Cytotoxicity and genotoxicity evaluations of oleic acid and conjugated linoleic acid

Abstract

Background and Aims: Oleic acid (OLA) and conjugated linoleic acid (CLA) occur in dairy products and meats and are also widespread at lower levels in many other foodstuffs. It is known that OLA and CLA are very bioactive compounds with sub- stantially anti-carcinogenic effects. The objective of this study was to evaluate the cytotoxic potentials of OLA and CLA which were tested against cancerous and non-cancerous cell lines and to determine their genotoxicity.
Methods: The cytotoxic activities of OLA and CLA against to cancer cell lines (U-87-MG, A549, MCF-7, CaCo-2, HeLa and PC- 3) and a control cell line (HEK293) were assessed by MTT assay. Ames MPFtm mutagenicity assay on 4 strains (TA98, TA100, TA 1535 and TA 1537) of Salmonella typhimurium was used for genotoxicity determination.
Results: CLA showed cytotoxic activity on PC-3 cells, while OLA was created on A549 and PC-3 cell lines with the IC50 of 20 nM and 15 nM, respectively. No cytotoxic activity was observed on MCF-7, HeLa, U-87-MG, and CaCo-2 cells with the ad- ministered doses of OLA and CLA. It has been proved that OLA and CLA are characterized by a high cytotoxic activity towards cancer cells, as observed in the cell line test. There was no evidence for a mutagenic effect of OLA and CLA in the Ames test, with or without metabolic activation (S9) against Salmonella typhimurium strains.
Conclusion: These in vitro test results indicate that these fatty acids can be considered a beneficial dietary supplement for enhancing anti-cancer therapy.

Keywords

• Fatty acid
• Conjugated linoleic acid
• Oleic acid
• Cytotoxicity
• Mutagenicity

References

1. Aydeniz, B., Güneser, O., & Yılmaz, E. (2014). Physico-chemical, sen- sory and aromatic properties of cold press produced safflower oil. Journal of the American Oil Chemists Society, 91, 99–100. http://doi. org/10.1007/s11746-013-2355-4
2. Bae, W. J., Kim, D. H., Lee, W. W., Kim, Y. H., & Son, C. G. (2015). Char- acterizing the human equivalent dose of herbal medicines in animal toxicity studies. Journal of Ethnopharmacology, 162, 1–6. http://doi.org/10.1016/j.jep.2014.12.023
3. Białek, A., Zagrodzki, P., Tokarz, A. (2016). Chemometric analysis of the interactions among different parameters describing health conditions, breast cancer risk and fatty acids profile in serum of rats supplemented with conjugated linoleic acids, Prostaglan- dins. Leukotrienes and Essential Fatty Acids, 106, 1-10. https:// dx.doi.org/10.1016/j.plefa.2015.12.006
4. Cao, S., Zhu, Q. H., Shen, W., Jiao, X., Zhao, X., Wang, B. M. … Liu, Q. (2013). Comparative profiling of miRNA expression in devel- oping seeds of high linoleic and high oleic safflower (Carthamus tinctorius L.) plants. Frontiers in Plant Science, 2, 489. http://doi. org/10.3389/fpls.2013.00489
5. Carrillo, C., Cavia, M., & Alonso-Torre, R. (2012). Antitumor effect of oleic acid; mechanisms of action: a review. Nutricion Hospitalaria, 27, 1860–1865. https://doi.org/10.1016/j.bbrc.2019.04.040
6. Cohen, L. A., Zhao, Z., Pittman, B., &Scimeca, J. (2003). Effect of soy protein isolate and conjugated linoleic acid on the growth of Dunning R-3327- AT-1 rat prostate tumors. Prostate, 54, 69–180. https://doi.org/10.1002/pros.10127
7. Engelbrecht, T. N., Schroeter, A., Hauss, T., & Neubert, R. H. (2011). Lipophilic penetration enhancers and their impact to the bilayer structure of stratum corneum lipid model membranes: neutron diffraction studies based on the example oleic acid. Biochimica et Biophysica Acta, 1808, 2798–2806. http://doi.org/10.1016/j. bbamem.2011.08.012
8. Guiberna, A. R., Aranda, J. H., Flores, R. C. J., Flores, M. R., Nieto, G. N., Garcia, Q. … Reyes, O. A. J. (2019). Isomers of conjugated linoleic acid induce insulin resistance through amechanism involving ac-tivation of protein kinase Cε in liver cells. Cell Signal, 53, 281–293. http://doi.org/10.1016/j.cellsig.2018.10.013

