Distinct Hypericum perforatum L. total extracts exert different antitumour activity on erythroleukemic K562 cells

Viability and Radiosensitivity of Human Tumor Cells from Breast and Colon Are Influenced by Hypericum perforatum Extract HP01

To enhance the treatment of tumors that are resistant to radio- and chemotherapy while minimizing the side effects of radiochemotherapy, researchers are continuously seeking new active compounds for use in combination with radiotherapy. Therefore, the aim of our study was to examine the cytotoxic and radiosensitizing effects of an extract from St. John's Wort (Hypericum perforatum), referred to as HP01, on human epithelial tumor cells in vitro. The growth of MCF-7 (breast carcinoma) and HT-29 (colon carcinoma) cells was examined under the influence of HP01. In combination with radiation, the effects of HP01 on cytotoxicity and long-term survival were assessed using a colony formation assay. The number of DNA double-strand breaks was analyzed using the γH2AX assay, while cell cycle distribution was examined via flow cytometry. A growth-inhibiting and cytotoxic effect was observed for both tumor cell lines starting at a concentration of 10 µg/mL HP01. Treatment with HP01 resulted in an inhibition of clonogenic survival of tumor cells after ionizing radiation (6 Gy). The number of DNA double-strand breaks (DSBs) in tumor cells increased with HP01 treatment, but the repair of radiation-induced DNA DSBs was not affected. Cell cycle analysis revealed that HP01, in addition to radiation, enhanced G2/M arrest in MCF-7 and HT-29 cells. Overall, HP01 not only showed a growth-inhibiting effect but also demonstrated a radiosensitizing effect on human tumor cells for the first time. We conclude that the HP01-induced G2/M accumulation of cells may be the main rationale for the drug-induced radiosensitivity. It is therefore a promising candidate for combined therapy in tumor diseases and warrants further investigation.

Hypericin Ameliorates Maternal Separation-Induced Cognitive Deficits and Hippocampal Inflammation in Rats

BACKGROUND AND OBJECTIVE

Maternal separation as an epigenetic agent provokes a severe change in the brain, such as inflammation response, which is a key risk factor for the progression of autism spectrum disorders (ASD). This study evaluated the preventive effect of hypericin on maternal separation-induced cognitive deficits and hippocampal inflammation.

METHODS

Here, we reported that pups are subjected to maternal separations for 1 h per day from postnatal days (PND) 1-9 displayed apparent memory impairment in young rats (postnatal day 34) compared to controls group. Furthermore, maternal separation significantly increased inflammation factors in the hippocampus area. Anti-inflammation constituent shed light on treating ASD.

RESULTS

In this study, we found that treatment with hypericin (10 and 50 mg/kg) significantly suppresses expression of hippocampal interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) in the maternal separation rat model. Also, we found that hypericin prevented the decrease of hippocampal dopamine levels in the offspring of maternal separation rats.

CONCLUSION

The data indicated that hypericin may play a neuroprotective role in hippocampal cell and ameliorates dysfunctions in memory and level of inflammation factor in this autism model. Thus, hypericin could be used as an intervention for treating ASD.

Cytotoxic activities of Hypericum perforatum L. extracts against 2D and 3D cancer cell models

Six extracts were obtained from plant species Hypericum perforatum L., collected at Samsun in Turkey. The aim of this study was to examine the mechanisms of the anticancer activity of these extracts. Methanol, ethyl-acetate and hexane were used as a solvents for extraction from both branch-body part of the plant (extracts 1, 2 and 3) and from plant flowers (extracts 4, 5 and 6). The cytotoxic effects of the extracts were determined against 2D and 3D cancer cell models. Cell cycle changes of treated HeLa cells were analyzed by flow cytometry. Measurements of gene and microRNA expression levels in treated HeLa cells were done by quantitative real time PCR. Five examined extracts (2-6) exerted selective concentration-dependent cytotoxic effects on HeLa, K562, and A549 cancer cells, while the extract 1 exhibited very weak cytotoxicity. The extract 6 showed the highest intensity of cytotoxic activity. All tested extracts (2-6) demonstrated the ability to induce apoptosis in HeLa cells through activation of caspase-3. These extracts remarkably decreased gene expression levels of MMP2, MMP9, TIMP3, and VEGFA in HeLa cells. Flower extracts might have stronger effects on miR128/193a-5p/335 level changes than branch-body extracts. Hypericum perforatum extracts exerted weaker cytotoxic effects on 3D HeLa spheroids when compared with their effects on 2D monolayer HeLa cells. Taken together, results of our research may suggest the promising anticancer properties of the Hypericum perforatum extracts.

