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Aim: We identified chemical components that exhibited antitumor activity against oral squamous cell carcinoma (OSCC) cells and examined their effective concentrations and additive and/or synergistic effects in combinational usage on the proliferation, apoptosis and cell cycle of OSCC cells., Materials and Methods: Using high-performance liquid chromatography, nuclear magnetic resonance spectroscopy and electrospray ionization-mass spectrometry, we identified the main chemical components of the methanol extracts from Paeonia lutea. We investigated the pharmaceutical effects of those components on the proliferation, apoptosis, and cell cycle of an OSCC cell line, SAS, using the tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and caspase assays, as well as flow cytometry cell cycle analysis. We also examined the effects of those components on the mitogen-activated protein kinase signal transduction pathway by western blotting. Finally, the effects on normal human epidermal keratinocyte cells were also examined in similar experiments., Results: Three chemicals have been identified in P. lutea leaves using high performance liquid chromatography: gallic acid methyl ester (GAME), pentagalloyl glucose (PGG) and paeoniflorin (PF). Both GAME and PGG significantly suppressed cell proliferation, and their combined effects were synergistic, while the effect of PF was minimal. However, those chemicals did not induce apoptosis. Cell cycle and western blotting analysis showed that the suppressive effects on cell proliferation resulted from G2 arrest and the suppression of phosphorylation of Akt/PKB. No effect was identified on normal human epidermal keratinocyte cells., Conclusion: These results indicate that GAME and PGG are the main chemical components of P. lutea leaves that have potential anti-cancer therapeutic effects., (Copyright © 2021 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Hypopigmentation diseases are usually managed using UVB light which increases the patients' risk for skin cancer. Here, we evaluated the melanogenesis stimulatory effects of leaf extracts of Erica multiflora, a medicinal plant from the Mediterranean region, and its active component, lup-20(29)-en-3-one, as possible therapeutic agents to address hypopigmentation disorders. B16 murine melanoma cells were treated with E. multiflora extracts or its active component lupenone to evaluate their effects on melanin biosynthesis. The mechanism underlying the observed effects was also determined. Bioactivity-guided fractionation of fifteen ethyl acetate fractions identified fraction 2 to have melanogenesis stimulatory effects due to its ability to decrease mitogen-activated protein kinase phosphorylated extracellular signal-regulated kinases 1 and 2 activation. Preparative TLC of ethyl acetate fraction 2 revealed the presence of lup-20(29)-en-3-one as the major bioactive component. B16 cells treated with lup-20(29)-en-3-one increased melanin content without cytotoxicity. To determine the mechanism for the observed effects of lup-20(29)-en-3-one, the tyrosinase enzyme activity, the tyrosinase protein expression, and the activation of phosphorylated extracellular signal-regulated kinases 1 and 2 were determined. In addition, the expression of the tyrosinase mRNA was quantified using real-time PCR. Results showed that lup-20(29)-en-3-one has no effect on the tyrosinase enzyme activity but can increase tyrosinase expression at both the transcriptional and translational levels. The increase in the tyrosinase mRNA expression was most likely due to the inhibited mitogen-activated protein kinase phosphorylated extracellular signal-regulated kinases 1 and 2 activation. We report for the first time that E. multiflora ethyl acetate extract and its active compound lup-20(29)-en-3-one stimulate melanogenesis by increasing the tyrosinase enzyme expression via mitogen-activated protein kinase phosphorylated extracellular signal-regulated kinases 1 and 2 phosphorylation inhibition, making it a possible treatment for hypopigmentation diseases., (Georg Thieme Verlag KG Stuttgart · New York.)

We examined the effects of acteoside (1a), which was isolated from Orobanche minor, and its derivatives on the aggregation of a 42-mer amyloid β protein (Aβ42) in our search for anti-amyloidogenic compounds for Alzheimer's disease (AD) therapy. Acteoside (1a) strongly inhibited the aggregation of Aβ42 in a dose-dependent manner. The structure-activity relationship for acteoside (1a) and related compounds suggests the catechol moiety of phenylethanoid glycosides to be essential for this inhibitory activity.

Two new monoterpene diglycosides, suffruyabiosides A and B, and seven known compounds 3-9 were isolated from Moutan Cortex (root cortex of Paeonia suffruticosa Andrews). The structures were elucidated on the basis of 2D NMR spectral data. Suffruyabiosides A and B are rare monoterpene diglycosides, including a cellobiose in the molecules. Salicylpaeoniflorin (4) had a antiproliferation effect similar to paeoniflorin (3) on human lung adenocarcinoma epitherial A549 cells. Galloylpaeoniflorin (8) and salicylpaeoniflorin (4) revealed a more pronounced radical scavenging effect than a-tocopherol (positive control). An increase in the number of phenolic hydroxyl groups produced a more effective radical scavenging effect [8 > mudanpioside E (6) > oxypaeoniflorin (5)]. Comparison of the effects of 4 and 5 showed that o-substitution with a phenolic hydroxyl group was more effective than p-substitution. The results suggest that salicylpaeoniflorin (4) may be useful as a cytotoxic and a radical scavenging agent.

