Inhibitory effect of eupatilin and jaceosidin isolated from Artemisia princeps in IgE-induced hypersensitivity

Stevia Genus: Phytochemistry and Biological Activities Update

The Stevia genus (Asteraceae) comprises around 230 species, distributed from the southern United States to the South American Andean region. Stevia rebaudiana, a Paraguayan herb that produces an intensely sweet diterpene glycoside called stevioside, is the most relevant member of this genus. Apart from S. rebaudiana, many other species belonging to the Stevia genus are considered medicinal and have been popularly used to treat different ailments. The members from this genus produce sesquiterpene lactones, diterpenes, longipinanes, and flavonoids as the main types of phytochemicals. Many pharmacological activities have been described for Stevia extracts and isolated compounds, antioxidant, antiparasitic, antiviral, anti-inflammatory, and antiproliferative activities being the most frequently mentioned. This review aims to present an update of the Stevia genus covering ethnobotanical aspects and traditional uses, phytochemistry, and biological activities of the extracts and isolated compounds.

Jaceosidin: A Natural Flavone with Versatile Pharmacological and Biological Activities

Nature always remains an inexhaustible source of treasures for mankind. It remains a mystery for every challenge until the completion of the challenge. While we talk about the complicated health issues, nature offers us a great variety of chemical scaffolds and their various moieties packed in the form of natural products e.g., plants, microorganisms (fungi, algae, protozoa), and terrestrial vertebrates and invertebrates. This review article is an update about jaceosidin, a bioactive flavone, from genus Artemisia. This potentially active compound exhibits a variety of pharmacological activities including anti-inflammatory, anti-oxidant, anti-bacterial, antiallergic and anti-cancer activities. The bioactivities and the therapeutic action of jaceosidin, especially the modulation of different cell signaling pathways (ERK1/2, NF-κB, PI3K/Akt and ATM-Chk1/2) which become deregulated in various pathological disorders, have been focused here. The reported data suggest that the bioavailability of this anti-cancer compound should be enhanced by utilizing various chemical, biological and computational techniques. Moreover, it is recommended that researchers and scientists should work on exploring the mode of action of this particular flavone to precede it further as a potent anti-cancer compound.

Anti-type I allergic effects of Jing-Fang powder extracts via PI3K/Akt pathway in vitro and in vivo

Jing-Fang powder (Schizonepeta tenuifolia Briq. and Saposhnikovia divaricata (Turcz.) Schischk.) was used to treat chronic bronchitis, asthma and chronic urticaria. Based on the preliminary results of screening research on the antiallergic effective parts of Jing-Fang powder, its ethyl acetate extract fractions (JFEE) and isolate D (JFEE-D) showed the best anti-allergic effect. RBL-2H3 cell activation degranulation model and mice passive cutaneous anaphylaxis (PCA) reaction model were used to investigate the effects and mechanisms of JFEE and JFEE-D on IgE-mediated type I allergic reactions. LC-MS was utilized to determine the composition of JFEE and JFEE-D. We found that JFEE and JFEE-D significantly reduced β-HEX, histamine, IL-4, IL-6 levels in cell supernatants, and improved the degree and morphology of cell degranulation. JFEE and JFEE-D significantly inhibited the increase of ear vascular permeability and abnormal increase of serum IgE, TNF-α, IL-6 levels. JFEE and JFEE-D inhibited mRNA expression of PI3K and Akt and down-regulated protein expression of PI3K, Akt, p-Akt, and PLCγ1 in sensitized RBL-2H3 cells. The combined use of JFEE and JFEE-D with pathway inhibitor Wortmannin revealed synergistic down-regulation of PI3K, Akt, and p-Akt protein expression. The combined use of pathway agonist IGF-1, JFEE and JFEE-D down-regulated increase of p-Akt/Akt protein expression. Moreover, JFEE and JFEE-D significantly inhibited protein expression of PI3K, p-Akt and PLCγ1 in PCA model mice. These results show that JFEE and JFEE-D inhibit type I allergic reactions by inhibiting PI3K/Akt signaling pathway.

Chemical characterization of eight herbal liqueurs by means of liquid chromatography coupled with ion mobility quadrupole time-of-flight mass spectrometry

Herbal liqueurs are a large group of diverse alcoholic beverages with an ancient tradition produced by maceration of various herbs and spices and are commonly drunken before or after a meal to aid in the digestion because of their potential functional properties. In the presented work, eight different commercial herbal liqueurs were investigated with regard to their composition of phenolic compounds by liquid chromatography ion mobility quadrupole time-of-flight mass spectrometry (LC-IM-QTOF-MS). This multidimensional analytical platform uses all-ion fragmentation for a deep coverage of the foodome. After an extensive data clean-up, 3225 features were found. 213 features were manually annotated due to the absence of databases and software tools able to consider the drift time or Collison Cross Section (CCS) together with high resolution MS/MS spectra for identification. The identified compounds reflected the large variance between the investigated samples and a wealth of potential bioactive compounds that these liqueurs harbor.

