Publications by authors named "Ying Shih"

16 Publications

  • Page 1 of 1

Dual IFN-γ/hypoxia priming enhances immunosuppression of mesenchymal stromal cells through regulatory proteins and metabolic mechanisms.

J Immunol Regen Med 2018 Mar 25;1:45-56. Epub 2018 Apr 25.

Department of Biomedical Engineering, Columbia University, New York, NY, USA.

The immunosuppressive capacity of human mesenchymal stromal cells (MSCs) renders them promising candidates for treating diverse immune disorders. However, after hundreds of clinical trials, there are still no MSC therapies approved in the United States. MSCs require specific cues to adopt their immunosuppressive phenotype, and yet most clinical trials use cells expanded in basic culture medium and growth conditions. We propose that priming MSCs prior to administration will improve their therapeutic efficacy. Interferon-gamma (IFN-γ) priming are cues common to situations of immune escape that have individually shown promise as MSC priming cues but have not been systematically compared. Using mixed lymphocyte reactions, we show that priming MSCs with either cue alone improves T-cell inhibition. However, combining the two cues results in additive effects and markedly enhances the immunosuppressive phenotype of MSCs. We demonstrate that IFN-γ induces expression of numerous immunosuppressive proteins (IDO, PD-L1, HLA-E, HLA-G), whereas hypoxia switches MSCs to glycolysis, causing rapid glucose consumption and production of T-cell inhibitory lactate levels. Dual IFN-γ/hypoxia primed MSCs display both attributes and have even higher induction of immunosuppressive proteins over IFN-γ priming alone (IDO and HLA-G), which may reflect another benefit of metabolic reconfiguration.
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http://dx.doi.org/10.1016/j.regen.2018.01.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6197483PMC
March 2018

Laminin-Alginate Beads as Preadipocyte Carriers to Enhance Adipogenesis In Vitro and In Vivo.

Tissue Eng Part A 2017 03 13;23(5-6):185-194. Epub 2016 Dec 13.

1 Institute of Biomedical Engineering, National Taiwan University , Taipei, Taiwan .

The use of autologous fat grafting in breast reconstruction still requires optimization. Fat survival and calcification are the main issues that affect the outcomes of the procedure. In this study, a cell-based therapy utilizing laminin-alginate beads (LABs) as carriers was proposed to promote cell survival and adipogenesis by providing short-term physical support and facilitate nutrient diffusion of the implants. Laminin-modified alginate beads were fabricated by immobilizing laminin onto ring-opened alginate, used to encapsulate 3T3-L1 preadipocytes, and evaluated in vitro and in vivo. LABs as preadipocyte carriers showed better biocompatibility and stability than unmodified alginate beads. Preadipocytes in LABs had higher survival rate and enhanced adipogenesis than those in unmodified alginate beads. In vivo studies showed that LABs gradually degraded and the sites were replaced by newly formed fat tissues, and new blood vessels were also observed. 7T-MRI study mimicking clinical fat grafting showed that LABs carrying adipose stem cells improved the results of conventional fat grafts. Therefore, we believe that LABs represent promising cell carriers and can be potentially used for the reconstruction of breasts or other soft tissues in the future.
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http://dx.doi.org/10.1089/ten.TEA.2016.0290DOI Listing
March 2017

Cinnamomum cassia essential oil and its major constituent cinnamaldehyde induced cell cycle arrest and apoptosis in human oral squamous cell carcinoma HSC-3 cells.

Environ Toxicol 2017 Feb 25;32(2):456-468. Epub 2016 Feb 25.

Department of Applied Chemistry, Providence University, 200, Sec. 7, Taiwan Boulevard, Taichung, 43301, Taiwan, Republic of China.

