# Mixture of Doxycycline, ML-7 and L-NAME Restores the Pro- and Antioxidant Balance during Myocardial Infarction—In Vivo Pig Model Study

## TL;DR

A drug mix of doxycycline, ML-7, and L-NAME reduces heart injury in pigs by balancing oxidative stress during heart attacks.

## Contribution

A novel multi-drug therapy using low concentrations of doxycycline, ML-7, and L-NAME to stabilize oxidative balance during myocardial infarction in an in vivo pig model.

## Key findings

- The drug mix reduced oxidative stress markers like TOS, OSI, and MDA in pig heart tissue.
- The treatment increased total antioxidant capacity and reduced MMP-2 and MMP-9 activity.
- The mix decreased the release of MLC1 and BNP-26 into plasma, indicating reduced heart damage.

## Abstract

The restoration of blood flow to the ischemic myocardium inflicts ischemia/reperfusion (I/R) heart injury (IRI). The main contributors to IRI are increased oxidative stress and subsequent excessive production of ROS, increased expression of NOS and peroxinitate, activation of MMPs, and enhanced posttranslational modifications of contractile proteins, which make them more susceptible to proteolytic degradation. Since the pathophysiology of IRI is a complex issue, and thus, various therapeutic strategies are required to prevent or reduce IRI and microvascular dysfunction, in the current study we proposed an innovative multi-drug therapy using low concentrations of drugs applied intracoronary to reach microvessels in order to stabilize the pro- and antioxidant balance during a MI in an in vivo pig model. The ability of a mixture of doxycycline (1 μM), ML-7 (0.5 μM), and L-NAME (2 μM) to modulate the pro- and antioxidative balance was tested in the left ventricle tissue and blood samples. Data showed that infusion of a MIX reduced the total oxidative status (TOS), oxidative stress index (OSI), and malondialdehyde (MDA). It also increased the total antioxidant capacity, confirming its antioxidative properties. MIX administration also reduced the activity of MMP-2 and MMP-9, and then decreased the release of MLC1 and BNP-26 into plasma. This study demonstrated that intracoronary administration of low concentrations of doxycycline in combination with ML-7 and L-NAME is incredibly efficient in regulating pro- and antioxidant balance during MI.