Methyl galbanate, a novel inhibitor of nitric oxide production in mouse macrophage RAW264.7 cells

Sesquiterpenes and Sesquiterpene Derivatives from Ferula: Their Chemical Structures, Biosynthetic Pathways, and Biological Properties

Ferula is a genus of flowering plants known for its edible and medicinal properties. Since ancient times, many species of Ferula have been used in traditional medicine to treat various health issues across countries, such as digestive disorders, respiratory problems, and even as a remedy for headaches and toothaches. In addition, they are also used as a flavoring agent in various cuisines. As the main active ingredients in Ferula, sesquiterpenes and their derivatives, especially sesquiterpene coumarins, sesquiterpene phenylpropanoids, and sesquiterpene chromones, have attracted the attention of scientists due to the diversity of their chemical structures, as well as their extensive and promising biological properties, such as antioxidative, anti-inflammatory, antibacterial properties. However, there has not been a comprehensive review of sesquiterpenes and their derivatives from this plant. This review aims to provide an overview of the chemical structures, biosynthetic pathways, and biological properties of sesquiterpenes and sesquiterpene derivatives from Ferula, which may help guide future research directions and possible application methods for this valuable edible and medicinal plant.

Comparative study on the impacts of visnagin and its methoxy derivative khellin on human lymphocyte proliferation and Th1/Th2 balance

BACKGROUND

Visnagin is a phenolic and natural compound in turmeric and fenugreek, and its anti-inflammatory effect has been indicated. Therefore, this study aimed to investigate and compare the anti-inflammatory properties of visnagin and its methoxy derivative khellin on human lymphocytes.

METHODS

Human lymphocytes were treated with khellin, visnagin (10, 30, and 100 µM), and dexamethasone (0.1 mM) in the presence of phytohemagglutinin (PHA). The levels of cell proliferation, nitric oxide (NO), glutathione (GSH), malondialdehyde (MDA), and MDA/GSH ratio were measured using biochemistry methods. Furthermore, the mRNA levels of interferon-γ (IFN-γ), interleukin (IL)-4, and IL-10 were assessed using real-time PCR, while IFN-γ/IL-4(Th₁/Th₂), IFN-γ/IL-10(Th₁/T_reg), and IL-4/IL-10(Th₂/T_reg) ratios were made by dividing their exact values.

RESULTS

In the PHA-stimulated group, GSH and IFN-γ/IL-4 levels were markedly diminished, but other variables were significantly elevated compared to the control group. Khellin and visnagin significantly declined the levels of cell proliferation, MDA, MDA/GSH ratio, and NO production. Khellin and visnagin concentration-dependently diminished IFN-γ and IL-4 levels and increased IL-10 levels compared to the PHA-stimulated group. Two higher concentrations of khellin and visnagin (30 and 100 μM) considerably diminished the IFN-γ, IFN-γ/IL-10, and IL-4/IL-10 values compared to the PHA-stimulated group. However, 100 µM of khellin and visnagin significantly increased GSH level compared to the PHA-stimulated group.

CONCLUSIONS

In PHA-stimulated lymphocytes, representing Th₂ dominant allergic diseases, khellin and visnagin provides more specific anti-oxidant, anti-inflammatory, and immunomodulatory functions than dexamethasone. In addition, the effects of khellin were more prominent than visnagin.

Crocetin regulates Th1/Th2 and Th17/Treg balances, nitric oxide production, and nuclear localization of NF-κB in Th2-provoked and normal situations in human-isolated lymphocytes

Crocetin is a natural carotenoid dicarboxylic acid derived from Crocus sativus. It has been utilized as natural biomedicine with healing effects. The immunoregulatory and anti-inflammatory properties may cause the biological activities of crocetin. Nevertheless, it is not still clear how this compound acts and causes an immune-modulatory impact on human lymphocytes. The effects of three concentrations (5, 10, and 20 μM) of crocetin or dexamethasone (0.1 mM) were assessed on gene expression and secretion of cytokines, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) level, and nitric oxide (NO) production in phytohaemagglutinin (PHA)-stimulated and non-stimulated lymphocytes. By incubation with PHA, gene expression and cytokine concentration comprising interferon (IFN)-γ, interleukin (IL)-17A, IL-10, and IL-4 were increased, along with NF-κB concentration and NO production (all, p < 0.001). In comparison with the controls, an alteration occurred in the T-helper (Th)2/Th1 and Th17/Treg balance in the stimulated lymphocyte toward a Th2 and Th17 response. In stimulated cells, crocetin and dexamethasone decreased pro-inflammatory significantly and increased anti-inflammatory cytokines and related gene expression, respectively. Moreover, Th17/Treg and Th1/Th2 balance was changed toward Treg and Th1 significantly reducing NF-κB and NO levels (p < 0.05 to p < 0.001). Promoting effects were represented by crocetin on T-cell subsets to Treg and Th1. Hence, it can have therapeutic value for treating predominant diseases of Th2 or Th17 cells.

