Symposium-in-Print Porphyrins and Related Compounds as Photoactivatable Insecticides. 3. Laboratory and Field Studies

Abstract

The exposure of populations of Ceratitis capitata (fruit fly), Bactrocera oleae (olive fly) and Stomoxis calcitrans (house fly) to a bait containing mumolar concentrations of porphyrin-type photosensitizers resulted in a significant accumulation of the porphyrin by the insects and a consequent development of photosensitivity upon exposure to visible light. The photoinsecticidal activity appeared to increase with increasing hydrophobicity of the porphyrin molecule: thus, the amphiphilic dicationic meso-di(cis-4N-methyl-pyridyl)-cis-diphenyl-porphine (n-octanol/water partition coefficient = 20) was markedly more efficient than its tricationic analogue or the dianionic hematoporphyrin (n-octanol/water partition coefficient = 12). The observed large decrease in the acetylcholinesterase activity of the photosensitized flies suggests that the damage of the nervous system gives an important contribution to the phototoxic action of porphyrins. Studies with C. capitata indicate that the photoinsecticidal action of porphyrins can be utilized to control the population of noxious insects also in open field conditions.

Enhanced efficiency of cell death by lysosome-specific photodamage

“…These observations are intriguing because are against several paradigms in this field, i.e. : stronger membrane binding results in cell damage 12 , 17 , a higher amount in the cell incorporation of similar PSs in the cells results in a greater efficiency of photo-induced cellular damage 12 , 17 , 30 . Base on these concepts, we hypothesize that the lack of relationship between the efficiency of cell killing (Fig.…”

“…ɛ 413nm = 503 000 M −1 cm −1 ) 29 and also Amor et al . that described ɛ 424nm = 182 000 M −1 cm −1 to CisDiMPyP in water 30 . Both molecules have very similar fluorescence spectra with small fluorescence quantum yields (ϕ f < 0.15 – Table 1 ).…”

“…This is indeed expected from the competition between aggregation and membrane binding equilibria 35 . Literature reports indicate that stronger membrane interaction is correlated not only with greater membrane damage but also with more effective photo-induced damage of whole cells and/or organisms 17 , 18 , 30 . Aiming to investigate further this premise, we evaluated the biological effects of both TPPS 2a and CisDiMPyP in HeLa cells.…”

Light based anti-infectives: ultraviolet C irradiation, photodynamic therapy, blue light, and beyond

“…The concept of using PDT inactivation of pest populations was realized as early as in the 1930’s using xanthene derivatives against Anopheles and Aedes larvae and the developments in this field have been reviewed by Ben Amor and Jori [164]. Among the limited reports in this area, porphyrins are particularly interesting as photo-insecticides because they exhibit several absorption bands in the UV/visible spectrum, being therefore efficiently excited by the solar spectrum [165]. Under this concept, Lucantoni et al tested the phototoxicity of a synthetic meso-substituted porphyrin meso-tri(N-methylpyridyl), meso-mono(N-tetradecylpyridil) porphine (C14) [166].…”

Novel, Meso-Substituted Cationic Porphyrin Molecule for Photo-Mediated Larval Control of the Dengue Vector Aedes aegypti

“…Several synthetic and naturally derived photosensitizers, such as thiophenes, xanthenes, phenothiazines, furocoumarins, acridines, tetraethynylsilanes and porphyrins, have been demonstrated to be effective photoinsecticides against a range of noxious insects, including flies [18]–[19] and mosquitoes [20]–[23]. In particular, porphyrin derivatives, such as chlorophyllin, pheophorbid and hematoporphyrin, exhibit a marked larvicidal activity on Culex and Aedes in the laboratory as well as in semi-field conditions [24]–[28].…”