{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,30]],"date-time":"2025-08-30T17:06:15Z","timestamp":1756573575676,"version":"3.37.3"},"reference-count":57,"publisher":"Springer Science and Business Media LLC","issue":"9","license":[{"start":{"date-parts":[[2021,8,19]],"date-time":"2021-08-19T00:00:00Z","timestamp":1629331200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.springer.com\/tdm"},{"start":{"date-parts":[[2021,8,19]],"date-time":"2021-08-19T00:00:00Z","timestamp":1629331200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.springer.com\/tdm"}],"funder":[{"DOI":"10.13039\/501100001321","name":"National Research Foundation","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100001321","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["Metabolomics"],"published-print":{"date-parts":[[2021,9]]},"DOI":"10.1007\/s11306-021-01825-z","type":"journal-article","created":{"date-parts":[[2021,8,19]],"date-time":"2021-08-19T05:07:57Z","timestamp":1629349677000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["The effect of combined oral contraceptives containing drospirenone and ethinylestradiol on serum levels of amino acids and acylcarnitines"],"prefix":"10.1007","volume":"17","author":[{"given":"Albe","family":"Swanepoel","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Janette","family":"Bester","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yolanda","family":"Kruger","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Elmarie","family":"Davoren","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5456-3931","authenticated-orcid":false,"given":"Ilse","family":"du Preez","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2021,8,19]]},"reference":[{"key":"1825_CR1","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1186\/1477-7827-10-49","volume":"10","author":"A Agarwal","year":"2012","unstructured":"Agarwal, A., Aponte-Mellado, A., Premkumar, B. J., Shaman, A., & Gupta, S. (2012). The effects of oxidative stress on female reproduction: A review. Reproductive Biology and Endocrinology, 10, 49.","journal-title":"Reproductive Biology and Endocrinology"},{"key":"1825_CR2","doi-asserted-by":"publisher","first-page":"1731","DOI":"10.1016\/j.jacc.2003.12.047","volume":"43","author":"JA Ambrose","year":"2004","unstructured":"Ambrose, J. A., & Barua, R. S. (2004). The pathophysiology of cigarette smoking and cardiovascular disease: An update. Journal of the American College of Cardiology, 43, 1731\u20131737.","journal-title":"Journal of the American College of Cardiology"},{"key":"1825_CR111","doi-asserted-by":"crossref","unstructured":"Amores-S\u00e1nchez, M. I., & Medina, M. A. (1999). Glutamine, as a precursor of glutathione, and oxidative stress. Molecular Genetics and Metabolism, 67, 100\u2013105.","DOI":"10.1006\/mgme.1999.2857"},{"key":"1825_CR3","doi-asserted-by":"publisher","first-page":"8","DOI":"10.1038\/s41387-018-0017-1","volume":"8","author":"J Bene","year":"2018","unstructured":"Bene, J., Hadzsiev, K., & Melegh, B. (2018). Role of carnitine and its derivatives in the development and management of type 2 diabetes. Nutrition and Diabetes, 8, 8.","journal-title":"Nutrition and Diabetes"},{"key":"1825_CR4","doi-asserted-by":"publisher","first-page":"54","DOI":"10.1016\/j.ijcard.2005.02.053","volume":"107","author":"LA Cal\u00f2","year":"2006","unstructured":"Cal\u00f2, L. A., Pagnin, E., Davis, P. A., Semplicini, A., Nicolai, R., Calvani, M., & Pessina, A. C. (2006). Antioxidant effect of L-carnitine and its short chain esters: Relevance for the protection from oxidative stress related cardiovascular damage. International Journal of Cardiology, 107, 54\u201360.","journal-title":"International Journal of Cardiology"},{"key":"1825_CR5","doi-asserted-by":"publisher","first-page":"379","DOI":"10.1093\/ajcn\/44.3.379","volume":"44","author":"G