[Studies on the Isolation and Molecular Mechanisms of Bioactive Phytochemicals]

Studies on the isolation and molecular mechanisms of phytochemicals with anti-tumor or anti-inflammatory properties are important to developing new drugs for cancer and neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. In the course of a study to screen bioactive isoflavones from Erythrina poeppigiana (Leguminosae), we isolated an isoflavone with potent apoptosis-inducing activity against human leukemia HL-60 cells. It was designated erypoegin K. The studies demonstrated an enantiomer, (S)-erypoegin K, displayed selective cytotoxic activity, was a novel inhibitor of topoisomerase II, and possessed anti-tumor activity both in vitro and in vivo. We identified other apoptosis-inducing isoflavones with the ability to inhibit glyoxalase I. Dimeric acridone alkaloids, carbazole alkaloids, and coumarin and quinoline derivatives-all obtained mainly from plants in the family Rutaceae-induced apoptosis of HL-60 cells via the production of reactive oxygen species and mitochondrial dysfunction. We also identified terpenoid coumarins, carbazole quinones, rotenoid derivatives, and quinolone alkaloids with anti-inflammatory activities. These compounds reduced nitric oxide (NO) production from RAW264.7 macrophage cells stimulated with lipopolysaccharides and interferon-γ. Some of the compounds displayed neuroprotective activity by reducing NO production. This review primarily describes our recent studies on erypoegin K, and other compounds with apoptosis-inducing and anti-inflammatory activities.

Anti-Inflammatory Activity of Ferula assafoetida Oleo-Gum-Resin (Asafoetida) against TNF-α-Stimulated Human Umbilical Vein Endothelial Cells (HUVECs)

Inflammation is the body’s biological reaction to endogenous and exogenous stimuli. Recent studies have demonstrated several anti-inflammatory properties of Ferula species. In this paper, we decided to study the anti-inflammatory effect of ethanolic extract of Ferula assafoetida oleo-gum-resin (asafoetida) against TNF-α-stimulated human umbilical vein endothelial cells (HUVECs). HUVECs were cultured in a flat-bottom plate and then treated with ethanolic extract of asafoetida (EEA, 0-500 μg/ml) and TNF-α (0-100 ng/ml) for 24 h. We used the MTT test to assess cell survival. In addition, the LC-MS analysis was performed to determine the active substances. HUVECs were pretreated with EEA and then induced by TNF-α. Intracellular reactive oxygen species (ROS) and adhesion of peripheral blood mononuclear cells (PBMCs) to HUVECs were evaluated with DCFH-DA and CFSE fluorescent probes, respectively. Gene expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and E-selectin and surface expression of ICAM-1 protein were measured using real-time PCR and flow cytometry methods, respectively. While TNF-α significantly increased intracellular ROS formation and PBMC adhesion to TNF-α-induced HUVECs, the pretreatment of HUVECs with EEA (125 and 250 μg/ml) significantly reduced the parameters. In addition, EEA pretreatment decreased TNF-α-induced mRNA expression of VCAM-1 and surface protein expression of ICAM-1 in the target cells. Taken together, the results indicated that EEA prevented ROS generation, triggered by TNF-α, and inhibited the expression of VCAM-1 and ICAM-1, leading to reduced PBMC adhesion. These findings suggest that EEA can probably have anti-inflammatory properties.

Crocin restores the balance of Th1/Th2 immune cell response in ConA-treated human lymphocytes

BACKGROUND

Following antigen stimulation, naive CD4⁺ T cells differentiate into different T helper (Th) subsets characterized by lineage-specific transcriptional factors and cytokines. The balance between cytokines from Th1 and Th2 cells is disrupted in autoimmune disorders, asthma, and allergic reactions. Crocin, the major carotenoid of saffron, has anti-inflammatory properties. We investigated crocin modifying effects on the human lymphocytes proliferation and Th1/Th2 balance as a possible mechanism of its anti-inflammatory effects.

