International Journal of Retina (IJRETINA) 2025.
Volume 8.
Number 2.
P-ISSN.
E-ISSN.
PROTECTIVE EFFECTS OF SELENIUM SUPPLEMENTATION AGAINST
HIGH FRUCTOSE CORN SYRUP-INDUCED RETINAL DAMAGE IN
RATS THROUGH REDUCTION OF INFLAMMATION AND APOPTOSIS
Usta Sofu G1.
Savran M2.
Ozkaya D1.
Karaca U3.
Karakuyu NF4 Department of Ophthalmology.
Faculty of Medicine.
Suleyman Demirel University.
Isparta.
Turkey.
Department of Pharmacology.
Faculty of Medicine.
Suleyman Demirel University.
Isparta.
Turkey.
Department of Ophthalmology.
Lara Anadolu Hospital.
Antalya.
Turkey.
Department of Pharmacology.
Faculty of Pharmacy.
Suleyman Demirel University.
Isparta.
Turkey.
Abstract Introduction: High fructose corn syrup (HFCS) consumption is associated with metabolic complications such as retinopathy.
This study aimed to investigate the potential protective effects of selenium (S.
against HFCS-induced retinal damage.
Methods: Forty Wistar albino rats were divided into four groups .
=7 eac.
: (I) control.
(II) high fructose corn syrup (HFCS, 20% in die.
HFCS Se .
% in diet, 0.
3 mg/kg orall.
and (IV) Se After six weeks, retinal damage was thoroughly assessed using histopathological and immunohistochemical analyses.
Histopathological assessment focused on retinal thickness measurements, whereas immunohistochemical analyses quantified the expression of tumor necrosis factor- (TNF-) and Caspase-3 (Cas-.
, key markers of inflammation and apoptosis.
Statistical analysis was performed using one-way ANOVA (Fisher's LSD), with results expressed as mean A SD, and a p-value of <0.
05 was considered statistically significant.
Results: Histopathological findings revealed a significant increase in retinal thickness in the HFCS group .
6 A 25.
37 AA.
compared to that in the control group .
43 A 5.
79 AA.
Notably, the HFCS Se group exhibited a significantly reduced average retinal thickness .
1 A 27.
08 AA.
compared with the HFCS group .
<0.
Immunohistochemical analysis showed a significant increase in TNF- expression in the HFCS group compared to that in the control and Se groups .
<0.
, although the decrease in the HFCS Se group was not statistically significant compared to that in the HFCS group .
>0.
Furthermore.
Caspase-3 expression was significantly elevated in the HFCS group compared to that in the control and Se groups .
<0.
001 for bot.
Importantly.
Caspase-3 expression was significantly decreased in the HFCS Se group compared to that in the HFCS group .
<0.
Conclusion: Selenium supplementation partially protects against HFCS-induced retinal damage in rats, primarily by significantly mitigating increased retinal thickness and reducing apoptosis, as evidenced by the decreased Caspase-3 expression.
Although TNF- levels showed a trend of reduction with Se, this change was not significant.
These findings highlight the potential therapeutic role of selenium in preventing or ameliorating HFCSinduced ocular complications.
Keywords: High fructose corn syrup.
Retinal damage.
Selenium.
TNF-.
Caspase-3.
Cite This Article: USTA.
Gulsah et al.
Selenium Supplementation Attenuates High Fructose Corn Syrup-Induced Retinal Damage in Rats.
International Journal of Retina, [S.
], v.
8, n.
2, sep.
ISSN 2614-8536.
Available at:
<https://w.
com/index.
php/ijretina/article/view/301>.
Date accessed: 30 sep.
doi: https://doi.
org/10.
35479/ijretina.
Published by: INAVRS https://w.
org/ | International Journal of Retina https://ijretina.
Selenium (S.
is an essential trace element known
INTRODUCTION
Retinopathy, a condition Correspondence to:
Usta Sofu G.
Suleyman Demirel University.
Isparta.
Turkey, gulsahusta@sdu.
that can significantly impair visual acuity and arises from shown to exacerbate inflammatory conditions and impair immune cell function.
18 Previous studies have Metabolic demonstrated the protective effects of Se.
Gonzylez de Vega et al.
showed that Se supplementation protected RPE cells from glucose- The global rise in the consumption induced damage.
19 Another study found that high of high fructose corn syrup (HFCS) products has doses of Se downregulated VEGF production in the been correlated with an increased prevalence of hypoxic retina.
20 Additionally, pretreatment with Se insulin resistance and diabetes, which are critical has proven more effective than post-treatment in (MetS).
Furthermore.
