Wavelength-dependent photoresponse of biological and aqueous model systems using the photodynamic plant pigment hypericin

Kubin, Andreas; Alth, G; Jindra, R. H.; G, Jessner; Ebermann, Robert

doi:10.1016/s1011-1344(96)07355-1

Cited by 21 publications

(14 citation statements)

References 13 publications

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“…In the past various methods of isolation have been developed which mainly consist of HPLC analyses on RP-C 18 columns [37,46]. In other cases isolation protocols include the application of successive column chromatographies over silica [47,48], polyamide [49] or Sephadex LH-20 [50,51] which render the whole procedure labour-intensive and time consuming and as a consequence very expensive. A very interesting work on different separation methods of hypericin and pseudohypericin from H. perforatum was published by Smelcerovic et al .…”

Section: Extraction Isolation and Synthesis Of Hypericin And Pseudohmentioning

confidence: 99%

Hypericins as Potential Leads for New Therapeutics

Karioti

Bilia

2010

IJMS

255

191

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70 years have passed since the first isolation of the naphthodianthrones hypericin and pseudohypericin from Hypericum perforatum L. Today, they continue to be one of the most promising group of polyphenols, as they fascinate with their physical, chemical and important biological properties which derive from their unique chemical structure. Hypericins and their derivatives have been extensively studied mainly for their antitumor, antiviral and antidepressant properties. Notably, hypericin is one of the most potent naturally occurring photodynamic agents. It is able to generate the superoxide anion and a high quantum yield of singlet oxygen that are considered to be primarily responsible for its biological effects. The prooxidant photodynamic properties of hypericin have been exploited for the photodynamic therapy of cancer (PDT), as hypericin, in combination with light, very effectively induces apoptosis and/or necrosis of cancer cells. The mechanism by which these activities are expressed continues to be a main topic of discussion, but according to scientific data, different modes of action (generation of ROS & singlet oxygen species, antiangiogenesis, immune responces) and multiple molecular pathways (intrinsic/extrinsic apoptotic pathway, ERK inhibition) possibly interrelating are implicated. The aim of this review is to analyse the most recent advances (from 2005 and thereof) in the chemistry and biological activities (in vitro and in vivo) of the pure naphthodianthrones, hypericin and pseudohypericin from H. perforatum. Extracts from H. perforatum were not considered, nor pharmakokinetic or clinical data. Computerised literature searches were performed using the Medline (PubMed), ChemSciFinder and Scirus Library databases. No language restrictions were imposed.

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Section: Extraction Isolation and Synthesis Of Hypericin And Pseudohmentioning

confidence: 99%

Hypericins as Potential Leads for New Therapeutics

Karioti

Bilia

2010

IJMS

255

191

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“…It seems to be a potent sensitizer for photodynamic destruction of malignant tumors (1)(2)(3) and photodynamic inactivation of lipid-enveloped viruses, including hepatitis C and human immunodeficiency viruses (3)(4)(5). Its physicochemical properties and phototoxity have been investigated during the last decade (3,(6)(7)(8)(9)(10)(11)(12)(13)(14). A selective accumulation in some tumors and a high fluorescence quantum yield facilitates its use not only for tumor destruction but also for cancer diagnostics, for example, for the visualization of bladder cancer (15).…”

Section: Introductionmentioning

confidence: 99%

Photobleaching of Hypericin Bound to Human Serum Albumin, Cultured Adenocarcinoma Cells and Nude Mice Skin¶

Uzdensky

Iani

et al. 2007

Photochemistry and Photobiology

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Hypericin is a promising photosensitizer for photodynamic therapy (PDT) characterized by a high yield of singlet oxygen. Photobleaching of hypericin has been studied by means of absorption and fluorescence spectroscopy in different biological systems: in human serum albumin solution, in cultured human adenocarcinoma WiDr cells and in the skin of nude mice. Prolonged exposure to light (up to 95 min, 100 mW/cm2) of wavelength around 596 nm induced fluence‐dependent photobleaching of hypericin in all studied systems. The photobleaching was not oxygen dependent, and singlet oxygen probably played no significant role. Emission bands in the spectral regions 420–560 nm and above 600 nm characterize the photoproducts formed. An emission band at 615–635 nm was observed after irradiation of cells incubated with hypericin or of mouse skin in vivo but not in albumin solution. The excitation spectrum of these products resembled that of hypericin. Hypericin appears to be more photostable than most sensitizers used in PDT, including mTHPC and Photofrin.

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“…Among them UVA penetrate skin most deeply and reach to subepidermal layers [35,36]. It is well known that UVA is attributed to photosensitized generation of singlet oxygen.…”

Section: I-2 Effect Of Uv Light For Redox Signalingmentioning

confidence: 99%

The Principle and the Potential Approach to ROS-dependent Cytotoxicity by Non-pharmaceutical Therapies: Optimal Use of Medical Gases with Antioxidant Properties

Нода¹,

Fujita²,

Lee³

et al. 2011

CPD

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Regulation of cellular redox balances is important for the homeostasis of human health. Thus, many important human diseases, such as inflammation, diabetes, glaucoma, cancers, ischemia and neurodegenerative diseases, have been investigated in the field of reactive oxygen species (ROS) and oxidative stress. To overcome the harmful effect of oxidative stress and ROS, one can directly eliminate them by medical gases such as carbon monoxide (CO), hydrogen sulphide (H(2)S), and molecular hydrogen (H(2)), or one can induce ROS-resistant proteins and antioxidant enzymes to antagonize oxidative stresses. This article reviews the molecular mechanisms how these medical gasses work as antioxidants, and how ROS resistant proteins are produced in the physiological context. Targeted therapeutic modalities to scavenge or prevent ROS might be applied in the prevention and treatment of ROS-related diseases in the near future.

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Wavelength-dependent photoresponse of biological and aqueous model systems using the photodynamic plant pigment hypericin

Cited by 21 publications

References 13 publications

Hypericins as Potential Leads for New Therapeutics

Hypericins as Potential Leads for New Therapeutics

Photobleaching of Hypericin Bound to Human Serum Albumin, Cultured Adenocarcinoma Cells and Nude Mice Skin¶

The Principle and the Potential Approach to ROS-dependent Cytotoxicity by Non-pharmaceutical Therapies: Optimal Use of Medical Gases with Antioxidant Properties

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