Hypericin, Cyanobacteria, Photosynthesis, Photodynamic Action The photodynamic action of hypericin on photosynthesis and respiration were monitored in Synechocystis sp PCC 6803 and Synechoccus ATCC 6311 (Anacystis nidulans). An oxygen electrode was used to measure net oxygen evolution or consumption. The amount of hyperi­ cin required to inhibit photosynthesis was quantitively determined. Photo...

The conventional photosensitizers used in photodynamic therapy (PDT), such as haematoporphyrin (HP), have not yet reached satisfactory therapeutic effects on port-wine stains (PWSs), due largely to the long-term dark toxicity. Previously we have showed that hypericin exhibited potent photocytotoxic effects on Roman chicken cockscomb model of PWSs. However, the molecular mechanism of hypericin-m...

Insulinomas cause neuroglycopenic symptoms, permanent neurological damage and even death. Current available therapies cannot satisfactorily treat malignant insulinomas and some benign insulinomas. The promising phototherapeutic results and harmless side effects of hypericin in some cancer treatments prompted us to explore possible anti-growth activity of photoactivated hypericin against RINm5F ...

Hypericin, an extract from St John's Wort (Hypericum perforatum L.), is a promising photosensitizer in the context of clinical photodynamic therapy due to its excellent photosensitizing properties and tumoritropic characteristics. Hypericin-PDT induced cytotoxicity elicits tumor cell death by various mechanisms including apoptosis, necrosis and autophagy-related cell death. However, limited rep...

The mechanism of the antiviral activity of hypericin was characterized and compared with that of rose bengal. Both compounds inactivate enveloped (but not unenveloped) viruses upon illumination by visible light. Human immunodeficiency and vesicular stomatitis viruses were photodynamically inactivated by both dyes at nanomolar concentrations. Photodynamic inactivation of fusion (hemolysis) by ve...

Rheumatoid arthritis is a chronic, destructive, autoimmune joint disease that affects one to two million Americans (or approximately 1% of the population of the United States). This disease can strike at any age and affects roughly three times as many women as men (http://ww2. arthritis.org/conditions/DiseaseCenter/RA/ra_who.asp). Symptoms include joint stiffness, swelling, and pain, as well as...

Photodynamic therapy (PDT) is currently being used as an alternative treatment modality for various types of cancers. PDT involves the selective uptake and retention of a photosensitizer in the tumor followed by light irradiation of an appropriate wavelength to cause the destruction of tumor cells by the formation of cytotoxic reactive oxygen species. The photosensitizer, hypericin, has shown g...

Rheumatoid arthritis (RA) is characterized by fibroblast-like synoviocyte (FLS) hyperplasia, which is partly ascribable to decreased apoptosis. In this study, we show that adrenomedullin (ADM), an antiapoptotic peptide, is constitutively secreted in larger amounts by FLS from joints with RA (RA-FLS) than with osteoarthritis (OA-FLS). ADM secretion was regulated by TNF-alpha. Peptidylglycine alp...