Use Of Hypericin Research Articles

Hypericin - a natural photosensitizer in photodynamic therapy on skin cancer cells

SignificanceThe aim of the study was to measure the effectiveness of hypericin in the photokilling of skin cancer cells after orange light irradiation. ApproachTests were carried out on the skin cancer cells SSC-25 and MUG-Mel2, and keratinocytes HaCaT cell line with the use of hypericin and PDT. We performed cytotoxicity tests, cellular uptake with flow cytometry, and TUNEL assay to detect apoptotic bodies. ResultsIn cytotoxicity experiments, don't observe difference in keratinocyte viability, but in cancer cells the after-viability was decreased by almost 50% after irradiation. In the TUNEL assay, the appearance of a large number of apoptotic bodies in cancer cell lines was observed. In the cellular uptake experiments, showed that the cell lines very fast uptake hypericin. ConclusionsMore studies are necessary to confirm the potential anticancer activity of hypericin and shed light on various cellular and molecular mechanisms which are behind our findings.

Effect of photodynamic therapy with hypericin on the secretion of selected cytokines of colorectal cancer cells tested in vitro

Introduction and aim. Photodynamic therapy is a complex process involving the introduction of photosensitizers into the patient’s body and irradiation of them in order to destroy the lesion, and activate the immune system. An important role in photodynamic therapy is played by photobiochemical and physical mechanisms that affect the tumor vessels and lead to the death of the damaged cell. The aim of the study is to determine the effect of photodynamic therapy with the use of Hypericin (Hyp) on the secretion of selected cytokines by colorectal cancer cells. Material and methods. Two colorectal cancer cell lines SW480 and SW620 were used in the study. Cells treated Hypericin were exposed to visible light. Then cell viability was determined by the MTT assay with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium. Assays were performed for control samples without hypericin and light exposure, with Hyp without light exposure, without Hyp and irradiated with light, and test samples with Hyp and light exposure. Results. In the experiment we reveal, that Hyp- photodynamic activity does not influence the secretion of cytokines. Conclusion. The obtaining results confirming the destructive effect of Hyp- PDT on the colon cancer cells, show a possibility of extending the indication for photodynamic therapy using Hyp, qualification of precancerous changes.

Hypericin maintians PDX1 expression via the Erk pathway and protects islet β-cells against glucotoxicity and lipotoxicity.

A decrease in islet β-cell mass is closely associated with the development and progression of diabetes. Therefore, protection against β-cell loss is an essential measure to prevent and treat diabetes. In this study, we investigated the protective effects of non-photoactivated hypericin, a natural compound, on β-cells both in vitro and in vivo. In vitro, hypericin greatly improved INS-1 cell viability under high-glucose and high-fatty-acid conditions by inhibiting glucotoxicity- and lipotoxicity-induced apoptosis and nitric oxide (NO) production. Then, we further demonstrated that hypericin elicited its protective effects against glucotoxicity and lipotoxicity in INS-1 cells by attenuating the reduction in pancreatic duodenal homeobox-1 (PDX1) expression and Erk activity. In vivo, prophylactic or therapeutic use of hypericin inhibited islet β-cell apoptosis and enhanced the anti-oxidative ability of pancreatic tissue in high-fat/high-sucrose (HFHS)-fed mice, thus alleviating β-cell loss and maintaining or improving β-cell mass and islet size. More importantly, hypericin treatment decreased fasting blood glucose, improved glucose intolerance and insulin intolerance, and alleviated hyperinsulinaemia in HFHS-fed mice. Therefore, hypericin showed preventive and therapeutic effects against HFHS-induced onset of type II diabetes in mice. Hypericin possesses great potential for development as an anti-diabetes drug in the future.

