Ethyl acetate fraction of Osmanthus fragrans var. aurantiacus and its triterpenoids suppress proliferation and survival of colorectal cancer cells by inhibiting NF-κB and COX2.

ETHNOPHARMACOLOGICAL RELEVANCE: Colorectal cancer (CRC) remains a significant global health concern, and targeting inflammation has emerged as a promising approach for its prevention and treatment. Medicinal plants and phytochemicals have garnered attention for their potential efficacy against inflammation with minimal toxicity. Osmanthus fragrans var. aurantiacus Makino (O. fragrans) has a history of traditional use in Korea and China in treating various inflammation-related conditions, but its potential use for CRC has not been uncovered. AIM OF THE STUDY: This study aims to explore the potential anti-proliferative and pro-apoptotic properties of O. fragrans, focusing on its impact on CRC treatment. By investigating O. fragrans, we aim to uncover its anti-proliferative and apoptotic effects in human CRC cells, potentially paving the way for effective and well-tolerated therapeutic strategies for CRC patients. MATERIALS AND METHODS: Ethanol (EtOH) extracts of O. fragrans leaf and flower, along with specific fractions (n-hexane, ethyl acetate (EtOAc), n-butanol, and the aqueous residue) were evaluated for their anti-proliferative effects in human CRC cells using MTT assays, and compared to normal colon cells. Mechanistic insights and chemical profiling were obtained through flow cytometry, colorimetric assays, western blotting, and molecular docking, and high-performance liquid chromatography (HPLC) system. RESULTS: Both flower and leaf EtOH extracts of O. fragrans exhibited significant anti-proliferative effects in human CRC cells, with the leaf extract demonstrating higher potency. The EtOAc fraction from the leaf extract displayed the strongest anti-CRC cell proliferative effects while no cytotoxic effects in normal colon cells. Chemical profiling of these fractions identified triterpenoids as significant components in the EtOAc fractions. The leaf EtOAc fraction caused cell cycle arrest and apoptosis, accompanied by elevating intracellular reactive oxygen species and mitochondrial dysfunction in CRC cells. Additionally, it inhibited NF-κB and ERK1/2 signaling, leading to reduced COX2 expression. Notably, two triterpenoids isolated from the leaf EtOAc fraction, maslinic acid and corosolic acid, displayed potent anti-cancer activity in CRC cells without affecting normal colon cells. Corosolic acid exhibited a strong binding affinity to COX2 and reduced its expression, supporting its role in the anti-inflammatory and anti-cancer effects. CONCLUSIONS: Our findings suggest that O. fragrans, particularly its triterpenoid-rich EtOAc fraction, holds promise as a novel therapeutic agent for CRC prevention and therapy. These results provide valuable insights into the potential application of O. fragrans and its bioactive compounds in combating CRC.

Anti-Inflammatory Food in Asthma Prepared from Combination of Raphanus sativus L., Allium hookeri, Acanthopanax sessiliflorum, and Dendropanax morbiferus Extracts via Bioassay-Guided Selection.

Asthma is a highly prevalent inflammatory disease of the respiratory airways and an increasing health risk worldwide. Hence, finding new strategies to control or attenuate this condition is necessary. This study suggests nutraceuticals that are a combination of herbal plant extracts prepared from Acanthopanax sessiliflorum (AS), Codonopsis lanceolate (CL), Dendropanax morbiferus (DM), Allium hookeri (AH), and Raphanus sativus L. (RS) that can improve immunomodulatory ability through the detoxification and diuresis of air pollutants. Herbal parts (AH whole plant, RS and CL roots, AS and DM stems, and DM leaves) were selected, and four types of mixtures using plant extracts were prepared. Among these mixtures, M2 and M4 exhibited antioxidant activities in potent 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and 1,1-diphenyl-ß-picrylhydrazine (DPPH) radical assays. Moreover, M4 exhibited a marked increase in glutathione S-transferase (GST) activity and significantly inhibited the inflammatory mediator, nitric oxide (NO) and proinflammatory cytokines, interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α generation. Furthermore, M4 exhibited the strongest antioxidant, hepatoprotective, and anti-inflammatory effects and was selected to prepare the product. Before manufacturing the product, we determined that the active mixture, M4, inhibited gene expression and generation of proinflammatory cytokines IL-1ß, IL-6 and TNF-α in ovalbumin (OVA)-, lipopolysaccharide (LPS)-, and particulate matter (PM)-induced asthmatic rat models. The granular product (GP) was manufactured using M4 along with additives, i.e., lactose, oligosaccharide, stevioside extract, and nutmeg seed essential oils (flavor masking), in a ratio of 1:4 using a granulation machine, dried and ultimately packaged. The GP inhibited the generation of proinflammatory cytokines IL-1ß, IL-6 and TNF-α in OVA-, LPS- and PM-induced asthmatic rat models. These results suggest that GP prepared from a combination of herbal plants (AS, CL, DM, AH and RS) is a potent functional food with anti-inflammatory activity that can be used to treat asthma caused by ambient air pollutants.