Antiproliferative Effects of St. John's Wort, Its Derivatives, and Other Hypericum Species in Hematologic Malignancies

Hypericum is a widely present plant, and extracts of its leaves, flowers, and aerial elements have been employed for many years as therapeutic cures for depression, skin wounds, and respiratory and inflammatory disorders. Hypericum also displays an ample variety of other biological actions, such as hypotensive, analgesic, anti-infective, anti-oxidant, and spasmolytic abilities. However, recent investigations highlighted that this species could be advantageous for the cure of other pathological situations, such as trigeminal neuralgia, as well as in the treatment of cancer. This review focuses on the in vitro and in vivo antitumor effects of St. John’s Wort (Hypericum perforatum), its derivatives, and other Hypericum species in hematologic malignancies. Hypericum induces apoptosis in both myeloid and lymphoid cells. Other Hypericum targets include matrix metalloproteinase-2, vascular endothelial growth factor, and matrix metalloproteinase-9, which are mediators of cell migration and angiogenesis. Hypericum also downregulates the expression of proteins that are involved in the resistance of leukemia cells to chemotherapeutic agents. Finally, Hypericum and its derivatives appear to have photodynamic effects and are candidates for applications in tumor photodynamic therapy. Although the in vitro studies appear promising, controlled in vivo studies are necessary before we can hypothesize the introduction of Hypericum and its derivatives into clinical practice for the treatment of hematologic malignancies.

Hypericum spp.: An Update on the Biological Activities and Metabolic Profiles

Plants from the genus Hypericum, one genus of the Hypericaceae family, have attracted a lot of attention for their potential pharmaceutical applications. Most of the studies in the literature focus on H. perforatum L. (common St. John's wort), whose complex spectrum of bioactive compounds makes this species one of the top herbal remedies and supplements in the world. It is also important to compare the studies on other Hypericum species, both from the phytochemical and biological point of view. The aim of this review was to provide an update of most recent studies about biological investigations of plants belonging to Hypericum genus. The metabolic profiles of Hypericum spp. were also discussed in order to present a spectrum of secondary metabolites not previously identified in this genus.

Ultrasound-assisted packed-bed extraction of hypericin from Hypericum perforatum L. and optimization by response surface methodology

This paper presents the successful application of ultrasound-assisted packed-bed (UAE-PB) method for the extraction of hypericin from the Hypericum perfuratum L. The Soxhlet system was utilized for the determination of suitable solvent from ethanol, methanol or from the mixture of different proportions of ethanol-methanol. The mixture of 50:50 v/v ethanol-methanol was obtained to be the most suitable solvent since it led to the highest extraction amount of hypericin. The extraction amount of hypericin increased by 13.6% and 21.4% when the solvent changed from pure methanol to the mixture of 50:50 v/v ethanol-methanol for the extraction time of 3 and 8 h, respectively. Subsequently, the extraction was conducted through the UAE-PB, and the effects of temperature, time, and the ratio of solvent to the dried plant were studied. The response surface method (RSM) was used to investigate the effect of parameters on the extraction in the UAE-PB system. At the temperature of 60 °C, extraction time of 105 min, and the solvent to plant ratio of 15.3, the maximum extraction yield of hypericin was achieved. In the optimal conditions, the amount of extraction was 0.112 mg hypericin/g dried plant, which was in accordance with the optimized predicted value (0.111 mg hypericin/g dried plant) from Design-Expert software.