Investigation of the Effects of Syringic Acid on Oxidative Stress, Cytokines, Apoptosis and Inflammation Against Cadmium-Induced Hepatotoxicity in Rats

Abstract

Cadmium (Cd) is a toxic heavy metal and a significant environmental contaminant known to cause hepatotoxicity through mechanisms involving oxidative stress, inflammation, and apoptosis. Syringic acid (Sa), a naturally occurring phenolic compound, exhibits potent antioxidant and anti-inflammatory activities. This study aimed to evaluate the protective effects of SA against Cd-induced liver injury in rats. Fifty adult male Sprague-Dawley rats were randomly allocated into five groups (n= 10 per group): Control, Sa 100, Cd, Sa 50+Cd and Sa 100+Cd. Cadmium and/or SA were administered orally for 7 consecutive days. Biochemical markers of oxidative stress (SOD, GSH, CAT, and MDA), pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and molecular indicators of inflammation (TLR-4, NF-κB) and apoptosis (Bax, Bcl-2, Caspase-3) were measured in liver tissue homogenates. Cadmium exposure significantly decreased the hepatic antioxidant enzyme activities (SOD, GSH, and CAT) and increased MDA and TLR-4 levels, indicating enhanced oxidative damage and inflammatory activation. Additionally, NF-κB, TNF-α, IL-1β, and IL-6 levels were markedly elevated following Cd administration. Apoptotic changes were evident by increased Bax and Caspase-3 expression and decreased Bcl-2 levels. Syringic acid co-administration dose-dependently ameliorated these pathological alterations, restoring oxidative balance, suppressing inflammation, and modulating apoptotic signaling. Syringic acid effectively attenuates cadmium-induced liver toxicity in rats by mitigating oxidative stress, suppressing pro-inflammatory responses, and regulating apoptosis-related pathways. These findings suggest that SA may serve as a promising hepatoprotective agent in conditions of heavy metal-induced hepatic injury.

Keywords

• Antioxidant
• Cadmium
• Cytokine
• İnflammation
• Oxidative stress.

Ratlarda Kadmiyum Kaynaklı Hepatotoksisiteye Karşı Siringik Asidin Oksidatif Stres, Sitokinler, Apoptozis ve İnflamasyon Üzerindeki Etkilerinin Araştırılması

Abstract

Kadmiyum (Cd), toksik bir ağır metal olup, oksidatif stres, inflamasyon ve apoptoz gibi mekanizmalar yoluyla hepatotoksisiteye neden olan önemli bir çevresel kirleticidir. Doğal olarak bulunan bir fenolik bileşik olan siringik asit (Sa), güçlü antioksidan ve anti-inflamatuar etkilere sahiptir. Bu çalışmanın amacı, siringik asidin kadmiyum kaynaklı karaciğer hasarına karşı olası koruyucu etkilerini değerlendirmektir. Elli adet erişkin erkek Sprague-Dawley rat rastgele olarak beş gruba ayrıldı (her grup için n= 10): Kontrol, Sa, Cd 100, Sa 50+Cd ve Sa 100+Cd. Kadmiyum ve siringik asit, ardışık yedi gün boyunca oral yolla uygulandı. Karaciğer doku homojenatlarında oksidatif stres belirteçleri (SOD, GSH, CAT ve MDA), pro-inflamatuar sitokinler (TNF-α, IL-1β, IL-6) ve inflamasyon (TLR-4, NF-κB) ile apoptoza (Bax, Bcl-2, Caspase-3) ilişkin moleküler göstergeler değerlendirildi. Kadmiyum uygulaması, karaciğerdeki antioksidan enzim aktivitelerinde (SOD, GSH ve CAT) anlamlı bir azalmaya, MDA ve TLR-4 düzeylerinde ise belirgin bir artışa neden olarak oksidatif hasar ve inflamatuar yanıtların arttığını gösterdi. Ayrıca, NF-κB, TNF-α, IL-1β ve IL-6 düzeyleri Cd maruziyeti sonrasında önemli ölçüde yükseldi. Apoptotik değişiklikler ise Bax ve Caspase-3 düzeylerinde artış ve Bcl-2 düzeyinde azalma ile belirlendi. Siringik asit uygulaması, bu patolojik değişiklikleri doz-bağımlı olarak iyileştirdi; oksidatif dengeyi yeniden sağladı, inflamasyonu baskıladı ve apoptoz ile ilişkili sinyalleri düzenledi. Siringik asit, kadmiyum kaynaklı karaciğer toksisitesini azaltmada etkili olup; bu etkisini oksidatif stresi hafifleterek, pro-inflamatuar yanıtları baskılayarak ve apoptozla ilişkili yolları modüle ederek göstermektedir. Bu bulgular, siringik asidin ağır metal kaynaklı hepatik hasarlarda potansiyel bir hepatoprotektif ajan olarak değerlendirilebileceğini göstermektedir.

