# Gallic Acid and Vitamin C Mitigate Histopathological Changes in the Retina by Attenuating Dyslipidemia and Mitigating Oxidative Stress, Inflammation, and Apoptosis in the Eyes of Type 2 Diabetic Rats Induced With Fructose/Streptozotocin

**Authors:** He Wang, Lina Guan, Hanyue Guan, Jingheng Zhong, Jiangtao Zhong

PMC · DOI: 10.1002/fsn3.70699 · 2025-07-29

## TL;DR

Gallic acid and vitamin C together improve retinal health in diabetic rats by reducing oxidative stress and inflammation.

## Contribution

The novel finding is that combining gallic acid and vitamin C enhances therapeutic effects on retinal histopathology in diabetic rats.

## Key findings

- Combined gallic acid and vitamin C improved retinal histopathology in diabetic rats.
- Vitamin C alone was more effective than gallic acid in improving HOMA-β and reducing HbA1C and VEGF.
- Combination therapy showed better results than individual treatments in mitigating diabetes-induced retinal damage.

## Abstract

The result of combined supplementation of gallic acid and vitamin C on histopathological changes in the retina of type 2 diabetic rats induced with fructose and streptozotocin (STZ) was studied. Albino male rats (numbering 25) were assigned into five groups of five rats each as follows: Normal control and diabetic control (non‐diabetic and diabetic rats given rat feeds and water); diabetic + gallic acid (diabetic rats given gallic acid, 20 mg/kg, orally), diabetic + vitamin C (diabetic rats given vitamin C, 25 mg/kg, orally), diabetic + gallic acid + vitamin C (diabetic rats given gallic acid, 20 mg/kg and vitamin C, 25 mg/kg, orally). The study lasted for 10 weeks. The diabetic rats had a marked increase (p < 0.05) in fasting blood glucose, glycated hemoglobin (HbA1C), insulin resistance (IR), lipase, dyslipidemia, vascular endothelial growth factor (VEGF), pro‐apoptotic marker level, oxidative stress and inflammatory mediators, and a significant decline (p < 0.05) in pancreatic beta cell function index (HOMA‐β), serum levels of amylase and vitamin C, body weights, anti‐apoptotic marker level as well as histopathological changes in their retina. These changes were improved after supplementing with gallic acid, vitamin C, and their combination. The HOMA‐β levels of the diabetic rats that received vitamin C (1.39 ± 0.59) and the combination of gallic acid and vitamin C (0.86 ± 0.77) were significantly higher (p < 0.05) than the diabetic rats that received gallic acid (−0.01 ± 0.62) while their HbA1C and VEGF levels were lower (p < 0.05) than the diabetic rats that received gallic acid. Vitamin C treatment was better than gallic acid, and its combination with gallic acid enhanced the therapeutic effect of gallic acid.

The study showed that vitamin C treatment was better than gallic acid, and its combination with gallic acid enhanced the therapeutic effect of gallic acid. Vitamin C and the combination of gallic acid and vitamin C produced better histological changes in the retina of the diabetic rats than gallic acid alone, while the combined therapy produced better retinal histological changes than the single therapies.

## Linked entities

- **Proteins:** amylase (pancreatic alpha-amylase-like)
- **Chemicals:** gallic acid (PubChem CID 370), vitamin C (PubChem CID 54670067), streptozotocin (PubChem CID 29327), insulin (PubChem CID 70678557)
- **Diseases:** Type 2 diabetes (MONDO:0005148)
- **Species:** Rattus norvegicus (taxon 10116)