Jaceosidin Ameliorates Insulin Resistance and Kidney Dysfunction by Enhancing Insulin Receptor Signaling and the Antioxidant Defense System in Type 2 Diabetic Mice

Emerging evidence has shown that flavonoids extracted from Artemisia have beneficial effects on metabolic disorders. However, whether and how jaceosidin ameliorates insulin resistance and diabetic nephropathy in type 2 diabetes mellitus is largely unknown. For 8 weeks, db/db diabetic mice were fed with or without jaceosidin. Oral jaceosidin supplementation reduced fasting blood glucose levels and insulin resistance through the upregulation of insulin receptor downstream pathways in the liver and skeletal muscles. While jaceosidin did not noticeably alter kidney filtration function, this dietary intervention contributed to attenuating the accumulation of advanced glycation end products in diabetic kidneys. The levels of VEGF-a (vascular endothelial growth factor-a) proteins in the diabetic kidneys were markedly diminished by jaceosidin treatments, which increased the expression and activity of Cu (copper) and Zn-SOD (zinc-superoxide dismutase). Therefore, it is suggested that jaceosidin supplementation elicits antidiabetic effects and treats diabetic nephropathy by augmenting insulin signaling, suppressing fibrosis, and enhancing antioxidant activity.

Eupatilin: a natural pharmacologically active flavone compound with its wide range applications

Eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone) is a pharmacologically active flavone which has been isolated from a variety of medicinal plants. Eupatilin is known to possess various pharmacological properties such as anti-cancer, anti-oxidant, and anti-inflammatory. It is speculated that eupatilin could be subjected to structural optimization for the synthesis of derivative analogs to reinforce its efficacy, to minimize toxicity, and to optimize absorption profiles, which will ultimately lead towards potent drug candidates. Although, reported data acclaim multiple pharmacological activities of eupatilin but further experimentations on its molecular mechanism of action are yet mandatory to elucidate full spectrum of its pharmacological activities.

Bidirectional Regulatory Mechanisms of Jaceosidin on Mitochondria Function: Protective Effects of the Permeability Transition and Damage of Membrane Functions

Many natural products could induce apoptosis through mitochondrial pathways. However, direct interactions between natural products and mitochondria have rarely been reported. In this work, the effects and regulatory mechanisms of Jaceosidin on the isolated rat liver mitochondria have been studied. The results of the experiments which by introducing exogenous Ca²⁺ illustrated that Jaceosidin has the protective effects on the structure and function of the isolated mitochondria. These protective effects were related to the chelation of Ca²⁺ with Jaceosidin. Besides, Jaceosidin could scavenge reactive oxygen species produced during electron transport, and weaken the mitochondrial lipid peroxidation rate, which may be attributed to the antioxidant effect of phenolic hydroxyl groups of Jaceosidin. In addition, Jaceosidin has some damage effects on mitochondrial function, such as the inhibition of mitochondrial respiration and the increase of mitochondrial membrane fluidity. These results of this work provided comprehensive information to clarify the mechanisms of Jaceosidin on mitochondria, which may be the bidirectional regulatory mechanisms.

Antithrombotic Effect of Artemisia princeps Pampanini Extracts in Vitro and in FeCl3 -Induced Thrombosis Rats

Extracts of several plants possess antithrombotic effects. Herein, we examined the antithrombotic effects of different extracts of Artemisia princeps Pampanini prepared using distilled water, hot distilled water, 70% ethanol, or subcritical water. The antithrombotic effects were determined using a co-culture system consisting of tumor necrosis factor-alpha (TNF-α)-treated EA.hy926 cells and THP-1 cells. In addition, the coagulation time of plasma collected from healthy volunteers was evaluated in terms of the prothrombin time and activated partial thromboplastin time. A carotid arterial thrombosis model was induced by ferric chloride in Sprague Dawley rats. The rats were treated with either sterile water or three different doses of the subcritical water extract for 2 weeks. The thrombus weight, gene expression of cell adhesion molecules, and histological characteristics were assessed. The results of in vitro studies revealed a significant inhibition in the adhesion of monocytes to EA.hy926 cells stimulated by TNF-α in the subcritical water extract-treated group. We also observed considerable suppression of the occlusion and mRNA expression of cell adhesion molecules in the in vivo experiments. This study suggests that Artemisia princeps Pampanini may have the potential to improve blood coagulation.

Eupatilin suppresses the allergic inflammatory response in vitro and in vivo

INTRODUCTION

Eupatilin, a pharmacologically active ingredient found in Artemisia asiatica, has been reported to have anti-oxidative, anti-inflammatory, and anti-apoptotic activities. However, molecular mechanisms underlying its anti-allergic properties are not yet clear. In this study, we investigated the effects of eupatilin on allergic inflammation in phorbol 12-myristate 13-acetate plus calcium ionophore A23187 (PMACI)-stimulated human mast cells and a compound 48/80-induced anaphylactic shock model.

METHODS

Cytokine assays, histamine assays, quantitative real-time polymerase chain reaction analysis, western blot analysis and compound 48/80-induced anaphylactic shock model were used in this study.

RESULTS

Eupatilin significantly suppresses the expression and production of pro-inflammatory cytokines, such as interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6 in vitro and in vivo. In addition, eupatilin inhibits nuclear factor kappa B (NF-κB) activation by regulating the phosphorylation and degradation of IκBα via the Akt/IKK(α/β) pathway. Eupatilin treatment also attenuates the phosphorylation of p38, ERK, and JNK MAPKs. Furthermore, eupatilin blocked anaphylactic shock and decreased the release of histamine.

CONCLUSIONS

Anti-allergic inflammation may involve the expression and production of regulating pro-inflammatory cytokines via Akt/IKK(α/β) and MAPK activation of NF-κB. On the basis of these data, eupatilin is a potential candidate for the treatment of allergic diseases.

