The lipophilic extract of Hypericum perforatum exerts significant cytotoxic activity against T24 and NBT-II urinary bladder tumor cells

Anticancer Activity of Essential Oils and Other Extracts from Aromatic Plants Grown in Greece

Aromatic plants have a long and significant history in the traditional medicine of many countries. Nowadays, there is an increasing interest in investigating the biological properties of aromatic plant extracts mainly due to their diversity, high availability, and low toxicity. Greece is abundant in aromatic plants, which can be attributed to the country’s geographical position, the morphology of its landscape, and its numerous mountainous and insular areas. In the past 15 years, a number of aromatic plant extracts of Greek origin have been studied for their bioactivities, including their antiproliferative potential against different types of cancer. Although the pharmacological activities of specific species of Greek origin have been reviewed before, no gathered information on explicitly Greek species exist. In this review, we summarize existing data on the antiproliferative activity of extracts isolated from Greek aromatic plants and discuss their molecular mode(s) of action, where available, in order to identify promising extracts for future research and link chemical constituents responsible for their activity. We conclude that essentials oils are the most frequently studied plant extracts exhibiting high diversity in their composition and anticancer potential, but also other extracts appear to be worthy of further investigation for cancer chemoprevention.

The potential of commercially available phytotherapeutic compounds as new photosensitizers for dental antimicrobial PDT: A photochemical and photobiological in vitro study

The present study evaluated the effectiveness of extracts of commercially available Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum as photosensitizers in Antimicrobial Photodynamic Therapy (aPDT). Each photosensitizer (PS) was analyzed in a spectrophotometer between 350 and 750 nm to determine the ideal light source. Once the absorption bands were determined, three light sources were selected. To determine the concentration of use, the compounds were tested at different concentrations on bovine dentin samples to evaluate the risk of staining. Once the concentration was determined, the PSs were evaluated for dark toxicity and phototoxicity on fibroblast and bacteria culture. Each compound was then irradiated with each light source and evaluated for the production of reactive oxygen species (ROS). The bacterial reduction was tested on E. faecalis culture in planktonic form and on biofilm using an energy of 10 J and an Energy Density of 26 J/cm². The tested compounds exhibited light absorption in three bands of the visible spectrum: violet (405 nm), blue (460 nm) and red (660 nm). At a 1:6 concentration, none of the compounds caused tooth staining as they did not exhibit significant toxicity in the cells or bacterial suspension. Additionally, significant ROS production was observed when the compounds were irradiated at each wavelength. When aPDT was performed on the plactonic and biofilm bacteria, significant microbial reduction was observed in both cases, reaching a reduction of up to 5Logs. In conclusion, extracts of Curcuma longa, Citrus lemon, Hamamelis virginiana and Hypericum perforatum exhibited potential for use as photosensitizing agents in aPDT.

Extraction Optimization of Flavonoids from Hypericum formosanum and Matrix Metalloproteinase-1 Inhibitory Activity

Hypericum formosanum is a valuable herb in Taiwan. In this study, response surface methodology was employed to optimize the ultrasound-assisted extraction of flavonoids from Hypericum formosanum. A central composite design with three variables (ethanol concentration, extraction time, and extraction temperature) was applied. Experimental results were fitted to the second order polynomial model and one-way analysis of variance was used to determine the goodness of fit of the model and the optimal conditions for responses. The optimal conditions for the maximum extraction yield of total flavonoid content (101.1 mg/g) using ultrasound-assisted extraction were ethanol concentration, 73.5%; extraction time, 38.3 min; and extraction temperature, 62.5 °C. The predicted result was consistent with the experimental result obtained under optimal extraction conditions. Hyperoside, astilbin, quercitrin, and quercetin from Hypericum formosanum extract (HFE) were identified by Ultra performance liquid chromatography-diode array detector-mass (UPLC-DAD-MS). HFE significantly reduced matrix metalloproteinase-1 protein expression in human skin keratinocyte cells, induced by advanced glycation end products.

Bioactive compounds from Hypericum humifusum and Hypericum perfoliatum: inhibition potential of polyphenols with acetylcholinesterase and key enzymes linked to type-2 diabetes

CONTEXT

Natural products are reported to have a wide spectrum of pharmacological properties such as antimicrobial, anti-inflammatory and anti-cholinesterase. The genus Hypericum (Hypericaceae) is a source of a variety of molecules with different biological activities, notably hypericin and various phenolics.

