Hypericin in cancer treatment: more light on the way

Agostinis, Patrizia; Vantieghem, Annelies; Merlevede, Wilfried; Witte, Peter de

doi:10.1016/s1357-2725(01)00126-1

Cited by 408 publications

(351 citation statements)

References 126 publications

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“…26 In recent times much work has been done on developing new PS27 , 28 for PDT, and although the vast majority of these compounds are based on the tetrapyrrole backbone 29 found in porphyrins, chlorins and phthalocyanines, other molecular structures are beginning to be studied both preclinically and clinically. 30,31 In this review we will cover the existing literature on fullerenes for PDT, summarize results from our laboratory and outline future possibilities concerning applications of fullerenes as PS for PDT. Fig.…”

Section: Introductionmentioning

confidence: 99%

Photodynamic therapy with fullerenes

Mróz

Tegos

Gali

et al. 2007

Photochem Photobiol Sci

274

209

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Fullerenes are a class of closed-cage nanomaterials made exclusively from carbon atoms. A great deal of attention has been focused on developing medical uses of these unique molecules especially when they are derivatized with functional groups to make them soluble and therefore able to interact with biological systems. Due to their extended π-conjugation they absorb visible light, have a high triplet yield and can generate reactive oxygen species upon illumination, suggesting a possible role of fullerenes in photodynamic therapy. Depending on the functional groups introduced into the molecule, fullerenes can effectively photoinactivate either or both pathogenic microbial cells and malignant cancer cells. The mechanism appears to involve superoxide anion as well as singlet oxygen, and under the right conditions fullerenes may have advantages over clinically applied photosensitizers for mediating photodynamic therapy of certain diseases.

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Section: Introductionmentioning

confidence: 99%

Photodynamic therapy with fullerenes

Mróz

Tegos

Gali

et al. 2007

Photochem Photobiol Sci

274

209

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“…H. perforatum has been traditionally used as an aromatic, expectorant, anxiolytic, sedative and anti-inflammatory to treat bladder complaints, chronic catarrh, colds, diarrhoea, jaundice, rheumatism, menopause, worms and nervous depression [16,39]. H. perforatum has been widely tested in vivo and in vitro for a variety of pharmacological effects such as antibacterial, anti-inflammatory [40], wound-healing [41,42], antitumoral [43], antiviral [44], inhibition of dopamine and norepinephrine reuptake [45], reduction of neuropathic pain [46] and treatment of mild-to-moderate depression [47,48] among others. Hydroalcoholic extracts of H. perforatum contain naphtodianthrones, flavonoids, phenylpropanes, phloroglucinols, proanthocyanidins secondary, tannins [40] but it is known that the activities mentioned before are mainly mediated by a single or a combination of hypericin, pseudohypericin and/or hyperforin (Fig.…”

Section: H Perforatum (Hypericaceae) St John's Wortmentioning

confidence: 99%

“…1). Hypericin is considered a potential new tool for the photodynamic therapy of cancer [44]. Hyperforin is known to be the key contributing metabolite for antidepressant activity and the main metabolite responsible for the antibacterial activity [40,47].…”

Section: H Perforatum (Hypericaceae) St John's Wortmentioning

confidence: 99%

Anglo-Saxon pharmacopoeia revisited: a potential treasure in drug discovery

Watkins

Pendry

Corcoran

et al. 2011

Drug Discovery Today

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Modern translations provide a new opportunity to revisit the Anglo-Saxon medicinal texts, a valuable resource for discovering and developing novel compounds from native British flora. Previous pharmacological studies of 16 th and 17 th century medicinal plants reported in the Anglo-Saxon medical texts, suggest some were effective and led to the identification and isolation of new natural compounds such as matricin from Achillea millefolium L., a prodrug that yields chamazulene carboxylic acid, a natural profen.New insights through multidisciplinary projects could further explore the manuscript content for the discovery of metabolites with potential pharmacological applications.