Identification of caffeoylquinic acid derivatives as natural protein tyrosine phosphatase 1B inhibitors from Artemisia princeps

Considerable attention has been paid to protein tyrosine phosphatase 1B (PTP1B) inhibitors as a potential therapy for diabetes, obesity, and cancer. Ten caffeoylquinic acid derivatives (1-10) from leaves of Artemisia princeps Pamp. (Asteraceae) were identified as natural PTP1B inhibitors. Among them, chlorogenic acid (3) showed the most potent inhibitory activity (IC₅₀ 11.1 μM). Compound 3 was demonstrated to be a noncompetitive inhibitor by a kinetic analysis. Molecular docking simulation suggested that compound 3 bound to the allosteric site of PTP1B. Furthermore, compound 3 showed remarkable selectivity against four homologous PTPs. According to these findings, compound 3 might be potentially valuable for further drug development.

Artemisia Extract Suppresses NLRP3 and AIM2 Inflammasome Activation by Inhibition of ASC Phosphorylation

Artemisia princeps var. orientalis (Asteraceae, A. princeps) is a well-known traditional medicinal herb used for treating various inflammatory disorders in Korea, Japan, China, and other Asian countries. In the present study, we investigated the effects of A. princeps extract (APO) on interleukin- (IL-) 1β regulation and inflammasome activation in bone marrow-derived macrophages (BMDMs) and monosodium urate- (MSU-) induced peritonitis mouse model in vivo. The APO treatment to BMDMs primed with lipopolysaccharide (LPS) attenuated the NLRP3 and AIM2 inflammasome activation induced by danger signals, such as ATP, nigericin, silica crystals, and poly (dA:dT), respectively. Mechanistic study revealed that APO suppressed the ASC oligomerization and speck formation, which are required for inflammasome activation. APO treatment also reduced the ASC phosphorylation induced by the combination of LPS and a tyrosine phosphatase inhibitor. In vivo evaluation revealed that intraperitoneal administration of APO reduced IL-1β levels, significantly (p < 0.05) and dose dependently, in the MSU-induced peritonitis mouse model. In conclusion, our study is the first to report that the extract of A. princeps inhibits inflammasome activation through the modulation of ASC phosphorylation. Therefore, APO might be developed as therapeutic potential in the treatment of inflammasome-mediated inflammatory disorders, such as gouty arthritis.

Topical Application of Eupatilin Ameliorates Atopic Dermatitis-Like Skin Lesions in NC/Nga Mice

Background

Atopic dermatitis (AD) is an inflammatory skin disorder with severe pruritus. Despite advancements in medicine, therapeutic treatments for AD are still limited. Eupatilin (5,7-dihydroxy-30,40,6-trimethoxyflavone) is one of the lipophilic flavonoids from Artemisia umbelliformis Lam. and Artemisia genipi Weber.

Objective

Although it has been reported to act a role in improving inflammation, its action on AD is uncertain. In this study, we examined the role of eupatilin on AD-like skin lesions in NC/Nga mice.

Methods

2,4-dinitrochlorobenzene was repeatedly applied to the ear of NC/Nga mice to produce AD-like skin lesions. Eupatilin (1%, once a day for 5 consecutive days/week) was applied topically for four weeks for the evaluation of its therapeutic effects.

Results

1% eupatilin cream significantly reduced the clinical severity score of AD-like lesions, compared to the vehicle (p<0.005). A histopathological analysis revealed that 1% eupatilin cream significantly decreased the mast cell infiltration as well as inflammatory cell infiltration, compared to the vehicle (p<0.005). We showed that 1% eupatilin cream significantly reduced the expression of thymic stromal lymphopoietin, tumor necrosis factor-α, interleukin-4, and interleukin-19, but not interferon-γ, compared to the vehicle (p<0.005).

Conclusion

Considering the therapeutic reaction of eupatilin on AD-like lesions as in this study, the substance has a promising to be an adjuvant topical agent for the control of AD.

Eupatilin prevents H2O2-induced oxidative stress and apoptosis in human retinal pigment epithelial cells

Eupatilin, a pharmacologically active flavone derived from the Artemisia plant species, is known to possess anti-oxidant activity. However, the effects of eupatilin on oxidative stress-induced retinal damage in retinal pigment epithelium (RPE) cells and the potential mechanisms involved have not been explored. Therefore, the aim of this study was to investigate the effects of eupatilin on oxidative stress-induced retinal damage in RPE cells. Our results showed that eupatilin significantly attenuated H₂O₂-induced cell injury and ROS production in ARPE-19 cells. In addition, eupatilin pretreatment greatly upregulated Bcl-2 expression, downregulated Bax expression, as well as suppressed caspase-3 activity in ARPE-19 cells exposed to H₂O₂. Furthermore, eupatilin pretreatment markedly enhanced phosphorylation levels of PI3K and Akt in ARPE-19 cells exposed to H₂O₂. In conclusion, our data showed that eupatilin protected against H₂O₂-induced oxidative stress and apoptosis through the activation of PI3K/Akt signaling pathway in ARPE-19 cells. Thus, eupatilin may be useful for the prevention or treatment of proliferative vitreoretinopathy (PVR).