Cinnamomum cassia essential oil (CC-EO) has various functional properties, such as anti-microbial, hypouricemic, anti-tyrosinase and anti-melanogenesis activities. The present study aimed to evaluate the anti-cancer activities of CC-EO and its major constituent, cinnamaldehyde, in human oral squamous cell carcinoma HSC-3 cells. Determination of the cell viability, apoptotic characteristics, DNA damage, cell cycle analysis, reactive oxygen species (ROS) production, mitochondrial membrane potential, cytosolic Ca level and intracellular redox status were performed. Our results demonstrated that CC-EO and cinnamaldehyde significantly decreased cell viability and caused morphological changes. The cell cycle analysis revealed that CC-EO and cinnamaldehyde induced G2/M cell cycle arrest in HSC-3 cells. The apoptotic characteristics (DNA laddering and chromatin condensation) and DNA damage were observed in the CC-EO-treated and cinnamaldehyde-treated HSC-3 cells. Moreover, CC-EO and cinnamaldehyde promoted an increase in cytosolic Ca levels, induced mitochondrial dysfunction and activated cytochrome c release. The results of ROS production and intracellular redox status demonstrated that CC-EO and cinnamaldehyde significantly increased the ROS production and thiobarbituric acid reactive substance levels, and the cellular glutathione content and glutathione peroxidase activity were significantly reduced in HSC-3 cells. Our results suggest that CC-EO and cinnamaldehyde may possess anti-oral cancer activity in HSC-3 cells. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 456-468, 2017.
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http://dx.doi.org/10.1002/tox.22250DOI Listing
February 2017

The melanogenesis alteration effects of Achillea millefolium L. essential oil and linalyl acetate: involvement of oxidative stress and the JNK and ERK signaling pathways in melanoma cells.

PLoS One 2014 17;9(4):e95186. Epub 2014 Apr 17.

Department of Food and Nutrition, Providence University, Taichung, Taiwan.

The mitogen-activated protein kinase (MAPK) family, including extracellular signal-regulated kinase (ERK)1/2, c-Jun N-terminal kinase (JNK)1/2 and p38 MAPK, is known to be activated by ultraviolet (UV) radiation in melanocytes to regulate melanin production. Reactive oxygen species (ROS) play important roles in the pathway of ERK and JNK activation. It has been established that the essential oil of Achillea millefolium L. (AM-EO) has activities that suppress the oxidative stress and inflammatory responses. Thus, we analyzed the effects of AM-EO on melanogenesis in melanocyte stimulating hormone (α-MSH) treated melanoma cells. The results demonstrated that AM-EO suppresses melanin production by decreasing tyrosinase activity through the regulation of the JNK and ERK signaling pathways. This effect might be associated with the AM-EO activity leading to the suppression of ROS, and linalyl acetate is its major functional component. Therefore, we propose that AM-EO has the potential to treat hyperpigmentation in the future.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0095186PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3990609PMC
December 2014

Chemical composition and tyrosinase inhibitory activity of Cinnamomum cassia essential oil.

Bot Stud 2013 Dec 21;54(1):10. Epub 2013 Aug 21.

Department of Food and Nutrition, Providence University, 200 Chung-Chi Road, Shalu, Taichung, 43301, Taiwan, R.O.C.

Background: Essential oils extracted from aromatic plants exhibit important biological activities and have become increasingly important for scientific research. The essential oil extracted from Cinnamomum cassia Presl (CC-EO) has various functional properties, however, little information is available regarding the tyrosinase inhibitory activity. Therefore, the objectives of this study were to investigate the chemical composition and tyrosinase inhibitory activity of the CC-EO.

Results: cis-2-methoxycinnamic acid (43.06%) and cinnamaldehyde (42.37%) were found to be the two major components of the CC-EO identified by gas chromatography-mass spectrometry (GC-MS). The inhibitory activities of CC-EO and its major constituents were further evaluated against mushroom tyrosinase. The results showed that CC-EO and cinnamaldehyde exhibited anti-tyrosinase activities with IC values of 6.16 ± 0.04 mg/mL and 4.04 ± 0.08 mg/mL, respectively. However, cis-2-methoxycinnamic acid did not show any anti-tyrosinase activity. The inhibition kinetics were analyzed by Lineweaver-Burk plots and second replots, which revealed that CC-EO and cinnamaldehyde were mixed-type inhibitors. The inhibition constants (Ki) for CC-EO and cinnamaldehyde were calculated to be 4.71 ± 0.09 mg/mL and 2.38 ± 0.09 mg/mL, respectively.

