TY - JOUR T1 - Determination of the antioxidant activity and antibacterial effect of the α-lipoic acid-NHS molecule in fisheries products TT - Alfa-lipoik asit-NHS molekülünün antioksidan aktivitesinin ve su ürünlerindeki antibakteriyel etkisinin belirlenmesi AU - Kalkan, Samet PY - 2025 DA - December Y2 - 2025 DO - 10.12714/egejfas.42.4.06 JF - Ege Journal of Fisheries and Aquatic Sciences JO - EgeJFAS PB - Ege Üniversitesi WT - DergiPark SN - 2148-3140 SP - 323 EP - 330 VL - 42 IS - 4 LA - en AB - Alpha-lipoic acid plays significant roles in metabolic pathways and provides substantial antioxidant defense. In this study, the N-hydroxysuccinimide ester derivative (α-lipoic acid–NHS) was examined for antioxidant performance and inhibitory effects on Gram-negative and Gram-positive bacterial strains isolated from aquatic environments. Antioxidant performance was evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging and CUPRAC (cupric ion reducing) assays. Additionally, The compound’s ability to mitigate oxidative stress was evaluated by quantifying reactive oxygen species (ROS) levels with the 8-OHdG ELISA method at different α-lipoic acid–NHS concentrations. Antibacterial activity was tested against four reference pathogens (Staphylococcus aureus, Aeromonas hydrophila, Salmonella enterica, Escherichia coli) and four environmental isolates (Bacillus cereus, B. toyonensis, Oceanisphaera sediminis, Pseudomonas putida) using the microdilution method. The results showed that α-lipoic acid–NHS exhibited negligible antioxidant activity in both DPPH and CUPRAC assays. In terms of antibacterial effects, however, complete inhibition of growth was observed in some bacterial strains at higher concentrations (5–10 mM). While ROS levels decreased modestly with increasing α-lipoic acid–NHS, this effect did not correlate with chemical antioxidant test results, suggesting the reduction was not due to direct antioxidant action. In conclusion, α-lipoic acid–NHS does not function as an effective direct radical scavenger but may exert indirect antioxidant effects and moderate antibacterial activity. It may have potential as a supportive compound in antioxidant systems and antibacterial therapies rather than as a standalone therapeutic agent. KW - Antibacterial effect KW - aquaculture KW - fish pathogen KW - minimum inhibitory concentration KW - oxidative stress KW - reactive oxygen species N2 - Alfa-lipoik asit, metabolik yolaklarda önemli roller üstlenir ve güçlü bir antioksidan savunma sağlar. Bu çalışmada, α-lipoik asidin N-hidroksisüksinimid ester türevinin (α-lipoik asit–NHS) antioksidan etkinliği ve sucul ortamlardan izole edilen Gram-negatif ve Gram-pozitif bakteri suşlarında inhibitör aktivitesi değerlendirilmiştir. Antioksidan performans, DPPH (2,2-diphenyl-1-picrylhydrazyl) radikal süpürme ve CUPRAC (Cu2+ iyon indirgeme) testleri ile analiz edilmiştir. Ayrıca, farklı α-lipoik asit–NHS konsantrasyonlarında, 8-OHdG ELISA yöntemi ile reaktif oksijen türleri (ROS) düzeyleri ölçülerek bileşiğin oksidatif stresi baskılama potansiyeli incelenmiştir. Antibakteriyel aktivite, dört referans patojen (Staphylococcus aureus, Aeromonas hydrophila, Salmonella enterica, Escherichia coli) ve dört çevresel izolat (Bacillus