Anti-Inflammatory Effects of Artemisia Leaf Extract in Mice with Contact Dermatitis In Vitro and In Vivo

The leaves of Artemisia argyi Lev. et Vant. and A. princeps Pamp. are well known medicinal herbs used to treat patients in China, Japan, and Korea with skin problems such as eczema and itching, as well as abdominal pain and dysmenorrhoea. We investigated the anti-inflammatory effects of Artemisia leaf extract (ALE) using CD mice and Raw 264.7 cells. The effects of ALE on histopathological changes and cytokine production in ear tissues were assessed in mice with CD induced by 1-fluoro-2,4-dinitrobenzene (DNFB). Moreover, the anti-inflammatory effects on production levels of prostaglandin E₂ (PGE₂) and nitric oxide (NO) and expression levels of cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) were investigated in Raw 264.7 cells. Topical application of ALE effectively prevented ear swelling induced by repeated DNFB application. ALE prevented epidermal hyperplasia and infiltration of immune cells and lowered the production of interferon- (IFN-) gamma (γ), tumour necrosis factor- (TNF-) alpha (α), and interleukin- (IL-) 6 in inflamed tissues. In addition, ALE inhibited expression of COX-2 and iNOS and production of NO and PGE₂ in Raw 264.7 cells. These results indicate that Artemisia leaf can be used as a therapeutic agent for inflammatory skin diseases and that its anti-inflammatory effects are closely related to the inhibition of inflammatory mediator release from macrophages and inflammatory cytokine production in inflamed tissues.

Ameliorative effects of Artemisia argyi Folium extract on 2,4‑dinitrochlorobenzene‑induced atopic dermatitis‑like lesions in BALB/c mice

Artemisia argyi Folium has been used to treat skin diseases, including eczema and dermatitis, in South Korean medicine. The present study investigated the curative effects of Artemisia argyi Folium extract (AAFE) on 2,4‑dinitrochlorobenzene (DNCB)‑induced atopic dermatitis (AD)‑like skin lesions in a BALB/c mouse model. Briefly, the dorsal skin of the BALB/c mice was sensitized three times with DNCB, whereas the ears were challenged twice. Repeated treatment with DNCB induced AD‑like lesions. The effects of AAFE on AD‑like lesions were evaluated by clinical observation, histopathological analysis, immunohistochemistry and enzyme‑linked immunosorbent assay. In addition, reverse transcription‑polymerase chain reaction and western blotting were performed. Treatment with AAFE reduced AD‑like lesions, as determined by clinical observation, histopathological analysis, and detection of the serum levels of histamine, immunoglobulin E and cytokines. With regards to its mechanism of action, AAFE inhibited the phosphorylation of Lck/yes‑related novel tyrosine kinase (Lyn), spleen tyrosine kinase (Syk), mitogen‑activated protein kinases (MAPKs), phosphoinositide 3‑kinase (PI3K)/Akt and IκBα, which have essential roles in the production of various cytokines in lymph nodes. The suppressive activity of AAFE may be due to the inhibition of a series of immunopathological events, including the release of proinflammatory cytokines. The results of the present study strongly suggest that AAFE exerts an anti‑AD effect by inhibiting the Lyn, Syk, MAPKs, PI3K/Akt and IκBα pathways. Therefore, AAFE may be considered an effective herbal remedy for the treatment of AD.

Roles of NF-κB in Cancer and Inflammatory Diseases and Their Therapeutic Approaches

Nuclear factor-κB (NF-κB) is a transcription factor that plays a crucial role in various biological processes, including immune response, inflammation, cell growth and survival, and development. NF-κB is critical for human health, and aberrant NF-κB activation contributes to development of various autoimmune, inflammatory and malignant disorders including rheumatoid arthritis, atherosclerosis, inflammatory bowel diseases, multiple sclerosis and malignant tumors. Thus, inhibiting NF-κB signaling has potential therapeutic applications in cancer and inflammatory diseases.

Identification of bitter components from Artemisia princeps Pamp

Identification of bitter components from the aerial parts of Artemisia princeps Pamp. was performed to search for a method to eliminate the bitter taste from A. princeps products. The aerial parts of A. princeps were extracted in an aqueous EtOH solution, and the obtained extracts were partitioned into essential-oil, flavonoid-rich, n-BuOH, and aqueous fractions. Two purified bitter sesquiterpenoids were identified through repeated column chromatography of the bitterest fraction, the flavonoid-rich fraction, through an activity-guided fractionation method. The compounds were identified to be 1α,6α,8α-trihydroxy-5α,7βH-guaia-3,9,11(13)-trien-12-oic acid and artecalin, respectively, based on the interpretation of NMR, MS, and IR spectroscopic data. Both compounds were 50 times bitterer than caffeine and had similar bitterness to quinine HCl. Neither eupatilin nor jaceosidin, the major active components of A. princeps, showed any bitterness.

Eupatilin ameliorates collagen induced arthritis

Eupatilin is the main active component of DA-9601, an extract from Artemisia. Recently, eupatilin was reported to have anti-inflammatory properties. We investigated the anti-arthritic effect of eupatilin in a murine arthritis model and human rheumatoid synoviocytes. DA-9601 was injected into collagen-induced arthritis (CIA) mice. Arthritis score was regularly evaluated. Mouse monocytes were differentiated into osteoclasts when eupatilin was added simultaneously. Osteoclasts were stained with tartrate-resistant acid phosphatase and then manually counted. Rheumatoid synoviocytes were stimulated with TNF-α and then treated with eupatilin, and the levels of IL-6 and IL-1β mRNA expression in synoviocytes were measured by RT-PCR. Intraperitoneal injection of DA-9601 reduced arthritis scores in CIA mice. TNF-α treatment of synoviocytes increased the expression of IL-6 and IL-1β mRNAs, which was inhibited by eupatilin. Eupatilin decreased the number of osteoclasts in a concentration dependent manner. These findings, showing that eupatilin and DA-9601 inhibited the expression of inflammatory cytokines and the differentiation of osteoclasts, suggest that eupatilin and DA-9601 is a candidate anti-inflammatory agent.