METHODS

The human peripheral blood mononuclear cells were isolated using Ficoll density gradient centrifugation. MTT was used to evaluate the effect of 72-h treatment with different concentrations of crocin with or without ConA on lymphocytes proliferation. INF-γ/IL-4 cytokine secretion and T-bet/GATA-3 transcription factor expression ratios (as indicators of Th1/Th2 response status) were measured in non-stimulated and ConA-stimulated cells in the presence or absence of crocin by ELISA and RT-qPCR methods, respectively.

RESULTS

The results showed crocin at a concentration of 50 μM and higher was toxic for human lymphocytes, and at a non-toxic concentration of 25 µM, it did not affect cell proliferation. The ratio of T-bet/GATA-3 and INF-γ/IL-4 was higher in the culture supernatant of ConA-stimulated cells compared to non-stimulated ones. Crocin-treated cells showed slightly lower T-bet/GATA-3 and INF-γ/IL-4 ratios compared to untreated cells. Crocin (25 μM) was also able to restore the increased ratio of Th1/Th2 immune response induced by ConA.

CONCLUSIONS

Crocin can alleviate inflammatory-stimulant effects of ConA on human lymphocytes by decreasing T-bet/GATA-3 and INF-γ/IL-4 ratios, which are indicative of restoring the balance of Th1/Th2 responses.

Anti-inflammatory, anti-oxidant, and immunomodulatory activities of the genus Ferula and their constituents: A review

Ferula is a genus of the family Apiaceae and it includes around 170 species of flowering plants mostly native to the Mediterranean region and eastern to central Asia. In Iran, Ferula spp. are widely used in cuisine and traditional medicine. This review discusses the anti-inflammatory, anti-oxidant, and immunomodulatory activities of different species of Ferula. To prepare the present review, Scopus, Google Scholar, PubMed, and Web of Science scientific databases were searched to retrieve relevant articles published from 1985 until December 2020. Based on our literature review, Ferula plants and their derivatives decrease the levels of inflammatory mediators and exert anti-apoptotic effects. Under oxidative stress conditions, these plants and their constituents were shown to decrease oxidative markers such as malondialdehyde, reactive oxygen species, and nitric oxide but increase superoxide dismutase, glutathione peroxidase, catalase activity, and glutathione level. Ferula plants and their constituents also showed immunomodulatory effects by affecting various cytokines. Besides, in vivo and in vitro studies showed hypotensive, neuroprotective, memory-enhancing, anti-oxidant, hepatoprotective, antimicrobial, anticarcinogenic, anticytotoxic, antiobesity, and anthelmintic effects for various species of Ferula and their constituents. These plants also showed a healing effect on gynecological issues such as miscarriage, unusual pain, difficult menstruation, and leukorrhea. All these beneficial effects could have resulted from the anti-inflammatory, anti-oxidant, and immunomodulatory effects of these plants and their constituents. Based on the available literature, members of the genus Ferula can be regarded as potential therapeutics against inflammatory conditions, oxidative stress, and immune dysregulation.

Umbelliprenin Increases the M1/M2 Ratio of Macrophage Polarization and Improves the M1 Macrophage Activity in THP-1 Cells Cocultured with AGS Cells

Background

Gastric adenocarcinoma is the fifth most diagnosed malignancy in the world. The immune system consists of a heterogeneous mixture of macrophages that defense the body through phagocytosis and the production of different cytokines and chemokines. Tumors cause macrophages to polarize differently in the manner of their favorite growth and angiogenesis. Umbelliprenin, a natural sesquiterpene coumarin, has been shown to have anticancer properties against some tumors, including gastric adenocarcinoma. The aim of our study was to investigate the effect of umbelliprenin on the polarization of macrophages in addition to the measurement of some of the soluble factors they produce.

Method

The values of IC₅ and IC₅₀ for umbelliprenin in the AGS and THP-1 cells were estimated using the MTT assay. THP-1 cells were treated with 10 μM umbelliprenin, either alone or cocultured with AGS cells. Flow cytometry analysis of treated THP-1 cells was performed for CD68, CD86, and CD206 markers to evaluate M0, M1, and M2 macrophages polarization, respectively. AGS cells were assessed for apoptosis and necrosis by flow cytometry after labeling with Annexin V-FITC and propidium iodide. Interleukin- (IL-) 10 and IL-12 contents were measured in the supernatant by the ELISA method. Griess Reaction assay technique was used to determine nitric oxide (NO) concentration.

