Vitamin K2 MK7: Protective Effects of Vitamin K2 (MK-7) on the Ovary | Research on Ovarian Ischemia-Reperfusion Injury

MK-7 Protects Against Ovarian Ischemia-Reperfusion Injury in a Rat Torsion–Detorsion Model: Potential Benefits for Ovarian Reserve and Fertility Preservation

MK-7 Shows Protective Effects Against Ovarian Torsion-Induced Ischemia-Reperfusion (I/R) Injury

Ovarian torsion is a gynecologic emergency caused by interruption of ovarian blood flow. Although surgical detorsion restores circulation, the reperfusion process can trigger severe oxidative stress and inflammatory responses, leading to ovarian ischemia-reperfusion (I/R) injury. This condition is closely associated with follicular loss, ovarian tissue damage, diminished ovarian reserve, and reduced fertility potential.
Recent evidence suggests that MK-7 (Menaquinone-7), the bioactive form of Vitamin K2, may exert powerful antioxidant and anti-inflammatory effects in various tissues. This experimental study is the first to evaluate whether MK-7 can protect ovarian tissue and preserve ovarian function following ischemia-reperfusion injury in an ovarian torsion–detorsion rat model.

1. Study Design

The study was conducted in rats and included four experimental groups:

Group Description
Control Group (n=8) Received sunflower oil for 7 days
Sham Group (n=8) Underwent laparotomy and closure only
Torsion–Detorsion (T/D) Group (n=8) Subjected to ovarian ischemia-reperfusion surgery
T/D + MK-7 Group (n=8) Received MK-7 at 30 mg/kg for 7 days following T/D surgery

2. Results

2-1. MK-7 Restored Serum AMH Levels and Preserved Ovarian Reserve

Parameter Control Sham T/D T/D + MK-7
Serum AMH (ng/mL) 4.4 ± 1.69 4.2 ± 1.7 2.2 ± 0.4 4.1 ± 1.2

Anti-Müllerian Hormone (AMH) is a key biomarker used to assess ovarian reserve.
In the ovarian torsion-detorsion group, AMH levels significantly decreased following ischemia-reperfusion injury. However, MK-7 treatment restored AMH concentrations to near-normal levels.
These findings suggest that MK-7 may help reduce follicular damage and preserve ovarian reserve after ovarian ischemic injury.

2-2. MK-7 Increased Antioxidant Enzyme Activity

Parameter Control Sham T/D T/D + MK-7
SOD (U/mg protein) 82.1 ± 17.6 91.9 ± 27.1 59.5 ± 15.8 89.0 ± 12.8
GSH-Px (IU/mg protein) 5.9 ± 1.2 5.7 ± 1.6 3.5 ± 0.9 4.9 ± 0.8
CAT (IU/mL) 266.4 ± 78.3 271.8 ± 43.4 172.8 ± 49.7 259.9 ± 40
Ischemia-reperfusion injury leads to excessive production of reactive oxygen species (ROS), which contribute to cellular and mitochondrial damage.

MK-7 treatment significantly restored the activity of major antioxidant enzymes, including:

  • Superoxide dismutase (SOD) 
  • Glutathione peroxidase (GSH-Px) 
  • Catalase (CAT) 

These results indicate that MK-7 may reduce oxidative stress and create a protective intracellular environment within ovarian tissue.

2-3. MK-7 Reduced Inflammatory Cytokine Levels

Parameter Control Sham T/D T/D + MK-7
TNF-α (pg/mg protein) 1490 ± 239 1560 ± 230 4500 ± 540 1700 ± 320
IL-1β (pg/mg protein) 1780 ± 310 1950 ± 430 5300 ± 850 2000 ± 450
IL-6 (pg/mg tissue) 940 ± 135 950 ± 190 1750 ± 340 1000 ± 220

Ovarian ischemia-reperfusion injury triggers a strong inflammatory response characterized by elevated pro-inflammatory cytokines such as:

  • TNF-α 
  • IL-1β 
  • IL-6 

MK-7 administration significantly reduced these inflammatory mediators, suggesting potent anti-inflammatory effects and improved tissue stabilization within the ovary.

2-4. Histopathological Findings: Reduced Ovarian Damage and Better Follicle Preservation

Group Histopathological Findings
Control Normal ovarian structure with follicles at multiple developmental stages
Sham No significant structural changes
T/D Reduced healthy follicles, increased atretic follicles and corpus luteum, vascular congestion, stromal edema, inflammatory infiltration, and focal hemorrhage
T/D + MK-7 Preserved ovarian architecture, significantly increased healthy follicles, reduced follicular loss, decreased vascular congestion, edema, and inflammatory infiltration

Histological analysis demonstrated that MK-7 not only improved biochemical markers but also protected the structural integrity of ovarian tissue.

3. Conclusion

This study demonstrated that MK-7 (Menaquinone-7) significantly attenuated ovarian ischemia-reperfusion injury caused by ovarian torsion-detorsion in rats.

MK-7 treatment was associated with:

  • Restoration of ovarian reserve markers (AMH) 
  • Enhanced antioxidant defense 
  • Reduction of oxidative stress 
  • Suppression of inflammatory cytokines 
  • Preservation of ovarian tissue structure 

These findings suggest that MK-7 may have promising therapeutic potential in ovarian protection, fertility preservation, and maintenance of ovarian function.

Further long-term fertility studies and human clinical trials are needed to determine whether MK-7 can become a novel therapeutic strategy for preventing and treating ovarian ischemia-reperfusion injury.

Writing date: 2026-05-26