Research Article

Determination of the antioxidant activity and antibacterial effect of the α-lipoic acid-NHS molecule in fisheries products

Volume: 42 Number: 4 December 10, 2025
TR EN

Determination of the antioxidant activity and antibacterial effect of the α-lipoic acid-NHS molecule in fisheries products

Abstract

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.

Keywords

Supporting Institution

Recep Tayyip Erdoğan University Scientific Research Projects Coordination Unit (BAP), Project No: FHD-2024-1686

Project Number

FHD-2024-1686

Ethical Statement

This research did not involve any studies with human participants or animals performed by the author. Therefore, no ethical approval was required.

References

  1. 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
  2. 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
  3. 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
  4. 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
  5. 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
  6. 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
  7. 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
  8. 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

Details

Primary Language

English

Subjects

Biochemistry and Cell Biology (Other) , Food Engineering , Fish Biology , Fish Pests and Diseases

Journal Section

Research Article

Early Pub Date

December 1, 2025

Publication Date

December 10, 2025

Submission Date

July 12, 2025

Acceptance Date

September 25, 2025

Published in Issue

Year 2025 Volume: 42 Number: 4

APA
Kalkan, S. (2025). Determination of the antioxidant activity and antibacterial effect of the α-lipoic acid-NHS molecule in fisheries products. Ege Journal of Fisheries and Aquatic Sciences, 42(4), 323-330. https://doi.org/10.12714/egejfas.42.4.06