Results

The results of the MTT showed lower toxicity of umbelliprenin in THP-1 (IC₅₀ = 75.79) compared to the AGS cell line (IC₅₀ = 48.81). Umbelliprenin significantly increased the M1/M2 ratio. IL-10 content decreased significantly in the supernatant of M1 and M2 cells after umbelliprenin treatment, while IL-12 increased in the supernatant of M1 cells and decreased in the supernatant of the M2 cells. Umbelliprenin caused an increase in the NO in the supernatant of the M1 cells.

Conclusion

Umbelliprenin alters the macrophage's secretions and its phenotypes in favor of tumor suppression.

Immuno-modulatory effects of methanolic extract of Ferula szowitsiana on isolated human Th1/Th2/Treg cytokines levels, and their genes expression and nitric oxide production

BACKGROUND

Anti-inflammatory and anti-oxidants activities of Ferula szowitsiana L. (F. szowitsiana) were shown in ancient texts and assayed by modern studies. However, immunomodulatory properties of the plant are poorly understood.

METHODS

The effects of F. szowitsiana extract (10, 40 and 160 µg/ml), dexamethasone and vehicle were investigated on nitric oxide (NO) level, cell proliferation, and cytokines (IL-4, IL10 and IFN-γ) expression at gene and protein levels in non-stimulated and phytohaemagglutinin-stimulated human lymphocytes (n = 15 in each group).

RESULTS

Cell proliferation, cytokines secretion, NO production and levels of genes expression were significantly inhibited but IFN-γ/IL-4 and IL-10/IL-4 ratios (T helper 1/Th2 and Treg/Th2 balances respectively) were increased by dexamethasone and all three concentrations of the extract compared to control group in stimulated lymphocytes (P < 0.001 for all cases). The effect of three concentrations of the extract in all experiments was significantly lower than dexamethasone (P < 0.001 for all cases).

CONCLUSION

The extract of F. szowitsiana concentration-dependently decreased NO level but increased Th₁/Th₂ and T_reg/Th₂ ratios toward Th₁ and T_reg. These results suggest the therapeutic potential of the plant's extract in inflammatory diseases with dominant Th2 polarization such as asthma or cancers.

To be ionized or not to be ionized: the vital role of physicochemical properties of galbanic acid derivatives in AChE assay

Alzheimer's disease is a progressive neurodegenerative disorder and patients suffer from memory loss, a decline in language skill and impairment in other cognitive functions. In the cholinergic hypothesis, dysfunction of cholinergic neurons especially in the hippocampus and cerebral cortex contributes to cognitive decline in patients. So agents that enhance acetylcholine concentration could improve cognitive function. AChEIs are among the most studied anti-Alzheimer agents. Galbanic acid as a natural compound with a sesquiterpene coumarin scaffold is a weak inhibitor of AChE. In the present contribution, we discussed the impact of carboxylic group ionization on inhibitory effects. We performed in vitro and in silico studies on galbanic acid, methyl and ethyl galbanates as AChE inhibitors. The order of inhibitory effect on AChE was obtained as ethyl galbanate ∼ methyl galbanate > galbanic acid. Our study highlights the important role of the physicochemical properties of natural lead compounds in each specific assay.Communicated by Ramaswamy H. Sarma.

Evaluation of anti-inflammatory potential of the leaves of Wendlandia heynei (Schult.) Santapau & Merchant in Sprague Dawley rat

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of W. heynei (family: Rubiaceae) are used by the folklore in swelling, wounds and body aches. In this study anti-inflammatory potential of W. heynei leaves has been evaluated during in vitro studies and in rat.

METHODS

Methanol extract of the leaves of W. heynei (WHLM) and its fractions; n-hexane (WHLH), chloroform (WHLC), ethyl acetate (WHLE), n-butanol (WHLB) and residual soluble aqueous (WHLA) were screened for phytochemical analysis and several active constituents (alkaloids, flavonoids, saponins, tannins, terpenoids, β-carotene and lycopene) were also quantified. Heat induced albumin denaturation assay and in vitro cell cultures was carried out for in vitro anti-inflammatory activity, while various in vivo assays like TPA induced ear edema, croton oil induced anus edema, formalin and carrageenan-induced hind paw edema was investigated in Sprague-Dawley rats. Alterations on levels of tumor necrosis factor (TNF-α), Interleukin-1β (IL-1β), IL-6 and prostaglandins (PGE₂) induced with WHLE was studied in serum after carrageenan induced paw edema in rat. Meanwhile, the dose dependent WHLE inhibition of NFκB pathway via regulation of the phosphorylation of IKKs, IκBα, and p65 subunit was studied in LPS-induced rat peritoneal macrophages. On account of marked anti-inflammatory activity of WHLE its bioactive components were analyzed by HPLC-DAD analysis.