Conclusion: These results demonstrate that CC-EO and its major component, cinnamaldehyde, possess potent anti-tyrosinase activities and may be a good source for skin-whitening agents.
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http://dx.doi.org/10.1186/1999-3110-54-10DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5432840PMC
December 2013

Cinnamomum cassia essential oil inhibits α-MSH-induced melanin production and oxidative stress in murine B16 melanoma cells.

Int J Mol Sci 2013 Sep 18;14(9):19186-201. Epub 2013 Sep 18.

Department of Food and Nutrition, Providence University, 200, Sec. 7, Taiwan Boulevard, Shalu Dist., Taichung City 43301, Taiwan.

Essential oils extracted from aromatic plants exhibit important biological activities and have become increasingly important for the development of aromatherapy for complementary and alternative medicine. The essential oil extracted from Cinnamomum cassia Presl (CC-EO) has various functional properties; however, little information is available regarding its anti-tyrosinase and anti-melanogenic activities. In this study, 16 compounds in the CC-EO have been identified; the major components of this oil are cis-2-methoxycinnamic acid (43.06%) and cinnamaldehyde (42.37%). CC-EO and cinnamaldehyde exhibited anti-tyrosinase activities; however, cis-2-methoxycinnamic acid did not demonstrate tyrosinase inhibitory activity. In murine B16 melanoma cells stimulated with α-melanocyte-stimulating hormone (α-MSH), CC-EO and cinnamaldehyde not only reduced the melanin content and tyrosinase activity of the cells but also down-regulated tyrosinase expression without exhibiting cytotoxicity. Moreover, CC-EO and cinnamaldehyde decreased thiobarbituric acid-reactive substance (TBARS) levels and restored glutathione (GSH) and catalase activity in the α-MSH-stimulated B16 cells. These results demonstrate that CC-EO and its major component, cinnamaldehyde, possess potent anti-tyrosinase and anti-melanogenic activities that are coupled with antioxidant properties. Therefore, CC-EO may be a good source of skin-whitening agents and may have potential as an antioxidant in the future development of complementary and alternative medicine-based aromatherapy.
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http://dx.doi.org/10.3390/ijms140919186DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3794828PMC
September 2013

Achillea millefolium L. essential oil inhibits LPS-induced oxidative stress and nitric oxide production in RAW 264.7 Macrophages.

Int J Mol Sci 2013 Jun 24;14(7):12978-93. Epub 2013 Jun 24.

Department of Food and Nutrition, Providence University, 200, Sec. 7, Taiwan Boulevard, Shalu Dist., Taichung 43301, Taiwan.

Achillea millefolium L. is a member of the Asteraceae family and has been used in folk medicine in many countries. In this study, 19 compounds in A. millefolium essential oil (AM-EO) have been identified; the major components are artemisia ketone (14.92%), camphor (11.64%), linalyl acetate (11.51%) and 1,8-cineole (10.15%). AM-EO can suppress the inflammatory responses of lipopolysaccharides (LPS)-stimulated RAW 264.7 macrophages, including decreased levels of cellular nitric oxide (NO) and superoxide anion production, lipid peroxidation and glutathione (GSH) concentration. This antioxidant activity is not a result of increased superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) activities, but rather occurs as a result of the down-regulation of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and heme oxygenase-1 (HO-1) expression, thus reducing the inflammatory response. Therefore, AM-EO can be utilized in many applications, including the treatment of inflammatory diseases in the future.
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http://dx.doi.org/10.3390/ijms140712978DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3742169PMC
June 2013

Advanced aqueous-phase phosphoramidation reactions for effectively synthesizing peptide-oligonucleotide conjugates trafficked into a human cell line.

Bioconjug Chem 2012 Dec 30;23(12):2417-33. Epub 2012 Nov 30.

Department of Medicinal and Applied Chemistry, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.