OBJECTIVES

The goals of the present work were the determination of total phenolic and flavonoid content, hypericin and hyperforin concentration as well as the evaluation of biological of Hypericum humifusum L. (Hhu) and Hypericum perfoliatum L. (Hper).

MATERIALS AND METHODS

The various extracts of aerial parts were powdered, and then extracted with methanol. Antibacterial activity was performed according to minimum inhibitory concentration (MIC) and minimum bactericidal (MBC) methods against four Gram-positive bacteria, four Gram-negative bacteria and yeast.

RESULTS

The results revealed that H. humifusum, bear the highest total phenolic and flavonoid content (48-113 mg GAE/g and 8-41 mg RE/g, respectively) as well as hypericin (60-90 mg/g) and hyperforin (8-30 mg/g) concentration. Both species showed significant antioxidant activity as revealed by DPPH, FRAP, ABTS, and metal chelating assays. H. humifusum exhibited a strong acetylcholinesterase (3.86-4.57 mg GALAEs/g), α-glucosidase (0.73-2.55 mmol ACEs/g) and α-amylase (3-8 mmol ACEs/g) inhibitory activity. The extract of H. humifusum exhibited strong antibacterial activity mainly against Staphylococcus epidermidis, Staphylococus aureus, and Enterococcus faecium (MIC values ranging from 200 to 250 μg/mL). The highest antifungal activity was showed for H. perfoliatum extract (MIC value = 250 μg/mL).

CONCLUSION

The data suggest that H. humifusum could be used as valuable new natural agents with functional properties for pharmacology industries.

Tricyclic Polyprenylated Acylphloroglucinols from St John's Wort, Hypericum perforatum

The new polyprenylated acylphloroglucinol derivatives 1-15 and the known furohyperforin (16) were isolated from the stems and leaves of Hypericum perforatum. Their structures were determined by analyses of NMR and HRESIMS data. Their absolute configurations were elucidated by a combination of electronic circular dichroism (ECD) and Rh₂(OCOCF₃)₄-induced ECD, as well as X-ray diffraction crystallography. The new hyperforatin F (9) contains a unique acetyl functionality at C-1 of the bicyclo[3.3.1]nonane core. Hyperforatins G (10) and H (11) are similarly the first examples of naturally occurring [3.3.1]-type polycyclic prenylated acylphloroglucinols possessing a carbonyl functionality at C-32. The compounds were tested for their acetylcholinesterase (AChE) inhibitory activities and cytotoxic activities against a panel of human tumor cell lines. Compounds 3, 5, 6, 8, and 9 exerted moderate inhibitory activities (IC₅₀ 3.98-9.13 μM) against AChE.

Cytotoxic and apoptogenic effect of hypericin, the bioactive component of Hypericum perforatum on the MCF-7 human breast cancer cell line

BACKGROUND

Breast cancer is the most prevalent malignancies among the women that have a high mortality. Previous studies demonstrated that hypericin, a bioactive component of Hypericum perforatum have a cytotoxic effect on the malignant cell lines. However, an anti-carcinogenic activity of hypericin on MCF-7 is uncertain. To investigate the cytotoxic effect of hypericin on MCF-7 cells, a human breast adenocarcinoma cell-line, that resistance to chemotherapy.

METHODS

The MCF-7 and fibroblast (as normal cell line) were treated with various concentrations of hypericin, and Cisplatin as a positive control for 24 and 48 h. Cytotoxicity activity was measured and confirmed by MTT assay and Trypan blue staining, respectively. In addition, Apoptosis were determined by Annexin V/Propidium Iodide assay. Immunocytochemistry (ICC) analysis for bcl2 and p53 proteins performed to further investigate different expression of these genes in different samples.

RESULTS

Both cisplatin and the hypericin exhibited a dose-dependent cytotoxic effect in the MCF-7 cell line. Although the LD50 of the hypericin was significantly lower when compared to cispaltin (5 vs. 20 μg/ml), it continued to decrease the growth rate of the MCF-7 cells when tested at higher concentration than LD50. In contrast, cisplatine, at higher concentration than LD50, completely inhibited the growth of the MCF-7 in 48 h. Regarding Annexin V/Propidium results, treatment of MCF-7 cells with LD50 concentration of cisplatin and hypericin showed 60 and 52 % apoptosis in 24 h, respectively. ICC analysis for bcl2 and p53 also confirmed our results; in treated samples for the dose of LD50 in 24 and 48 h of cisplatin and hypercin, more cells expressed p53 (guardian of cells in front of tumor formation/progression) and less expressed bcl2 (which has anti apoptotic activity) compared to untreated samples.

