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Background: L-citrulline, L-arginine, and L-glutamic acid are amino acids which are vital in the human body. L-citrulline boosts immunity, combats sarcopenia, detoxifies the liver, and enhances male fertility. L-arginine boosts internal production of nitric oxide, prevents abnormal blood clotting and accelerates healing of wounds. L-glutamic acid cleanses the central nervous system and improves overall brain health. Deficiency of these amino acids can lead to accumulation of ammonia and impact negatively to the nervous systems of the human body. This study aimed to identify and determine the levels of L-citrulline, L-arginine, and L-glutamic acid in selected fruits, vegetables, nuts, and seeds sold in markets in Nairobi City County, Kenya using Liquid Chromatography- Mass Spectrometry (LC-MS).

Materials and Methods: Data was collected from 28 selected samples and data analysis was done using Statistical Analysis Software (SAS) version 9.4.

Results: LC-MS showed the presence of both L-arginine and L-citrulline in most fruits, vegetables, and nuts while L-glutamic acid was present in the seeds. The levels of the amino acids in the fruits and vegetables were in the following range: L-citrulline (0.65- 19.41 mg/100g) in the button mushroom, cucumber, pumpkin, amaranthus, and kales, (3.16-3.79 mg/100g) in the watermelons and (1.57-10.21 mg/100g) in the nuts. L-arginine was in the range; 1.73 - 16.48 mg/100g in the amaranthus, kales, button mushroom, butternut squash, and cucumber, 5.44-6.56 mg/100g in the watermelons and 0.93-10.73 mg/100g in the nuts and L-glutamic acid (0.013-0.28 mg/100g) in the seeds of pumpkin, butternut, and watermelons.

Conclusion: The results showed that locally available vegetables, fruits and nuts are rich in L-citrulline and L-arginine.