Phototoxicity in a laryngeal cancer cell line enhanced by a targeting amphiphilic chlorin photosensitizer

BackgroundPhotodynamic therapy (PDT) has been established in several countries as an alternative therapy for the treatment of various malignancies. This therapy involves the incorporation of a photosensitizer (PS) that is activated by visible light and form reactive oxygen species leading to target cell death by apoptosis or necrosis. Previously, our group has demonstrated that CHL-T (semi-synthesized from chlorophyll a and containing a linked solubilizing group TRISMA®) presented a pronounced potential to induce death in HeLa cell line after PDT. In the present study, besides confirm the high cytotoxicity in another cell line, we have further investigated the cell death mechanisms caused by CHL-T as a photosensitizer in laryngeal carcinoma cells. MethodsCells were exposed to different concentrations of three photosensitizers, namely, hypericin (HY), unmodified chlorin (CHL) and a synthesized amphiphilic chlorin derivative (CHL-T). PSs accumulation and localization were accessed by fluorescence assays. Photosensitization was induced at 6Jcm−2 using red LEDs (630±10nm). Viability was assessed by mitochondrial function (MTT); whereas apoptosis/necrosis was evaluated by fluorescence microscopy and flow cytometry. Expression of pro-apoptotic p53 protein was studied by Western blot. Results and conclusionsAll PS showed similar localization profile in the HEp-2 cells. The use of CHL-T increased the percentage of apoptotic cells and also p53 expression in comparison with the use of HY and CHL as photosensitizers. This study shows a significant effect of CHLT associated with red light (630±10nm and 18mWcm−2) irradiation on a cancer cell line, indicating the potential of this amphiphilic chlorin in enhancing the therapeutic effectiveness of Photodynamic Therapy (PDT).

Differential diagnosis of gallstones by using hypericin as a fluorescent optical imaging agent.

To explore the feasibility of using hypericin as an optical imaging probe with affinity for cholesterol for differential fluorescent detection of human gallstones. Cholesterol, mixed and pigment stones from cholecystectomy patients were incubated with hypericin or solvent. After 72 h, the stones were analysed for fluorescence (365 nm) and treated with 2-propanol/dimethyl sulfoxide for high performance liquid chromatography (HPLC) analysis. Rats with virtual gallbladder containing human cholesterol, mixed or pigment gallstones (VGHG) received 5 mg/kg hypericin or solvent and VGHG rats with cholesterol stones were given different hypericin doses (5-15 mg/kg). Twelve hours later, the stones were analysed at 365 nm. Biliary excretion and metabolites of hypericin were assessed in common bile duct (CBD) cannulated rats for 9 h using fluorospectrometry, HPLC and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Homogeneous high fluorescence was seen on cholesterol stones either pre-incubated with hypericin or extracted from VGHG rats receiving hypericin. Mixed stones showed a dotted fluorescent pattern, whereas pigment and solvent-treated ones lacked fluorescence. HPLC showed 7.68, 6.65 and 0.08 × 10(-3) M of cholesterol in extracts from cholesterol, mixed, and pigment gallstones, respectively. Hypericin accounted for 2.0, 0.5 and 0.2 × 10(-6) M in that order. On cholesterol stones from VGHG rats receiving different hypericin doses, a positive correlation was observed between dose and fluorescence. In the bile from CBD-cannulated rats, fluorescence represented 20% of the injected dose with two peaks in 9 h. HPLC analysis revealed that hypericin conjugates reached 60% of the peak area. By MALDI-TOF MS, hypericin-glucuronide was detected. This study proves the potential use of hypericin for differential fluorescent detection of human gallstones regarding their chemical composition.

In vitro anti-neoplastic activity of the ethno-pharmaceutical plant Hypericum adenotrichum Spach endemic to Western Turkey

