Effects of depsidones from Hypogymnia physodes on HeLa cell viability and growth.

The anti-proliferative activitiy of Hypogymnia physodes methanol extracts (ME) and its main constituents, physodalic acid (P1), physodic acid (P2), and 3-hydroxy physodic acid (P3), was tested on human cancer HeLa cell lines. Three lichen depsidones, P1, P2 and P3, were isolated from H. physodes ME using column chromatography and their structures were determined by UV, ESI TOF MS, 1H and 13C NMR. The content of P1, P2 and P3 in ME was determined using reversed-phase highperformance liquid chromatography with photodiode array detection. P1-3 represented even 70 % of the studied extract. The HeLa cells were incubated during 24 and 72 h in the presence of ME and depsidones P1, P2 and P3, at concentrations of 10-1000 µg/ml. Compounds P2 and P3 showed higher activity than compound P1. Half maximal inhibitory concentrations (IC50, µg/ml) of P1, P2, P3 and ME for 24-h incubation were 964, 171, 97 and 254 µg/ml, respectively, while for 72-h incubation they were 283, 66, 63 and 68 µg/ml. As far as we know, this is the first report on the effect of H. physodes ME and their depsidones on HeLa cells.

Do other Hypericum species have medical potential as St. John's wort (Hypericum perforatum)?

Among 484 Hypericum L. (Guttiferae/Hypericaceae) species, widespread in warm temperate areas throughout the world, only H. perforatum is widely used in official medicine. Hypericum perforatum has been reported as an antidepressant, antiviral, antimicrobial, anti-inflammatory, and a healing agent. The main constituents of the Hypericum species are naphthodianthrones, primarily represented by hypericin and pseudohypericin, phloroglucinol derivatives, especially hyperforin, and flavonoids, such as quercetin, quercitrin, hyperoside and rutin. Hypericin and pseudohypericin have been found to possess antiretroviral activity. Hyperforin may also have an important contribution to the antidepressant activity of Hypericum extracts. The content of the above active constituents in some Hypericum species is higher than in H. perforatum. Also, a number of studies of the biological activities of Hypericum species have shown that the most recognized species of this genus, H. perforatum, was not the most active. Comprehensive analysis of the published research on the chemical composition and biological activity, showed that H. richeri has a similar pharmacological potential as St. Jon's wort. The species, with high content of naphtodianthrones,which might be used against viruses and retroviruses, are: H. androseamum,H. annulatum, H. barbatum, H. boissieri, H. elegans, H. hirsutum, H. hyssopifolium, H. humifusum, H. montanum. H. montbretii, H. triquetrifolium, H. richeri, H. rochelii, H. rumeliacum, H. thasium, andH. patulum. Very few species (e.g. H. inodorum and H. moseranum) contained the similar amounts of hyperforine as H. perforatum. Since hyperforin was recognized as one of the most crucial components for the antidepressive activity, it seems that H. perforatum barely has an alternative for this purpose. Plant species containing considerable amounts of other acylphloroglucinol derivatives have the potential to demonstrate antibacterial and cytotoxic activity. Some of these species are: H. sampsonii, H. ascyron, H. foliosum, H. geminiflorum and H. scabrum. However, only a few studies concerning the activity of extracts and isolated compounds were done in vivo. Also, data on the safe usage of Hypericum constituents as phytotherapeutics are scarce. Since some of Hypericum species are scarcely distributed or endemic as well as some of the secondary metabolites are presented in very small amounts, bio-production, especially endophytes, could represent an abundant and reliable source of pharmacologically active metabolites of Hypericum species for exploitation in pharmaceutical industry.

Phytochemical analysis of nine Hypericum L. species from Serbia and the F.Y.R. Macedonia.

The methanol extracts of the aerial parts of nine Hypericum species (H. barbatum, H. hirsutum, H. linarioides, H. maculatum, H. olympicum, H. perforatum, H. richeri, H. rumeliacum and H. tetrapterum), collected on different locations in Serbia and the F.Y.R. Macedonia, were obtained by accelerated solvent extraction (ASE) and analyzed for the content of four constituents (hyperoside, quercitrin, hyperforin and hypericin) by LC-MS/ MS. All studied extracts contained the characteristic four constituents, but their contents varied between different species and locations. The content of hypericin in H. barbatum was significantly higher (3.9 times) than that in H. perforatum.

The separation of hypericine and pseudohypericine from Hypericum perforatum L.

The extraction of Hypericum perforatum L. was carried out by the method of ultrasonic maceration. The separation of H. perforatum L. extract in order to obtain hypericine and pseudohypericine rich fractions was carried out by the following chromatographic methods: flash column chromatography, high speed countercurrent chromatography, XAD solid phase extraction and Sephadex column chromatography. The separation by the Sephadex column chromatography gave the best results. Preparative HPLC was used to isolate hypericine and pseudohypericine from fraction 4 obtained by the Sephadex column chromatography procedure.