## Full-text entities

- **Genes:** Bcl2 (BCL2, apoptosis regulator) [NCBI Gene 24224] {aka Bcl-2}, Tnf (tumor necrosis factor) [NCBI Gene 24835] {aka RATTNF, TNF-alpha, Tnfa}, Nos2 (nitric oxide synthase 2) [NCBI Gene 24599] {aka Nos2a, iNos}, INS (insulin) [NCBI Gene 3630] {aka IDDM, IDDM1, IDDM2, ILPR, IRDN, MODY10}, Pnlip (pancreatic lipase) [NCBI Gene 25702] {aka PANLI}, PNLIP (pancreatic lipase) [NCBI Gene 5406] {aka PL, PNLIPD, PTL}, Vegfa (vascular endothelial growth factor A) [NCBI Gene 83785] {aka VEGF-A, VEGF111, VEGF164, VPF, Vegf}, Nfkb1 (nuclear factor kappa B subunit 1) [NCBI Gene 81736] {aka EBP-1, NF-kB, NFKB-p50, p50}, Bax (BCL2 associated X, apoptosis regulator) [NCBI Gene 24887], Casp3 (caspase 3) [NCBI Gene 25402] {aka CPP32-beta, Lice, Yama}, Cat (catalase) [NCBI Gene 24248] {aka CS1, Cas1, Cat01, Catl, Cs-1}, Hpgds (hematopoietic prostaglandin D synthase) [NCBI Gene 58962] {aka Ptgds2}, Il10 (interleukin 10) [NCBI Gene 25325] {aka IL10X, If2a}, Lipg (lipase G, endothelial type) [NCBI Gene 291437] {aka lipase}
- **Diseases:** impaired (MESH:D060825), DR (MESH:D003930), T2DM (MESH:D003924), retinal neovascularization (MESH:D015861), weight gain (MESH:D015430), mitochondrial damage (MESH:D028361), DM (MESH:D003920), retinal hemorrhage (MESH:D012166), cardiomyopathy (MESH:D009202), neuropathy (MESH:D009422), nephropathy (MESH:D007674), micro-vascular and macro-vascular complications (MESH:D014652), retinopathy (MESH:D058437), retinal detachment (MESH:D012163), Dyslipidemia (MESH:D050171), type 1 (MESH:D003922), obesity (MESH:D009765), ocular diseases (MESH:D005128), fibrosis (MESH:D005355), retinal atrophy (MESH:D012173), Inflammation (MESH:D007249), cancer (MESH:D009369), hyperplasia (MESH:D006965), metabolic disorder (MESH:D008659), IR (MESH:D007333), IE (MESH:D004487), pancreatic dysfunction (MESH:D010195), inflammatory cytokine (MESH:D000080424), amyloid cross-beta (MESH:C537866), retinal degeneration (MESH:D012162), complications (MESH:D008107), diabetic nephropathy (MESH:D003928), Hyperglycemia (MESH:D006943), cardiovascular diseases (MESH:D002318), vitreous hemorrhage (MESH:D014823), Loss of weight (MESH:D015431), blindness (MESH:D001766), diabetic complications (MESH:D048909)
- **Chemicals:** STZ (MESH:D013311), formalin (MESH:D005557), H2O2 (MESH:D006861), sodium citrate (MESH:D000077559), superoxide (MESH:D013481), 3,4,5-trihydroxybenzoic acid (MESH:D005707), monoacylglycerols (MESH:D050178), Chemicals (-), citric acid (MESH:D019343), maltose (MESH:D008320), cholesterol (MESH:D002784), Ca (MESH:D002118), Glucose (MESH:D005947), EDTA (MESH:D004492), polyunsaturated fatty acids (MESH:D005231), xylazine (MESH:D014991), vitamin E (MESH:D014810), GSH (MESH:D005978), hematoxylin (MESH:D006416), Mg (MESH:D008274), maltotriose (MESH:C008317), blood glucose (MESH:D001786), paraffin (MESH:D010232), ethanol (MESH:D000431), phosphate (MESH:D010710), polyol (MESH:C024617), HO (MESH:D006695), polyphenol (MESH:D059808), MDA (MESH:D008315), Vit C (MESH:D001205), fatty acids (MESH:D005227), water (MESH:D014867), free fatty acids (MESH:D005230), dehydroascorbic acid (MESH:D003683), NADPH (MESH:D009249), H&amp;E (MESH:D006371), TAG (MESH:D014280), Lipid (MESH:D008055), carbohydrate (MESH:D002241), Fructose (MESH:D005632), eosin (MESH:D004801), starch (MESH:D013213)
- **Species:** Homo sapiens (human, species) [taxon 9606], Rattus norvegicus (brown rat, species) [taxon 10116]

## Figures

8 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12305670/full.md

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Source: https://tomesphere.com/paper/PMC12305670