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

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.

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.

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