cereus, B. toyonensis, Oceanisphaera sediminis, Pseudomonas putida) üzerinde mikrodilüsyon yöntemiyle test edilmiştir. Sonuçlar, α-lipoik asit–NHS’nin hem DPPH hem de CUPRAC testlerinde ihmal edilebilir düzeyde antioksidan aktivite gösterdiğini ortaya koymuştur. Buna karşılık, antibakteriyel etki açısından bakıldığında, bazı bakteri suşlarında yüksek konsantrasyonlarda (5–10 mM) tam büyüme inhibisyonu gözlenmiştir. Artan α-lipoik asit–NHS dozunda ROS düzeylerinde hafif bir azalma görülmüşsede, bu etki kimyasal antioksidan test sonuçlarıyla paralellik göstermemiştir; yani gözlenen azalmanın doğrudan antioksidan etkiden kaynaklanmadığı düşünülmektedir. Sonuç olarak, α-lipoik asit–NHS, etkili bir doğrudan serbest radikal süpürücü olarak işlev görmez; ancak dolaylı antioksidan etkiler ve orta düzeyde antibakteriyel aktivite gösterebilir. Tek başına tedavi edici bir ajan olmaktan ziyade, antioksidan sistemlerde ve antibakteriyel tedavilerde destekleyici bir bileşik olarak potansiyele sahiptir. CR - Akbulut, C., Kaymak, G., Esmer, H.E., Yön, N.D., & Kayhan, F.E. (2014). Oxidative stress mechanisms induced by heavy metals and pesticides in fish. Ege Journal of Fisheries and Aquatic Sciences, 31(3), 155-160. https://doi.org/10.12714/egejfas.2014.31.3.07 CR - Alfadda, A.A., & Sallam, R.M. (2012). Reactive oxygen species in health and disease. Biomed Research International, 2012(1), 936486. https://doi.org/10.1155/2012/936486 CR - Apak, R., Güçlü, K., Özyürek, M., & Karademir, S.E. (2004). Novel total antioxidant capacity index for dietary polyphenols and vitamins C and E, using their cupric ion reducing capability in the presence of neocuproine: CUPRAC method. Journal of Agricultural and Food Chemistry, 52(26), 7970-7981. https://doi.org/10.1021/jf048741x CR - Apak, R., Güçlü, K., Özyürek, M., Bektaşoğlu, B., & Bener, M. (2008). Cupric ion reducing antioxiant capacity assay for food antioxidants: Vitamins, polyphenolics, and flavonoids in food extracts. Methods in Molecular Biology, 477, 163–193. https://doi.org/10.1007/978-1-60327-517-0_14 CR - Atila, N., Kaya, Z., Atila, A., Halici, Z., Bayir, Y., Sirin, B., Kahramanlar, A., Cadirci, E., Ozkaraca., M., Keles, O., & Ozmen, S. (2022). Are Antibiotics Sufficient for Treating Bacterial Rhinosinusitis? The Influence of Alpha-Lipoic Acid, a Potent Antioxidant, As an Additional Treatment in Bacterial Rhinosinusitis. B-ENT, 18(4). https://doi.org/10.5152/b-ent.2022.21476 CR - Blois, M.S. (1958). Antioxidant determinations by the use of a stable free radical. Nature, 181(4617), 1199 1200. https://doi.org/10.1038/1811199a0 CR - Brand-Williams, W., Cuvelier, M.E., & Berset, C. (1995). Use of a free radical method to evaluate antioxidant activity. Food Science and Technology, 28(1), 25–30. https://doi.org/10.1016/S0023-6438(95)80008-5 CR - Charlton, N.C., Mastyugin, M., Török, B., & Török, M. (2023). Structural features of small molecule antioxidants and strategic modifications to improve potential bioactivity. Molecules, 28(3), 1057. https://doi.org/ 10.3390/molecules28031057 CR - Clinical and Laboratory Standards Institute (2024, September 25). Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically (12th ed.; CLSI standard M07). Wayne, PA: CLSI. https://clsi.org/shop/standards/m07/ CR - Cronan, J.E. (2020). Progress in the enzymology of the mitochondrial diseases of lipoic acid requiring enzymes. Frontiers in Genetics, 11, 510. https://doi.org/10.3389/fgene.2020.00510 CR - Dean, R.T., Fu, S., Stocker, R., & Davies, M.J. (1997). Biochemistry and pathology of radical-mediated protein oxidation. Biochemical Journal, 324(1), 1-18. https://doi.org/10.1042/bj3240001 CR - Diment, D., Musl, O., Balakshin, M., & Rigo, D. (2024). Guidelines for evaluating the antioxidant activity of lignin via the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. ChemSusChem, 18(10), e202402383. https://doi.org/10.1002/cssc.202402383 CR - Dunn, O.J., & Clark, V.A. (2009). Basic statistics: a primer for the biomedical sciences. John Wiley & Sons. 4th ed. Hoboken, NJ: Wiley. CR - European Committee on Antimicrobial Susceptibility Testing (EUCAST). (2024, September 25). Broth microdilution—EUCAST reading guide (Version 5.0). https://www.eucast.org/ast_of_bacteria/mic_determination?utm. CR - Giri, A., Aquib, M., Choudhury, A., Kannaujiya, V.K., Lim, J.L., Gu, Z., Lenardon, M., & Boyer, C. (2025). Lipoic Acid Based Redox‐Responsive Degradable Antimicrobial Polymers. Macromolecular Rapid Communications, 46(17), e00224. https://doi.org/10.1002/marc.202500224 CR - Gorąca, A., Huk-Kolega, H., Piechota, A., Kleniewska, P., Ciejka, E., & Skibska, B. (2011). Lipoic acid–biological activity and therapeutic potential. Pharmacological Reports, 63(4), 849-858. https://doi.org/10.1016/S1734-1140(11)70600-4 CR - Guimaraes, A., Abrunhosa, L., Pastrana, L.M., & Cerqueira, M.A. (2018). Edible films and coatings as carriers of living microorganisms: A new strategy towards biopreservation and healthier foods. Comprehensive Reviews in Food Science and Food Safety, 17(3), 594-614. https://doi.org/10.1111/1541-4337.12345 CR - Gülçin, I. (2008). Measurement of antioxidant ability of melatonin and serotonin by the DMPD and CUPRAC methods as trolox equivalent. Journal of Enzyme Inhibition and Medicinal Chemistry, 23(6), 871-876. https://doi.org/10.1080/14756360701626223 CR - Hajtuch, J., Santos-Martinez, M.J., Wojcik, M., Tomczyk, E., Jaskiewicz, M., Kamysz, W., & Inkielewicz-Stepniak, I. (2022). Lipoic acid-coated silver nanoparticles: Biosafety potential on the vascular microenvironment and antibacterial properties. Frontiers in Pharmacology, 12, 733743. https://doi.org/10.3389/fphar.2021.733743 CR - Han, D., Handelman, G., Marcocci, L., Sen, C.K., Roy, S., Kobuchi, H., Tritschler, H., Flohé, L., & Packer, L. (1997). Lipoic acid increases de novo synthesis of cellular glutathione by improving cystine utilization. Biofactors, 6(3), 321-338. https://doi.org/10.1002/biof.5520060303 CR - Hermanson, G.T. (2013). Bioconjugate techniques. (third ed.), Academic Press, Boston https://doi.org/10.1016/C2009-0-64240-9 CR - Howarth, M., Liu, W., Puthenveetil, S., Zheng, Y., Marshall, L.F., Schmidt, M. M., & Ting, A. Y. (2008). Monovalent, reduced-size quantum dots for imaging receptors on living cells. Nature Methods, 5(5), 397-399. https://doi.org/10.1038/nmeth.1206 CR - Jia, Z., Zhu, H., Vitto, M.J., Misra, B.R., Li, Y., & Misra, H.P. (2009). Alpha-lipoic acid potently inhibits peroxynitrite-mediated DNA strand breakage and hydroxyl radical formation: implications for the