Se deficiency has been Syndrome 16,17 components of MetS.
Research indicates that reducing cell damage and apoptosis in retinal MetS, which affects approximately 35% of the ischemia-reperfusion injuries.
21 However, despite American these promising findings, the specific potential determinant of diabetes mellitus, a condition protective role of Se against retinal damage directly associated with alterations in the retinal blood caused by HFCS consumption has not been fully Specifically, experimental studies have shown that Therefore, this study aimed to comprehensively excessive consumption of HFCS can lead to oxidative investigate the protective effect of selenium Tumor Necrosis Factor supplementation on HFCS diet-induced retinal (TNF)- and caspase (Ca.
-3 are essential markers of damage by evaluating changes through both apoptosis and inflammation that are crucial for understanding the pathophysiological mechanisms underlying the effects of HFCS consumption.
Studies expressio.
have reported that HFCS consumption has been METHODS stress and inflammation.
etinal (TNF- Caspase-3 associated with increased expression of TNF-, a Chemicals pro-inflammatory cytokine implicated in both the The HFCS (F55:56% fructose and 37% glucos.
kidney and liver.
In recent years, studies have used in this study was procured from a local reported that HFCS consumption plays a role in manufacturer (Toposmanoglu.
Isparta.
Turke.
The apoptosis in the hippocampus and heart because of Se used for treatment was acquired from Sigma the activation of Cas-3.
10,11
Moreover, studies have (USA).
All chemicals used were of analytical grade.
shown that TNF- levels are elevated in individuals Animals and ethical approval Adult female Wistar Albino rats .
-350 .
were Retinal pigment epithelial (RPE) cell housed in a controlled environment .
-22AC.
death is associated with the activation of Cas-3.
60A5% humidit.
with a 12:12-hour light/dark cycle.
Interestingly, early retinal findings in rats fed a high- Rats were kept in standard cages and provided with fructose diet were primarily associated with glucose a commercially available chow diet (Korkuteli Yem, metabolism deregulation.
Recently, protective Antalya.
Turke.
Tap water was provided ad libitum treatment regimens against HFCS-induced retinal and changed daily as needed.
The study was damage have been investigated.
approved by the Committee on Animal Research of Suleyman Demirel University.
Isparta Published by: INAVRS https://w.
org/ | International Journal of Retina https://ijretina.
(Ethic No.
11/02/2021-01/.
and abided by the primary and secondary antibodies were purchased ARVO Statement for the Use of Animals in Ophthalmic and Vision Research.
Caspase-3 antibody was obtained from Santa Cruz High Fructose Corn Syrup (HFCS) Model Biotechnology (Santa Cruz.
CA.
USA).
All primary Abcam (Cambridge.
UK).
The groups in the study design were exposed to antibodies were used at a 1/100 dilution.
The first a diet that would trigger MetS by adding 20% .
step in the immunohistochemistry process was HFCS solution to their drinking water, which was incubating the primary antibodies for 60 seconds.
prepared daily.
Se was administered to the selected The Expose Mouse and Rabbit Specific HRP/DAB groups via oral gavage daily at 0.
3 mg/kg.
Detection IHC Kit .
was used as the Forty rats were randomly divided into four groups secondary antibody system, with diaminobenzidine .
=7 per grou.
(DAB) as the chromogen.
The primary antiserum step Control Group: Standard chow and drinking water.
was excluded from negative controls.
For each HFCS Group: Standard chow and HFCS diet.
group, immunopositivity was assessed by evaluating HFCS Se group: Standard chow.
HFCS, and Se diet.
images of 100 cells from ten different fields per Se Group: Standard chow, drinking water, and Se.
After six weeks, all rats were sacrificed under Database Manual Cell Sens Life Science Imaging anesthesia with 50Ae 80 mg/kg ketamine (Bioveta.
Software System (Olympus Co.
Tokyo.
Japa.
was Czech Republi.
and 8Ae10 mg/kg xylazine (Doa lay.
Turke.
Following Table 1.
Immunohistochemical scores of retinal tissues formalin solution until necropsy.
Staining Intensity Score Description Absence of staining After enucleation, eyeball samples Slight staining were removed and fixed in 10% neutral Medium staining Marked staining Histopathological Analyses Standard Statistical Analysis processing was performed (ASP300S.
Wetzlar.
German.
The samples were then embedded in paraffin and cut into 4 AAm slices using a Leica RM2155 (Leica Microsystems.
Wetzlar.
German.
Retinal hematoxylin and eosin (HE) for morphological Subsequently, eyeballs were fixed in 10% buffered The semiquantitative analysis, as shown in Table 1, was employed to score the staining intensity on a scale of 0Ae3.
