A convenient semisynthetic route to hypericin

Falk, Heinz; Meyer, Joachim-Ernst; Oberreiter, M.

doi:10.1007/bf00810594

Cited by 117 publications

(67 citation statements)

References 12 publications

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“…Hypericin was synthesized as reported previously (28). The stock solutions of hypericin were made in polyethylene glycol 400 and kept at -20˚C in the dark.…”

Section: Methodsmentioning

confidence: 99%

Enhancing the photodynamic effect of hypericin in human bladder transitional cell carcinoma spheroids by the use of the oxygen carrier, perfluorodecalin

Kamuhabwa¹,

Huygens²,

Roskams³

et al. 2006

Int J Oncol

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Abstract. In the present study, we evaluated the possibility of enhancing the photodynamic effect of hypericin in transitional cell carcinoma (TCC) spheroids by the use of the oxygen carrier, perfluorodecalin. Following incubation with hypericin, RT-112 TCC spheroids were irradiated in the presence or absence of perfluorodecalin, at light doses of 7 J/cm 2 or 28 J/ cm 2 , delivered at a fluence rate of 15 mW/cm 2 . The photodynamic therapy (PDT) efficacy was evaluated and apoptotic cells were visualized. The results show that, in the absence of perfluorodecalin, spheroidal TCC cells are inadequately sensitive to hypericin PDT. As was shown by fluorescence microscopy, this lack of activity was not due to insufficient photoactive concentrations of hypericin reaching the inner parts of the spheroids. Conversely, enhanced oxygenation of spheroids by perfluorodecalin led to a dramatic enhancement of hypericin PDT efficacy. The detection of nuclear shrinkage or fragmentation with DAPI staining and the assessment of cell morphology by light microscopy indicated that apoptosis was the most prominent response of spheroids to hypericin PDT in the presence of perfluorodecalin. In conclusion, the results of this study suggest that perfluorocarbons, such as perfluorodecalin, are useful in enhancing the oxygenation of tumor tissue, resulting in highly efficient hypericin PDT. Since hypericin becomes concentrated specifically in human bladder urothelial carcinoma lesions and the bladder is very well suited to instillation with a perfluorocarbon, combining the techniques looks very promising for an efficient and selective whole bladder wall photodynamic antitumoral treatment in a urological clinical setting.

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“…Hypericin was synthesized as reported previously (28). The stock solutions of hypericin were made in polyethylene glycol 400 and kept at -20˚C in the dark.…”

Section: Methodsmentioning

confidence: 99%

Enhancing the photodynamic effect of hypericin in human bladder transitional cell carcinoma spheroids by the use of the oxygen carrier, perfluorodecalin

Kamuhabwa¹,

Huygens²,

Roskams³

et al. 2006

Int J Oncol

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“…tail injection of hypericin (5 mg kg À1 ). Hypericin (synthesised from emodin anthraquinone according to Falk et al (1993)) was dissolved in a mixture of 25% dimethylsulphoxide (DMSO), 25% polyethylene glycol (PEG) 400 and water (2 mg ml À1 ) immediately before injection. Tumour tissues were harvested, weighed and frozen at À201C until determination of the hypericin content.…”

Section: Hypericin Accumulation In Tumour Tissuementioning

confidence: 99%

Elucidation of the tumoritropic principle of hypericin

Putte¹,

Roskams

Vandenheede

et al. 2005

Br J Cancer

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Hypericin is a potent agent in the photodynamic therapy of cancers. To better understand its tumoritropic behaviour, we evaluated the major determinants of the accumulation and dispersion of hypericin in subcutaneously growing mouse tumours. A rapid exponential decay in tumour accumulation of hypericin as a function of tumour weight was observed for each of the six tumour models investigated, and a similar relationship was found between tumour blood flow and tumour weight. Moreover, there was a close correlation between the higher hypericin uptake in RIF-1 tumours compared to R1 tumours and tumour vessel permeability. To define the role of lipoproteins in the transport of hypericin through the interstitial space, we performed a visual and quantitative analysis of the colocalisation of hypericin and DiOC 18 -labelled lipoproteins in microscopic fluorescent overlay images. A coupled dynamic behaviour was found early after injection (normalised fluorescence intensity differences were on the whole less than 10%), while a shifted pattern in localisation of hypericin and DiOC 18 was seen after 24 h, suggesting that during its migration through the tumour mass, hypericin is released from the lipoprotein complex. In conclusion, we were able to show that the tumour accumulation of hypericin is critically determined by a combination of biological (blood flow, vessel permeability) and physicochemical elements (affinity for interstitial constituents).

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“…1(A, B)), found naturally in St John's wort (genus, Hypericum) or obtained semisynthetically from emodine (1). Hypericin has been shown to have antiviral and antineoplastic activities (2).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of tumor affinity of mono‐[¹²³I]iodohypericin and mono‐[¹²³I]iodoprotohypericin in a mouse model with a RIF‐1 tumor

Fonge

Putte

Huyghe

et al. 2007

Contrast Media & Molecular

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In this study we have compared the tumour-seeking properties of mono-[(123)I]iodoprotohypericin and mono-[(123)I]iodohypericin in C3H mice with a subcutaneous radiation-induced fibrosarcoma-1 tumor. After intravenous injection, both tracers were rapidly cleared from all organs and were retained by the tumors. There was no significant difference in tumor uptake of the two tracers at all studied time points (p > 0.05). To study the plausible mechanism of hypericin and mono-iodohypericin uptake in tumor, their plasma binding profile was investigated. Both agents show high affinity for low-density lipoproteins and to a lesser extent high-density lipoproteins and other heavy proteins. Mono-[(123)I]iodohypericin appears to be more promising as a tumor diagnostic agent, given its faster clearance from all organs.

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A convenient semisynthetic route to hypericin

Cited by 117 publications

References 12 publications

Enhancing the photodynamic effect of hypericin in human bladder transitional cell carcinoma spheroids by the use of the oxygen carrier, perfluorodecalin

Enhancing the photodynamic effect of hypericin in human bladder transitional cell carcinoma spheroids by the use of the oxygen carrier, perfluorodecalin

Elucidation of the tumoritropic principle of hypericin

Evaluation of tumor affinity of mono‐[¹²³I]iodohypericin and mono‐[¹²³I]iodoprotohypericin in a mouse model with a RIF‐1 tumor

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A convenient semisynthetic route to hypericin

Cited by 117 publications

References 12 publications

Enhancing the photodynamic effect of hypericin in human bladder transitional cell carcinoma spheroids by the use of the oxygen carrier, perfluorodecalin

Enhancing the photodynamic effect of hypericin in human bladder transitional cell carcinoma spheroids by the use of the oxygen carrier, perfluorodecalin

Elucidation of the tumoritropic principle of hypericin

Evaluation of tumor affinity of mono‐[123I]iodohypericin and mono‐[123I]iodoprotohypericin in a mouse model with a RIF‐1 tumor

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Evaluation of tumor affinity of mono‐[¹²³I]iodohypericin and mono‐[¹²³I]iodoprotohypericin in a mouse model with a RIF‐1 tumor