Factors affecting growth of cell suspension cultures of hypericum perforatum L. (St. John's wort) and production of hypericin

Summary Use of Hypericum perforatum L., commonly known as St. John's wort, has increased recently due to the pharmaceutical potential of hypericin, found in its leaves. Hypericin has been reported to effect a natural treatment for mild and moderate depression by increasing the concentration of neurotransmitters in the central nervous system. We have developed a novel cell culture system for in vitro growth and production of this species, suggesting a possible technology for large-scale production of hypericin. Leaf explants grown in Murashige and Skoog salts supplemented with 2,4-dichlorophenoxyacetic acid (0.90 μM) and kinetin (0.11 μM) gave maximum percentage callus formation compared to other medium treatments evaluated. Hypericin localization in cell phase and leaves was found to vary, with cell phase accumulating hypericin in special organelles and leaves accumulating it in vacuoles. Light and dark conditions, with cell aggregate size, played important roles in growth and hypericin production in cell suspension cultures.     

贯叶连翘的水培及其代谢产物检测

水培可诱导贯叶连翘组培苗生根能力强,根活力也增加;生根苗在1/6MS培养液中培养6周后的金丝桃素(HP)、假金丝桃素(PHP)和贯叶金丝桃素(HF)含量分别比基质[腐质土 蛭石(1:1)]中培养的提高10.13%、16.00%和61.36%。     

Simultaneous determination of total hypericin and hyperforin in St. John's wort extracts by HPLC with electrochemical detection

An analytical procedure was developed for the simultaneous determination of total hypericin (protopseudohypericin, pseudohypericin, protohypericin and hypericin) and hyperforin in Hypericum perforatum (St. John's wort) extracts and its preparations. The determination of total hypericin and hyperforin in one step was achieved by exposing the samples to artificial daylight in amber glass vials. This procedure allows both the photoconversion of the protoforms into the appropriate hypericins and the protection of the photosensitive hyperforin. For quantification, an HPLC method with electrochemical detection was applied. As an example of the application of the principle, two preparations containing St. John's wort were assayed.     

Fast high-performance liquid chromatographic analysis of naphthodianthrones and phloroglucinols from Hypericum perforatum extracts

Hypericum perforatum L. (St. John's Wort) has been used in modern medicine for treatments of depression and neuralgic disorders. An HPLC method with photodiode array detection for the rapid determination of the major active compounds, naphthodianthrones and phloroglucinols, has been developed. The method permits the determination of hypericin, protohypericin, pseudohypericin, protopseudohypericin, hyperforin and adhyperforin in an extract in less than 5 min. Good linearity over the range 0.5-200 microg/mL for hyperforin and 0.02-100 microg/mL for hypericin was observed. Intra-assay accuracy and precision varied from 0.1 to 17% within these ranges. Lower levels of quantitative determination were 2 microg/mL for hyperforin and 0.5 microg/mL for hypericin, while detection limits were 0.1 and 0.02 microg/mL, respectively.     

Differential effects of light and nitrogen on production of hypericins and leaf glands in Hypericum perforatum

The effect of light intensity and root nitrogen supply on the levels of leaf hypericins was examined for St. John’s wort (Hypericum perforatum L.) grown in a sand culture system with artificial lighting. Increasing the light intensity illuminating St. John’s wort plants from 106 to 402 μmol·m^–2·s^–1 resulted in a continuous increase in the level of leaf hypericins. Using a leaf dissection approach, the association of hypericins with the dark glands on the leaves was shown, and it was found that increasing light intensity resulted in a parallel increase in the number of dark glands. In this respect, a linear relationship was observed between leaf gland number and the level of leaf hypericins (R = 0.901). While a decrease in nitrogen supply to St. John’s wort plants also yielded an increase in the level of leaf hypericins, this response occurred in a discontinuous manner over the range of nitrogen levels tested and no significant effect upon the number of dark leaf glands was observed. Overall, these effects of increased light intensity and decreased nitrogen supply on leaf hypericins appear to be independent and additive, and may reflect differences in the sites and processes where these environmental parameters impact production of these phytochemicals.