Screening for antiproliferative activity of six southern Brazilian species of Hypericum

Chemical Composition and New Biological Activities of Essential Oil and Hydrosol of Hypericum perforatum L. ssp. veronense (Schrank) H. Lindb

The chemical profile, antiproliferative, antioxidant and antiphytoviral activities of the species Hypericum perforatum ssp. veronense (Schrank) H. Lindb. (Clusiaceae) were investigated. Free volatiles were isolated and the chemical composition was determined in the lipophilic fraction (essential oil) and for the first time in the water fraction (hydrosol). The aim is to provide phytochemical data for H. perforatum ssp. veronense useful for distinguishing ssp. veronense from ssp. angustifolium, as there are taxonomic disagreements between them and the composition of the secretory products may be helpful in this respect. In the essential oil, the most abundant compounds identified were α-pinene and n-nonane, while in the hydrosol, myrtenol, carvacrol and α-pinene were the most abundant. Overall, the class of monoterpenes and oxygenated monoterpenes dominated in the EO and hydrosol samples. The essential oil showed high antioxidant activity, in contrast to the antiproliferative activity, where the hydrosol showed exceptional activity against three cancer cell lines: Hela (cervical cancer cell line), HCT116 (human colon cancer cell line) and U2OS (human osteosarcoma cell line). Both the essential oil and hydrosol showed antiphytoviral activity against tobacco mosaic virus infection on the local host plants. This is the first report dealing with biological activities of hydrosol of H. perforatum ssp. veronense, and the obtained results suggest that this traditional medicinal plant is a valuable source of volatiles with promising antiproliferative, antioxidant and antiphytoviral activities.

Structural diversity and biological activities of phloroglucinol derivatives from Hypericum species

Plants of the genus Hypericum (Hypericaceae) are used in folk medicine all over the world, H. perforatum being the most well-known species. Standardized extracts of this plant are commercially-available to treat mild to moderate depression cases. The present review summarizes the literature published up to 2016 concerning the phloroglucinol derivatives isolated from Hypericum species, together with their structural features and biological activities. These phytochemical studies led to the isolation of 101 prenylated phloroglucinols, chromanes and chromenes, 35 dimeric acylphloroglucinols, 235 polycyclic polyprenylated acylphloroglucinols, 25 simple benzophenones and 33 phloroglucinol-terpene adducts. These compounds show a diverse range of biological activities, such as antimicrobial, cytotoxic, antinociceptive and antidepressant-like effects.

Hypericum caprifoliatum and Hypericum connatum affect human trophoblast-like cells differentiation and Ca(2+) influx

OBJECTIVE

To study the effect of crude methanol and n-hexane extracts of Hypericum connatum (H. connatum) and Hypericum caprifoliatum on trophoblast-like cells.

METHODS

BeWo and JEG-3 trophoblast-like cells were submitted to different extract concentrations (1, 5, 10 and 15 µg/mL) and evaluated in relation to cell viability and in vitro trophoblast differentiation and function. Cell viability was evaluated using WST-1 reagent. Differentiation was measured by luciferase production, hCG production/release, and mitogen-activated protein kinase signaling pathway activation. The function of the trophoblast-like cells was measured by (45)Ca(2+) influx evaluation.

RESULTS

The results showed a decrease in cell viability/proliferation. Both plants and different extracts induced a significant decrease in hCG production/release and luciferase production. H. connatum did not cause mitogen-activated protein kinase signaling pathway disturbance; however, Hypericum caprifoliatum n-hexane extract at 15 µg/mL inhibited extracellular signal-regulated kinase 1/2 activation. The significant increase in Ca(2+) influx by JEG-3 cells was seen after short and long incubation times with H. connatum methanolic extract at 15 µg/mL.

CONCLUSIONS

The results indicated that these two Hypericum species extracts can interfere on trophoblast differentiation and Ca(2+) influx, according to their molecular diversity. Although in vivo experiments are necessary to establish their action on placental formation and function, this study suggests that attention must be paid to the potential toxic effect of these plants.

Benzophenones from Hypericum elegans with antioxidant and acetylcholinesterase inhibitory potential

BACKGROUND

Hypericum elegans is used in Bulgarian folk medicine for treatment of wounds, depression, gastrointestinal and bacterial diseases.

OBJECTIVE

RECENTLY, NEW NATURAL BENZOPHENONES: Elegaphenone and O-glycosides: Hypericophenonoside, Neoannulatophenonoside and Elegaphenonoside as well as already known 7-Epiclusianone were isolated from the titled species. The aim of the present study was to evaluate the antioxidant and acetyl cholinesterase inhibitory potential of the isolated compounds.

MATERIALS AND METHODS

1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) di-ammonium salt (ABTS) free radicals, ferric reducing antioxidant power (FRAP) assay as well as inhibition of lipid peroxidation in linoleic acid system were used for determination of antioxidant activity. Modified Ellman's colorimetric method was carried out to assess the acetyl cholinesterase inhibition potential. Hyperoside and Galantamine hydrobromide were used as positive controls.

RESULTS

Hypericophenonoside was found to possess the strongest DPPH radical scavenging activity (IC50 = 181.85 ± 6.82 μM), while Neoannulatophenonoside showed the highest ABTS (IC50 = 0.25 ± 0.005 μM) and lipid peroxidation inhibitor activity. FRAP activity was demonstrated only by prenylated aglycones - Elegaphenone [942.16 ± 4.03 μM Trolox Equivalent (TE)] and 7-Epiclusianone (642.95 ± 3.95 μM TE) and was stronger compared to the control Hyperoside (421.75 ± 9.29 μM TE). Elegaphenone and 7-Epiclusianone were found to possess moderate acetyl cholinesterase inhibitory potential with IC50 values of 192.19 ± 3.54 μM and 142.97 ± 4.62 μM, respectively.