Cederblad","year":"1986","unstructured":"Cederblad, G., F\u00e5hraeus, L., & Lindgren, K. (1986). Plasma carnitine and renal-carnitine clearance during pregnancy. American Journal of Clinical Nutrition, 44, 379\u2013383.","journal-title":"American Journal of Clinical Nutrition"},{"key":"1825_CR6","doi-asserted-by":"publisher","first-page":"22","DOI":"10.3390\/jcm6020022","volume":"6","author":"K Cervantes Gracia","year":"2017","unstructured":"Cervantes Gracia, K., Llanas-Cornejo, D., & Husi, H. (2017). CVD and oxidative stress. Journal of Clinical Medicine, 6, 22.","journal-title":"Journal of Clinical Medicine"},{"key":"1825_CR101","doi-asserted-by":"crossref","unstructured":"Chandrashekar, K. N., & Muralidhara. (2010). D-Aspartic acid induced oxidative stress and mitochondrial dysfunctions in testis of prepubertal rats. Amino Acids, 38, 817\u2013827.","DOI":"10.1007\/s00726-009-0288-x"},{"key":"1825_CR7","doi-asserted-by":"publisher","first-page":"e86","DOI":"10.1002\/cpbi.86","volume":"68","author":"J Chong","year":"2019","unstructured":"Chong, J., Wishart, D. S., & Xia, J. (2019). Using MetaboAnalyst 4.0 for comprehensive and integrative metabolomics data analysis. Current Protocols in Bioinformatics, 68, e86.","journal-title":"Current Protocols in Bioinformatics"},{"key":"1825_CR8","doi-asserted-by":"publisher","first-page":"428","DOI":"10.1055\/s-0028-1093407","volume":"10","author":"BD Cox","year":"1978","unstructured":"Cox, B. D., & Calame, D. P. (1978). Changes in plasma amino acid levels during the human menstrual cycle and in early pregnancy. A preliminary report. Hormone and Metabolic Research, 10, 428\u2013433.","journal-title":"Hormone and Metabolic Research"},{"key":"1825_CR9","doi-asserted-by":"publisher","first-page":"301","DOI":"10.1042\/cs0410301","volume":"41","author":"IL Craft","year":"1971","unstructured":"Craft, I. L., & Peters, T. J. (1971). Quantitative changes in plasma amino acids induced by oral contraceptives. Clinical Science, 41, 301\u2013307.","journal-title":"Clinical Science"},{"key":"1825_CR102","doi-asserted-by":"crossref","unstructured":"Dalazen, G. R., Terra, M., Jacques, C. E., Coelho, J. G., Freitas, R., Mazzola, P. N., & Dutra-Filho, C. S. (2014). Pipecolic acid induces oxidative stress in vitro in cerebral cortex of young rats and the protective role of lipoic acid. Metabolic Brain Disease, 29, 175\u2013183.","DOI":"10.1007\/s11011-013-9466-3"},{"issue":"62","key":"1825_CR10","first-page":"1","volume":"14","author":"K Daniels","year":"2013","unstructured":"Daniels, K., & Mosher, W. D. (2013). Contraceptive methods women have ever used: United States, 1982\u20132010. National Health Statistics Report, 14(62), 1\u201315.","journal-title":"National Health Statistics Report"},{"key":"1825_CR109","doi-asserted-by":"crossref","unstructured":"D\u00edaz-Flores, M., Cruz, M., Duran-Reyes, G., Munguia-Miranda, C., Loza-Rodr\u00edguez, H., Pulido-Casas, E., Torres-Ram\u00edrez, N., Gaja-Rodriguez, O., Kumate, J., Baiza-Gutman, L. A., & Hern\u00e1ndez-Saavedra, D. (2013). Oral supplementation with glycine reduces oxidative stress in patients with metabolic syndrome, improving their systolic blood pressure. Canadian Journal Of Physiology And Pharmacology, 91, 855\u2013860.","DOI":"10.1139\/cjpp-2012-0341"},{"key":"1825_CR110","doi-asserted-by":"crossref","unstructured":"El-Hafidi, M., Franco, M., Ram\u00edrez, A. R., Sosa, J. S., Flores, J. A. P., Acosta, O. L., Salgado, M. C., & Cardoso-Salda\u00f1a, G. (2018). Glycine increases insulin sensitivity and glutathione biosynthesis and protects against oxidative stress in a model of sucrose-induced insulin resistance. Oxidative Medicine and Cellular Longevity, 2018, 