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

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.

[Insecticide effects of natural amides from Piper and of the synthetic derivative tetrahydropiperine on Lucilia cuprina (Diptera: Calliphoridae) and Musca domestica (Diptera: Muscidae)]. / Efeito inseticida de amidas naturais de Piper e do derivado sintético tetraidropiperina sobre Lucilia cuprina (Diptera: Calliphoridae) E Musca domestica (Diptera: Muscidae).

The insecticide activity of piperine, cinamoil amide, and tetrahydropiperine against Lucilia cuprina and Musca domestica adults were conducted at the Federal Rural University of Rio de Janeiro. Chemicals were topically applied on thoracic areas of the flies and the toxicity was determined after 24 and 48 hr post treatment and LD50 were calculated using Probit Analysis. Tetrahydropiperine (THP amide) was the only substance which demonstrated insecticide activity against both species of flies. LD50 against L. cuprina and M. domestica were 16.25 and 7.65 microg/fly, respectively, after 24 hr of treatment. Similar results were observed after 48 hr post treatment because the LD50's were 18.03 and 6.57 microg/fly, respectively. Males of L. cuprina were more resistant to tetrahydropiperine than females. However females of M. domestica were more resistant to the insecticide than males.