Statistical analysis was performed on the output of the image analyzer.
measurements were performed using a Nikon One-way ANOVA (Fisher's LSD) was used to Eclipse Ni microscope.
compare the retinal thickness and retinal lesion Immunohistochemical Analyses scores between the experimental groups (GraphPad Samples were then immunostained with TNF- Prism softwar.
The results are expressed as mean A [Anti-TNF- Antibody .
] and Caspase-3 [Anti SD.
Caspase-3 significant at p < 0.
Antibody .
A1.
:sc-56.
All Differences Published by: INAVRS https://w.
org/ | International Journal of Retina https://ijretina.
RESULTS
Histopathological finding As shown in Fig.
1, the Control and Se groups exhibited normal retinal tissue architecture.
Conversely, the HFCS group showed congestion in retinal vessels and increased vascularity compared to the control group.
Notably, these pathological findings were reduced in the HFCS Se group.
Retinal thickness measurements revealed a significant increase in the HFCS group .
6 A 25.
37 AA.
compared to the control group .
79 AA.
< 0.
Additionally, the HFCS Se group exhibited a significantly reduced average retinal thickness .
1 A 27.
08 AA.
compared with the HFCS group .
< 0.
The Se group showed a median retinal thickness .
A 11.
18 AA.
that was not significantly different from that of the control group .
=0.
Fig.
1 Histopathological appearance of the retina in the different groups.
(A) Normal retinal architecture in the control group.
(B) Increased congestion in the retinal vascular vessels and vascularity in the HFCS group.
(C) Regeneration of epithelial cells in the HFCS Se group.
(D) Normal retinal tissue patterns were observed only in the Se group.
HFCS, high fructose corn syrup.
Se:
Selenium.
II.
All bars indicate mean values ASD .
=7 per grou.
**** represent p<0.
0001, *** represent p=0.
One-way ANOVA (Fisher's LSD) test results of retinal thickness(AA.
Published by: INAVRS https://w.
org/ | International Journal of Retina https://ijretina.
Immunohistochemical findings As shown in Fig.
2, in immunohistochemical analyses, the TNF- staining score was significantly elevated in the HFCS group compared to the Control and Se groups .
<0.
Although the HFCS Se group showed a decrease in TNF- staining score, this reduction was not statistically significant compared to that in the HFCS group .
=0.
The Se group showed no immunostaining, which was not significantly different from that in the control group .
>0.
Fig.
2 TNF- expression in the different groups.
A) No TNF- expression in control group (B) Medium ( ) TNF- immunostaining in HFCS group.
(C) Slight ( ) TNF- immunostaining in the HFCS Se group.
(D) No TNF- expression in the Se group (TNF.
DAB, 200X).
HFCS, high fructose corn syrup.
Se: Selenium.
II.
All bars indicate the TNF- expression analysis score .
=7 per grou.
TNF- expression analysis score of the retina results with Fisher's LSD test ** represent p<0.
01, * represent p<0.
As shown in Fig.
3, in immunohistochemical analyses, the Cas-3 staining score was significantly increased in the HFCS group compared to the Control and Se groups .
<0.
001 for bot.
This score was significantly decreased in the HFCS Se group compared to that in the HFCS group .
<0.
The Control, and Se groups exhibited no significant differences in Cas-3 staining scores .
=0.
Published by: INAVRS https://w.
org/ | International Journal of Retina https://ijretina.
Fig.
3 Caspase-3 expression in the different groups.
A) No Cas -3 expression in control group.
(B) Medium Cas-3 immunostaining in the HFCS group.
(C) Slight Cas -3 expression in the HFCS Se group.
(D) No Cas -3 expression in the Se group (CAS-3.
DAB, 200X).
HFCS, high fructose corn syrup.
Se: Selenium.
II.
All bars indicate the Cas-3 expression analysis score of the retina .
=7 per grou.
Cas -3 expression analysis score of the retina results with Fisher's LSD test.
*** represents p<0.
001, ** represents p<0.
005, *
represents p<0.
linked to various metabolic disorders, including DISCUSSION This study aimed to analyze retinal changes due metabolic syndrome, insulin resistance, and organ- to high blood glucose from HFCS in rats.
The results specific damage4.
However, a growing body of of this study showed increased congestion in the evidence has verified the role of inflammation in this retinal arteries and vascularity, along with increased state22,23.
retinal thickness, in the HFCS group.
This confirms consumption increases the expression of TNF- and the successful establishment of an experimental Cas-3 in kidney tissue8.