2101562.","DOI":"10.1155\/2018\/2101562"},{"key":"1825_CR11","doi-asserted-by":"publisher","first-page":"1602","DOI":"10.1093\/humrep\/den109","volume":"23","author":"SM Fenkci","year":"2008","unstructured":"Fenkci, S. M., Fenkci, V., Oztekin, O., Rota, S., & Karagenc, N. (2008). Serum total L-carnitine levels in non-obese women with polycystic ovary syndrome. Human Reproduction, 23, 1602\u20131606.","journal-title":"Human Reproduction"},{"key":"1825_CR12","doi-asserted-by":"publisher","first-page":"30","DOI":"10.1186\/1743-7075-7-30","volume":"7","author":"JL Flanagan","year":"2010","unstructured":"Flanagan, J. L., Simmons, P. A., Vehige, J., Willcox, M. D., & Garrett, Q. (2010). Role of carnitine in disease. Nutrition and Metabolism (london), 7, 30.","journal-title":"Nutrition and Metabolism (london)"},{"key":"1825_CR13","first-page":"64","volume":"74","author":"IF Godsland","year":"1992","unstructured":"Godsland, I. F., Walton, C., Felton, C., Proudler, A., Patel, A., & Wynn, V. (1992). Insulin resistance, secretion, and metabolism in users of oral contraceptives. Journal of Clinical Endocrinology and Metabolism, 74, 64\u201370.","journal-title":"Journal of Clinical Endocrinology and Metabolism"},{"key":"1825_CR14","doi-asserted-by":"publisher","first-page":"1918","DOI":"10.3390\/ijms21061918","volume":"21","author":"C Gutmann","year":"2020","unstructured":"Gutmann, C., Siow, R., Gwozdz, A. M., Saha, P., & Smith, A. (2020). Reactive oxygen species in venous thrombosis. International Journal of Molecular Sciences, 21, 1918.","journal-title":"International Journal of Molecular Sciences"},{"key":"1825_CR119","doi-asserted-by":"crossref","unstructured":"Ha, H. C., Sirisoma, N. S., Kuppusamy, P., Zweier, J. L., Woster, P. M., & Casero, R. A., Jr. (1998). The natural polyamine spermine functions directly as a free radical scavenger. Proceedings of the National Academy of Sciences of the United States of America, 95, 11140\u201311145.","DOI":"10.1073\/pnas.95.19.11140"},{"key":"1825_CR15","doi-asserted-by":"publisher","first-page":"46","DOI":"10.1093\/ajcn\/50.1.46","volume":"50","author":"N Hrboticky","year":"1989","unstructured":"Hrboticky, N., Leiter, L. A., & Anderson, G. H. (1989). Menstrual cycle effects on the metabolism of tryptophan loads. American Journal of Clinical Nutrition, 50, 46\u201352.","journal-title":"American Journal of Clinical Nutrition"},{"key":"1825_CR16","doi-asserted-by":"publisher","first-page":"3167","DOI":"10.1210\/en.2007-1227","volume":"149","author":"RW Irwin","year":"2008","unstructured":"Irwin, R. W., Yao, J., Hamilton, R. T., Cadenas, E., Brinton, R. D., & Nilsen, J. (2008). Progesterone and estrogen regulate oxidative metabolism in brain mitochondria. Endocrinology, 149, 3167\u20133175.","journal-title":"Endocrinology"},{"key":"1825_CR116","doi-asserted-by":"crossref","unstructured":"Katayama, S., & Mine, Y. (2007). Antioxidative activity of amino acids on tissue oxidative stress in human intestinal epithelial cell model. Journal Of Agricultural And Food Chemistry, 55, 8458\u20138464.","DOI":"10.1021\/jf070866p"},{"key":"1825_CR17","doi-asserted-by":"publisher","first-page":"315","DOI":"10.1007\/s00726-006-0407-x","volume":"34","author":"S Kaul","year":"2008","unstructured":"Kaul, S., Sharma, S. S., & Mehta, I. K. (2008). Free radical scavenging potential of L-proline: Evidence from in vitro assays. Amino Acids, 34, 315\u2013320.","journal-title":"Amino Acids"},{"key":"1825_CR18","doi-asserted-by":"publisher","first-page":"14","DOI":"10.1016\/j.contraception.2017.10.003","volume":"97","author":"ML Kavanaugh","year":"2018","unstructured":"Kavanaugh, M. L., & Jerman, J. (2018). Contraceptive method use in the United States: Trends and characteristics between 2008, 2012 and 2014. Contraception, 97, 