RESULTS

The phytochemical analysis yielded alkaloids, saponins, tannins, coumarins, glycosides, quinones and vitamin C in WHLM and in all fractions. Fraction (WHLE) was enriched with alkaloids (20.20 ± 2.5%), flavonoids (25.26 ± 2.11%) and tannins (307.2 ± 2.03 mg of GAE/g of extract), while terpenoids (21.60 ± 1.65%) were the major constituents of WHLH. Ethyl acetate fraction convincingly protected heat induced albumin denaturation. WHLE exhibited highest edema inhibition in models of TPA-induced ear edema (74.51 ± 2.05) and croton oil-induced anal edema (75.38 ± 2.83). The pretreatment with WHLE significantly (p < 0.05) reduced the paw edema with formalin (78.99 ± 2.26%) assessed after 6 h and in carrageenan (75.71 ± 4.46%) was detected after 4 h. Level of anti-inflammatory markers; IL-1β, IL-6, TNF-α and PGE₂ in carrageenan induced paw edema in serum of rat was significantly (p < 0.001) decreased with WHLE pretreatment to rat. WHLE significantly inhibited the NFκB by reducing the phosphorylation of IKKs, IκBα, and p65 subunit in LPS-induced inflammation in rat peritoneal macrophages. HPLC-DAD analysis of WHLE indicated the presence of rutin, gallic acid, catechin, caffeic acid and myricetin.

CONCLUSIONS

It is concluded that WHLM fractions have marked anti-inflammatory activity and this study endorsed the folklore use of W. heynei leaves for swelling related disorders.

Evaluation of the anti-oxidant and anti-inflammatory effects of the methanolic extract of Ferula szowitsiana root on PHA-induced inflammation in human lymphocytes

Inflammation is defined as a defensive response of the body against either the endogenous or exogenous triggers, while this process becomes chronic leading to various disorders such as asthma, cancers, and multiple sclerosis. Recently, pharmacological properties of different constituents of F. szowitsiana have been reported. In the present study, we aimed to evaluate the anti-oxidative and anti-inflammatory effects of the methanolic extract of F. szowitsiana root on human isolated lymphocytes. The effects of either F. szowitsiana (10, 40 and 160 μg/ml) or dexamethasone (0.1 mM) were evaluated on the levels of cell proliferation, reactive oxygen species (ROS), nitric oxide (NO) production, malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) activities, and total glutathione content (GSH) as well as the secretion of inflammatory cytokines [interleukin 6 (IL-6) and tumor necrosis factor (TNF)-α] in the presence or absence of phytohemagglutinin (PHA) stimulation (n = 8 for each group). PHA stimulation notably elevated ROS, NO, MDA, IL-6, and TNF-α levels as well as diminished GSH, CAT and SOD levels. In PHA-stimulated, the results also revealed that F. szowitsiana (10-160 µg/ml) significantly decreased MDA, ROS, NO, IL-6 and TNF-α levels as well as increased CAT, SOD and GSH levels. Collectively, F. szowitsiana is able to attenuate the overproduction of inflammatory and oxidative stress markers in the presence of PHA-stimulated T lymphocytes, while to propagate the anti-oxidative defense. Contextually, the plant has promising healing effects in the different inflammatory disorders associated with the interference of the acquired immune system such as multiple sclerosis and asthma.

Insights on the molecular mechanism of anti-inflammatory effect of formula from Islamic traditional medicine: An in-silico study

Background and aim

Traditional medicine is an important source for drug discovery. However, many challenges face the scientific community to develop novel drugs from it. To investigate the rationale behind the medical legacy of centuries of precious knowledge from traditional medicine, we aimed at performing virtual screening to identify potential leads from the middle-age textbook, The Canon of Medicine.

Experimental procedure

A database of chemical constituents of plants mentioned within the book was built and docked against different molecular targets associated with inflammation such as phospholipase A2, p38 alpha mitogen activated protein kinase, cyclooxygenase-2 and leukotriene B4 dehydrogenase, after that literature survey was done to determine the consistency of traditional uses and molecular docking results with the current knowledge obtained from previous studies and reports.