Peptide-oligonucleotide conjugates (POCs) have held promise as effective therapeutic agents in treating microbial infections and human genetic diseases including cancers. In clinical applications, POCs are especially useful to circumvent cellular delivery and specificity problems of oligonucleotides. We previously reported that nucleic acid phosphoramidation reactions performed in aqueous solutions have the potential for facile POC synthesis. Here, we carried out further studies to significantly improve aqueous-phase two-step phosphoramidation reaction yield. Optimized reactions were employed to effectively synthesize POCs for delivery into human A549 cells. We achieved optimization of aqueous-phase two-step phosphoramidation reaction and improved reaction yield by (1) determining appropriate co-solutes and co-solute concentrations to acquire higher reaction yields, (2) exploring a different nucleophilicity of imidazole and its derivatives to stabilize essential nucleic acid phosphorimidazolide intermediates prior to POC formation, and (3) enhancing POC synthesis by increasing reactant nucleophilicity. The advanced two-step phosphoramidation reaction was exploited to effectively conjugate a well-studied cell penetrating peptide, the Tat(48-57) peptide, with oligonucleotides, bridged by either no linkers or a disulfide-containing linker, to have the corresponding POC yields of 47-75%. Phosphoramidation-synthesized POCs showed no cytotoxicity to human A549 cells at studied POC concentrations after 24 h inoculation and were successfully trafficked into the human A549 cell line as demonstrated by flow cytometry, fluorescent microscopy, and confocal laser scanning microscopy study. The current report provides insight into aqueous-phase phosphoramidation reactions, the knowledge of which was used to develop effective strategies for synthesizing POCs with crucial applications including therapeutic agents for medicine.
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http://dx.doi.org/10.1021/bc300444yDOI Listing
December 2012

Sensitive and simple flow injection analysis of formaldehyde using an activated barrel plating nickel electrode.

J AOAC Int 2011 Sep-Oct;94(5):1585-91

Providence University, Department of Cosmetic Science, Taichung 433, Taiwan.

A flow injection analysis coupled with electrochemical detection at an activated barrel plating nickel electrode (Ni-BPE) was developed as a sensitive, simple, and low-cost formaldehyde sensor. The mechanism of Ni-BPE toward the electrocatalytic oxidation of formaldehyde in alkaline medium at ambient temperature was proposed to be based on the electrocatalytic oxidation of formaldehyde by Ni(III)O(OH) species. Under the optimized conditions (flow rate = 1.2 mL/min; detection potential = +0.5 V versus Ag/AgCl), a good linearity in the window of 0.037 to 10 microg/mL formaldehyde was observed, and the LOD of 0.23 microg/L was calculated. The RSDs of intraday (n = 10) and interday (n = 6) replicate measurements of 0.185-5 microg/mL formaldehyde ranged from 1.45 to 3.60%, indicating good reproducibility of the proposed method. The proposed method was successfully applied to the determination of formaldehyde in commercial nail polish samples and a drinking water sample.
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http://dx.doi.org/10.5740/jaoacint.10-378DOI Listing
January 2012

Selective determination of arbutin in cosmetic products through online derivatization followed by disposable electrochemical sensor.

J AOAC Int 2011 May-Jun;94(3):985-90

National Chung Hsing University, Department of Chemistry, Taichung 402, Taiwan.

An online derivatization followed by a disposable electrochemical sensor was used for the determination of arbutin (AR) in cosmetic products. The AR was chemically oxidized by MnO2 and subsequently reduced at inexpensive screen-printed carbon electrodes using a low detection potential which improved the selectivity of the method. The effects of various parameters, such as solution pH, detection potential, and flow rate of the mobile phase, were studied in detail. Under optimal conditions [pH 1.6 (0.1 M H3PO4), detection potential 0.0 V (versus Ag/AgCl), flow rate 0.6 mL/min], the linear range for AR was 0.1-1500 ppm (r2 = 0.999) with LOD of 30.06 ppb (S/N = 3). The practical application of the proposed method was demonstrated by the determination of arbutin concentration in commercial cosmetic products.
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August 2011

Screen-printed carbon electrodes modified with cobalt phthalocyanine for selective sulfur detection in cosmetic products.

Int J Mol Sci 2011 9;12(6):3810-20. Epub 2011 Jun 9.

Department of Cosmetic Science, Providence University 200 Chungchi Rd., Taichung 43301, Taiwan; E-Mails: (P.-Y.C.); (M.-C.C.); (F.-J.T.); (N.-F.C.).