14\u201321.","journal-title":"Contraception"},{"key":"1825_CR19","doi-asserted-by":"publisher","first-page":"336","DOI":"10.1016\/j.contraception.2005.09.015","volume":"73","author":"C Kluft","year":"2006","unstructured":"Kluft, C., Endrikat, J., Mulder, S. M., Gerlinger, C., & Heithecker, R. (2006). A prospective study on the effects on hemostasis of two oral contraceptives containing drospirenone in combination with either 30 or 20 microg ethinyl estradiol and a reference containing desogestrel and 30 microg ethinyl estradiol. Contraception, 73, 336\u2013343.","journal-title":"Contraception"},{"key":"1825_CR20","doi-asserted-by":"publisher","first-page":"90","DOI":"10.1016\/j.mehy.2005.01.031","volume":"65","author":"P Kovacic","year":"2005","unstructured":"Kovacic, P. (2005). Unifying mechanism for addiction and toxicity of abused drugs with application to dopamine and glutamate mediators: Electron transfer and reactive oxygen species. Medical Hypotheses, 65, 90\u201396.","journal-title":"Medical Hypotheses"},{"key":"1825_CR21","doi-asserted-by":"publisher","first-page":"374","DOI":"10.1016\/S0002-9378(16)34545-8","volume":"99","author":"FR Lecocq","year":"1967","unstructured":"Lecocq, F. R., Bradley, E. M., & Goldzieher, J. W. (1967). Metabolic balance studies with norethynodrel and chlormadinone acetate. American Journal of Obstetrics and Gynecology, 99, 374\u2013381.","journal-title":"American Journal of Obstetrics and Gynecology"},{"key":"1825_CR107","doi-asserted-by":"crossref","unstructured":"Lee, B. J., Lin, J. S., Lin, Y. C., & Lin, P. T. (2014). Effects of L-carnitine supplementation on oxidative stress and antioxidant enzymes activities in patients with coronary artery disease: A randomized, placebo-controlled trial. Nutrition Journal, 13, 79.","DOI":"10.1186\/1475-2891-13-79"},{"key":"1825_CR22","doi-asserted-by":"publisher","first-page":"933","DOI":"10.1136\/gut.34.7.933","volume":"34","author":"A Lerner","year":"1993","unstructured":"Lerner, A., Gruener, N., & Iancu, T. C. (1993). Serum carnitine concentrations in coeliac disease. Gut, 34, 933\u2013935.","journal-title":"Gut"},{"key":"1825_CR105","doi-asserted-by":"crossref","unstructured":"Liang, X., Zhang, L., Natarajan, S. K., & Becker, D. F. (2013). Proline mechanisms of stress survival. Antioxidants & Redox Signaling, 19, 998\u20131011.","DOI":"10.1089\/ars.2012.5074"},{"key":"1825_CR23","doi-asserted-by":"publisher","first-page":"97","DOI":"10.1093\/emph\/eox009","volume":"1","author":"JL Lovett","year":"2017","unstructured":"Lovett, J. L., Chima, M. A., Wexler, J. K., Arslanian, K. J., Friedman, A. B., Yousif, C. B., & Strassmann, B. I. (2017). Oral contraceptives cause evolutionarily novel increases in hormone exposure: A risk factor for breast cancer. Evolution, Medicine, and Public Health, 1, 97\u2013108.","journal-title":"Evolution, Medicine, and Public Health"},{"key":"1825_CR106","doi-asserted-by":"crossref","unstructured":"Luo, S., & Levine, R. L. (2009). Methionine in proteins defends against oxidative stress. Faseb Journal: Official Publication Of The Federation Of American Societies For Experimental Biology, 23, 464\u2013472.","DOI":"10.1096\/fj.08-118414"},{"key":"1825_CR24","doi-asserted-by":"publisher","first-page":"68","DOI":"10.1186\/1750-1172-7-68","volume":"7","author":"PL Magoulas","year":"2012","unstructured":"Magoulas, P. L., & El-Hattab, A. W. (2012). Systemic primary carnitine deficiency: An overview of clinical manifestations, diagnosis, and management. Orphanet Journal of Rare Diseases, 7, 68.","journal-title":"Orphanet Journal of Rare Diseases"},{"key":"1825_CR104","unstructured":"Maralani, M. N., Movahedian, A., & Javanmard, S. H. (2012). Antioxidant and cytoprotective effects of L-serine on\nhuman endothelial cells. Research In Pharmaceutical Sciences, 7, 209\u2013215."