neuroprotective effects of alpha-lipoic acid. Molecular and Cellular Biochemistry, 323(1), 131-138. https://doi.org/10.1007/s11010-008-9971-6 CR - Jomova, K., Raptova, R., Alomar, S.Y., Alwasel, S.H., Nepovimova, E., Kuca, K., & Valko, M. (2023). Reactive oxygen species, toxicity, oxidative stress, and antioxidants: Chronic diseases and aging. Archives of Toxicology, 97(10), 2499-2574. https://doi.org/10.1007/s00204-023-03562-9 CR - Kalkan, S. (2022). Multimodal analysis of south-eastern Black Sea sediment bacterial population diversity. Marine Pollution Bulletin, 183, 114063. https://doi.org/10.1016/j.marpolbul.2022.114063 CR - Kilgore, H.R., Olsson, C.R., D’Angelo, K.A., Movassaghi, M., & Raines, R.T. (2020). n→ π* Interactions modulate the disulfide reduction potential of epidithiodiketopiperazines. Journal of the American Chemical Society, 142(35), 15107-15115. https://doi.org/10.1021/jacs.0c06477 CR - Koniev, O., & Wagner, A. (2015). Developments and recent advancements in the field of endogenous amino acid selective bond forming reactions for bioconjugation. Chemical Society Reviews, 44(15), 5495-5551. https://doi.org/ 10.1039/c5cs00048c CR - Kowald, A., & Kirkwood, T.B. (2018). Resolving the enigma of the clonal expansion of mtDNA deletions. Genes, 9(3), 126. https://doi.org/10.3390/genes9030126 CR - Luo, Q., Han, Q., Chen, L., Fan, X., Wang, Y., Fei, Z., Zhang, H., Wang, Y. (2020). Redox response, antibacterial and drug package capacities of chitosan-α-lipoic acid conjugates. International Journal of Biological Macromolecules, 154, 1166 1174. https://doi.org/10.1016/j.ijbiomac.2019.10.271 CR - Na, M.H., Seo, E.Y., & Kim, W.K. (2009). Effects of α-lipoic acid on cell proliferation and apoptosis in MDA-MB-231 human breast cells. Nutrition Research and Practice, 3(4), 265 271. https://doi.org/10.4162/nrp.2009.3.4.265 CR - Nikaido, H. (2003). Molecular basis of bacterial outer membrane permeability revisited. Microbiology and Molecular Biology Reviews, 67(4), 593-656. https://doi.org/10.1128/mmbr.67.4.593-656.2003 CR - Packer, L., Witt, E.H., & Tritschler, H.J. (1995). Alpha-lipoic acid as a biological antioxidant. Free Radical Biology and Medicine, 19(2), 227-250. https://doi.org/10.1016/0891-5849(95)00017-R CR - Perzanowska, O., Majewski, M., Strenkowska, M., Głowala, P., Czarnocki-Cieciura, M., Mazur, M., & Jemielity, J. (2021). Nucleotide-decorated AuNPs as probes for nucleotide-binding proteins. Scientific Reports, 11(1), 15741. https://doi.org/10.1038/s41598-021-94983-y CR - Petersen Shay, K., Moreau, R.F., Smith, E.J., & Hagen, T.M. (2008). Is α‐lipoic acid a scavenger of reactive oxygen species in vivo? Evidence for its initiation of stress signaling pathways that promote endogenous antioxidant capacity. IUBMB life, 60(6), 362-367. https://doi.org/10.1002/iub.40 CR - Prior, R.L., Wu, X., & Schaich, K. (2005). Standardized methods for the determination of antioxidant capacity and phenolics in foods and dietary supplements. Journal of Agricultural and Food Chemistry, 53(10), 4290-4302. https://doi.org/ 10.1021/jf0502698 CR - Saso, L., & Firuzi, O. (2014). Pharmacological applications of antioxidants: lights and shadows. Current Drug Targets, 15(13), 1177-1199. https://doi.org/ 10.2174/1389450115666141024113925 