Hypericum perforatum (St. John's wort) is well-established for its antidepressant activity throughout the world and also various other species within this genus are used in different folk medicines. Hyperforin of St. John's wort inhibited growth of cancer cell lines and the use of hypericin (another compound of H. perforatum) in cancer photodynamic therapy is proposed. Therefore, we investigated the anti-cancer properties of H. adenotrichum Spach (Guttiferae), an endemic species in Turkey called 'kantaron', which is used for wound healing and antiseptic effects. Freeze-dried plant was extracted with petroleum ether, dichloromethane, ethyl acetate, and methanol and the bioactivity of these extracts was analysed by proliferation assay, cell death determination, by investigating protein expression profiles specific for cell cycle arrest and apoptosis as well as composition by HPLC. The strongest anti-proliferative activity was determined for the petroleum ether extract with an IpC50 of approximately 5.8 microg/ml medium (referring to 1 mg dried plant) which correlated with cyclin D1 suppression and p21 induction. This extract also induced phosphorylation of H2AX, and activated caspase-3 followed by signature-type cleavage of PARP resulting in approximately 50% apoptosis at 23.2 microg/ml after 24 h of treatment. Neither hyperforin, hypericin, or amentoflavone contributed to these properties. To the best of our knowledge, we report for the first time that the endemic plant H. adenotrichum Spach exhibits potent p53-independent anti-neoplastic properties due to yet unexplored Hypericum constituents.

Novel photodynamic diagnosis of bladder cancer: Ex vivo fluorescence cytology using hypericin

In this study we have evaluated the use of hypericin ex vivo urine fluorescence cytology as a non-invasive method for detecting early bladder cancers. To date this is the first study reported using this technique with hypericin. Urine samples from patients with early bladder cancers were processed for fluorescence cytology by incubation with hypericin, a novel photosensitizer. Normal urine samples incubated with hypericin served as normal controls. Laser confocal microscopy and spectroscopy was used to detect the fluorescence in the exfoliated low-grade urothelial tumor cells. Fluorescence cytology was considered positive if hypericin fluorescence of the low-grade urothelial tumor cells was detected to be stronger (>8.5 times) compared to the baseline fluorescence established for normal urine samples. Automated analysis for an objective reproducible outcome appears possible. The possibility of detection of malignant urothelial cells in early cancer makes ex vivo fluorescence cytology promising for routine diagnostic screening.

Macro-microscopic fluorescence of human bladder cancer using hypericin fluorescence cystoscopy and laser confocal microscopy

The early detection of carcinoma is very essential for the diagnosis and prognosis of a bladder cancer patient. In this study we have investigated the use of hypericin as a fluorescent tumour marker and laser confocal microscopy as a diagnostic tool to aid the diagnosis of such cancers. Both cellular and clinical studies have been conducted. In the cellular studies, we have compared two bladder cell lines for the uptake and sub-cellular localization of hypericin. It was found that there was a rapid uptake and clearance of hypericin and significant localization in mitochondria and lysosomes. The study also revealed that there was a time-dependent increase in fluorescence intensity in bladder cells. The optimum localization was found to be 2-4 h post drug incubation. In the clinical study, consisting of 30 patients, both white light and fluorescence cystoscopy were performed after hypericin instillation. Biopsies taken from fluorescing regions were imaged using the confocal microscope. The order of fluorescence was detected to be as follows: normal < inflammation < grade 1 < grade 2 < CIS < grade 3. It was also found that the fluorescence intensity increased with the stage of the disease thereby enabling the determination of the degree of invasiveness of cancer. This enables the use of hypericin as a prognostic marker and laser confocal microscopy as a tool to aid in diagnosis of bladder cancer.

An electroreflectance and photoelectrochemical study of hypericin at bare and modified gold electrodes

Two consecutive one-electron transfer processes of the reduction of hypericin were studied at a bare and an alkanethiol-modified polycrystalline gold electrode in acetonitrile by means of cyclic voltammetry and electroreflectance (ER) spectroscopy. The voltammetric response of hypericin at a bare gold electrode was found to be quasi-reversible at low sweep rates, and the participation of adsorbed hypericin in the voltammetric response was not detected. The redox reaction of hypericin was not inhibited but rather enhanced by the presence of an octadecanethiol film on the electrode surface, into which hypericin was presumably partitioned. In situ electroreflectance spectra displayed a feature of absorption spectral difference between hypericin and its reduction product at the electrode interface. The ER data were used to discuss the absorption spectra of one- and two-electron reduced forms of hypericin in the visible wavelength region. The use of hypericin as a photo-excitation center was examined in a photo-induced electron transfer system prepared by co-modification of a gold electrode with alkanethiol and N -butyl- N ′-(4-mercaptobutyl)-4,4′-bipyridinium dihexafluorophosphate. The photo-induced electron transfer from photo-excited hypericin to the gold electrode with the help of mediation by a viologen moiety was observed.