},{"key":"1825_CR25","doi-asserted-by":"publisher","first-page":"378","DOI":"10.3390\/ijms16010378","volume":"16","author":"L Marseglia","year":"2014","unstructured":"Marseglia, L., Manti, S., D\u2019Angelo, G., Nicotera, A., Parisi, E., Di Rosa, G., Gitto, E., & Arrigo, T. (2014). Oxidative stress in obesity: A critical component in human diseases. International Journal of Molecular Sciences, 16, 378\u2013400.","journal-title":"International Journal of Molecular Sciences"},{"key":"1825_CR112","doi-asserted-by":"crossref","unstructured":"Mat\u00e9s, J. M., P\u00e9rez-G\u00f3mez, C., N\u00fa\u00f1ez De Castro, I., Asenjo, M., & M\u00e1rquez, J. (2002). Glutamine and its relationship with intracellular redox status, oxidative stress and cell proliferation\/death. The International Journal Of Biochemistry & Cell Biology, 34, 439\u2013458.","DOI":"10.1016\/S1357-2725(01)00143-1"},{"key":"1825_CR26","doi-asserted-by":"publisher","first-page":"179","DOI":"10.1007\/s002280050089","volume":"50","author":"SE Moller","year":"1996","unstructured":"Moller, S. E., Moller, B. M., Olesen, M., & Fjalland, B. (1996). Effects of oral contraceptives on plasma neutral amino acids and cholesterol during a menstrual cycle. European Journal of Clinical Pharmacology, 50, 179\u2013184.","journal-title":"European Journal of Clinical Pharmacology"},{"key":"1825_CR113","doi-asserted-by":"crossref","unstructured":"Moosmann, B., & Behl, C. (2000). Cytoprotective antioxidant function of tyrosine and tryptophan residues in transmembrane proteins. European Journal of Biochemistry, 267, 5687\u20135692.","DOI":"10.1046\/j.1432-1327.2000.01658.x"},{"key":"1825_CR103","doi-asserted-by":"crossref","unstructured":"Parker, S. J., & Metallo, C. M. (2016). Chasing one-carbon units to understand the role of serine in epigenetics. Molecular Cell, 61, 185\u2013186.","DOI":"10.1016\/j.molcel.2016.01.006"},{"key":"1825_CR120","doi-asserted-by":"crossref","unstructured":"Phang, J. M., Liu, W., & Zabirnyk, O. (2010). Proline metabolism and microenvironmental stress. Annual Review of Nutrition, 30, 441\u2013463.","DOI":"10.1146\/annurev.nutr.012809.104638"},{"key":"1825_CR121","doi-asserted-by":"crossref","unstructured":"Phang, J. M., Pandhare, J., & Liu, Y. (2008). The metabolism of proline as microenvironmental stress substrate. The Journal Of Nutrition, 138, 2008s\u20132015s.","DOI":"10.1093\/jn\/138.10.2008S"},{"key":"1825_CR27","doi-asserted-by":"publisher","first-page":"782","DOI":"10.1124\/jpet.107.134072","volume":"325","author":"A Razmara","year":"2008","unstructured":"Razmara, A., Sunday, L., Stirone, C., Wang, X. B., Krause, D. N., Duckles, S. P., & Procaccio, V. (2008). Mitochondrial effects of estrogen are mediated by estrogen receptor \u03b1 in brain endothelial cells. Journal of Pharmacology and Experimental Therapeutics, 325, 782\u2013790.","journal-title":"Journal of Pharmacology and Experimental Therapeutics"},{"key":"1825_CR28","doi-asserted-by":"publisher","first-page":"34628","DOI":"10.18632\/oncotarget.26015","volume":"9","author":"P-A Regidor","year":"2018","unstructured":"Regidor, P.-A. (2018). The clinical relevance of progestogens in hormonal contraception: Present status and future developments. Oncotarget, 9, 34628\u201334638.","journal-title":"Oncotarget"},{"key":"1825_CR29","doi-asserted-by":"publisher","first-page":"e1","DOI":"10.1136\/jfprhc-2012-100397","volume":"39","author":"S Reif","year":"2013","unstructured":"Reif, S., Snelder, N., & Blode, H. (2013). Characterisation of the pharmacokinetics of ethinylestradiol and drospirenone in extended-cycle regimens: Population pharmacokinetic analysis from a randomised Phase III study. The Journal of Family Planning and Reproductive Health Care, 39, e1\u2013e13.","journal-title":"The Journal of