CONCLUSIONS

Considering that hypericin showed to be cytotoxic, it seems to be a chemopreventive agent and a good candidate for antineoplastic drug development.

Pleomorphic hepatocellular carcinoma following consumption of hypericum perforatum in alcoholic cirrhosis

Hepatocellular carcinoma (HCC) often develops in patients with underlying liver disease, yet HCC with syncytial giant cells (SGCs) is extremely rare. Herein, we report a 55-year-old man with a 6-year history of alcoholic cirrhosis who during his regular checkup presented with marked elevation of alpha-fetoprotein. Clinical examination and imaging analyses revealed a tumor-like lesion in segment 4 of the liver, which was removed by limited wedge resection. Histological analysis by hematoxylin and eosin staining indicated pleomorphic and atypical nodules, with some SGCs, embedded within the boundaries of the neoplastic lesion. The adjacent liver parenchyma showed microvesicular steatosis, pericellular fibrosis, and moderate hemosiderin accumulation (grade 2, as determined by Prussian blue iron stain) in hepatocytes and Kupffer cells but no copper accumulation (as determined by orcein stain). Immunohistochemical analysis showed hepatocyte antigen-positive staining for the neoplastic cells and SGCs. The diagnosis was made for cirrhosis-related HCC with SGCs. The previous reports of pleomorphic HCC have featured osteoclast-like (i.e., mesenchymal type) giant cells, making this case of epithelial type giant cells very rare. The patient’s 6-month history of hypericum perforatum/St John’s wort self-medication may have prompted the cirrhosis or HCC progression or the unusual SGC manifestation.

Hypericum androsaemum water extract inhibits proliferation in human colorectal cancer cells through effects on MAP kinases and PI3K/Akt pathway

MAP kinase and PI3K/Akt signalling pathways are commonly altered in colorectal carcinoma (CRC) leading to tumor growth due to increased cell proliferation and inhibition of apoptosis. Several species of the genus Hypericum are used in Portugal to prepare herbal teas to which digestive tract effects are attributed. In the present study, the antiproliferative and proapoptotic effects of the water extracts of H. androsaemum (HA) and H. perforatum (HP) were investigated in two human colon carcinoma-derived cell lines, HCT15 and CO115, which harbour activating mutations of KRAS and BRAF, respectively. Contrarily to HP, HA significantly inhibited cell proliferation and induced apoptosis in both cell lines. HA decreased BRAF and phospho-ERK expressions in CO115, but not in HCT15. HA also decreased Akt phosphorylation in CO115 and induced p38 and JNK in both cell lines. HA induced cell cycle arrest at S and G2/M phases as well as caspase-dependent apoptosis in both cell lines. Chlorogenic acid (CA), the main phenolic compound present in the HA extract and less represented in the HP water extract, did, however, not show any of those effects when used individually. In conclusion, water extract of HA, but not of HP, controlled CRC proliferation and specifically acted on mutant and not wild-type BRAF. The effect of HA was, however, not due to CA alone.

Hyperforin, a new lead compound against the progression of cancer and leukemia?

Extracts of the plant St John's wort, Hyperforin perforatum L., have been used for centuries in traditional medicine, notably for the treatment of depression. One of their main lipophilic components, a natural prenylated phloroglucinol termed hyperforin (HF), has been identified as the major molecule responsible for the antidepressant effects of this plant. Within the last few years, a number of studies have demonstrated that HF displays, in addition, several other biological properties of potential pharmacological interest. They include an antibacterial capacity and inhibitory effects on inflammatory mediators. It is worth noting that HF also promotes apoptosis of various cancer cells from solid tumors and hematological malignancies, including B-cell chronic lymphocytic leukemia. In addition, HF inhibits the capacity of migration and invasion of different tumor cells, as well as exhibiting antiangiogenic effects. Altogether, these properties qualify HF as a lead structure for the development of new therapeutic molecules in the treatment of various diseases, including some malignant tumors.