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“…Previous reports show that, in response to physical or chemical stress, cells can activate signalling pathways, including the mitogen-activated protein kinase (MAPK) and phosphotidylinositol-3-kinase pathways (Oleinick and Evans, 1998;Moor, 2000;Agostinis et al, 2002). Specifically in HeLa cells photosensitisation with hypericin resulted in the rapid and sustained activation of Jun N-terminal kinase-1 and MAPK (Assefa et al, 1999).…”

Section: Hypericin-induced Photodynamic Therapymentioning

confidence: 99%

“…The anthraquinone, hypericin, is synthesised by the hypericum genus of plants and it is probably the most powerful photosensitiser found in nature. Hypericin exhibits the characteristics that are fundamental for the application of PDT, including bright fluorescence, a high singlet oxygen quantum yield upon illumination and minimal dark toxicity (Agostinis et al, 2002). Previous PDT studies on the effect of hypericin on cultured fibroblasts or murine keratinocytes have shown concentrationand light-dependent phototoxicity (Yu et al, 1996;Theodossiou et al, 2004).…”

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confidence: 99%

Photochemical internalisation of chemotherapy potentiates killing of multidrug-resistant breast and bladder cancer cells

et al. 2007

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Multidrug resistance (MDR) is the major confounding factor in adjuvant solid tumour chemotherapy. Increasing intracellular amounts of chemotherapeutics to circumvent MDR may be achieved by a novel delivery method, photochemical internalisation (PCI). PCI consists of the co-administration of drug and photosensitiser; upon light activation the latter induces intracellular release of organellebound drug. We investigated whether co-administration of hypericin (photosensitiser) with mitoxantrone (MTZ, chemotherapeutic) plus illumination potentiates cytotoxicity in MDR cancer cells. We mapped the extent of intracellular co-localisation of drug/ photosensitiser. We determined whether PCI altered drug-excreting efflux pump P-glycoprotein (Pgp) expression or function in MDR cells. Bladder and breast cancer cells and their Pgp-overexpressing MDR subclones (MGHU1, MGHU1/R, MCF-7, MCF-7/R) were given hypericin/MTZ combinations, with/without blue-light illumination. Pilot experiments determined appropriate sublethal doses for each. Viability was determined by the 3-[4,5-dimethylthiazolyl]-2,5-diphenyltetrazolium bromide assay. Intracellular localisation was mapped by confocal microscopy. Pgp expression was detected by immunofluorescence and Pgp function investigated by Rhodamine123 efflux on confocal microscopy. MTZ alone (0.1 -0.2 mg ml À1 ) killed up to 89% of drug-sensitive cells; MDR cells exhibited less cytotoxicity (6 -28%). Hypericin (0.1 -0.2 mM) effects were similar for all cells; light illumination caused none or minimal toxicity. In combination, MTZ /hypericin plus illumination, potentiated MDR cell killing, vs hypericin or MTZ alone. (MGHU1/R: 38.65 and 36.63% increase, Po0.05; MCF-7/R: 80.2 and 46.1% increase, Po0.001). Illumination of combined MTZ/hypericin increased killing by 28.15% (Po0.05 MGHU1/R) compared to dark controls. Intracytoplasmic vesicular co-localisation of MTZ/hypericin was evident before illumination and at serial times post-illumination. MTZ was always found in sensitive cell nuclei, but not in dark resistant cell nuclei. In illuminated resistant cells there was some mobilisation of MTZ into the nucleus. Pgp expression remained unchanged, regardless of drug exposure. Pgp efflux was blocked by the Pgp inhibitor verapamil (positive control) but not impeded by hypericin. The increased killing of MDR cancer cells demonstrated is consistent with PCI. PCI is a promising technique for enhancing treatment efficacy.

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Hypericin in cancer treatment: more light on the way

Cited by 408 publications

References 126 publications

Photodynamic therapy with fullerenes

Photodynamic therapy with fullerenes

Anglo-Saxon pharmacopoeia revisited: a potential treasure in drug discovery

Photochemical internalisation of chemotherapy potentiates killing of multidrug-resistant breast and bladder cancer cells

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