Morphological and physiological changes in Leishmania promastigotes induced by yangambin, a lignan obtained from Ocotea duckei

• Published in: Experimental parasitology 2011, Vol.127 (1), p.215-221
• Main Authors: Neto, Rubens L. Monte, Sousa, Louisa M.A., Dias, Celidarque S., Filho, José M. Barbosa, Oliveira, Márcia R., Figueiredo, Regina C.B.Q.
• Format: Article
• Language: English
• Subjects: acidification; Acridine Orange; Animals; apoptosis; autophagy; Biological and medical sciences; Cell death; cell movement; Confocal microscopy; Dogs; fluorescence; Fluorescent Dyes; Fundamental and applied biological sciences. Psychology; Furans - chemistry; Furans - pharmacology; Image Processing, Computer-Assisted; Lauraceae; Leishmania; Leishmania amazonensis; Leishmania chagasi; Leishmania donovani; Leishmania infantum - drug effects; Leishmania infantum - physiology; Leishmania infantum - ultrastructure; Leishmania mexicana - drug effects; Leishmania mexicana - physiology; Leishmania mexicana - ultrastructure; Life cycle. Host-agent relationship. Pathogenesis; lignans; Lignans - chemistry; Lignans - pharmacology; microscopy; Microscopy, Confocal; Microscopy, Electron, Transmission; microtubules; Ocotea; Ocotea - chemistry; Ocotea duckei; organelles; parasites; parasitology; Plant Extracts - chemistry; Plant Extracts - pharmacology; promastigotes; Protozoa; Transmission electron microscopy; Yangambin
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/j.exppara.2010.07.020

We have previously demonstrated that yangambin, a lignan obtained from Ocotea duckei Vattimo (Lauraceae), shows antileishmanial activity against promastigote forms of Leishmania chagasi and Leishmania amazonensis. The aim of this study was to determine the in vitro effects of yangambin against these parasites using electron and confocal microscopy. L. chagasi and L. amazonensis promastigotes were incubated respectively with 50 μg/mL and 65 μg/mL of pure yangambin and stained with acridine orange. Treated-parasites showed significant alterations in fluorescence emission pattern and cell morphology when compared with control cells, including the appearance of abnormal round-shaped cells, loss of cell motility, nuclear pyknosis, cytoplasm acidification and increased number of acidic vesicular organelles (AVOs), suggesting important physiological changes. Ultrastructural analysis of treated-promatigotes showed characteristics of cell death by apoptosis as well as by autophagy. The presence of parasites exhibiting multiples nuclei suggests that yangambin may also affect the microtubule dynamic in both Leishmania species. Taken together our results show that yangambin is a promissing agent against Leishmania.