Journal ArticleDOI
Protoporphyrin IX-induced structural and functional changes in human red blood cells, haemoglobin and myoglobin.
TLDR
Spectrophotometric studies reveal that protoporphyrin IX interacts with haemoglobin and myoglobin forming ground state complexes, which may have a role in establishing efficacy of therapeutic uses of porphyrins as well as in elucidating their mechanisms of action as therapeutic agents.Abstract:
Protoporphyrin IX and its derivatives are used as photosensitizers in the photodynamic therapy of cancer. Protoporphyrin IX penetrates into human red blood cells and releases oxygen from them. This leads to a change in the morphology of the cells. Spectrophotometric studies reveal that protoporphyrin IX interacts with haemoglobin and myoglobin forming ground state complexes. For both proteins, the binding affinity constant decreases, while the possible number of binding sites increases, as the aggregation state of the porphyrin is increased. The interactions lead to conformational changes of both haemoglobin and myoglobin as observed in circular dichroism studies. Upon binding with the proteins, protoporphyrin IX releases the heme-bound oxygen from the oxyproteins, which is dependent on the stoichiometric ratios of the porphyrin : protein. The peroxidase activities of haemoglobin and myoglobin are potentiated by the protein-porphyrin complexation. Possible mechanisms underlying the relation between the porphyrin-induced structural modifications of the heme proteins and alterations in their functional properties have been discussed. The findings may have a role in establishing efficacy of therapeutic uses of porphyrins as well as in elucidating their mechanisms of action as therapeutic agents.read more
Citations
More filters
Journal ArticleDOI
A direct and simultaneous detection of zinc protoporphyrin IX, free protoporphyrin IX, and fluorescent heme degradation product in red blood cell hemolysates
Qiuying Chen,Rhoda Elison Hirsch +1 more
TL;DR: A novel method is established for comparing relative FHDP, PPIX and ZPP levels in hemolysates without performing red cell porphyrin extractions, and these fluorescent species serves as biomarkers for alterations in Hb synthesis and Hb stability.
Journal ArticleDOI
Comparison of in vitro photodynamic antimicrobial activity of protoporphyrin IX between endoscopic white light and newly developed narrowband endoscopic light against Helicobacter pylori 26695.
TL;DR: Conclusively, either the bactericidal effect in high concentration or the decrease of bacterial loading in low concentration of PpIX, would be expected with PDT using endoscopic light (NBI or WL).
Journal ArticleDOI
Porphyrin J-aggregates stabilized by ferric myoglobin in neutral aqueous solution.
TL;DR: J-aggregates of a diacid form of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (H2TPPS4-) were stabilized by binding with ferric myoglobin (metMb) in aqueous solution at neutral pH and the hydrophobic nature of the J-aggregate seems to play an important role for denaturation of metMb.
Journal ArticleDOI
Topical formulations of delta-aminolevulinic acid for the treatment of actinic keratosis: Characterization and efficacy evaluation
Laura Risaliti,Vieri Piazzini,Maria Giuseppina Di Marzo,Luigi Brunetti,Roberto Cecchi,Patrizia Lencioni,Anna Rita Bilia,Maria Camilla Bergonzi +7 more
TL;DR: Three galenic gel formulations containing 10% w/w of ALA are provided for the treatment of AK with PDT and their comparison with a lipophilic cream used in the Hospital is compared to offer an appealing topical treatment that improves patients’ observance and compliance.
Journal ArticleDOI
Attenuation of Glucose-Induced Myoglobin Glycation and the Formation of Advanced Glycation End Products (AGEs) by (R)-α-Lipoic Acid In Vitro
Hardik Ghelani,Valentina Razmovski-Naumovski,Valentina Razmovski-Naumovski,Rajeswara Rao Pragada,Srinivas Nammi +4 more
TL;DR: The anti-glycation properties of ALA suggest that ALA supplementation may be beneficial in the prevention of AGEs-mediated diabetic and cardiovascular complications.
References
More filters
Book
Photodynamic Therapy
TL;DR: A comprehensive review of mechanisms of subcellular and tumor localization of photosensitizing agents, as well as of molecular, cellular, and tumor responses associated with photodynamic therapy, are discussed.
Journal ArticleDOI
Determination of the secondary structures of proteins by circular dichroism and optical rotatory dispersion.
Journal ArticleDOI
Biological effects of the superoxide radical.
TL;DR: Can the superoxide radical exert deleterious effects independent of participating with H2O2 in the production of the hydroxyl radical?
Journal ArticleDOI
5-Aminolevulinic acid-based photodynamic therapy. Clinical research and future challenges.
Qian Peng,Trond Warloe,Kristian Berg,Johan Emelian Moan,Magne Kongshaug,Karl Erik Giercksky,Jahn M. Nesland +6 more
TL;DR: Studies have shown that a higher accumulation of ALA‐derived PpIX in rapidly proliferating cells may provide a biologic rationale for clinical use of ALa‐based PDT and diagnosis, however, no review updating the clinical data has appeared so far.