CONCLUSION

The results obtained revealed that H. elegans is a potential natural source of bioactive compounds and benzophenones could be useful in therapy of free radical pathologies and neurodegenerative disorders.

Evaluation of the cytotoxicity, mutagenicity and antimutagenicity of a natural antidepressant, Hypericum perforatum L. (St. John's wort), on vegetal and animal test systems

Background

St. John’s wort (Hypericum perforatum L.) is an herbaceous plant that is native to Europe, West Asia and North Africa and that is recognized and used worldwide for the treatment of mild and moderate depression. It also has been shown to be therapeutic for the treatment of burns, bruises and swelling and can be used for its wound healing, antiviral, antimicrobial, antioxidant, analgesic, hepato-protective and anxiolytic properties. The aim of this study was to evaluate the potential cytotoxic, mutagenic and antimutagenic action of H. Perforatum.

Methods

Meristematic cells were used as the test system for Allium cepa L., and bone marrow cells from Rattus norvegicus, ex vivo, were used to calculate the mitotic index and the percentage of chromosomal aberration. Statistical analysis was performed using the chi-square test.

Results

This medicinal plant had no cytotoxic potential in the vegetal test system evaluated. In the animal test system, none of the acute treatments, including intraperitoneal gavage and subchronic gavage, were cytotoxic or mutagenic. Moreover, this plant presented antimutagenic activity against the clastogenic action of cyclophosphamide, as confirmed in pre-treatment (76% reduction in damage), simultaneous treatment (95%) and post-treatment (97%).

Conclusions

Thus, the results of this study suggest that the administration of H. perforatum, especially by gavage similar to oral consumption used by humans, is safe and with beneficial antimutagenic potential.

Protective effects of solvent fractions of Mentha spicata (L.) leaves evaluated on 4-nitroquinoline-1-oxide induced chromosome damage and apoptosis in mouse bone marrow cells

Spearmint leaves (Mentha spicata L.) contain high levels of antioxidants that are known to protect against both exogenous and endogenous DNA damage. In this study, the protective effects of the hexane fraction (HF), chloroform fraction (CF) and ethyl acetate fraction (EAF) in an ethanol extract from M. spicata were evaluated against 4-nitroquinoline-1-oxide (4-NQO) induced chromosome damage and apoptosis in bone marrow cells of Swiss albino mice. Two (EAF; 80 and 160 mg/ kg body weight - bw) or three (HF and CF; 80, 160 and 320 mg/ kg bw) doses of solvent fractions or vehicle control (25% DMSO in water) were administered orally for five consecutive days. Upon the sixth day, 4-NQO was injected intraperitoneally. The animals were killed the following day. Other control groups were comprised of animals treated with either the vehicle control or the various doses of solvent fractions, but with no 4-NQO treatment. 4-NQO induced micro-nucleated polychromatic erythrocytes (MnPCEs) in all the test groups. However, pre-treatment of animals with the solvent fractions significantly reduced the 4-NQO-induced MnPCEs as well as the percentage of apoptotic cells. The reduction of both MnPCE and apoptosis was more evident following the pre-treatment of animals with 160 mg/kg bw EAF.

Synergistic effect of three benzopyrans isolated from Hypericum polyanthemum in U-373 MG glioblastoma cell line

The antiproliferative activity of three benzopyrans isolated from the chloroform extract of the aerial parts of Hypericum polyanthemum was analysed in order to determine their effect on the growth and cell cycle in the U-373 MG glioblastoma cell line. Compound 1 was less cytotoxic than compounds 2 and 3. A synergistic effect was noticed when the three benzopyrans were used simultaneously. The cytotoxicity noted could be related to an arrest in G2/M phase, leading to apoptosis in the U-373 MG glioblastoma cell line.

Identification of human intracellular targets of the medicinal Herb St. John's Wort by chemical-genetic profiling in yeast

St. John's wort (SJW; Hypericum perforatum L.) is commonly known for its antidepressant properties and was traditionally used to promote wound healing, but its molecular mechanism of action is not known. Here, chemical-genetic profiling in yeast was used to predict the human intracellular targets of an aqueous extract of SJW. SJW source material was authenticated by TLC, digital microscopy, and HPLC and further characterized by colorimetric methods for antioxidant activity, protein content, and total soluble phenolic content. SJW extract contained 1.76 microg/mL hyperforin, 10.14 microg/mL hypericin, and 46.05 microg/mL pseudohypericin. The effect of SJW extract on approximately 5900 barcoded heterozygous diploid deletion strains of Saccharomyces cerevisiae was investigated using high-density oligonucleotide microarrays. Seventy-eight yeast genes were identified as sensitive to SJW and were primarily associated with vesicle-mediated transport and signal transduction pathways. Potential human intracellular targets were identified using sequence-based comparisons and included proteins associated with neurological disease and angiogenesis-related pathways. Selected human targets were confirmed by cell-based immunocytochemical assays. The comprehensive and systematic nature of chemical-genetic profiling in yeast makes this technique attractive for elucidating the potential molecular mechanisms of action of botanical medicines and other bioactive dietary plants.