Staurosporine from Streptomyces sanyensis activates Programmed Cell Death in Acanthamoeba via the mitochondrial pathway and presents low in vitro cytotoxicity levels in a macrophage cell line

Abstract

Recently, the search for novel therapeutic agents against Acanthamoeba species has been focused on the evaluation of natural resources. Among them, marine microorganisms have risen as a source of bioactive compounds with the advantage of the ability to obtain unlimited and constant amounts of the compounds in contrast to other natural sources such as plants. Furthermore, marine actinomycetes have recently been reported as highly rich in bioactive agents including salinosporamides, xiamycines, indolocarbazoles, naphtyridines, phenols, dilactones such as antimycines and macrolides among others. In this study, staurosporine (STS) was isolated from a strain of Streptomyces sanyensis and tested against Acanthamoeba to characterize the therapeutic potential of STS against this protozoan parasite. We have established that STS is active against both stages of the Acanthamoeba life cycle, by the activation of Programmed Cell Death via the mitochondrial pathway of the trophozoite. We have also established that STS has relatively low toxicity towards a macrophage cell line. However, previous studies have highlighted higher toxicity levels induced on other vertebrate cell lines and future research to lower these toxicity issues should be developed.

Antiamoebic Activities of Indolocarbazole Metabolites Isolated from Streptomyces sanyensis Cultures

“…The lack of effectiveness due to drug resistance and high toxicity are the main drawbacks of currently used chemotherapeutics, which evidence that the search for new chemical entities to fight parasitic infections remains a critical need. Recently, we have reported a detailed study on the activity and mechanism of action of STS in Acanthamoeba and the programmed cell death via mitochondrial pathway [18]. The aim of this research is based on the isolation and identification of the minor metabolites 7OSTS ( 2 ), 4′D4′OSTS ( 3 ), and SCZB ( 4 ) (Figure 1) from a mangrove-derived bacterium S. sanyensis PBLC04 strain collected in the coast of Ecuador, and to value their anti- Acanthamoeba activity.…”

In vitro evaluation of commercial foam Belcils® on Acanthamoeba spp

“…The experiment was carried out by following the manufacturer's recommendations, and 10 5 cells/well were incubated in a 96-well plate for 0.5, 1.5, 4 and 24 h with the previously calculated IC 90 . The double-staining pattern allows the identification of three groups in a cellular population: live cells will show only a low level of fluorescence, cells undergoing PCD will show a higher level of blue fluorescence (as chromatin condenses), and dead cells will show low-blue and high-red fluorescence (as the Propidium Iodide stain enters the nucleus) ( Cartuche et al, 2019 ).…”

“…The cells were treated with the IC 90 of the eye cleanser for 1.5, 4 and 24 h and exposed to CellROX® Deep Red (5 μM, 30 min) at 26 °C in the dark. Cells were observed with an EVOS FL Cell Imaging System AMF4300, Life Technologies, USA ( Cartuche et al, 2019 ).…”

“…Images were taken on an EVOS FL Cell Imaging System AMF4300, Life Technologies, USA. The staining pattern allows the identification of two groups in a cellular population: live cells will show only red fluorescence; cells with low mitochondrial potential, (undergoing PCD) will show a higher level of green and red fluorescence ( Cartuche et al, 2019 ).…”

“…Subsequently, the SYTOX® Green dye was added at a final concentration of 1 μM for 15 min in the dark. Cells were observed in an EVOS FL Cell Imaging System AMF4300, Life Technologies, USA ( Cartuche et al, 2019 ).…”