Antioxidant Compounds, Kirenol and Methyl ent-16α, 17-dihydroxy-kauran-19-oate Bioactivity-Guided Isolated from Siegesbeckia glabrescens Attenuates MITF-Mediated Melanogenesis via Inhibition of Intracellular ROS Production.

Siegesbeckia glabrescens (Compositae), an annual herb indigenous to Korean mountainous regions and has been eaten as a food in Korea. This study investigated ABTS, DPPH and nitric oxide (NO) radical-scavenging activities, and melanin production and TYR inhibitory effects-guided fractionation to identify therapeutic phytochemicals from S. glabrescens that can attenuate oxidation and melanogenesis in murine melanoma B16F10 cells. Nine compounds with inhibitory effects on melanin production, and TYR activity, and ABTS, DPPH, and NO radical scavenging activity were isolated from the 100% ethanol fraction from S. glabrescens. Among the nine compounds, kirenol (K), methyl ent-16α, 17-dihydroxy-kauran-19-oate (MDK) had strong inhibitory effects on melanin production and TYR activity with antioxidant effects. Western blot analysis revealed that K and MDK suppressed tyrosinase-related protein (TYRP)-1, TYRP-2 and microphthalmia-associated transcription factor (MITF) expression. Moreover, these two compounds inhibited intracellular reactive oxygen species (ROS) level in tert-butyl hydroperoxide (t-BHP)-treated B16F10 cells. Our results suggest that S. glabrescens containing active compounds such as K and MDK, which has antioxidant and antimelanogenesis effects, is the potent therapeutic and functional material for the prevention of oxidation-induced hyperpigmentation.

Eckol from Ecklonia cava Suppresses Immunoglobulin E-mediated Mast Cell Activation and Passive Cutaneous Anaphylaxis in Mice.

Eckol, a precursor compound belonging to the dibenzo-1,4-dioxin class of phlorotannins, is a phloroglucinol derivative that exerts various activities. In the present study, we investigated the antiallergic effects of eckol isolated from the marine brown algae, Ecklonia cava using immunoglobulin E (IgE)/bovine serum albumin (BSA)-stimulated mouse bone marrow-derived cultured mast cells (BMCMC) and a mouse model of anaphylaxis. Eckol inhibited IgE/BSA-induced BMCMC degranulation by reducing ß-hexosaminidase release. A flow cytometric analysis revealed that eckol decreases FcεRI expression on cell surface and IgE binding to the FcεRI in BMCMC. Moreover, eckol suppressed the production of the cytokines, interleukin (IL)-4, IL-5, IL-6, and IL-13 and the chemokine, thymus activation-regulated chemokine (TARC) by downregulating, IκB-α degradation and NF-κB nuclear translocation. Furthermore, it attenuated the passive cutaneous anaphylactic reaction induced by IgE/BSA-stimulation in the ear of BALB/c mice. These results suggest that eckol is a potential therapeutic candidate for the prevention and treatment of allergic disorders.

Inhibitory Effects of Eriodictyol-7-O-ß-d-glucuronide and 5,7-Dihydroxy-4-chromene Isolated from Chrysanthemum zawadskii var. latilobum in FcεRI-Mediated Human Basophilic KU812F Cell Activation.

Chrysanthemum zawadskii var. latilobum (CZL) has been used in Eastern medicine for the treatment of various diseases, such as pneumonia, bronchitis, cough, the common cold, pharyngitis, bladder-related disorders, gastroenteric disorders, and hypertension. In the present study, we isolated two strong antiallergic compounds from CZL, namely, eriodictyol-7-O-ß-d-glucuronide (EDG) and 5,7-dihydroxy-4-chromene (DC), and investigated their antiallergic effects in FcεRI-mediated human basophilic KU812F cells. EDG and DC downregulated the protein and messenger RNA (mRNA) expression of FcεRI on the cell surface. Moreover, Western blotting analysis showed that EDG and DC inhibited the expression of protein tyrosine kinases such as Syk and Lyn, and extracellular-regulated kinases (ERK) 1/2. These results suggested that EDG and DC, antiallergic constituents of CZL, are potential therapeutic candidates for protection against and for the treatment of allergic disorders.

Anti-inflammatory activity of mulberrofuran K isolated from the bark of Morus bombycis.

Morus bombycis Koidzumi, commonly known as silkworm mulberry, is a plant belonging to family Moraceae. It has been used in Asian countries as a traditional medicine for treating hypertension, diabetes, and inflammatory disorders. In this study, we isolated eleven compounds from the cortex of M. bombycis and evaluated their inhibitory effects on nitric oxide (NO) production as an indicator of their anti-inflammatory activities using lipopolysaccharide (LPS)-stimulated murine macrophages. Compound 4 showed the most potent inhibitory activity on NO production. It was identified as mulberrofuran K (MFK). Anti-inflammatory activity of MFK was then carried out using LPS-stimulated RAW264.7 cells. MFK suppressed the production of NO, reactive oxygen species (ROS), and proinflammatory cytokines (interleukin (IL)-1ß, IL-6 and tumor necrosis factor alpha (TNF-α)) in a concentration-dependent manner. Western blot analysis revealed that MFK treatment inhibited expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). MFK also inhibited transcriptional activation of nuclear factor-κB (NF-κB) and extracellular-regulated kinases (ERK) 1/2 in LPS-stimulated murine macrophages. These results suggest that MFK, an anti-inflammatory constituents of M. bombycis cortex, has potential as a therapeutic candidates for preventing and treating inflammatory diseases.

