Ultrastructural Analysis of Leishmania infantum chagasi Promastigotes Forms Treated In Vitro with Usnic Acid

Abstract

Leishmaniasis is considered by the World Health Organization as one of the infectious parasitic diseases endemic of great relevance and a global public health problem. Pentavalent antimonials used for treatment of this disease are limited and new phytochemicals emerge as an alternative to existing treatments, due to the low toxicity and cost reduction. Usnic acid is uniquely found in lichens and is especially abundant in genera such as Alectoria, Cladonia, Evernia, Lecanora, Ramalina, and Usnea. Usnic acid has been shown to exhibit antiviral, antiprotozoal, antiproliferative, anti-inflammatory, and analgesic activity. The aim of this study was to evaluate the antileishmanial activity of usnic acid on Leishmania infantum chagasi promastigotes and the occurrence of drug-induced ultrastructural damage in the parasite. Usnic acid was effective against the promastigote forms (IC50 = 18.30 ± 2.00 µg/mL). Structural and ultrastructural aspects of parasite were analyzed. Morphological alterations were observed as blebs in cell membrane and shapes given off, increasing the number of cytoplasmic vacuoles, and cellular and mitochondrial swelling, with loss of cell polarity. We concluded that the usnic acid presented antileishmanial activity against promastigote forms of Leishmania infantum chagasi and structural and ultrastructural analysis reinforces its cytotoxicity. Further, in vitro studies are warranted to further evaluate this potential.

Usnik Asitin Broylerlerdeki Anticoccidial Etkinliği

“…There are a number of research articles proving anticoccidial activity of natural products including plants [5] , pre-and probiotics [4,5] and fungi [6,7] . Natural products are expected to be alternative in the coccidiosis control promisingly by including new therapeutic molecules to which Eimeria strains have not yet developed resistance [8][9][10] .…”

“…It is shown to exert a number of biological activities including anti-inflammatory, analgesic and antipyretic, antibiotic, antiviral, antimicrobial, antiproliferative, gastroprotective, antitumor, antioxidant, antimycotic, antigrowth and antiinsect properties [22,23] . Although few studies [9,[24][25][26][27] dealing with antiprotozoal effect of usnic acid are available, its anticoccidial effect is largely unknown. The present experiment was set out to investigate therapeutic action of usnic acid against coccidiosis in broilers.…”

Antimicrobial and antioxidant activity of Evernia prunastri extracts and their isolates

“…In vitro studies suggest that lichen extracts may have a broad spectrum of activity against Gram-positive and -negative bacteria, fungi, and protozoan parasites (e.g., Schistosoma mansoni, Leishmania spp., Toxoplasma gondii, Plasmodium berghei, Trypanosoma cruzi) as well as antiviral activity (Schmeda-Hirschmann et al 2008;Fritis et al 2013;Lauinger et al 2013;Luz et al 2015;Ranković and Kosanić 2015;Si et al 2016;Pastrana-Mena et al 2016;Calcott et al 2018;Araújo et al 2019). Additionally to a Fig.…”

Microwave-Assisted Semisynthesis and Leishmanicidal Activity of Some Phenolic Constituents from Lichens

“…The pentavalent antimony preparations commonly used to treat this disease are limited. Therefore, new natural products could serve as alternatives to existing treatments [2] or could pave the way for the discovery of new leishmanicidal agents [3].…”