*Article* **Hydroxychloroquine Mitigates the Production of 8-Isoprostane and Improves Vascular Dysfunction: Implications for Treating Preeclampsia**

**Rahana Abd Rahman 1,2,3,\*, Padma Murthi 2,4,\*,**†**, Harmeet Singh 2, Seshini Gurungsinghe 1, Bryan Leaw 2, Joanne C. Mockler 1, Rebecca Lim 1,2 and Euan M. Wallace 1,2,\***

1 Department of Obstetrics and Gynaecology, School of Clinical Sciences, Monash University, Monash Medical Centre, Clayton, Victoria 3168, Australia; seshini.gurusinghe@monash.edu (S.G.); joanne.mockler@monash.edu(J.C.M.);rebecca.lim@hudson.org.au(R.L.)


Received: 19 March 2020; Accepted: 31 March 2020; Published: 3 April 2020

**Abstract:** In preeclampsia, widespread maternal endothelial dysfunction is often secondary to excessive generation of placental-derived anti-angiogenic factors, including soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), along with proinflammatory cytokines such as tumour necrosis factorα (TNFα) and activin A, understanding of which o ffers potential opportunities for the development of novel therapies. The antimalarial hydroxychloroquine is an anti-inflammatory drug improving endothelial homeostasis in lupus. It has not been explored as to whether it can improve placental and endothelial function in preeclampsia. In this in vitro study, term placental explants were used to assess the e ffects of hydroxychloroquine on placental production of sFlt-1, sEng, TNFα, activin A, and 8-isoprostane after exposure to hypoxic injury or oxidative stress. Similarly, human umbilical vein endothelial cells (HUVECs) were used to assess the e ffects of hydroxychloroquine on in vitro markers of endothelial dysfunction. Hydroxychloroquine had no effect on the release of sFlt-1, sEng, TNFα, activin A, or 8-isoprostane from placental explants exposed to hypoxic injury or oxidative stress. However, hydroxychloroquine mitigated TNFα-induced HUVEC production of 8-isoprostane and Nicotinanamide adenine dinucleotide phosphate (NADPH) oxidase expression. Hydroxychloroquine also mitigated TNFα and preeclamptic serum-induced HUVEC monolayer permeability and rescued the loss of zona occludens protein zona occludens 1 (ZO-1). Although hydroxychloroquine had no apparent e ffects on trophoblast function, it may be a useful endothelial protectant in women presenting with preeclampsia.

**Keywords:** hydroxychloroquine; preeclampsia; sFlt-1; sEng; TNFα; endothelial dysfunction