Hypericin in phototherapy

We describe the first local use of hypericin as photosensitizer for photodynamic therapy in a patient with recurrent malignant mesothelioma. Hypericin is a polycyclic quinone, which has been shown to possess in vivo and in vitro antiretroviral and photosensitizing activity; moreover, it is used in depressive disorders. The semiquinone radical, singlet oxygen, and superoxide anion radical are reported to be the toxic agents in hypericin phototherapy. Our first experience with locally applied hypericin in a superficial tumor-plate was performed 8 weeks after the systemic administration of hematoporphyrin derivatives. For tumor light illumination we used an argon pumped dye laser tuned to 632 nm. Owing to satisfactory results, we repeated the same therapy 4 weeks later — and no therapeutic effect was noted. Following this, we proved the interstitial application of HPD and the combination of interstitial HDP and superficially applied hypericin. The subsequent light illumination 6 hours later had no efficacy in the HDP-photosensitized area but there was tumor destruction in the field with both administered photosensitizers. Our first experience suggests a potentiation of two photosensitizers: hematoporphyrin derivatives and hypericin.

Inhibition of cellular growth and induction of apoptosis in pituitary adenoma cell lines by the protein kinase C inhibitor hypericin: potential therapeutic application.

Protein kinase C (PKC) is an enzyme involved in the regulation of cellular growth, proliferation, and differentiation in a number of tissues including the anterior pituitary, in which it is also believed to play a role in hormone secretion. Protein kinase C activity and expression have been found to be greater in adenomatous pituitary cells than in normal human and rat pituitary cells and higher in invasive pituitary tumor cells than in noninvasive ones. Inhibition of PKC activity has been shown in a variety of tumor cells to inhibit growth in a dose-related fashion. The purpose of the current study was to determine whether hypericin, a potent inhibitor of PKC activity that may be administered clinically, alters the growth and proliferation in established pituitary adenoma lines and to determine if inhibition of PKC activity induces apoptosis, as reported in some other tumor cell types. Two established pituitary adenoma cell lines, AtT-20 and GH4C1, were treated with hypericin in tissue culture for defined periods following passage. Inhibition of growth was found to be dose dependent in all three cell lines in low micromolar concentrations of hypericin, as determined by viable cell counts, methylthiotetrazole assay, and [3H]thymidine uptake studies. Concentrations of hypericin as low as 100 nM also induced apoptosis in these established lines, whereas treatment of normal human fibroblasts with a concentration of 10 microM failed to induce apoptosis. The potential use of hypericin in the therapy of pituitary adenomas warrants additional in vitro investigations with the aim of later moving toward therapeutic trials in selected patients in whom surgical or medical therapy has failed.

Chemiluminescent activation of the antiviral activity of hypericin: a molecular flashlight.

Hypericin is a naturally occurring photosensitizer that displays potent antiviral activity in the presence of light. The absence of light in many regions of the body may preclude the use of hypericin and other photosensitizers as therapeutic compounds for the treatment of viral infections in vivo. The chemiluminescent oxidation of luciferin by the luciferase from the North American firefly Photinus pyralis was found to generate sufficiently intense and long-lived emission to induce antiviral activity of hypericin. Light-induced virucidal activity of hypericin was demonstrated against equine infectious anemia virus, a lentivirus structurally, genetically, and antigenically related to the human immunodeficiency virus. The implications for exploiting chemiluminescence as a "molecular flashlight" for effecting photodynamic therapy against virus-infected cells and tumor cells are discussed.