References

  1. W. D. Price, R. A. Jockusch, and E. R. Williams, ''Is arginine a zwitterion in the gas phase?,'' J. Am Chem Soc. doi:10.1021/ja9711627, Vol. 119, no.49, pp.11988-11989, 1997.
     Google Scholar
  2. G. Wu, ''Amino acids: metabolism, functions, and nutrition,'' Amino Acids, doi:10.1007/s00726-009-0269-0, Vol.37, no.1, pp.1-17, 2009.
     Google Scholar
  3. Y-Z. Fang, S. Yang, and G. Wu, ''Free radicals, antioxidants, and nutrition,'' Nutrition, Vol. 18, no. 10, pp. 872-879, 2002.
     Google Scholar
  4. E. Curis, I. Nicolis, and C. Moinard, ''Almost all about citrulline in mammals,'' Amino Acids, doi:10.1007/s00726-005-0235-4, Vol. 29, no.3 pp.177-205, 2005.
     Google Scholar
  5. K. Komori, A. Tsujimura, and T. Takao, ''Nitric oxide synthesis leads to vascular endothelial growth factor synthesis via the NO/cyclic guanosine 3’,5’-monophosphate (cGMP) pathway in human corpus cavernosal smooth muscle cells,'' J. Sex Med, doi:10.1111/j.1743-6109.2008.00772.x, Vol.5, no.7, pp. 1623-1635, 2008.
     Google Scholar
  6. A. Figueroa, J. A. Trivino, M. A. Sanchez-Gonzalez, and F. Vicil, ''Oral L-citrulline supplementation attenuates blood pressure response to cold pressor test in young men,'' Am J. Hypertens. doi:10.1038/ajh.2009.195, Vol. 23, no.1, pp.12-16, 2010.
     Google Scholar
  7. W. H. Waugh, C. W. 3rd Daeschner, B. A. Files, M. E. McConnell, and S. E. Strandjord. ''Oral citrulline as arginine precursor may be beneficial in sickle cell disease: early phase two results,'' J. Natl Med Assoc. 2001;93(10):363-371.
     Google Scholar
  8. S. Bahri, N. Zerrouk, and C. Aussel, ''Citrulline: from metabolism to therapeutic use,'' Nutrition, doi:10.1016/j.nut.2012.07.002, Vol. 29, no.3, pp. 479-484, 2013.
     Google Scholar
  9. A. J. Cruz-Jentoft, J. P. Baeyens, and J. M. Bauer,'' Sarcopenia: European consensus on definition and diagnosis: Report of the European Working Group on Sarcopenia in Older People,'' Age Ageing, doi:10.1093/ageing/afq034. Vol. 39, no.4, pp. 412-423, 2010.
     Google Scholar
  10. L. Cynober, C. Moinard, J-P De Bandt and The 2009 ESPEN Sir David Cuthbertson, ''Citrulline: a new major signaling molecule or just another player in the pharmaconutrition game?,'' Clin Nutr. doi:10.1016/j.clnu.2010.07.006. Vol. 29, no.5, pp. 545-551, 2010.
     Google Scholar
  11. K. Akashi, C. Miyake, and A. Yokota, ''Citrulline, a novel compatible solute in drought-tolerant wild watermelon leaves, is an efficient hydroxyl radical scavenger,'' FEBS Lett. doi:10.1016/s0014-5793(01)03123-4. Vol. 508, no.3, pp. 438-442, 2000.
     Google Scholar
  12. P. Crenn, K. Vahedi, A. Lavergne-Slove, L. Cynober, C. Matuchansky, and B. Messing, ''Plasma citrulline: A marker of enterocyte mass in villous atrophy-associated small bowel disease,'' Gastroenterology. doi:10.1016/s0016-5085(03)00170-7, Vol.124, no.5, pp. 1210-1219, 2003.
     Google Scholar
  13. J. A. Kanaley, ''Growth hormone, arginine and exercise,'' Curr Opin Clin Nutr Metab Care, doi:10.1097/MCO.0b013e3282f2b0ad, Vol.11, no.1. pp. 50-54, 2008.
     Google Scholar
  14. G. Wu, L. A. Jaeger, F. W. Bazer, and J. M. Rhoads, ''Arginine deficiency in preterm infants: biochemical mechanisms and nutritional implications,'' J. Nutr Biochem, doi:10.1016/j.jnutbio.2003.11.010, Vol. 15, no.8, pp. 442-451, 2004.
     Google Scholar
  15. B. S. Meldrum, ''Glutamate as a neurotransmitter in the brain: review of physiology and pathology,'' J. Nutr. doi:10.1093/jn/130.4.1007S, Vol. 130, no.4S Suppl, pp. 1007S-1015S, 2000.
     Google Scholar
  16. C. Kulkarni, K. Kulkarni, and B. Hamsa, ''L-Glutamic acid and glutamine: Exciting molecules of clinical interest,'' Indian J. Pharmacol. doi:10.4103/0253-7613.16210, Vol.37, no.3, pp. 148-154, 2005.
     Google Scholar
  17. W. Ren, Y. Li, and X. Yu, ''Glutamine modifies immune responses of mice infected with porcine circovirus type 2,'' Br J. Nutr. doi:10.1017/S0007114512006101, Vol. 110, no.6, pp. 1053-1060,2013.
     Google Scholar
  18. Y. Yamaguchi, K. Yamamoto, Y. Sato, S. Inoue, T. Morinaga, and E. Hirano, ''Combination of aspartic acid and glutamic acid inhibits tumor cell proliferation,'' Biomed Res. doi:10.2220/biomedres.37.153, Vol. 37, no.2, pp. 153—159, 2016.
     Google Scholar
  19. A. M. Rimando, and P. M. Perkins-Veazie, ''Determination of citrulline in watermelon rind,'' J. Chromatogr A. doi:10.1016/j.chroma.2005.05.009, Vol.1078, no.1-2, pp.196-200, 2005.
     Google Scholar
  20. P. L. Urban, ''Quantitative mass spectrometry: an overview,'' Philos Trans A Math Phys Eng Sci, doi:10.1098/rsta.2015.0382, Vol. 374, no. 2079, pp. 20150382, 2016.
     Google Scholar
  21. R. Davis Angela, Webber, L. Charles, W. Fish Wayne, Wehner, C. Todd, S. King, Perkins-Veazie, ARA-D. Penelope, ''L- citrulline levels in watermelon cultigens tested in two environments,'' Hortscience, Vol. 46, no.12, pp. 1572-1575, 2011.
     Google Scholar
  22. B. Giannesini, Y. Le Fur, P. J. Cozzone, M. Verleye, M-E. Le Guern, and D. Bendahan, ''Citrulline malate supplementation increases muscle efficiency in rat skeletal muscle,'' Eur J. Pharmacol, doi:10.1016/j.ejphar.2011.05.068, Vol. 667, no.1-3, pp.100-104, 2011.
     Google Scholar
  23. C. Rouge, C. Des Robert, and A. Robins, ''Manipulation of citrulline availability in humans,'' Am J. Physiol Gastrointest Liver Physiol, doi:10.1152/ajpgi.00289, Vol.293, no.5, pp.1061-1067, 2007.
     Google Scholar
  24. S. R. Collier, E. Collins, and J. A. Kanaley, ''Oral arginine attenuates the growth hormone response to resistance exercise,'' J. Appl Physiol, doi:10.1152/japplphysiol.00285.2006, Vol. 101, no.3, pp.848-852, 2006.
     Google Scholar
  25. H. Haufe, K. Muschter, J. Siegert, and H. Böttcher, dd. EndNote.
     Google Scholar
  26. H. Osiecki, ''The Role of Chronic Inflammation in Cardiovascular Disease and its Regulation by Nutrients,'' Altern Med Rev, Vol. 9, pp. 32-53, 2004.
     Google Scholar
  27. O. Sodipo, A. Kwaghe, and U. Sandabe, ''Uses of Cucumis metuliferus: A Review,'' Cancer Biol, Vol. 55, pp. 24-34, 2015.
     Google Scholar
  28. W. Fish, ''A Reliable Methodology for Quantitative Extraction of Fruit and Vegetable Physiological Amino Acids and Their Subsequent Analysis with Commonly Available HPLC Systems,'' Food Nutr Sci, doi:10.4236/fns.2012.36115, pp. 03, 2012.
     Google Scholar
  29. R. Ridwan, H. R. Abdul Razak, M. Adenan, and W. Saad, ''Development of Isocratic RP-HPLC Method for Separation and Quantification of L-Citrulline and L-Arginine in Watermelons,'' Int J. Anal Chem, doi:10.1155/2018/4798530, pp.1-9, 2018.
     Google Scholar
  30. L. D. Rochmatika, H. Kusumastuti, and S. Marwati, ''An Analysis of Antioxidants Activity in Face Mask with Basic Ingredients of a Watermelon, Int Conf Chem Agric Med Sci, pp.10-12, 2013.
     Google Scholar