Cobalt phthalocyanine (CoPc) films were deposited on the surface of a screen-printed carbon electrode using a simple drop coating method. The cyclic voltammogram of the resulting CoPc modified screen-printed electrode (CoPc/SPE) prepared under optimum conditions shows a well-behaved redox couple due to the (Co(I)/Co(II)) system. The CoPc/SPE surface demonstrates excellent electrochemical activity towards the oxidation of sulfur in a 0.01 mol·L(-1) NaOH. A linear calibration curve with the detection limit (D(L), S/N = 3) of 0.325 mg·L(-1) was achieved by CoPc/SPE coupled with flow injection analysis of the sulfur concentration ranging from 4 to 1120 mg·L(-1). The precision of the system response was evaluated (3.60% and 3.52% RSD for 12 repeated injections), in the range of 64 and 480 mg·L(-1) sulfur. The applicability of the method was successfully demonstrated in a real sample analysis of sulfur in anti-acne creams, and good recovery was obtained. The CoPc/SPE displayed several advantages in sulfur determination including easy fabrication, high stability, and low cost.
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http://dx.doi.org/10.3390/ijms12063810DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3131592PMC
January 2015

Quantification of ellagic acid in cosmetic products by using a partially preanodized screen-printed carbon electrode coupled with flow injection analysis.

Anal Methods 2011 Jan;3(1):205-209

Department of Cosmetic Science Providence University, 200 Chungchi Rd., Taichung, 43301, Taiwan.

A partially preanodized screen-printed carbon electrode (PSPCE*) coupled with flow injection analysis (FIA) was developed to raise the selectivity of ellagic acid (EA). To confirm the effectiveness of partial preanodization, two pretreated screen-printed carbon electrodes were electrochemically compared. One was a PSPCE* fabricated by potential cycling (-1.0 - +1.0 V vs. Ag/AgCl) to make the electrode surface partially preanodized and the other was a SPCE* fabricated by a high treatment potential (+2.0 V vs. Ag/AgCl). Cyclic voltammograms showed that the catalytic current of EA was observed at both the PSPCE* and SPCE*. No catalytic current of ascorbic acid 2-glucoside (AA2G) and magnesium ascorbyl phosphate (MAP) was observed at the PSPCE*. The PSPCE* selectively detected EA. The factors, which influence the EA response current, have previously been discussed. At the detection limit (0.012 ppm, S/N = 3), the linear calibration plot (R2 = 0.998) was attained for 0.1-50 ppm of EA solutions. A relative standard deviation of 4.37 and 3.90% was conducted for consecutive injections (n = 10) of 1 and 50 ppm EA, respectively. Finally, a practical application of the proposed method was demonstrated by the quantitative analysis of EA in skin whitening creams, and good recovery was obtained.
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http://dx.doi.org/10.1039/c0ay00592dDOI Listing
January 2011

Determination of thioglycolic acid in hair-waving products by disposable electrochemical sensor coupled with high-performance liquid chromatography.

J AOAC Int 2009 Mar-Apr;92(2):574-9

National Chung Hsing University, Department of Chemistry, Taichung 402, Taiwan.

A disposable electrochemical sensor coupled with high-performance liquid chromatography (HPLC) was developed for the determination of thioglycolic acid (TGA) in commercial hair-waving products. The quantitative determination of TGA was first investigated by using a preanodized (*) screen-printed carbon electrode (SPCE*). Because of the electrocatalytic effect of the SPCE*, the peak potential (Epa) was shifted less positively as the current magnitude increased. HPLC was used in this study to eliminate interference from the matrix of real samples. The effects of various parameters, such as preanodization potential, preanodization time, solution pH, detection potential, and mobile phase, were studied in detail. Under optimized conditions, the linear range for TGA is up to 20 ppm, correlation coefficient (r2) = 0.998, with a detection limit of 0.042 ppm (signal-to-noise ratio = 3). The practical application of the proposed method was demonstrated by the determination of TGA concentration in commercial hair-waving products.
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July 2009

Amplified spontaneous emission from ZnO in n-ZnO/ZnO nanodots-SiO(2) composite/p-AlGaN heterojunction light-emitting diodes.

Nanotechnology 2009 Apr 31;20(16):165201. Epub 2009 Mar 31.

Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan, Republic of China.