6-Methoxyluteolin from Chrysanthemum zawadskii var. latilobum suppresses histamine release and calcium influx via down-regulation of FcεRI α chain expression.

Mast cells and basophils are important effector cells in immunoglobulin-E (IgE)-mediated allergic reactions. Using the human basophilic KU812F cells, we assessed the inhibitory effects of 6-methoxyluteolin, isolated from Chrysanthemum zawadskii, in the FcεRI-mediated allergic reaction. We determined that 6-methoxyluteolin inhibited anti-FcεRI α chain antibody (CRA-1)-induced histamine release, as well as elevation of intracellular calcium concentration [Ca2+]i in a dose-dependent manner. Moreover, the inhibitory effects of 6-methoxyluteolin on the cell surface expression and the mRNA level of the FcεRI α chain were determined by flow cytometric analysis and reverse transcription-polymerase chain reaction (RTPCR), respectively. Therefore, these results show that 6- methoxyluteolin is a potent inhibitor of histamine release and calcium influx via down-regulation of the FcεRI α chain.

Down-regulation of FcepsilonRI expression by Houttuynia cordata Thunb extract in human basophilic KU812F cells.

Human basophilic KU812F cells express a high-affinity immunoglobulin (Ig) E receptor, FcepsilonRI, which plays an important role in IgE-mediated allergic reactions. Houttuynia cordata Thunb (Family Saururaceae), which is rich in polyphenols, has been shown to have various physiological properties, including antiviral, antioxidative, anticancer, and anti-inflammatory activities. The effect of H. cordata extract on the expression of FcepsilonRI in human KU812F cells was examined. Flow cytometric analysis showed that the FcepsilonRI expression and the IgE binding activity were suppressed when the cells were cultured with H. cordata extract. Reverse transcription-polymerase chain reaction analysis showed that levels of the mRNAs for FcepsilonRI alpha- and gamma-chains were decreased by the treatment of H. cordata extract. Addition of H. cordata extract to culture medium was also observed to result in a reduction in the release of histamine from the cells. These results suggest that H. cordata extract may exert its anti-allergic activity through down-regulation of FcepsilonRI expression and a subsequent decrease in histamine release.

Kaempferol isolated from Nelumbo nucifera stamens negatively regulates FcepsilonRI expression in human basophilic KU812F cells.

Mast cells and basophils perform important functions as pivotal effector cells in IgE-mediated allergic reactions. KU812F cells, a human basophilic cell line isolated originally from chronic myelocytic leukemia, express a high affinity receptor of IgE, FcepsilonRI. Kaempferol was extracted and isolated from a methanolic extract of flavonoid-rich Nelumbo nucifera stamens. In the present study, the inhibitory effects of kaempferol on FcepsilonRI expression in human basophilic KU812F cells was examined. Flow cytometric analysis revealed that FcepsilonRI expression on the cell surface was suppressed in a concentration-dependent manner when the cells were cultured with kaempferol. Moreover, RTPCR analysis showed that the mRNA levels for FcepsilonRI alpha- and gamma-chains were reduced as the result of kaempferol treatment in a concentration-dependent manner. Kaempferol showed its suppressive effects on intracellular Ca2+ concentration and histamine release from anti-FcepsilonRI alpha- chain antibody-stimulated cells in a concentration-dependent manner. These observations indicate that kaempferol may exert antiallergic effect via downregulation of FcepsilonRI expression and degranulation.

Ecklonia cava extract suppresses the high-affinity IgE receptor, FcepsilonRI expression.

Basophils and mast cells express FcepsilonRI, a high-affinity receptor for IgE, on the cell surface and act as effector cells in allergic reactions. In this study, we investigated the inhibitory effect of Ecklonia cava (EC) methanolic extract on the expression of FcepsilonRI in human basophilic KU812F cells. Flow cytometric analysis revealed that EC extract caused a concentration-dependent reduction in the cell surface expression of FcepsilonRI. The extract was also capable of reducing the binding between IgE or serum IgE and cell surface FcepsilonRI. RT-PCR analysis revealed that EC extract reduced the mRNA expression of total cellular FcepsilonRI alpha-chain. Moreover, data obtained by fluorescence spectrophotometry showed that the extract inhibited the FcepsilonRI-mediated release of histamine in a concentration-dependent manner. These results suggest that EC extract may exert its anti-allergic activity through negative-regulation of FcepsilonRI expression and a decrease in histamine release.