Production and laser-induced fluorescence spectroscopy (L.I.F.S.) of different Hypericum perforatum L. extracts

Dimitris Skalkos; George Filippidis; Dimitris Kapsokalyvas; Heiko Meyer; Theodore Papazoglou; Eleni Karentzou; Heleni Dimitriou; M. Kalmanti

doi:10.1117/12.587484

8 April 2005 Production and laser-induced fluorescence spectroscopy (L.I.F.S.) of different Hypericum perforatum L. extracts

Dimitris Skalkos, George Filippidis, Dimitris Kapsokalyvas, Heiko Meyer, Theodore Papazoglou, Eleni Karentzou, Heleni Dimitriou, M. Kalmanti

Author Affiliations +

Proceedings Volume 5689, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XIV; (2005) https://doi.org/10.1117/12.587484
Event: SPIE BiOS, 2005, San Jose, CA, United States

Abstract

We are reporting elsewhere, the promising photodynamic effect of Hypericum perforatum L. extract (PMF) against T24, NBT-II tumor bladder cells, and HL-60 leukemic cells (using 630nm, and 530nm laser light respectively). The main advantages of the extract as a photosensitizer are its low cost, extensive availability, adequate solubility, minimal toxicity, and use with a range of wavelengths. Extraction of dry herb with methanol yields the methanolic extract (ME) in 11%, which is then fractionated using liquid / liquid extraction, yielding the polar methanolic fraction (PMF) in 9,9% overall yield. Hypericin, a photosensitizing ingredient of the herb, was found in these extracts in concentrations as low as 0,51%, and 0,57% respectively. Laser induced fluorescence spectra from the ME and PMF were recorded in order to evaluate their photodiagnostic capacity. An Argon-ion laser was employed for the excitation of the samples. It was shown that the extracts resulted in different fluorescence spectra related both to their intensity, and shape. The intensities of these spectra were only 8 times less compared to the fluorescence of pure hypericin. The dependence of the signal on the pH of the medium of pure hypericin and of PMF was also investigated in order to determine specific spectra variations. According to the results hypericin fluorescence signal fades smoothly in highly acidic medium, while it decreases sharply in highly basic environment. On the contrary PMF gives a slow decrease of fluorescence in both acidic and basic medium. These data suggest that PMF-induced fluorescence is highly sensitive in basic and acidic environment.

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Dimitris Skalkos, George Filippidis, Dimitris Kapsokalyvas, Heiko Meyer, Theodore Papazoglou, Eleni Karentzou, Heleni Dimitriou, and M. Kalmanti "Production and laser-induced fluorescence spectroscopy (L.I.F.S.) of different Hypericum perforatum L. extracts", Proc. SPIE 5689, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XIV, (8 April 2005); https://doi.org/10.1117/12.587484

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