title: Optimizing conditions for the use of chlorophyll derivatives for photodynamic control of parasites in aquatic ecosystems.
abstract: Recently, it was demonstrated that mosquito larvae can be killed by means of photodynamic processes after the larvae have incorporated the photosensitizer chlorophyllin or pheophorbid, and were treated with light. The water-soluble substances were applied to and incorporated by the larvae in darkness. With Chaoborus sp. a dark incubation of about 3 h is sufficient to yield mortality of about 90% and ≥6 h resulted in almost 100% mortality during subsequent illumination. Temperature did not influence mortality of the larvae significantly in a treatment of 6 h dark incubation and subsequent 3 h illumination. At 10°C, 20°C, or 30°C, between 80% and 100% of the treated larvae died when the light intensity from a solar simulator was above 30 W/m(2). Lower irradiances were less effective. The LD(50) value of magnesium chlorophyllin was about 22.25 mg/l and for Zn chlorophyll 17.53 mg/l, while Cu chlorophyll (LD(50) 0.1 mg/l) was shown to be toxic also without light. Chlorophyllin, which was lyophilized immediately after extraction, was far more lethal to the larvae (LD(50) 14.88 mg/l) than air-dried Mg chlorophyllin.
authors: Department of Pharmacy and Medicine, University of Joinville Region, Rua Paulo Malschitzki, n° 10 Campus Universitário, Joinville, Brazil. gerzinger@univille.br
authors: Gilmar Sidnei
authors: GS
authors: Erzinger
authors: Stephanie
authors: S
authors: Wohllebe
authors: Fernanda
authors: F
authors: Vollrath
authors: Suellen Carolina
authors: SC
authors: Souza
authors: Peter
authors: P
authors: Richter
authors: Michael
authors: M
authors: Lebert
authors: Donat-Peter
authors: DP
authors: Häder
mesh_terms: D000818:Animals; D000977:Antiparasitic Agents / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism*; D003624:Darkness; D004175:Diptera / Q000187:drug effects* / Q000378:metabolism; D017753:Ecosystem; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D007928:Lethal Dose 50; D008027:Light; D017319:Photosensitizing Agents / Q000378:metabolism*; D016019:Survival Analysis; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000469:parasitology*
chemical_list: D000977:Antiparasitic Agents; D017319:Photosensitizing Agents; D014867:Water; D002734:Chlorophyll