A wavelength dependent mechanism for rose bengal-sensitized photoinhibition of red cell acetylcholinesterase

Allen, Mary Tedd; Lynch, Michael J.; Lagos, Alexandra; Redmond, Robert W.; Kochevar, Irene E.

doi:10.1016/0304-4165(91)90072-o

Cited by 50 publications

(27 citation statements)

References 25 publications

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“…Such specimens might be expected to exhibit some evidence of migration of RB within remaining tissue fluids and within the surrounding film of preservation compound. The lack of such migration suggests that topically applied RB is persistently associated with certain cellular components (such as cell membranes) in the epidermis [25,[31][32][33][34][35]. Confocal LSM examination of these samples corroborates this conjecture, showing that epidermal RB is primarily confined to cell walls and internal membranes, wherein the amphipathic properties of RB may yield favorable partitioning.…”

Section: Rb Penetration Into Normal Skinsupporting

confidence: 52%

Topical rose Bengal: Pre‐clinical evaluation of pharmacokinetics and safety

Wachter¹,

Dees²,

Harkins³

et al. 2003

Lasers Surg Med

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Section: Rb Penetration Into Normal Skinsupporting

confidence: 52%

Topical rose Bengal: Pre‐clinical evaluation of pharmacokinetics and safety

Wachter¹,

Dees²,

Harkins³

et al. 2003

Lasers Surg Med

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“…The scavenging potential of PL was compared with that of the known 1 O 2 scavenger NaN 3 used as reference compound. The results for PL and KA (absence of NaN 3 ) were obtained in triplicate and the inhibition of 1 O 2 production was expressed as percent of control values (33)(34)(35).…”

Section: Singlet Oxygen Assaymentioning

confidence: 99%

The antioxidant action of Polypodium leucotomos extract and kojic acid: reactions with reactive oxygen species

Gomes

Lunardi

González

et al. 2001

Braz J Med Biol Res

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Two natural products Polypodium leucotomos extract (PL) and kojic acid (KA) were tested for their ability to scavenge reactive oxygen species (in phosphate buffer. Hydroxyl radicals were generated by the Fenton reaction, and the rate constants of scavenging were 1.6 x 10 9 M -1 s -1 for KA and 1.0 x 10 9 M -1 s -1 for PL, similar to that of ethanol (1.4 x 10 9 M -1 s -1 ). With superoxide anions generated by the xanthine/hypoxanthine system, KA and PL (0.2-1.0 mg/ml) inhibited · O 2 -dependent reduction of nitroblue tetrazolium by up to 30 and 31%, respectively. In the detection of 1 O 2 by rose bengal irradiation, PL at 1.0 mg/ml quenched singlet oxygen by 43% relative to azide and KA by 36%. The present study demonstrates that PL showed an antioxidant effect, scavenging three of four reactive oxygen species tested here. Unlike KA, PL did not significantly scavenge hydrogen peroxide. Correspondence

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“…Concentrations of RB2-in acetonitrile were measured using a molar absorption coefficient (E) of 1.1 X lo5 M -' cm-' at 558 nm. This value was determined from a linear BeerLambert plot of 12 concentrations of RB2-in acetonitrile at a maximum concentration of 10 (LM and compares with a value of 9.5 X lo4 M -' cm-I previously reported for ?RB2-in aqueous solution (31) at 548 nm and to 1.12 X lo5 M-I cm-' reported in ethanol at 557 nm (21).…”

Section: Methodsmentioning

confidence: 99%

Electron Transfer Quenching of the Rose Bengal Triplet State

Lambert¹,

Kochevar²

1997

Photochem & Photobiology

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The potential for electron transfer quenching of rose bengal triplet (jRB2--) to compete with energy transfer quenching by oxygen was evaluated. Rate constants for oxidative and reductive quenching were measured in buffered aqueous solution, acetonitrile and in small unilamellar liposomes using laser flash photolysis. Biologically relevant quenchers were used that varied widely in structure, reduction potential and charge. Radical ion yields (+i) were measured by monitoring the absorption of the rose bengal semireduced (RBo3-) and semioxidized (RB'-) radicals. The results in solution were analyzed as a function of the free energy for electron transfer (AG) calculated using the Weller equation including electrostatic terms. Exothermic oxidative quenching was about 10-fold faster than exothermic reductive quenching in aqueous solution. The quenching rate constants decreased as AG approached zero in both aqueous and acetonitrile solution. Exceptions to these generalizations were observed that could be rationalized by specific steric or electrostatic effects or by a change in mechanism. The results suggest that electron transfer reactions with some potential quenchers in cells could compete with formation of singlet oxygen [O,(lA,)]. Values of +i were generally greater for reductive quenching and, for oxidative quenching, greater in acetonitrile than in buffer. Electran transfer quenching of 3FU3-in liposomes, below the phase transition temperature was slower than in solution for both lipid-soluble and water-soluble quenchers indicating that these reactions may not compete with formation of O,(lAg) during cell photosensitization.

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A wavelength dependent mechanism for rose bengal-sensitized photoinhibition of red cell acetylcholinesterase

Cited by 50 publications

References 25 publications

Topical rose Bengal: Pre‐clinical evaluation of pharmacokinetics and safety

Topical rose Bengal: Pre‐clinical evaluation of pharmacokinetics and safety

The antioxidant action of Polypodium leucotomos extract and kojic acid: reactions with reactive oxygen species

Electron Transfer Quenching of the Rose Bengal Triplet State

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