Distinguishing Activities in the Photodynamic Arsenals of the Pigmented Ciliates Blepharisma sinuosum Sawaya, 1940 and Blepharisma japonicum Suzuki, 1954 (Ciliophora: Heterotrichea)

• Published in: Photochemistry and photobiology Vol. 96; no. 6; pp. 1251 - 1266
• Main Authors: Cavaleiro, Jéssica, Oliveira, Nathally B., Ribeiro, Talita A., Guimarães, Lohaine F., Fernandes, Noemi M., Silva‐Neto, Inácio D., Marszaukowski, Flávia, Wohnrath, Karen, Barreto, Cleber B., Schweikert, Michael, Petroni, Giulio, Ortenzi, Claudio, Buonanno, Federico, Picciani, Paulo H. S., Oliveira, Osvaldo N., Soares, Carlos Augusto G.
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01-11-2020
• Subjects: Biocompatibility; Biological activity; Biological properties; Blepharisma; Blepharisma japonicum; Ciliates; Cluster analysis; Clustering; Comparative analysis; High-performance liquid chromatography; Hypericin; Liquid chromatography; Phospholipids; Pigments; Redox properties; Tumor cells
• ISSN: 0031-8655; 1751-1097
• DOI: 10.1111/php.13288

Blepharismins are photodynamic hypericin‐like dianthrones produced as a variable pigment blend in Blepharisma ciliates and mostly studied in the Afro‐Asiatic Blepharisma japonicum. The present work describes the bioactivity of pigments from the Brazilian Blepharisma sinuosum. Comparative analyses showed that the pigments from both species can trigger photo‐induced modifications in phospholipids, but different redox properties and biological activities were assigned for each pigment blend. Stronger activities were detected for B. sinuosum pigments, with the lethal concentration LC50 10 × lower than B. japonicum pigments in light‐irradiated tests against Bacillus cereus and less than half for treatments on the human HeLa tumor cells. HPLC showed B. sinuosum producing a simpler pigment blend, mostly with the blepharismin‐C (~ 70%) and blepharismin‐E (~ 30%) types. Each blepharismin engaged a specific dose–response profile on sensitive cells. The blepharismin‐B and blepharismin‐C were the most toxic pigments, showing LC50 ~ 2.5–3.0 µm and ~ 100 µm on B. cereus and HeLa cells, respectively, after illumination. Similarity clustering analysis compiling the bioactivity data revealed two groups of blepharismins: the most active, B and C, and the less active, A, D and E. The B. sinuosum pigment blend includes one representative of each clade. Functional and medical implications are discussed.
Blepharismins are photodynamic hypericin‐like dianthrones produced as variable pigment blends in Blepharisma ciliates. The present work shows that these pigments display photo‐induced activity on Bacillus cereus and HeLa tumor cells. Comparative data show that the pigments from Blepharisma sinuosum and Blepharisma japonicum form photodynamic arsenals with different redox and bioactivity properties. The B. sinuosum pigments impose stronger inhibitory activities on sensitive cells, composing a peculiar blepharismin blend, mostly with the blepharismin‐C and blepharismin‐E types. The blepharismin‐A to blepharismin‐E types, originally described in B. japonicum, have specific bioactivity with the blepharismin‐B and blepharismin‐C types exhibiting the highest toxicities after illumination.