Results and conclusion

The in-silico study revealed the ability of several chemical constituents, in the plants under investigation, to bind effectively to different targets associated with inflammation, which was consistent with previous reports, indicating that Islamic traditional medicine can be considered as a reliable promising source for developing new anti-inflammatory agents with low toxicity and minimal side effects.

Auraptene regulates Th1/Th2/TReg balances, NF-κB nuclear localization and nitric oxide production in normal and Th2 provoked situations in human isolated lymphocytes

BACKGROUND

Auraptene as member of dietary coumarins, is found in citrus fruits. Former studies have demonstrated its anti-inflammatory and anti-cancer activity.

PURPOSE

The mechanism of action and immune-modulatory property of this compound on human lymphocytes are greatly unknown.

STUDY DESIGN/METHODS

The effect of three concentrations (10, 30 and 90 µM) of auraptene or dexamethasone (0.1 mM) were evaluated on percentage of cell proliferation and nitric oxide (NO) production as well as secretion and gene expression of cytokines, and NF-κB level in PHA-stimulated and non-stimulated lymphocytes.

RESULTS

In non-stimulated cells, all three concentrations of auraptene significantly increased the gene expression index of IL-10 (P < 0.05-0.001). The IFN-γ gene expression index, IFN-γ/IL-4 and IL-10/IL-4 gene expression ratio were significantly increased due to the high concentration (90 µM) of auraptene treatment compared to control group (P < 0.05-0.001). In PHA stimulation, all three concentrations of the extract significantly decreased proliferation, cytokines (IL-4, IL-10 and IFN-γ) and NF-κB level as well as NO production, but IFN-γ/IL-4 and IL-10/IL-4 ratio were significantly increased compared control group (P < 0.05-0.001). Gene expression of IL-10 and IL-4 was decreased but that of IFN-γ as well as FN-γ/IL-4 and IL-10/IL-4 ratio were significantly increased due to all three concentrations of auraptene.

CONCLUSION

The results showed promoting effects of auraptene on T cell subsets toward Th₁ (IFN-γ) and T_reg (IL-10), which suggest its therapeutic value for treatment of Th₂ cells predominant diseases including allergic disease such as asthma and atopic dermatitis as well as cancers.

The influence of hydro-ethanolic extract of Portulaca oleracea L. on Th1/Th2 balance in isolated human lymphocytes

ETHNOPHARMACOLOGICAL RELEVANCE

The anti-inflammatory and anti-oxidants activity of Portulaca oleracea L. (P. oleracea) were mentioned in traditional texts. In previous studies, different anti-inflammatory and anti-oxidant effects of P. oleracea were demonstrated. However, the mechanism of action and immunomodulatory property of this plant are greatly unknown. In the present study, the effect of the extract of this plant on IL-4, IL10, IFN-γ and T helper (h)1/Th2 balance in non-stimulated and stimulated human lymphocytes was examined.

MATERIALS AND METHODS

The effect of three concentrations (160, 40 and 10µg/ml) of P. oleracea or dexamethasone were evaluated on percentage of cell proliferation and nitric oxide (NO) production as well as secretion of cytokines (IL-4, IL10 and IFN-γ) in PHA-stimulated and non-stimulated lymphocytes, and compared to control and dexamethasone as positive control (n=15 for each group).

RESULTS

In stimulated cells, dexamethasone significantly inhibited the percentage of cell proliferation, NO production, and secretion of cytokines in comparison to control group (P<0.001 for all cases). The percentage of cell proliferation, NO production, and secretion of cytokines were significantly decreased while Th1/Th2 (IFN-γ/IL-4) and Treg/Th2 (IL-10/IL-4) balances significantly enhanced in treated groups with all three concentrations of extract compared to control group (P<0.001 for all cases). The effect of all concentrations of the extract on cell proliferation, NO production and secretion of cytokines as well as Treg/Th2 balance were significantly lower than dexamethasone (P<0.001 for all cases), but Th1/Th2 ratio obtained in the presence of only low extract concentration was lower than dexamethasone (P<0.01).

CONCLUSION

Different concentrations of extract promoted Th1/Th2 and Treg/Th2 balances which may suggest the therapeutic value of the plant in inflammatory disease associated with decreased Th1/Th2 balance such as asthma or cancers.

Natural and Synthetic Coumarins with Effects on Inflammation

In this review, we will present the different aspects of coumarins and derivatives, from natural origins or synthetically prepared, and their action on inflammation. Coumarins and also furo- and pyranocoumarins are found in many different plants. These compounds are very often investigated for antioxidant properties. Other biological properties are also possible and anti-inflammation activity is one of these. As coumarins are also available quite easily via synthesis, natural ones can be prepared this way but derivatives with special substituents are also feasible. A review on the same topic appeared in 2004 and our contribution will take into account everything published since then.