Targeting apoptosis pathways in cancer and perspectives with natural compounds from mother nature

Although the incidences are increasing day after day, scientists and researchers taken individually or by research group are trying to fight against cancer by several ways and also by different approaches and techniques. Sesquiterpenes, flavonoids, alkaloids, diterpenoids, and polyphenolic represent a large and diverse group of naturally occurring compounds found in a variety of fruits, vegetables, and medicinal plants with various anticancer properties. In this review, our aim is to give our perspective on the current status of the natural compounds belonging to these groups and discuss their natural sources, their anticancer activity, their molecular targets, and their mechanism of actions with specific emphasis on apoptosis pathways, which may help the further design and conduct of preclinical and clinical trials. Unlike pharmaceutical drugs, the selected natural compounds induce apoptosis by targeting multiple cellular signaling pathways including transcription factors, growth factors, tumor cell survival factors, inflammatory cytokines, protein kinases, and angiogenesis that are frequently deregulated in cancers and suggest that their simultaneous targeting by these compounds could result in efficacious and selective killing of cancer cells. This review suggests that they provide a novel opportunity for treatment of cancer, but clinical trials are still required to further validate them in cancer chemotherapy.

Flavonoids from the capitula of Eriocaulon australe

A flavan, eriocaulin A (1), and three flavone acyl glucosides, eriocaulosides A-C (2-4) were isolated from the capitula of Eriocaulon australe R. Br. (Eriocaulaceae), a Chinese medicine and an herb for health care beverages, together with seven known flavones and three isoflavones (5-14). The new flavonoids were elucidated as (2S)-3',4'-methylenedioxy-5-methoxy-7-hydroxyflavan (1), hispidulin 7-O-β-D-(6-O-cinnamoyl)glucopyranoside (2), jaceosidin 7-O-β-D-(6-O-p-coumaroyl)glucopyranoside (3), jaceosidin 7-O-β-D-(6-O-p-hydroxybenzoyl)glucopyranoside (4) based on their spectroscopic data. All the 14 flavonoids were obtained from this species for the first time. The in vitro cytotoxicity of compounds 1-14 against human lung adenocarcinoma A549, human breast adenocarcinoma MCF-7, and human cervical carcinoma HeLa cell lines was evaluated using the MTT colourimetric assay. Compounds 1, 7, and 9 were cytotoxic to A549, compounds 1, 2, 7, 9, 12, and 14 to MCF-7, and compounds 7, 9, and 14 to HeLa cells, with IC50 values ranging from 7.17 to 29.57 μg/ml, while the others were inactive (IC50>50 μg/ml).

5,7-Dihydroxy-3,4,6-trimethoxyflavone inhibits intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 via the Akt and nuclear factor-κB-dependent pathway, leading to suppression of adhesion of monocytes and eosinophils to bronchial epithelial cells

5,7-Dihydroxy-3',4',6'-trimethoxyflavone (eupatilin), the active pharmacological ingredient from Artemisia asiatica Nakai (Asteraceae), is reported to have a variety of anti-inflammatory properties in intestinal epithelial cells. However, little information is known about the molecular mechanism of eupatilin-induced attenuation of bronchial epithelial inflammation. This study investigates the role of eupatilin in the adhesion of inflammatory cells such as monocytes and eosinophils to bronchial epithelial cells. Stimulation of a human bronchial epithelial cell line (BEAS-2B) with tumour necrosis factor-α (TNF-α) increased the expression of surface adhesion molecules, including intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), in which eupatilin significantly inhibited the expression of those adhesion molecules in a dose-dependent manner. Eupatilin suppressed the TNF-α-induced activation of IκBα and nuclear factor-κB (NF-κB) signals in BEAS-2B cells. The IκB kinase (IKK) activation was also significantly reduced in eupatilin-pre-treated BEAS-2B and primary normal human bronchial epithelial (NHBE) cells. However, eupatilin did not influence AP-1 activity in TNF-α-stimulated cells. Suppression of NF-κB signalling induced by eupatilin resulted in the inhibition of the expression of adhesion molecules and the adhesion of monocytes and eosinophils to BEAS-2B cells. Furthermore, eupatilin suppressed the phosphorylation of Akt in TNF-α-stimulated BEAS-2B and NHBE cells, leading to down-regulation of NF-κB activation and adhesion molecule expression and finally to suppression of the inflammatory cell adhesion to epithelial cells. These results suggest that eupatilin can inhibit the adhesion of inflammatory cells to bronchial epithelial cells via a signalling pathway, including activation of Akt and NF-κB, as well as expression of adhesion molecules.

The Memory-Ameliorating Effects of Artemisia princeps var. orientalis Against Cholinergic Dysfunction in Mice

Artemisia princeps var. orientalis (Compositae) is widely distributed in China, Japan and Korea and is known to have anti-inflammatory and anti-oxidative activities. The ethyl acetate fraction of ethanolic extract of A. princeps var. orientalis (AEA) was found to inhibit acetylcholinesterase activity in a dose-dependent manner in vitro (IC50 value: 541.4 ± 67.5 μg/ml). Therefore, we investigated the effects of AEA on scopolamine-induced learning and memory impairment using the passive avoidance, the Y-maze, and the Morris water maze tasks in mice. AEA (100 or 200 mg/kg, p.o.) significantly ameliorated scopolamine-induced cognitive impairments in the passive avoidance and Y-maze tasks (p < 0.05). In the Morris water maze task, AEA (200 mg/kg, p.o.) significantly shortened escape latencies in training trials and increased both swimming time spent in the target zone and probe crossing numbers during the probe trial as compared with scopolamine-treated mice (p < 0.05). Additionally, the ameliorating effect of AEA on scopolamine-induced memory impairment was antagonized by a subeffective dose of MK-801. These results suggest that AEA could be an effective treatment against cholinergic dysfunction and its effect is mediated by the enhancement of the cholinergic neurotransmitter system via NMDA receptor signaling or acetylcholinesterase inhibition.

