# Propolis alleviates brain tissue damage and oxidative abnormalities in streptozotocin (STZ)-induced diabetes

**Authors:** Ahmed M. Ashour

PMC · DOI: 10.1016/j.jgeb.2026.100663 · 2026-02-09

## TL;DR

Propolis, a natural bee product, reduces brain damage and oxidative stress in diabetic rats, suggesting it could be a promising natural treatment for diabetes-related brain complications.

## Contribution

This study demonstrates propolis's neuroprotective effects in a diabetic rat model through antioxidant and anti-inflammatory mechanisms.

## Key findings

- Propolis treatment reduced fasting blood glucose and insulin levels in diabetic rats.
- Propolis improved lipid profiles and decreased oxidative stress and inflammation in brain tissue.
- Histological analysis showed reduced brain tissue damage in propolis-treated diabetic rats.

## Abstract

Diabetes is a serious and rapidly growing global health issue that can affect many organs, including the brain. It is often linked to complications such as cardiovascular disease and cerebral ischemia. Propolis, a natural resin produced by honey bees, is rich in phenols and flavonoids known for their antioxidant, anti-inflammatory, and immune-modulating properties.

This primary aim in this research was to evaluate the neuroprotective effects of propolis on brain tissue in rats that have diabetes which is introduced through nicotinamide (NA) and streptozotocin (STZ).

Male Wistar rats were separated into categories. Except for the control category, all were fed a diet that had high fat levels. Diabetes was induced using intraperitoneal injections of NA and STZ. After induction, diabetic rats received oral propolis at doses of 50 or 100 mg/kg daily for eight weeks. Throughout the study, lipid profiles, fasting blood glucose, insulin levels, and oxidative stress markers were assessed by taking measurements. At the end of the experiment, brain tissues were analyzed for cytokine levels, antioxidant activity, and DNA damage using the COMET assay, in addition to histopathological and immunohistochemical examinations.

Treatment with propolis significantly reduced fasting blood glucose and insulin levels, improved profiles of lipid, and decreased oxidative stress and inflammatory mediators. Histological analysis showed that rats treated with propolis had noticeably less brain tissue damage compared to untreated diabetic rats.

Propolis demonstrated clear neuroprotective effects in diabetic rats, likely through its antioxidant and anti-inflammatory mechanisms. These findings suggest that propolis may present a considerably potential solution as a natural therapeutic agent for reducing diabetes-induced brain damage.

## Linked entities

- **Chemicals:** streptozotocin (PubChem CID 29327), nicotinamide (PubChem CID 936)
- **Diseases:** diabetes (MONDO:0005015)
- **Species:** Rattus norvegicus (taxon 10116)

## Full-text entities

- **Diseases:** inflammatory (MESH:D007249), brain damage (MESH:D001925), brain tissue damage (MESH:D017695), cerebral ischemia (MESH:D002545), Diabetes (MESH:D003920), cardiovascular disease (MESH:D002318)
- **Chemicals:** glucose (MESH:D005947), NA (MESH:D009536), flavonoids (MESH:D005419), fat (MESH:D005223), lipid (MESH:D008055), Propolis (MESH:D011429), phenols (MESH:D010636), STZ (MESH:D013311)
- **Species:** Rattus norvegicus (brown rat, species) [taxon 10116], Apis mellifera (bee, species) [taxon 7460]

## Figures

12 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12907228/full.md

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Source: https://tomesphere.com/paper/PMC12907228