Cyanotoxins at low doses induce apoptosis and inflammatory effects in murine brain cells: Potential implications for neurodegenerative diseases

Cyanotoxins have been shown to be highly toxic for mammalian cells, including brain cells. However, little is known about their effect on inflammatory pathways. This study investigated whether mammalian brain and immune cells can be a target of certain cyanotoxins, at doses approximating those in the guideline levels for drinking water, either alone or in mixtures. We examined the effects on cellular viability, apoptosis and inflammation signalling of several toxins on murine macrophage-like RAW264.7, microglial BV-2 and neuroblastoma N2a cell lines. We tested cylindrospermopsin (CYN), microcystin-LR (MC-LR), and anatoxin-a (ATX-a), individually as well as their mixture. In addition, we studied the neurotoxins β-N-methylamino-l-alanine (BMAA) and its isomer 2,4-diaminobutyric acid (DAB), as well as the mixture of both. Cellular viability was determined by the MTT assay. Apoptosis induction was assessed by measuring the activation of caspases 3/7. Cell death and inflammation are the hallmarks of neurodegenerative diseases. Thus, our final step was to quantify the expression of a major proinflammatory cytokine TNF-α by ELISA. Our results show that CYN, MC-LR and ATX-a, but not BMAA and DAB, at low doses, especially when present in a mixture at threefold less concentrations than individual compounds are 3–15 times more potent at inducing apoptosis and inflammation. Our results suggest that common cyanotoxins at low doses have a potential to induce inflammation and apoptosis in immune and brain cells. Further research of the neuroinflammatory effects of these compounds in vivo is needed to improve safety limit levels for cyanotoxins in drinking water and food.

Herpes Simplex Virus 1 Suppresses the Function of Lung Dendritic Cells via Caveolin-1

Caveolin-1 (Cav-1), the principal structural protein of caveolae, has been implicated as a regulator of virus-host interactions. Several viruses exploit caveolae to facilitate viral infections. However, the roles of Cav-1 in herpes simplex virus 1 (HSV-1) infection have not fully been elucidated. Here, we report that Cav-1 downregulates the expression of inducible nitric oxide synthase (iNOS) and the production of nitric oxide (NO) in dendritic cells (DCs) during HSV-1 infection. As a result, Cav-1 deficiency led to an accelerated elimination of virus and less lung pathological change following HSV-1 infection. This protection was dependent on iNOS and NO production in DCs. Adoptive transfer of DCs with Cav-1 knockdown was sufficient to confer the protection to wild-type (WT) mice. In addition, Cav-1 knockout (KO) (Cav-1(-/-)) mice treated with an iNOS inhibitor exhibited significantly reduced survival compared to that of the nontreated controls. We found that Cav-1 colocalized with iNOS and HSV-1 in caveolae in HSV-1-infected DCs, suggesting their interaction. Taken together, our results identified Cav-1 as a novel regulator utilized by HSV-1 to evade the host antiviral response mediated by NO production. Therefore, Cav-1 might be a valuable target for therapeutic approaches against herpesvirus infections.

Formulation, characterization, and geno/cytotoxicity studies of galbanic acid-loaded solid lipid nanoparticles

CONTEXT

Galbanic acid (GBA) is a sesquiterpene coumarin with different medicinal properties and anticancer effects.

OBJECTIVE

To improve the anticancer activities of GBA, in the current study, we aimed to fabricate GBA-loaded solid lipid nanoparticles (GBA-SLNs) and study their biological activities in vitro.

MATERIALS AND METHODS

Hot homogenization was used for preparation of GBA-SLNs. The encapsulation efficiency (EE) and drug loading (DL) and in vitro release were determined. MTT, DAPI, DNA fragmentation, comet, and Anexin V apoptosis assays were used to compare the anti-cell proliferation and genotoxicity properties of GBA and GBA-SLNs against A549 cells and HUVEC to detect apoptosis and DNA damage in the final concentration of 100 µM after 48 h treatment.