This study demonstrates amplified spontaneous emission (ASE) of the ultraviolet (UV) electroluminescence (EL) from ZnO at lambda~380 nm in the n-ZnO/ZnO nanodots-SiO(2) composite/p- Al(0.12)Ga(0.88)N heterojunction light-emitting diode. A SiO(2) layer embedded with ZnO nanodots was prepared on the p-type Al(0.12)Ga(0.88)N using spin-on coating of SiO(2) nanoparticles followed by atomic layer deposition (ALD) of ZnO. An n-type Al-doped ZnO layer was deposited upon the ZnO nanodots-SiO(2) composite layer also by the ALD technique. High-resolution transmission electron microscopy (HRTEM) reveals that the ZnO nanodots embedded in the SiO(2) matrix have diameters of 3-8 nm and the wurtzite crystal structure, which allows the transport of carriers through the thick ZnO nanodots-SiO(2) composite layer. The high quality of the n-ZnO layer was manifested by the well crystallized lattice image in the HRTEM picture and the low-threshold optically pumped stimulated emission. The low refractive index of the ZnO nanodots-SiO(2) composite layer results in the increase in the light extraction efficiency from n-ZnO and the internal optical feedback of UV EL into n-ZnO layer. Consequently, significant enhancement of the UV EL intensity and super-linear increase in the EL intensity, as well as the spectral narrowing, with injection current were observed owing to ASE in the n-ZnO layer.
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http://dx.doi.org/10.1088/0957-4484/20/16/165201DOI Listing
April 2009

Flow injection analysis of zinc pyrithione in hair care products on a cobalt phthalocyanine modified screen-printed carbon electrode.

Talanta 2004 Apr;62(5):912-7

Department of Applied Cosmetology, Hung Kuang University, Taichung 433, Taiwan, ROC.

Zinc pyrithione (ZPT) is an antibacterial and antifungal reagent that is often utilized for the antidandruff activity in hair-care shampoos with a composition level up to 1% in the formulation. It has some adverse effects to human and animal if consumed orally. A disposable type of cobalt phthalocyanide modified screen-printed carbon electrode (CoPc/SPE) in couple with flow injection analysis (FIA) was developed for easy and selective analysis of ZPT in commercial hair-care products. Under the optimized FIA conditions, the CoPc/SPE yielded a linear calibration plot in the window of 6-576muM with sensitivity and detection limit of 1.65nAmuM(-1) and 0.9muM (i.e. 1.42pg in 5mul sample loop), respectively, in 0.1M KOH solution at an applied potential of 0.3V versus Ag/AgCl. Since the approach is simple, easy, selective, and inexpensive, it offers a potential application of daily ZPT analysis in hair-care products.
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http://dx.doi.org/10.1016/j.talanta.2003.10.039DOI Listing
April 2004

Determination of tranexamic acid in cosmetic products by high-performance liquid chromatography coupled with barrel plating nickel electrode.

J Pharm Biomed Anal 2008 Dec 19;48(5):1446-50. Epub 2008 Sep 19.

Department of Applied Cosmetology, Hung Kuang University, Taichung 433, Taiwan.

Tranexamic acid (TA) is an important reagent in cosmetic skin-whitening formulation and a drug for the inhibition of plasminogen to plasmin in blood. Since there is no chromophore in tranexamic acid molecule to enable direct analysis by UV-visible absorption spectrophotometry, derivatization is thus required by excluding use of UV or fluorescence detection. We report here a relatively simple electrochemical TA detection method by using a barrel plating nickel electrode. Chromatographic separation was performed on a Hamilton PRP-X100 anion-exchange column (150 mm x 4.1 mm i.d., 10 microm particle size) with a (85:15, v/v) mixture of 0.1 mol l(-1) NaOH and acetonitrile as mobile phase and pumped at a flow rate of 0.9 ml min(-1). By detecting at +0.55 V vs. Ag/AgCl, the calibration plot was linear in the concentration window of 3-1000 ppm with regression coefficient and detection limit (S/N=3) of 0.9993 and 0.13 ppm (0.84 micromol l(-1)), respectively. Successive injections (n=10) of 50 ppm tranexamic acid showed a R.S.D. value of only 0.3% indicating good reproducibility of the proposed system. The method was successfully applied to the analysis of the content of tranexamic acid in cosmetic products and proved to be suitable for rapid and reliable quality control.
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http://dx.doi.org/10.1016/j.jpba.2008.09.019DOI Listing
December 2008
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