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...

Th is work compares the polyphenolic compounds content in the in vitro shoot cultures of Hypericum rumeliacum, H. tetrapterum and in the hypericin non-producing H. calycinum, which are characteristic for the Balkan fl ora. In addition, the impact of diff erent vitamin supplementation to culture medium on secondary metabolites is discussed. Th ough Gamborg’s vitamins supplementation improved gro...

The wound healing potential of the aerial parts Hypericum triquetrifolium Turra (Hypericaceae) was evaluated using an in vivo excision model rats. Adult male Sprague Dawley rats were randomly assigned into seven groups; blank vehicles (olive oil and petroleum jelly), negative control, treatments [H. ethanolic extract jelly (5% 10%) H. olive macerate (100 200 g/L)], positive control (MEBO). Trea...

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/cm2 or 28 J/ cm2, delivered at a fluence rate of 15 m...

Photoactivated hypericin has a potent cytotoxic effect over a wide range of cells. However, very recently hypericin has been shown to have antitumoral and antimetastatic effects in the dark. The aim of this study was to test whether hypericin in the dark affects angiogenesis. Different in vitro assays were used to study the potential effects of this compound on key steps of angiogenesis, namely...

Changes in phenolic metabolism after elicitation with Colletotrichum gloeosporioides (CG) has been studied in Hypericum perforatum L. (HP) cell suspension cultures. Soluble phenolics were analysed by HPLC-DAD and HPLC-DAD-MS/MS. HP cultures elicited with the CG elicitor showed a significant increase in xanthone accumulation. Xanthone accumulation increased twelve fold when the cells were primed...

with the tremendous expansion in the use of herbal medicine worldwide, safety and efficacy as well as quality control of herbal medicine have become important concerns for both health authority and public. in this paper, the analysis of two st. john's wort (hypericum perforatum) products and four liquorice (glycyrrhiza glabra) products by spectrophotometric and hplc methods, is explained. moreo...

St. John's Wort (SJW), an over-the-counter antidepressant, contains hypericin, which absorbs light in the UV and visible ranges and is phototoxic to skin. To determine if it also could be phototoxic to the eye, we exposed human lens epithelial cells to 0.1-10 microM hypericin and irradiated them with 4 J/cm2 UV-A or 0.9 J/cm2 visible light. Neither hypericin exposure alone nor light exposure al...

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...