Family Planning and Reproductive Health Care"},{"key":"1825_CR30","first-page":"614","volume":"6","author":"M Ruoppolo","year":"2014","unstructured":"Ruoppolo, M., Campesi, I., Scolamiero, E., Pecce, R., Caterino, M., Cherchi, S., Mercuro, G., Tonolo, G., & Franconi, F. (2014). Serum metabolomic profiles suggest influence of sex and oral contraceptive use. American Journal of Translational Research, 6, 614\u2013624.","journal-title":"American Journal of Translational Research"},{"key":"1825_CR31","doi-asserted-by":"publisher","DOI":"10.1095\/biolreprod.110.088120","author":"A Sawai","year":"2018","unstructured":"Sawai, A., Tsuzuki, K., Yamauchi, M., Kimura, N., Tsushima, T., Sugiyama, K., Ota, Y., Sawai, S., & Tochikubo, O. (2018). The effects of estrogen and progesterone on plasma amino acids levels: Evidence from change plasma amino acids levels during the menstrual cycle in women. Biological Rhythm Research. https:\/\/doi.org\/10.1095\/biolreprod.110.088120","journal-title":"Biological Rhythm Research"},{"key":"1825_CR32","doi-asserted-by":"publisher","first-page":"256","DOI":"10.1210\/jc.2013-2835","volume":"99","author":"GI Smith","year":"2014","unstructured":"Smith, G. I., Yoshino, J., Reeds, D. N., Bradley, D., Burrows, R. E., Heisey, H. D., Moseley, A. C., & Mittendorfer, B. (2014). Testosterone and progesterone, but not estradiol, stimulate muscle protein synthesis in postmenopausal women. The Journal of Clinical Endocrinology and Metabolism, 99, 256\u2013265.","journal-title":"The Journal of Clinical Endocrinology and Metabolism"},{"key":"1825_CR33","doi-asserted-by":"publisher","first-page":"e385","DOI":"10.1097\/MD.0000000000000385","volume":"94","author":"B Stocco","year":"2015","unstructured":"Stocco, B., Fumagalli, H. F., Franceschini, S. A., Martinez, E. Z., Marzocchi-Machado, C. M., De Sa, M. F., & Toloi, M. R. (2015). Comparative study of the effects of combined oral contraceptives in hemostatic variables: An observational preliminary study. Medicine (baltimore), 94, e385.","journal-title":"Medicine (baltimore)"},{"key":"1825_CR34","doi-asserted-by":"publisher","first-page":"404","DOI":"10.1089\/omi.2020.0009","volume":"24","author":"AC Swanepoel","year":"2020","unstructured":"Swanepoel, A. C., Bester, J., Emmerson, O., Soma, P., Beukes, D., van Reenen, M., Loots, D. T., & du Preez, I. (2020). Serum metabolome changes in relation to prothrombotic state induced by combined oral contraceptives with drospirenone and ethinylestradiol. OMICS: A Journal of Integrative Biology, 24, 404\u2013414.","journal-title":"OMICS: A Journal of Integrative Biology"},{"key":"1825_CR35","doi-asserted-by":"publisher","first-page":"594","DOI":"10.1002\/jemt.22378","volume":"77","author":"AC Swanepoel","year":"2014","unstructured":"Swanepoel, A. C., Lindeque, B. G., Swart, P. J., Abdool, Z., & Pretorius, E. (2014). Estrogen causes ultrastructural changes of fibrin networks during the menstrual cycle: A qualitative investigation. Microscopy Research and Technique, 77, 594\u2013601.","journal-title":"Microscopy Research and Technique"},{"key":"1825_CR36","doi-asserted-by":"publisher","first-page":"29","DOI":"10.1002\/bdd.1816","volume":"34","author":"I Tamai","year":"2013","unstructured":"Tamai, I. (2013). Pharmacological and pathophysiological roles of carnitine\/organic cation transporters (OCTNs: SLC22A4, SLC22A5 and Slc22a21). Biopharmaceutics and Drug Disposition, 34, 29\u201344.","journal-title":"Biopharmaceutics and Drug Disposition"},{"key":"1825_CR108","doi-asserted-by":"crossref","unstructured":"Terruzzi, I., Montesano, A., Senesi, P., Villa, I., Ferraretto, A., Bottani, M., Vacante, F., Spinello, A., Bolamperti, S., Luzi, L., & Rubinacci, A. (2019). L-carnitine reduces oxidative stress and promotes cells differentiation and bone matrix proteins expression in human osteoblast-like cells. Biomed Research International, 2019, 5678548.","DOI":"10.1155\/2019\/5678548"},{"key":"1825_CR117","unstructured":"Ushmorov, A., Hack, V., & Dr\u00f6ge, W. (1999). Differential reconstitution of mitochondrial respiratory chain activity and plasma redox state by cysteine and ornithine in a model of cancer cachexia. Cancer Research, 59, 3527\u20133534."