Keywords

• Antioksidan
• Kadmiyum
• Sitokin
• İnflamasyon
• Oksidatif stres.

References

1. Akarsu SA, Gür C, İleritürk M, Akaras N, Küçükler S, Kandemir FM. Effect of syringic acid on oxidative stress, autophagy, apoptosis, inflammation pathways against testicular damage induced by lead acetate. J Trace Elem Med Biol 2023; 80: 127315.
2. Bass JJ, Wilkinson DJ, Rankin D, Phillips BE, Szewczyk NJ, Smith K, Atherton PJ. An overview of technical considerations for Western blotting applications to physiological research. Scand J Med Sci Sports 2017; 27(1): 425.
3. Bhattacharyya K, Sen D, Laskar P, Saha T, Kundu G, Ghosh Chaudhuri A, Ganguly S. Pathophysiological effects of cadmium(II) on human health-a critical review. J Basic Clin Physiol Pharmacol 2023; 34(3): 249-61.
4. Cao Z, Yang F, Lin Y, Shan J, Cao H, Zhang C, Zhuang Y, Xing C, Hu G. Selenium antagonizes cadmium induced ınflammation and oxidative stress via suppressing the interplay between NLRP3 inflammasome and HMGB1/NF-κB pathway in duck hepatocytes. Int J Mol Sci 2022; 23(11): 6252.
5. Cordiano R, Di Gioacchino M, Mangifesta R, Panzera C, Gangemi S, Minciullo PL. Malondialdehyde as a potential oxidative stress marker for allergy-oriented diseases: an update. Molecules 2023; 28(16): 5979.
6. Gheena S, Ezhilarasan D, Shree Harini K, Rajeshkumar S. Syringic acid and silymarin concurrent administration inhibits sodium valproate-induced liver injury in rats. Environ Toxicol 2022; 37(9): 2143-52.
7. Gong X, Guo C, Liu J, Li Z, Ruan J, Tang M, Gu J, Shi H. Unraveling cadmium-driven liver inflammation with a focus on arachidonic acid metabolites and TLR4/ IκBα /NF-κB pathway. Ecotoxicol Environ Saf 2024; 286: 117177.
8. Grunnet LG, Aikin R, Tonnesen MF, Paraskevas S, Blaabjerg L, Størling J, Rosenberg L, Billestrup N, Maysinger D, Mandrup-Poulsen T. Proinflammatory cytokines activate the intrinsic apoptotic pathway in β-Cells. Diabetes 2009; 58(8): 1807-15.

