 %.
Zhang Yulong,Cao Jinjia,Zhang Biao,Zheng Xiaochang,Chen Wei 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.7
Accurate reconstruction of radiation field and path planning are very important for the safety of operators in the process of dismantling nuclear facilities. Based on radial basis function (RBF) interpolation algorithm, this paper discussed the application of inverse multiquadric radial basis Function (IMRBF) interpolation method to the reconstruction of gamma radiation field, and proved the feasibility of reconstructing a radiation field with multiple γ sources. The average relative errors of IMRBF interpolation results were 4.28% and 8.76%, respectively, for the experimental scenarios with single and double gamma sources. After comparing the consistency between the simulated scene and the experimental scene, IMRBF method and Cubic Spline method were respectively used to reconstruct the gamma radiation field by Geant4 simulation data. The results showed that the interpolation accuracy of IMRBF method was superior to that of Cubic Spline method. Further, more RBF interpolation algorithms were used to reconstruct the multi-γ source radiation field, and then the Probabilistic Roadmap (PRM) algorithm was used to optimize the human walking path in the radiation field reconstructed by different interpolation methods. The optimal paths in radiation fields generated by multiple interpolation methods were compared. The results herein contribute to a comprehensive understanding of RBF interpolation methods in reconstructing γ radiation fields and their application in optimizing paths in radiation environments. The insights may provide valuable information for decision-making in radiation protection during the decommissioning of nuclear facilities.