CR - Setlow, P. (2014). Germination of spores of Bacillus species: what we know and do not know. Journal of Bacteriology, 196(7), 1297-1305. https://doi.org/10.1128/jb.01455-13 CR - Scott, B.C., Aruoma, O.I., Evans, P.J., O’Neill, C., Van der Vliet, A., Cross, C.E., Tritschler, H., & Halliwell, B. (1994). Lipoic and dihydrolipoic acids as antioxidants: A critical evaluation. Free Radical Research, 20(2), 119–133. https://doi.org/ 10.3109/10715769409147509 CR - Sharifi-Rad, M., Anil Kumar, N.V., Zucca, P., Varoni, E.M., Dini, L., Panzarini, E., Rajkovic, J., Fokou, P.V.T., Azzini, E., Peluso, I., Mishra, P.A., Nigam, M., El Rayess, Y., El Beyrouthy, M., Polito, L., Iriti, M., Martins, N., Martorell, M., Docea, A.O., Setzer, W.N., Calina, D., Cho, W.C., & Sharifi-Rad, J. (2020). Lifestyle, oxidative stress, and antioxidants: back and forth in the pathophysiology of chronic diseases. Frontiers in Physiology, 11, 552535. https://doi.org/10.3389/fphys.2020.00694 CR - Shay, K.P., Moreau, R.F., Smith, E.J., Smith, A.R., & Hagen, T.M. (2009). Alpha-lipoic acid as a dietary supplement: molecular mechanisms and therapeutic potential. Biochimica et Biophysica Acta (BBA)-General Subjects, 1790(10), 1149 1160. https://doi.org/10.1016/j.bbagen.2009.07.026 CR - Shi, C., Sun, Y., Zhang, X., Zheng, Z., Yang, M., Ben, H., Song, Cao, Y., Chen, Y., Liu, X., Dong, R., & Xia, X. (2016). Antimicrobial effect of lipoic acid against Cronobacter sakazakii. Food Control, 59, 352-358. https://doi.org/10.1016/j.foodcont.2015.05.041 CR - Spicer, C.D., Pashuck, E.T., & Stevens, M.M. (2018). Achieving controlled biomolecule–biomaterial conjugation. Chemical reviews, 118(16), 7702-7743. https://doi.org/10.1021/acs.chemrev.8b00253 CR - Superti, F., & Russo, R. (2024). Alpha-lipoic acid: biological mechanisms and health benefits. Antioxidants, 13(10), 1228. https://doi.org/10.3390/antiox13101228 CR - Tahiluddin, A.B., Maribao, I.P., Amlani, M.Q., & Sarri, J.H. (2022). A review on spoilage microorganisms in fresh and processed aquatic food products. Food Bulletin, 1(1), 21 36. https://doi.org/10.29329/foodb.2022.495.05 CR - Uçak, İ. (2020). Determination of antioxidant and antimicrobial effects of pomegranate peel extract in trout burgers stored at cold temperatures (4±1°C). Ege Journal of Fisheries & Aquatic Sciences, 37(4). 415-422. https://doi.org/10.12714/egejfas.37.4.13 CR - Valavanidis, A., Vlachogianni, T., Fiotakis, K. (2009). "8-hydroxy-2' -deoxyguanosine (8-OHdG): A critical biomarker of oxidative stress and carcinogenesis." Journal of Environmental Science and Health, Part C, 27(2), 120-139. https://doi.org/10.1080/10590500902885684 CR - Valko, M., Leibfritz, D., Moncol, J., Cronin, M.T., Mazur, M., & Telser, J. (2007). Free radicals and antioxidants in normal physiological functions and human disease. The international Journal of Biochemistry & Cell Biology, 39(1), 44-84. https://doi.org/10.1016/j.biocel.2006.07.001 CR - Zhao, F., & Liu, Z.Q. (2011). Comparison of antioxidant effectiveness of lipoic acid and dihydrolipoic acid. Journal of Biochemical and Molecular Toxicology, 25(4), 216-223. https://doi.org/ 10.1002/jbt.20378 UR - https://doi.org/10.12714/egejfas.42.4.06 L1 - https://dergipark.org.tr/tr/download/article-file/5047462 ER -