},{"key":"1825_CR37","doi-asserted-by":"publisher","first-page":"65","DOI":"10.2174\/157015909787602823","volume":"7","author":"B Uttara","year":"2009","unstructured":"Uttara, B., Singh, A. V., Zamboni, P., & Mahajan, R. T. (2009). Oxidative stress and neurodegenerative diseases: A review of upstream and downstream antioxidant therapeutic options. Current Neuropharmacology, 7, 65\u201374.","journal-title":"Current Neuropharmacology"},{"key":"1825_CR38","doi-asserted-by":"publisher","first-page":"1445","DOI":"10.1093\/ije\/dyw147","volume":"45","author":"Q Wang","year":"2016","unstructured":"Wang, Q., Wurtz, P., Auro, K., Morin-Papunen, L., Kangas, A. J., Soininen, P., Tiainen, M., Tynkkynen, T., Joensuu, A., Havulinna, A. S., Aalto, K., Salmi, M., Blankenberg, S., Zeller, T., Viikari, J., Kahonen, M., Lehtimaki, T., Salomaa, V., Jalkanen, S., \u2026 Ala-Korpela, M. (2016). Effects of hormonal contraception on systemic metabolism: Cross-sectional and longitudinal evidence. International Journal of Epidemiology, 45, 1445\u20131457.","journal-title":"International Journal of Epidemiology"},{"key":"1825_CR39","doi-asserted-by":"publisher","first-page":"1053","DOI":"10.1007\/s00726-010-0715-z","volume":"40","author":"G Wu","year":"2011","unstructured":"Wu, G., Bazer, F. W., Burghardt, R. C., Johnson, G. A., Kim, S. W., Knabe, D. A., Li, P., Li, X., McKnight, J. R., Satterfield, M. C., & Spencer, T. E. (2011). Proline and hydroxyproline metabolism: Implications for animal and human nutrition. Amino Acids, 40, 1053\u20131063.","journal-title":"Amino Acids"}],"container-title":["Metabolomics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s11306-021-01825-z.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1007\/s11306-021-01825-z\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1007\/s11306-021-01825-z.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,9,22]],"date-time":"2021-09-22T04:32:39Z","timestamp":1632285159000},"score":1,"resource":{"primary":{"URL":"https:\/\/link.springer.com\/10.1007\/s11306-021-01825-z"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,8,19]]},"references-count":57,"journal-issue":{"issue":"9","published-print":{"date-parts":[[2021,9]]}},"alternative-id":["1825"],"URL":"https:\/\/doi.org\/10.1007\/s11306-021-01825-z","relation":{},"ISSN":["1573-3882","1573-3890"],"issn-type":[{"type":"print","value":"1573-3882"},{"type":"electronic","value":"1573-3890"}],"subject":[],"published":{"date-parts":[[2021,8,19]]},"assertion":[{"value":"18 January 2021","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"27 July 2021","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"19 August 2021","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The authors declare that they have no conflict of interest.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Conflict of interest"}},{"value":"All procedures performed in this study, involving human participants, were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. The ethical committee of the University of Pretoria approved this study (No: 307\/2016).","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethical approval"}},{"value":"All collected specimens were anonymised at the time of collection, and participants gave written informed consent.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent to participate"}}],"article-number":"75"}}