Sodium perborate tetrahydrate triggers mitochondrial dysfunction in Leishmania infantum parasites and enhances antileishmanial activity in macrophages.

Sodium Perborate Tetrahydrate (SPT) is a potent semimetal element possessing intrinsic antimicrobial activities against various microorganisms including protozoan parasites. The crucial role of boron in antimicrobial therapy is associated with both its biocidal properties and the ability to reduce inflammatory processes. High water solubility and bioavailability of the compound took advantage of its medical use. The objective of this study is to evaluate the antileishmanial potential of SPT for Leishmaniasis on Leishmania (L.) infantum parasites and Leishmania-infected RAW264.7 macrophage cell line as well as non-infected macrophages. The antileishmanial mechanism was analyzed through cell viability, mitochondrial membrane potential, measurement of Reactive Oxygen Species (ROS) and glutathione level, cell cycle, and gene expression levels on a molecular basis. Accordingly, SPT treatment with a 50 % inhibitory concentration (IC50) value of 71.99 ± 7.51 µM indicated a significant efficacy on L. infantum parasites without causing any toxicity on healthy macrophages. ≥ 100 µM concentrations of SPT treatment led to a decrease in the mitochondrial membrane potential of L. infantum promastigotes, which was reduced to below 53 % and 35 % at 24 and 48 h, respectively. In parallel, cell cycle arrest at the S and G2/M phases, and apoptotic cell death of 41.52 ± 5.79 % after 150 µM SPT treatment verified the antileishmanial therapy. Moreover, the division of L. infantum parasites within the infected macrophages remained at 73.67 % by ≥ 75 µM SPT concentrations. SPT had no significant effect on intracellular macrophage ROS levels. Metacaspase5 gene expression was consistent with mitochondrial membrane potential data confirming the higher apoptotic-like death at 100 µM SPT treatment. Furthermore, pro-inflammatory IFN-γ levels overexpressed significantly in ≥ 50 µM SPT treatment, whereas only 200 µM SPT upregulated the TNF-α and IL-12(B) inflammation markers. Anti-inflammatory IL-10 and TGF-ß1gene expressions were downregulated in infected macrophages upon treatment with 100 µM SPT. The antileishmanial efficacy of SPT highlights the potential therapy for future in vivo studies.