# Procoagulant Effects of Isothiazolinone Biocides, Benzisothiazolinone and Octylisothiazolinone in Platelets

## TL;DR

This study shows that isothiazolinone biocides BIT and OIT can trigger harmful blood clotting effects by damaging platelets, potentially increasing cardiovascular disease risk.

## Contribution

The study reveals a novel procoagulant mechanism of BIT and OIT through mitochondrial dysfunction and platelet activation.

## Key findings

- BIT and OIT deplete glutathione and increase mitochondrial ROS in platelets.
- Mitochondrial dysfunction caused by BIT and OIT leads to procoagulant activity via phosphatidylserine externalization.
- N-acetyl-L-cysteine reduces BIT- and OIT-induced effects, indicating a thiol-dependent mechanism.

## Abstract

Isothiazolinones are commonly used biocides that are extensively used in industrial areas and household products. The extensive usage of isothiazolinones raises concerns regarding their adverse human health effects. Isothiazolinones are readily absorbed and enter circulation. However, the potential systemic effects of isothiazolinones on the circulatory system remain unclear. Here, we examined whether the isothiazolinones, benzisothiazolinone (BIT) and octylisothiazolinone (OIT) affected platelets. In isolated platelets, BIT and OIT depleted intracellular glutathione, which led to mitochondrial reactive oxygen species (ROS) accumulation. Excessive mitochondrial ROS led to mitochondrial dysfunction, altering intracellular calcium and adenosine triphosphate homeostasis. These intracellular events activated phospholipid scramblase, externalizing phosphatidylserine, thereby enhancing procoagulant activity, as evidenced by thrombin generation. Overall, OIT showed a more potent effect than BIT. Notably, supplementation with N-acetyl-L-cysteine mitigated BIT- and OIT-induced effects, suggesting a thiol-dependent mechanism. Taken together, BIT and OIT stimulated the platelet-mediated coagulation pathway, which may increase prothrombotic risk and contribute to cardiovascular disease. These results could improve our understanding of the systemic adverse effects after isothiazolinone exposure.