9. Guner A., Kızılsahin S., Nalbantsoy A., Karabay Yavasoglu N. U. (2020). Apoptosis-inducing activity of Safflower (Carthamus tinc- torius L.) seed oil in lung, colorectal and cervix cancer cells. Biolo- gia, 75, 1465–1471. http://doi.org/10.2478/s11756-020-00458-2
10. Hughes-Fulford, M., Chen, Y., &Tjandrawinata, R. R. (2001). Fatty acid regulates gene expression and growth of human pros- tate cancer PC-3 cells. Carcinogenesis, 22, 701–707. http://doi. org/10.1093/carcin/22.5.701
11. Khalid, N., Khan, S.R., Hussain, I.M., Farooq, M., Ahmad, A., & Ahmed, I. (2017). A comprehensive characterisation of safflower oil for its potential applications as a bioactive food ingredient - A review. Trends in Food Science & Technology, 66, 176–186. http:// doi.org/10.1016/j.tifs.2017.06.009
12. Kritchevsky, D. (2002). Antimutagenic and some other effects of conjugated linoleic acid. British Journal of Nutrition, 8, 459–465. https://doi.org/10.1017/S0007114500000581
13. Lee D. H., Ahna J., Jang J. Y., Ha T. Y., & Jung H. C. (2019). Oleic acid- induced defective autolysosome shows impaired lipid-degrada- tion. Biochemical and Biophysical Research Communications, 513, 553–559. http://doi.org/10.1016/j.bbrc.2019.04.040
14. Liu, K., Johnson, N. E., Blackshaw, E. R., Hossain, Z., & Gan, Y. (2019). Improving the productivity and stability of oilseed cropping sys- tems through crop diversification. Crops Research, 237, 65–73. https://10.1016/j.fcr.2019.03.020
15. Madan, N., Mudgal, V., Mishra, S., Srivastava, A. K., & Singh, R. B. (2011). Studies on the biochemical role of accumulation of heavy metals in safflower. Open Nutraceuticals, 4, 199–204. http://doi. org/10.2174/1876396001104010199
16. Małgorzata, B., Agnieszka, G., Iwona, M., Hanna, T. & Andrzej, T. (2017). Impact of conjugated linoleic acid administered to rats prior and after carcinogenic agent on arachidonic and linoleic acid metabolites in serum and tumors. Prostaglandins, Leukotri- enes and Essential Fatty Acids, 126, 1–8. http://doi.org/10.1016/j. plefa.2017.08.013
17. Maron, D. M., & Ames, B. N. (1983). Revised methods for the Sal- monella mutagenicity test. Mutation Research, 113, 173–215. http://doi.org/10.1016/0165-1161(83)90010-9
18. Martinez, N., Sosa, N., Higa, R., Fornes, D., & Capobianco, E. (2012). Dietary treatments enriched in olive and safflower oils regulate sericand placental matrix metalloproteinases in maternal diabetes. Placenta, 33, 8–16. http://doi.org/10.1016/j.placenta.2011.10.015
19. Menéndez, J.A., Barbacid, M., Montero, S., Sevilla, E., Escrichc, E., Solanas, M. … Colomer, R. (2001) Effects of gamma-linolenic acid and oleic acid on paclitaxel cytotoxicity in human breast cancer cells. European Journal of Cancer,37:402-413. http://doi. org/10.1016/s0959-8049(00)00408-1
20. Mosmann, T. (1983). Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity as- says. Journal of Immunological Methods, 65, 55–63. http://doi. org/10.1016/0022-1759(83)90303-4
21. OECD Guidelines for the testing of chemicals No: 471. Bacterial Reverse Mutation Test, 1997, 1–11.
22. Palombo, J. D., Ganguly, A., Bistrian, B. R., & Menard, M. P. (2002). The antiproliferative effects of biologically active isomers of con- jugated linoleic acid on human colorectal and prostatic cancer cells. Cancer Letters, 177, 163–172. http://doi.org/10.1016/s0304- 3835(01)00796-0
23. Simonsen, N. R., Navajas, J. F., Moreno, J. M., Strain, J. J., Huttunen, J. K., Martin, B. C. … Kohlmeier, L. (1998). Tissue stores of individ- ual monounsaturated fatty acids and breast cancer: the Euramic study. The American Journal of Clinical Nutrition, 68, 134–141. https://doi.org/10.1093/ajcn/68.1.134
24. Tanmahasamut, P., Liu, J., Hendry, L. B., &Sidell, N. (2004). Conjugat- ed linoleic acid blocks estrogen signaling in human breast cancer cells. Journal of Nutrition, 134, 674–680. https://doi.org/10.1093/ jn/134.3.674
25. Woodcock, R.S., Salvatore, R.S., Freeman, A.B., Schopfer J.F. (2021). Synthesis of 9- and 12-nitro conjugated linoleic acid: Regio- specific isomers of naturally occurring conjugated nitrodienes. Tetrahedron Letters, 81, 153371. https://doi.org/10.1016/j.tet- let.2021.153371
26. Yang, J., Wang, R., Feng, Q., Wang, X. Y., Zhang, Y. Y., Wu, H. W. … Qi, J. P. (2018). Safflower polysaccharide induces cervical cancer cell apoptosis via inhibition of the PI3K/Akt pathway. South Af- rican Journal of Botany, 118, 209–215. http://doi.org/10.1016/j. sajb.2018.07.028
27. Yanli, Y., Jian, Y., Zhenyun, D., Peipei, W., & Kan, D. (2018). Structural elucidation and immune-enhancing activity of an arabinogalac- tan from flowers of Carthamus tinctorius L. Carbohydrate Polymers, 202, 134–142. http://doi.org/10.1016/j.carbpol.2018.08.098
28. Zhang, T., Li, M., Yang, R., Zhang, D., Guan, J., Yu, J. …Wang, Y. (2018). Therapeutic efficacy of lipid emulsions of docetaxel-linoleic acid conjugate in breast cancer. International Journal of Pharmaceutics, 546, 61-69. https://doi.org/10.1016/j.ijharm.2018.05.032
29. Zhang, Z., Xie, K., Liu, A., Chen, R., Chen, D., Yang, L., & Dai, J. (2019). Enzymatic biosynthesis of benzylisoquinoline alkaloid glycosides via promiscuous glycosyltransferases from Carthamus tinctorius. Chinese Chemical Letters, 30, 443–446. https://doi.org/10.1016/j. cclet.2018.05.010