In another study, it was model demonstrating retinal issues due to a high- reported that even a short-term high-fat fructose fructose diet within 6 weeks.
diet in rats led to the inhibition of hippocampal Studies HFCS insulin signaling and activation of Cas-310.
Moreover, consumption of HFCS, which is prevalent in studies have reported that a high dietary intake of processed foods owing to its lower cost, has been refined carbohydrates, including HFCS.
Over Published by: INAVRS https://w.
org/ | International Journal of Retina https://ijretina.
may contribute to the development of retinal Additionally, we investigated the effect of HFCS To our knowledge, no histopathological on Cas-3 expression in the retina.
In a study, one of evaluation has reported the protective effects of the consequences of microglial activation due to selenium against HFCS-induced retinal damage.
metabolic changes in diabetic retinopathy was Therefore, this study evaluated the protective effect increased apoptosis28.
Similar to that study, in the of Se against retinal damage caused by HFCS consumption by measuring retinal thickness, as well immunostaining in the Cas-3 score in the HFCS as inflammatory and apoptotic markers.
The results group, indicating some level of retinal damage and of this study demonstrated that HFCS consumption Moreover, the HFCS Se group showed led to a significantly higher retinal thickness than significantly reduced scores compared to the HFCS that in the control group.
Moreover, the HFCS S e group, suggesting that Se also has a protective effect group showed significantly reduced retinal thickness against HFCS-induced apoptosis.
compared to the HFCS group, suggesting a protective effect of Se against HFCS-induced retinal Although this study provides important evidence for the potential protective role of Se in HFCSinduced retinal damage, it has important limitations.
In hyperglycemic conditions, inflammation may occur due to First, the six-week study duration, while sufficient to altered expression of induce detectable retinal damage in the HFCS group, may not fully capture the long-term consequences microenvironmental changes.
Studies have reported of HFCS consumption and Se supplementation on that Hyperglycemia induces inflammation in aortic retinal health.
This study did not examine diabetic endothelial cells, leading to increased expression of inflammatory mediators, especially TNF-, and treatment that would reduce retinal damage before endothelial dysfunction .
Furthermore, studies have the underlying pathophysiology develops.
Second, shown that hyperglycemia stimulates the release of although this study provides valuable information pro-inflammatory cytokines, such as TNF-, which contribute to retinal inflammation and damage26.
Since the literature indicates the regression of document the specific molecular mechanisms inflammation by anti-TNF agents , in the current underlying HFCS-induced retinal damage or Se study, it was preferred to show histopathological findings in this animal model are promising, the TNF- Indeed, the findings of immunohistochemical analyses in this study showed that HFCS increased TNF- production in the retina.
However, although there was a slight decrease in TNF- production in the HFCS Se group, the difference with the HFCS group was not statistically Moreover.
Se alone did not result in TNF immunostaining.
Furthermore, translatability of these results to humans is uncertain.
These results suggest that Se supplementation can effectively protect against retinal changes caused by HFCS consumption.
Considering the design of this study, further experiments, including detailed analyses, will help to better understand the disease process and identify new treatment targets.
Published by: INAVRS https://w.
org/ | International Journal of Retina https://ijretina.
Authors Contributions GUS:
Conceptualization.
Kearney FM.
Fagan XJ.
Al-Qureshi S.
Review Investigation, of the role of refined dietary sugars .
ructose Methodology.
Project administration.
Supervision, and glucos.
in the genesis of retinal disease.
Writing Ae original draft.
MS: Methodology.
Data Clin Exp Ophthalmol.
2014 Aug 1.
:564Ae Ae UK:
Investigation.
Data curation, formal analysis, writing review and editing.
Dyn: Data curation, formal yC.
Ocular findings in metabolic syndrome: a analysis, writing Ae review and editing.
NFK: Data Porto Biomed J.
:104.
curation, formal analysis, writing Ae review and the diet reverses inflammation, mitochondrial This study was supported by the Scientific Research dysfunction, and oxidative stress in Project Unit of Suleyman Demirel University (Project Antioxidants.
2021 Mar Code: TSG-2021-8.
All data are included in the article.
Mazzoli A.
Spagnuolo MS.
Nazzaro M.
Gatto C.
Iossa S.
Cigliano L.
Fructose removal from Funding Data Availability Lima-Fontes M.
Barata P.
Falcyo M.
Carneiro 10.
:1Ae17.
Ma X.
Nan F.
Liang H.
Shu P.
Fan X.
Song X, et al.
Excessive intake of sugar: An Conflict of interest accomplice of inflammation.
Vol.
The authors declare no conflicts of interest.
Frontiers in Immunology.
Frontiers Media REFERENCES