The effect of hot water extracts of LYCIUM CHINENSE fruits (LCF) on the β-hexosaminidase (β-hexo) release by IgE sensitized BSA stimulated rat basophilic leukemia (RBL-2H3) cells was investigated. The ethylacetate (EtOAc) layer of the extract has shown an inhibitory effect on β-hexo release from RBL-2H3 cells at the antigen antibody binding stage. The water (H₂O) fraction (EFW) of the chloroform (CHCl₃) extract from the EtOAc layer also inhibited β-hexo release at the same stage in a dose-dependent manner. With column chromatography preparation, proton and carbon nuclear magnetic resonance (¹H and ¹³C NMR) spectra, electron ionization mass spectrometer (EI-MS) spectra, and high-performance liquid chromatography (HPLC) analysis, the active component was determined to be 5-(hydroxymethyl)furfural (5-HMF). Thus, the 5-HMF showed an inhibitory effect on β-hexo release at the antigen-antibody binding stage and the antibody-receptor binding stage. Furthermore, 5-HMF suppressed [Ca²+] I influx in the IgE-sensitized BSA-stimulated RBL-2H3 cells. Our results show that 5-HMF may be useful for the treatment or prevention of type I allergic diseases., (© Georg Thieme Verlag KG Stuttgart · New York.)

An aqueous methanol extract of the moss Rhynchostegium pallidifolium, which often forms large pure colonies on soils and rocks, inhibited the growth of cress (Lepidium sativum), alfalfa (Medicaga sativa), lettuce (Lepidium sativum), ryegrass (Lolium multiflorum), timothy (Phleum pratense) and Digitaria sanguinalis seedlings. Increasing the extract concentration increased the inhibition. These results suggest that R. pallidifolium may show allelopathic activity. The extract was purified and a putative compound causing this growth inhibitory effect was isolated. The chemical structure of the growth inhibitor was determined by MS, and (1)H and (13)C NMR spectral data as 3-hydroxy-beta-ionone. 3-Hydroxy-beta-ionone inhibited the shoot and root growth of cress seedlings at concentrations greater than 1 and 3 micromol/L, respectively. The doses required for 50% growth inhibition on the shoot and roots of cress seedlings were 16.3 and 14.9 micromol/L, respectively. The endogenous concentration of 3-hydroxy-beta-ionone in R. pallidifolium was 28.2 microg/g and the concentration of 3-hydroxy-beta-ionone in the growth medium of R. pallidifolium was 6.7 microg/g. These results suggest that 3-hydroxy-beta-ionone was likely secreted into the medium during the incubation of R. pallidifolium. In addition, 3-hydroxy-beta-ionone was found in the soil under the pure colonies of R. pallidifolium. Therefore, 3-hydroxy-beta-ionone may play an important role in the allelopathic activity of R. pallidifolium and may help competition with neighboring plants, resulting in the formation of pure colonies., (Copyright 2009 Elsevier GmbH. All rights reserved.)

Skin pigmentation is the result of melanogenesis that occurs in melanocytes and/or melanoma cells. Although melanogenesis is necessary for the prevention of DNA damage and cancer caused by UV irradiation, excessive accumulation of melanin can also cause melanoma. Thus, we focused on the antimelanogenesis effect of an extract from Thymelaea hirsuta, a Tunisian herb. Murine melanoma B16 cells were treated with T. hirsuta extract, and then cell viability and synthesized melanin content were measured. We found that the T. hirsuta extract decreased the synthesized melanin content in B16 cells without cytotoxicity. Tyrosinase is a key enzyme of melanogenesis and extracellular signal-regulated kinase (ERK)-1/2 phosphorylation is known to be related to melanogenesis inhibition. To clarify its mechanism, we also determined ERK1/2 phosphorylation and tyrosinase expression level. ERK1/2 was immediately phosphorylated in cells just after treatment with the extract. The tyrosinase expression was inhibited after 24 h of stimulation with the extract. The T. hirsuta extract was fractionated, and we found that one fraction considerably decreased the melanin synthesis in B16 cells and that this fraction contains daphnanes as the main component. This indicates that our findings might be attributable to daphnanes.