9. Hassan RE, Saleh EM, Hamdy GM. Aloe vera gel relieves cadmium triggered hepatic injury via antioxidative, anti-inflammatory, and anti-apoptotic routes. Biol Trace Elem Res 2025; 203(1): 218-28.
10. Jomova K, Alomar SY, Alwasel SH, Nepovimova E, Kuca K, Valko M. Several lines of antioxidant defense against oxidative stress: antioxidant enzymes, nanomaterials with multiple enzyme-mimicking activities, and low-molecular-weight antioxidants. Arch Toxicol 2024; 98(5): 1323-67.
11. Kannan K, Jain SK. Oxidative stress and apoptosis. Pathophysiol 2000; 7(3): 153-63.
12. Kayama F, Yoshida T, Elwell MR, Luster MI. Role of tumor necrosis factor-α in cadmium-induced hepatotoxicity. Toxicol Appl Pharmacol 1995; 131(2): 224-34.
13. Liu L, Zhao Q, Huang J, Lei S. Cadmium-induced hepatotoxicity in mice – prophylactic supplementation of quercetin exerts hepatoprotective effect by modulating PI3K/Akt/NF-κB signaling pathway. Physiol Res 2024; 73(5): 703.
14. Niture S, Lin M, Qi Q, Moore JT, Levine KE, Fernando RA, Kumar D. Role of autophagy in cadmium-induced hepatotoxicity and liver diseases. J Toxicol 2021; 2021(1): 9564297.
15. Okkay IF, Okkay U, Gundogdu OL, Bayram C, Mendil AS, Ertugrul MS, Hacimuftuoglu A. Syringic acid protects against thioacetamide-induced hepatic encephalopathy: behavioral, biochemical, and molecular evidence. Neuroscience Letters 2022; 769:136385.
16. Qu F, Zheng W. Cadmium exposure: mechanisms and pathways of toxicity and implications for human health. Toxics 2024;12(6): 388.
17. Renu K, Chakraborty R, Myakala H, Koti R, Famurewa AC, Madhyastha H, Vellingiri B, George A, Valsala Gopalakrishnan A. Molecular mechanism of heavy metals (Lead, Chromium, Arsenic, Mercury, Nickel and Cadmium) - induced hepatotoxicity - A review. Chemosphere 2021; 271: 129735.
18. Sengul E, Yildirim S, Cinar İ, Tekin S, Dag Y, Bolat M, Gok M, Warda M. Mitigation of acute hepatotoxicity ınduced by cadmium through morin: modulation of oxidative and pro-apoptotic endoplasmic reticulum stress and ınflammatory responses in rats. Biol Trace Elem Res 2024; 202(11): 5106–17.
19. Shi Y, Wang K, Ling H, Mao J, Xu B, Liu Z, Wang J. Quercetin attenuates cadmium-induced hepatotoxicity by suppressing oxidative stress and apoptosis in rat. J Trace Elem Med Biol 2024; 2024; 86: 127554.
20. Sun B, Song J, Wang Y, Jiang J, An Z, Li J, Zhang Y, Wang G, Li H, Alexis NE, Jaspers I, Wu W. Associations of short-term PM2.5 exposures with nasal oxidative stress, inflammation and lung function impairment and modification by GSTT1-null genotype: A panel study of the retired adults. Environ Pollut 2021; 285: 117215.
21. Tylutka A, Walas Ł, Zembron-Lacny A. Level of IL-6, TNF, and IL-1β and age-related diseases: a systematic review and meta-analysis. Front Immunol 2024; 15: 1330386.
22. Vijiyakumar N, Prince SE. A comprehensive review of cadmium-induced toxicity, signalling pathways, and potential mitigation strategies. Toxicol Environ Health Sci 2024; 17(1): 79-94.
23. Wang Y, Chi H, Xu F, He Z, Li Z, Wu F, Li Y, Zhang G, Peng X, Yu S, Yang J, Zhang W, Yang X. Cadmium chloride-induced apoptosis of HK-2 cells via interfering with mitochondrial respiratory chain. Ecotoxicol Environ Saf 2022; 236: 113494.
24. Wang Y, Wu Y, Luo K, Liu Y, Zhou M, Yan S, Shi H, Cai Y. The protective effects of selenium on cadmium-induced oxidative stress and apoptosis via mitochondria pathway in mice kidney. Food Chem Toxicol 2013; 58: 61-7.
25. Xu Y, Mu W, Li J, Ba Q, Wang H. Chronic cadmium exposure at environmental-relevant level accelerates the development of hepatotoxicity to hepatocarcinogenesis. Sci Total Environ 2021; 783: 146958.
26. Yang Z, He Y, Wang H, Zhang Q. Protective effect of melatonin against chronic cadmium-induced hepatotoxicity by suppressing oxidative stress, inflammation, and apoptosis in mice. Ecotoxicol Environ Saf 2021; 228: 112947.
27. Yesildag K, Gur C, Ileriturk M, Kandemir FM. Evaluation of oxidative stress, inflammation, apoptosis, oxidative DNA damage and metalloproteinases in the lungs of rats treated with cadmium and carvacrol. Mol Biol Rep 2022; 49(2): 1201-11.
28. Yuan Y, Zhang Y, Zhao S, Chen J, Yang J, Wang T, Zou H, Wang Y, Gu J, Liu X, Bian J, Liu Z. Cadmium-induced apoptosis in neuronal cells is mediated by Fas/FasL-mediated mitochondrial apoptotic signaling pathway. Sci Rep 2018; 8(1): 1-11.
29. Zhang LJ, Wang XZ. Interleukin-10 and chronic liver disease. World J Gastroenterol 2006; 12(11): 1681.
30. Zou C, Chen Y, Li H, Li W, Wei J, Li Z, Wang X, Chen T, Huang H. Engineered bacteria EcN-MT alleviate liver injury in cadmium-exposed mice via its probiotics characteristics and expressing of metallothionein. Front Pharmacol 2022; 13: 857869.