Suppressive effects of Schizandra chinensis Baillon water extract on allergy-related cytokine generation and degranulation in IgE-antigen complex-stimulated RBL-2H3 cells

Schizandra chinensis Baillon is a traditional folk medicine plant that is used to treat and prevent several inflammatory diseases and cancer in Korea, but the underlying mechanisms involved in its anti-allergic activity are not fully understood. This study was designed to investigate mechanisms of anti-allergic activity of a Schizandra chinensis Baillon water extract (SCWE) in immunoglobulin E (IgE)-antigen complex-stimulated RBL2H3 cells and to assess whether gastric and intestinal digestion affects the anti-allergic properties of SCWE. Oxidative stress is an important consequence of the allergic inflammatory response. The antioxidant activities of SCWE increased in a concentration-dependent manner. RBL-2H3 cells were sensitized with monoclonal anti-dinitrophenol (DNP) specific IgE, treated with SCWE, and challenged with the antigen DNP-human serum albumin. SCWE inhibited β-hexosaminidase release and expression of interleukin (IL)-4, IL-13, and tumor necrosis factor-alpha (TNF-α) mRNA and protein in IgE-antigen complex-stimulated RBL2H3 cells. We found that digested SCWE fully maintained its antioxidant activity and anti-allergic activity against the IgE-antigen complex-induced activation of RBL-2H3 cells. SCWE may be useful for preventing allergic diseases, such as asthma. Thus, SCWE could be used as a natural functional ingredient for allergic diseases in the food and/or pharmaceutical industries.

Anti-inflammatory effects of low-molecular weight chitosan oligosaccharides in IgE-antigen complex-stimulated RBL-2H3 cells and asthma model mice

The anti-inflammatory effects of low-molecular weight chitosan oligosaccharides (LM-COS) prepared from high-molecular weight chitosan by enzymatic digestion were investigated against allergic reaction and allergic asthma in vivo and in vitro. Allergic asthma is an inflammatory disease of the airways associated with enhanced degranulation and cytokine generation. The LM-COS (<1 kDa), consisting of glucosamine (GlcN)(n), n=3-5, were capable of inhibiting both antigen-stimulated degranulation and cytokine generation in rat basophilic leukemia RBL-2H3 cells. The protective effect of LM-COS against ovalbumin (OVA)-induced lung inflammation in asthma model mice was also examined. Oral administration of LM-COS (16 mg/kg body weight/day) resulted in a significant reduction in both mRNA and protein levels of interleukin (IL)-4, IL-5, IL-13, tumor necrosis factor (TNF)-α in the lung tissue and bronchoalveolar lavage fluid (BALF); The protein levels of IL-4, IL-13 and TNF-α in BALF were decreased by 5.8-fold, 3.0-fold and 9.9-fold, respectively, compared to those in the OVA-sensitized/challenged asthma control group. These results suggest that the oral administration of LM-COS is effective in alleviating the allergic inflammation in vivo and thus can be a good source material for the development of a potent therapeutic agent against mast cell-mediated allergic inflammatory responses and airway inflammation in allergic inflammatory diseases, including asthma.

Δ-lactam derivative from thermophilic soil fungus exhibits in vitro anti-allergic activity

From cultures of thermophilic soil fungus Humicola grisea var thermoidea, a δ-lactam derivative (3-(2-(4-hydroxyphenyl)-2-oxoethyl)-5,6-dihydropyridin-2(1H)-one) that displayed anti-allergic activity was isolated, which was predicted by in silico computational chemistry approaches. The in vitro anti-allergic activity was investigated by β-hexosaminidase release assay in rat basophilic leukaemia RBL-2H3 cells. The δ-lactam derivative exhibited similar anti-allergic activity (IC(50) = 18.7 ± 6.7 µM) in comparison with ketotifen fumarate (IC(50) = 15.0 ± 1.3 µM) and stronger anti-allergic activity than azelastine (IC(50) = 32.0 µM). Also, the MTT cytotoxicity assay with RBL-2H3 cells showed that δ-lactam does not display cytotoxicity at concentrations lower than 50 µM. This study suggests that the δ-lactam derivative has the potential to be used as a lead compound in the development of anti-allergic drugs for clinical use in humans.

Effects of flavonoids and other polyphenols on inflammation

Flavonoids are a family of polyphenolic compounds which are widespread in nature (vegetables) and are consumed as part of the human diet in significant amounts. There are other types of polyphenols, including, for example, tannins and resveratrol. Flavonoids and related polyphenolic compounds have significant antiinflammatory activity, among others. This short review summarizes the current knowledge on the effects of flavonoids and related polyphenolic compounds on inflammation, with a focus on structural requirements, the mechanisms involved, and pharmacokinetic considerations. Different molecular (cyclooxygenase, lipoxygenase) and cellular targets (macrophages, lymphocytes, epithelial cells, endothelium) have been identified. In addition, many flavonoids display significant antioxidant/radical scavenging properties. There is substantial structural variation in these compounds, which is bound to have an impact on their biological profile, and specifically on their effects on inflammatory conditions. However, in general terms there is substantial consistency in the effects of these compounds despite considerable structural variations. The mechanisms have been studied mainly in myeloid cells, where the predominant effect is an inhibition of NF-κB signaling and the downregulation of the expression of proinflammatory markers. At present there is a gap in knowledge of in vitro and in vivo effects, although the pharmacokinetics of flavonoids has advanced considerably in the last decade. Many flavonoids have been studied for their intestinal antiinflammatory activity which is only logical, since the gastrointestinal tract is naturally exposed to them. However, their potential therapeutic application in inflammation is not restricted to this organ and extends to other sites and conditions, including arthritis, asthma, encephalomyelitis, and atherosclerosis, among others.

