# Synergistic therapeutic effects of metformin and curcumin on polycystic ovary syndrome via regulation of insulin resistance and oxidative stress in a rat model

**Authors:** Lina Zheng, Baohua Wu, Junli Zhang, Yianduo Zhang, Zhiling Yang, Caifeng Deng, Chaolin Huang, Ling Lu

PMC · DOI: 10.3389/fendo.2026.1675883 · Frontiers in Endocrinology · 2026-02-16

## TL;DR

Combining metformin and curcumin improves PCOS symptoms in rats by reducing insulin resistance and oxidative stress.

## Contribution

The study demonstrates a synergistic effect of metformin and curcumin in treating PCOS through combined regulation of insulin resistance and oxidative stress.

## Key findings

- Combined treatment restored estrous cycles and improved ovarian morphology in PCOS rats.
- The combination reduced testosterone and luteinizing hormone levels and improved insulin resistance.
- Oxidative stress markers were decreased, and antioxidant enzyme activities were enhanced with combined treatment.

## Abstract

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder characterized by insulin resistance, hyperandrogenism, and elevated oxidative stress. The present study aimed to investigate the synergistic therapeutic effects of metformin and curcumin on insulin resistance and oxidative stress in a rat model of PCOS.

Thirty female Sprague-Dawley rats were randomly assigned to blank control (n = 6) and experimental (PCOS) groups (n = 24). The PCOS model was induced through daily subcutaneous injections of dehydroepiandrosterone (DHEA, 60 mg/kg) for 20 days. Subsequently, the experimental group was subdivided into four groups: PCOS-only, PCOS-metformin (300 mg/kg), PCOS-curcumin (50 mg/kg), and PCOS-metformin-curcumin (combined treatment). Treatments were administered daily via oral gavage for another 20 days. Estrous cycles, ovarian morphology, serum sex hormones, insulin resistance, and oxidative stress in ovarian tissues were assessed.

Combined treatment with metformin and curcumin significantly restored estrous cyclicity, improved ovarian morphology, reduced serum testosterone and luteinizing hormone levels, decreased LH/FSH ratio, and ameliorated insulin resistance compared to monotherapy groups. Moreover, the combined treatment markedly decreased ovarian oxidative stress markers (ROS and MDA) and enhanced antioxidant enzyme activities (GPx, SOD, GSH), surpassing the effects of either agent alone.

Combined administration of metformin and curcumin demonstrated synergistic therapeutic effects in PCOS rats by concurrently addressing insulin resistance and oxidative stress. These findings support the clinical potential of this combination as an effective strategy for managing PCOS. Further clinical studies are necessary to validate these promising preclinical findings.

## Linked entities

- **Chemicals:** metformin (PubChem CID 4091), curcumin (PubChem CID 969516), dehydroepiandrosterone (PubChem CID 5881), MDA (PubChem CID 1614), GPx (PubChem CID 135460989), GSH (PubChem CID 124886)
- **Diseases:** polycystic ovary syndrome (MONDO:0008487)

## Full-text entities

- **Genes:** Prl (prolactin) [NCBI Gene 24683] {aka Gha1, PRLB, PRLSD1, Prl1a1, Prol, RATPRLSD1}, Amh (anti-Mullerian hormone) [NCBI Gene 25378] {aka MIS}, INS (insulin) [NCBI Gene 3630] {aka IDDM, IDDM1, IDDM2, ILPR, IRDN, MODY10}, Pparg (peroxisome proliferator-activated receptor gamma) [NCBI Gene 25664] {aka PPARgamma2}, Prkaa2 (protein kinase AMP-activated catalytic subunit alpha 2) [NCBI Gene 78975] {aka Ampk, Ampka2}, Nfe2l2 (NFE2 like bZIP transcription factor 2) [NCBI Gene 83619]
- **Diseases:** metabolic syndrome (MESH:D024821), hyperandrogenism (MESH:D017588), chronic inflammation (MESH:D007249), follicular cysts (MESH:D005497), dyslipidemia (MESH:D050171), PCOS (MESH:D011085), endocrine and metabolic disorder (MESH:D004700), diabetic (MESH:D003920), gastrointestinal intolerance (MESH:D005767), Insulin resistance (MESH:D007333), obesity (MESH:D009765), nausea (MESH:D009325), nausea, vomiting (MESH:D020250), diarrhea (MESH:D003967), development (MESH:D002658), chronic ovarian inflammation (MESH:D010049), polycystic (MESH:D007690), impaired glucose tolerance (MESH:D018149), metabolic and reproductive abnormalities (MESH:D060737), metabolic abnormalities (MESH:D008659), sex hormone (MESH:D058533), bloating (MESH:C535647)
- **Chemicals:** H&amp;E (MESH:D006371), T (MESH:D014316), Curcumin (MESH:D003474), paraffin (MESH:D010232), -3750B (-), hematoxylin (MESH:D006416), MDA (MESH:D015104), E2 (MESH:D004958), MDA (MESH:D008315), sodium pentobarbital (MESH:D010424), sesame oil (MESH:D012715), F (MESH:D005461), methylene blue (MESH:D008751), Metformin (MESH:D008687), GSH (MESH:D005978), water (MESH:D014867), E (MESH:D004540), biguanide (MESH:D001645), testosterone (MESH:D013739), Lipid (MESH:D008055), paraformaldehyde (MESH:C003043), DHEA (MESH:D003687), luteinizing hormone (MESH:D007986), Progesterone (MESH:D011374), eosin (MESH:D004801), ROS (MESH:D017382), glucose (MESH:D005947)
- **Species:** Rattus norvegicus (brown rat, species) [taxon 10116], Homo sapiens (human, species) [taxon 9606], Rodentia (rodent, order) [taxon 9989], Curcuma longa (turmeric, species) [taxon 136217]

## Full text

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## Figures

5 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12950547/full.md

## References

39 references — full list in the complete paper: https://tomesphere.com/paper/PMC12950547/full.md

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Source: https://tomesphere.com/paper/PMC12950547