RESULTS

Scanning electron microscopy (SEM) and particle size analysis showed spherical SLNs (92 nm), monodispersed distribution, and zeta potential of -23.39 mV. High EE (>98%) and long-term in vitro release were achieved. The stability of GBA-SLNs in aqueous medium was approved after 3 months in terms of size and polydispersity index. GBA was able to inhibit A549 growth with an IC50 value of 62 µM at 48 h. Although GBA-SLNs could also inhibit the growth rate of A549 cells, the effect is perceived after 48 h, as approved by the quantitative expression of Bcl-xL and Casp 9 genes, and also genotoxicity assays.

CONCLUSION

Long-term apoptotic effect of GBA-SLNs compared with GBA may be due to the accumulation of GBA-SLNs in the tumor site because of deviant tumor pathology. Our data confirmed that SLNs could be exploited for sustained lipophilic GBA delivery.

Synthesis, biosynthesis and biological activities of galbanic acid - A review

Abstract Context: Galbanic acid (GA) is a biologically active sesquiterpene coumarin from Ferula species (Apiaceae). This compound showed various biological properties including anticancer, cancer chemopreventive, anticoagulant, antiviral, and antileishmanial activities. Objectives: This article is a review on the synthesis, biosynthesis, and biological activities of GA. In addition, we discussed gaps in our knowledge about GA that deserve future research. In this article, we also evaluated the drug-likeness of GA in silico. Methods: All relevant databases were searched for the terms "galbanic acid", "methyl galbanate", "Ferula" and "sesquiterpene coumarin" without limitation, up to May 2013. Information on GA was collected via electronic search using Pubmed, Scopus, Web of Science, and Sciencedirect. All physicochemical parameters used for the prediction of drug-likeness were calculated using MarvinSketch (version 5.11, academic package, ChemAxon). Results: This compound showed various biological properties including anticancer, cancer chemopreventive, anticoagulant, antiviral and antileishmanial activities. GA can inhibit the growth of prostate cancer cells via decreasing androgen receptor abundance. In silico physicochemical studies on GA showed that this compound has drug-like properties, the parameters that are important to predict potential of a compound for being a future drug. Conclusion: GA is a valuable natural product with various biological activities. New discoveries with GA are to be expected.

Inhibitory effect of carbazolequinone derivatives on lipopolysaccharide and interferon-γ-induced nitric oxide production in mouse macrophage RAW264.7 cells

Objectives

The aim of this study was to examine the mechanism underlying the inhibitory effect of our synthesized carbazolequinone derivatives on nitric oxide (NO) production in activated macrophages.

Methods

Lipopolysaccharide (LPS) and interferon-γ (IFN-γ)-stimulated RAW264.7 macrophages were treated with carbazolequinone derivatives. The NO and prostaglandin E2 (PGE2) levels in cell culture supernatants fractions were measured by Greiss and ELISA assay, respectively. The expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) was assessed by the real-time RT-PCR method. Nuclear factor kappa B (NF-κB) activation was detected by an NF-κB-dependent luciferase reporter assay.

Key findings

Our synthesized carbazolequinone derivatives (7-methoxy-2-methylcarbazole-1,4-quinone, 6-methoxy-2-methylcarbazole-1,4-quinone and 6-chloro-2-methylcarbazole-1,4-quinone) significantly inhibited LPS/IFN-γ-induced NO production and iNOS expression in RAW264.7 cells. They also inhibited the LPS/IFN-γ-mediated induction of COX-2 expression and PGE2 production. In addition, the LPS/IFN-γ-induced transcription activity of NF-κB was attenuated. Using the RAW264.7-tsAM5NE co-culture system, we found that these carbazolequinone derivatives protected neuronally differentiated tsAM5NE cells from NO-induced cell death by inhibiting the production of NO.

Conclusions

These results suggest that the three carbazolequinone derivatives inhibit LPS/IFN-γ-induced NO production via iNOS and COX-2 downregulation due to NF-κB inhibition. Therefore, these three carbazolequinone derivatives may be useful for developing a new drug against NO-mediated neurodegenerative diseases.

Anti-inflammatory and neuroprotective effects of auraptene, a citrus coumarin, following cerebral global ischemia in mice

Cerebral ischemia causes delayed neuronal cell death in the hippocampus resulting in sequential cognitive impairments. Hyper-activated inflammation following ischemia is one of the etiologies for delayed neuronal cell death. In the present study, using a transient global ischemia mouse model, we showed that auraptene (AUR), a citrus coumarin, effectively inhibited microglia activation, cyclooxygenase-2 expression by astrocytes, and neuronal cell death in the hippocampus following ischemic insults. These results suggest that AUR acts as a neuroprotective agent in the ischemic brain, which may be mediated by suppression of the inflammatory response.