In vitro metabolism of jaceosidin and characterization of cytochrome P450 and UDP-glucuronosyltransferase enzymes in human liver microsomes

Jaceosidin is an active component in Artemisia species as well as Eupatorium species and it exhibits antiallergic, anticancer, antioxidant, anti-inflammatory, and antimutagenic activities. Jaceosidin was metabolized to jaceosidin glucuronide, 6-O-desmethyljaceosidin, hydroxyjaceosidin, 6-O-desmethyljaceosidin glucuronide, and hydroxyjaceosidin glucuronide in human liver microsomes. This study characterized the human liver cytochrome P450 (CYP) and UDPglucuronosyltransferase (UGT) enzymes responsible for the metabolism of jaceosidin. CYP1A2 was identified as the major enzyme responsible for the formation of 6-O-desmethyljaceosidin and hydroxyjaceosidin from jaceosidin on the basis of a combination of correlation analysis and experiments including immuno-inhibition, chemical inhibition in human liver microsomes, and metabolism by human cDNA-expressed CYP enzymes. Jaceosidin glucuronidation was catalyzed by UGT1A1, UGT1A3, UGT1A7, UGT1A8, UGT1A9, and UGT1A10. These results suggest that the pharmacokinetics of jaceosidin may be dramatically affected by polymorphic CYP1A2, UGT1A1, and UGT1A7 responsible for the metabolism of jaceosidin or by the coadministration of relevant CYP1A2 or UGT inhibitors or inducers.

Effects of eupatilin and jaceosidin on cytochrome p450 enzyme activities in human liver microsomes

Eupatilin and jaceosidin are bioactive flavones found in the medicinal herbs of the genus Artemisia. These bioactive flavones exhibit various antioxidant, antiinflammatory, antiallergic, and antitumor activities. The inhibitory potentials of eupatilin and jaceosidin on the activities of seven major human cytochrome P450 enzymes in human liver microsomes were investigated using a cocktail probe assay. Eupatilin and jaceosidin potently inhibited CYP1A2-catalyzed phenacetin O-deethylation with 50% inhibitory concentration (IC₅₀) values of 9.4 μM and 5.3 μM, respectively, and CYP2C9-catalyzed diclofenac 4-hydroxylation with IC₅₀ values of 4.1 μM and 10.2 μM, respectively. Eupatilin and jaceosidin were also found to moderately inhibit CYP2C19-catalyzed [S]-mephenytoin 4'-hydroxylation, CYP2D6-catalyzed bufuralol 1'-hydroxylation, and CYP2C8-catalyzed amodiaquine N-deethylation. Kinetic analysis of human liver microsomes showed that eupatilin is a competitive inhibitor of CYP1A2 with a K_i value of 2.3 μM and a mixed-type inhibitor of CYP2C9 with a K_i value of 1.6 μM. Jaceosidin was shown to be a competitive inhibitor of CYP1A2 with a K_i value of 3.8 μM and a mixed-type inhibitor of CYP2C9 with K_i value of 6.4 μM in human liver microsomes. These in vitro results suggest that eupatilin and jaceosidin should be further examined for potential pharmacokinetic drug interactions in vivo due to inhibition of CYP1A2 and CYP2C9.

Eupatilin inhibits T-cell activation by modulation of intracellular calcium flux and NF-kappaB and NF-AT activity

Eupatilin, one of the pharmacologically active ingredients of Artemisia princeps, exhibits a potent anti-ulcer activity, but its effects on T-cell immunity have not been investigated. Here, we show that eupatilin has a profound inhibitory effect on IL-2 production in Jurkat T cells as well as in human peripheral blood leukocytes. Eupatilin neither influenced clustering of CD3 and LFA-1 to the immunological synapse nor inhibited conjugate formation between T cells and B cells in the presence or absence of superantigen (SEE). Eupatilin also failed to inhibit T-cell receptor (TCR) internalization, thereby, suggesting that eupatilin does not interfere with TCR-mediated signals on the membrane proximal region. In unstimulated T cells, eupatilin significantly induced apoptotic cell death, as evidenced by an increased population of annexin V(+)/PI(+) cells and cleavage of caspase-3 and PARP. To our surprise, however, once cells were activated, eupatilin had little effect on apoptosis, and instead slightly protected cells from activation-induced cell death, suggesting that apoptosis also is not a mechanism for eupatilin-induced T-cell suppression. On the contrary, eupatilin dramatically inhibited I-kappaBalpha degradation and NF-AT dephosphorylation and, consequently, inhibited NF-kappaB and NF-AT promoter activities in PMA/A23187-stimulated T cells. Interestingly, intracellular calcium flux was significantly perturbed in cells pre-treated with eupatilin, suggesting that calcium-dependent cascades might be targets for eupatilin action. Collectively, our results provide evidence for dual regulatory functions of eupatilin: (1) a pro-apoptotic effect on resting T cells and (2) an immunosuppressive effect on activated T cells, presumably through modulation of Ca(2+) flux.

