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Titolo:
The uptake, location and fluorescence of hypericin in bovine intact lens
Autore:
Sgarbossa, A; Angelini, N; Gioffre, D; Youssef, T; Lenci, F; Roberts, JE;
Indirizzi:
Fordham Univ, Lincoln Ctr, New York, NY 10023 USA Fordham Univ New York NY USA 10023 v, Lincoln Ctr, New York, NY 10023 USA CNR, Ist Biofis, Pisa, Italy CNR Pisa ItalyCNR, Ist Biofis, Pisa, Italy UdR Parma, INFM, Parma, Italy UdR Parma Parma ItalyUdR Parma, INFM, Parma, Italy RIO, Giza, Egypt RIO Giza EgyptRIO, Giza, Egypt
Titolo Testata:
CURRENT EYE RESEARCH
fascicolo: 2, volume: 21, anno: 2000,
pagine: 597 - 601
SICI:
0271-3683(200008)21:2<597:TULAFO>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
SEASONAL AFFECTIVE-DISORDER; APOPTOSIS; KINETICS; PROTEINS; EXTRACT; EYE;
Keywords:
hypericin; St. John's Wort; ocular phototoxicity; fluorescence; hypericum; light therapy; cataracts;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
23
Recensione:
Indirizzi per estratti:
Indirizzo: Roberts, JE Fordham Univ, Lincoln Ctr, Campus,Room 813,113 W 60th St, New York, NY 10023 USA Fordham Univ Campus,Room 813,113 W 60th St New York NY USA 10023
Citazione:
A. Sgarbossa et al., "The uptake, location and fluorescence of hypericin in bovine intact lens", CURR EYE R, 21(2), 2000, pp. 597-601

Abstract

Purpose. To determine the uptake, location and fluorescence of hypericin, the active ingredient in St. John's Wort, in situ in the isolated intact calf lens. Methods. The absorption and fluorescence spectra of hypericin 10(-5) M were measured in DMSO/phosphate buffer, pH 7.4) [PBS] (1/10 in volume) in the presence of alpha -crystallin (0.5 and 1.1 mg/ml). Bovine lenses were incubated in the dark for 24 hours in 10(-4) M hypericin in a DMSO/PBS (1/10 in volume) mixture. Diffused hypericin fluorescence emission was detected witha fluorescence stereomicroscope from the PBS washed lens surface. A lens-holder specially built for front-surface excitation-detection was used to measure fluorescence emission and excitation spectra of intact lenses incubated with hypericin solutions. Results. As increasing concentrations of alpha -crystallin were added, theabsorption and fluorescence spectra of hypericin in DMSO/PBS (1/10 in volume) changed, indicating a binding between the chromophore and the lens protein. Fluorescence emission spectra detected from the lens surface (lambda (cm) = 601 and 651 nm; lambda (exc) = 550 nm) confirmed that hypericin does bind to the ocular tissues. Conclusions. The results we obtained in simplified model systems can provide dues to investigate the effects of hypericin on lens properties in physiological conditions. Hypericin could in fact bind to lens protein thus increasing the retention time of hypericin in the eye and possibly altering alpha -crystallin properties as a chaperone. Should therefore hypericin be taken up by the lens, this can be detected, non-invasively by its fluorescence. Therefore, ophthalmologists may use a slit-lamp or scanning fluorometry to monitor the uptake of hypericin in the eyes of patients using St. John's Wort or receiving high doses of hypericin while undergoing photodynamic therapy.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 12/07/20 alle ore 04:33:19