Suppression of type-I allergic responses by oral administration of grape marc fermented with Lactobacillus plantarum

We investigated the inhibitory effects of fermented grape marc (FGM), lyophilized fine powder of skin, and seeds of Vitis vinifera Koshu grape prepared by fermentation with Lactobacillus plantarum, on type-I allergic responses in mice. Repeated oral administration of FGM, but not non-fermented grape marc (GM), to BALB/c mice primed with ovalbumin (OVA) resulted in a significant reduction of serum IgE levels, compared with those of immunized controls. After OVA challenge, increased numbers of eosinophils in bronchial alveolar lavage fluids (BALF) significantly decreased by treatment with FGM but not with GM. For passive cutaneous anaphylaxis (PCA) reaction, BALB/c mice received intradermal sensitization with anti-OVA IgE serum and were challenged intravenously with OVA containing Evans blue at 24 h after IgE sensitization. Oral administration of FGM at 30 min before OVA challenge significantly suppressed the PCA reaction. On the other hand, Lactobacillus alone and non-fermented GM did not show any suppressive effects. Interestingly, FGM samples prepared from grapes for red wine, such as Negroamaro (rich in resveratrol) or Tannat (rich in oligomeric procyanidin), did not suppress the reaction. These results indicate that oral administration of FGM, prepared from Koshu grape for white wine but not from grapes for red wine, could suppress both phases of type-I allergic responses. A fraction extractable with acetone was responsible for the suppressive effects of FGM.

Anti-inflammatory effects of Artemisia princeps in antigen-stimulated T cells and regulatory T cells

Objectives

The aim was to investigate the anti-inflammatory effects of Artemisia princeps extract on the activity of anti-CD3/CD28-stimulated CD4+CD25- T cells and antigen-expanded regulatory T cells.

Methods

CD4+CD25- T cells were activated with coated anti-CD3 and anti-CD28 and cultured in the presence or absence of various concentrations of A. princeps extract. The cultures were pulsed on Day 6 with [3H]thymidine and, after harvesting the cells, [3H] thymidine incorporation was measured. For analysis of interleukin-2 and interferon-γ secreted from CD4+CD25- T cells, culture supernatants were collected on Days 2 and 6. For the analysis of interleukin-10 secreted from the CD4+CD25- T cells and expanded regulatory T cells, supernatants were collected after 2 and 7 days, respectively. Cytokine levels were determined using an enzyme-linked immunosorbent assay. Potential medicinal components of the A. princeps extract were determined using gas chromatography–mass spectrometry.

Key findings

A. princeps (30 μg/ml) effectively suppressed proliferation of CD4+CD25- T cells that were stimulated with anti-CD3/CD28 without causing cytotoxicity in spleen cells incubated under conditions lacking antigen stimulation. A. princeps inhibited production of the pro-inflammatory cytokines interleukin-2 and interferon-γ in anti-CD3/CD28-stimulated CD4+CD25- T cells. Also, the extract slightly increased production of the anti-inflammatory cytokine interleukin-10 in these cells. In regulatory T cells expanded by anti-CD3/CD28, A. princeps increased production of interleukin-10 and Foxp3.

Conclusions

The results suggest that A. princeps may be useful in the treatment of autoimmune diseases and organ transplantation rejection by inhibiting proliferation of inflammatory T cells, suppressing inflammatory processes in antigen-stimulated CD4+CD25- T cells and increasing activity of expanded regulatory T cells.

Inhibitory effect of eupatilin and jaceosidin isolated from Artemisia princeps on carrageenan-induced inflammation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia princeps Pampanini (family Asteraceae) is an herbal medicine widely used as a hepatoprotective, antioxidative, anti-inflammatory, and antibacterial agent in Korea, China, and Japan.

AIM OF THE STUDY

This study aimed to elucidate the anti-inflammatory effect of the main constituents, eupatilin and jaceosidin, isolated from Artemisia princeps.

MATERIALS AND METHODS

We used carrageenan-induced inflammation in an air pouch on the back of mice and carrageenan-induced hind paw edema in rats to determine the anti-inflammatory effects of eupatilin and jaceosidin. Inflammatory makers, such as expression of pro-inflammatory cytokines and cyclooxygenase (COX)-2, and activation of nuclear factor-kappa B (NF-kappaB), were measured by enzyme-linked immunosorbent assays and immunoblot analyses.

RESULTS

Eupatilin and jaceosidin blocked carrageenan-induced increase in leukocyte number and protein levels in air pouch exudates. Eupatilin and jaceosidin inhibited COX-2 expression and NF-kappaB activation, and markedly reduced TNF-alpha, IL-1beta, and prostaglandin E2 (PGE(2)) levels. They also inhibited hind paw edema induced by carrageenan. Eupatilin and jaceosidin had similar activity.

CONCLUSIONS

These findings suggest that eupatilin and jaceosidin may reduce inflammation by inhibiting NF-kappaB activation, and that Artemisia princeps inhibits inflammation because of these constituents.

Therapeutic Potential of Kalanchoe Species: Flavonoids and other Secondary Metabolites

The Kalanchoe genus (syn. Bryophyllum), family Crassulaceae, comprises 125 species, most of them native to Madagascar. The great importance of several of these species for the traditional medicine in several regions of the World, esspecially India, Africa, China and Brazil, stimulated research programs into these plants from both a pharmacological and chemical point of view. The present review focuses on the main results obtained during the last decade on the secondary metabolites isolated from these species – endowed or not with a specific biological profile – with emphasis on flavonoids. The distribution of these molecules in the genus will be summarized and special attention will be given to K. brasiliensis and K. pinnata, two species well-known for healing inflammatory and infectious processes. Ornamental Kalanchoe species are also discussed as a potential source of bioactive compounds. This review covers the period 1970–2008.