In vitro and in vivo anti-inflammatory effect of Rhodomyrtus tomentosa methanol extract

Potential applications of Rhodomyrtus tomentosa leaf extract as natural anti-staphylococcal additive in food systems: Efficacy and in vivo safety evaluation

This work aimed to explore the potential use of Rhodomyrtus tomentosa ethanol leaf extract (RTEL) as an alternative food preservative agent for controlling the growth of Staphylococcus aureus. Antibacterial activities against food-isolated S. aureus were performed using disc diffusion and broth microdilution assays, followed by evaluating in vivo subacute oral toxicity of the extract. Salad dressing was used as a food model to study bactericidal properties and consumer acceptability. RTEL remarkably inhibited S. aureus with minimum inhibitory concentrations (MICs) ranging from 7.81-62.5 µg/mL. Repeated oral doses (5, 50, and 300 mg/kg RTEL) for 28 days did not affect any of the measured toxicity parameters. The no-observed-adverse-effect-level (NOAEL) of RTEL was noted as more than 300 mg/kg body weight/day. The utilization of RTEL (12.5 mg/mL) in the vinaigrette salad dressing did not affect the consumer acceptability of the product, remarkably killed the pathogen within 3-9 h of exposure. The results indicated that RTEL is safe and effective as a natural anti-staphylococcal controlling agent that could be utilized in food systems. Further work is required on the effects of enterotoxin production, an important virulence factor of S. aureus responsible for food-borne disease.

Antiedema and antinociceptive potential of the essential oil of Pectis elongata Kunt (Asteraceae) from the Brazilian Amazon

ETHNOPHARMACOLOGICAL RELEVANCE

Pectis elongata, a herbaceous species that is known in northern Brazil as "cominho" or "limãozinho", is traditionally used in the region for the treatment of fevers, colds, hypotension, genitourinary and gastric disorders, and pain.

AIM OF THE STUDY

Determine the chemical composition and acute oral toxicity and evaluate whether Pectis elongata essential oil (PeEO) has antiedema and antinociceptive activity.

MATERIALS AND METHODS

The chemical composition was determined using gas chromatography coupled to mass spectrometry (GC/MS) and the degree of toxicity determined by the LD50. The antiedema and antinociceptive potential was evaluated via the λ-carrageenan-induced paw edema test and formalin test, respectively.

RESULTS

Citral (geranial and neral) was characterized as a major component of the PeEO, representing 89% of the total identified compounds. According to OECD criteria (2002), the EO was considered non-toxic since it presented LD50 values over 2000 mg kg-1. Its antiedema potential was observed at doses of 200 and 400 mg kg-1 (p ≤ 0.05). At a dose of 400 mg kg-1, PeEO also showed antinociceptive potential (p ≤ 0.05), both in the neurogenic phase and in the inflammatory phase.

CONCLUSIONS

PeEO, which is rich in citral, did not induce any characteristic signs of acute oral toxicity and was also efficient in reducing carrageenan-induced paw edema, in addition to presenting antinociceptive potential and acting on both central and peripheral pain. It is thus a promising candidate for the development of a new herbal medicine with anti-inflammatory and analgesic action.

Transferosomes stabilized hydrogel incorporated rhodomyrtone-rich extract from Rhodomyrtus tomentosa leaf fortified with phosphatidylcholine for the management of skin and soft-tissue infections

Rhodomyrtus tomentosa leaf (RT)-incorporated transferosomes were developed with lecithin and cholesterol blends with edge activators at different ratios. RT-transferosomes were characterized and employed in transferosomal gel formulations for the management of skin and soft-tissue infections. The optimized formulation entrapped up to 81.90 ± 0.31% of RT with spherical vesicles (405.3 ± 2.0 nm), polydispersity index value of 0.16 ± 0.08, and zeta potential of - 61.62 ± 0.86 mV. Total phenolic and flavonoid contents of RT-transferosomes were 15.65 ± 0.04 μg GAE/g extract and 43.13 ± 0.91 μg QE/g extract, respectively. RT-transferosomes demonstrated minimum inhibitory and minimum bactericidal concentrations at 8-256 and 64-1024 μg/mL, respectively. Free radical scavenging assay showed RT-transferosomes with high scavenging activity against DPPH and ABTS radicals. Moreover, RT-transferosomes demonstrated moderate activity against mushroom tyrosinase, with IC50 values of 245.32 ± 1.32 μg/mL. The biocompatibility results against L929 fibroblast and Vero cells demonstrated IC50 at 7.05 ± 0.17 and 4.73 ± 0.13 μg/mL, respectively. In addition, nitric oxide production significantly decreased by 6.78-88.25% following the treatment with 31.2-500 ng/mL RT-transferosomes (p < 0.001). Furthermore, the freeze-thaw stability study displayed no significant change in stability in the sedimentation and pH of gel fortified with RT-transferosomes. The results suggested that RT-transferosome formulation can be effectively employed as natural biomedicines for scar prevention and the management of skin soft-tissue infections.

Anti-Inflammatory and Anti-Angiogenic Aattributes of Moringa olifera Lam. and its Nanoclay-Based Pectin-Sericin films

Background: Inflammation is a strong reaction of the non-specific natural immune system that helps to start protective responses against encroaching pathogens and develop typical immunity against intruding factors. However, prolonged inflammation may lead to chronic autoimmune diseases. For thousands of years, medicinal plants have served as an excellent source of treatment for chronic pathologies such as metabolic diseases.

Purpose: The present study aims to evaluate the anti-inflammatory and anti-angiogenic potential of Moringa olifera Lam. extract (MO) and Moringa-loaded nanoclay films.

Methods: The extract preparation was done through the maceration technique using absolute methanol (99.7%) and labelled as Mo. Me. Mo. Me-loaded nanoclay-based films were prepared by using pectin and sericin (Table 1). The in vitro studies characterized the film thickness, moisture, and phytochemical contents. The in vivo anti-inflammatory tests involved using a cotton pellet-induced granuloma model assay. In addition, the chick chorioallantoic membrane (CAM) assay was employed for angiogenesis activity.

Results: The phytochemical analysis of the extract confirmed the presence of alkaloids, glycosides, flavonoids and phytosterol. This extract contained quercetin in a large quantity. Cotton-pellet induced granuloma model study revealed a comparable (p > 0.05) effect of a high dose of Mo. Me (500 mg/kg) as compared with standard drug. Noteworthy, data obtained through the RT-PCR technique manifested the dose-dependent anti-oedematous effect of Moringa olifera via downregulation of TNF-α and interleukin-1ß. The findings of the CAM assay exhibited a remarkable anti-angiogenic activity of Mo. Me loaded nanoclay films, showing diffused vasculature network in the macroscopic snapshot.

Conclusion:Moringa olifera and its nanocomposite films have therapeutic potential against inflammation.

Anti-Inflammatory and Anti-Remodelling Potential of Ethanol Extract Rhodomyrtus Tomentosa in Combination of Asthma and Coal Dust Models

BACKGROUND

Combination of asthma and coal dust is a chronic and recurring airway disease related to inflammation cell activation. The Rhodomyrtus tomentosa flowering plants native to South Kalimantan exhibit a broad therapeutic potential, like anti-inflammatory and anti-remodelling properties. This study aims to analyze the effect of ethanol extract of R. tomentosa leaves (EERTL) nebulizer on the number of inflammatory cells and histomorphometry of lung tissue in a mice-like model of a combination of asthma and coal dust.

METHODS

The 24 BALB/c mice were divided into four treatment groups (n= 6 per group), were sensitized with normal saline (K), OVA + coal dust (P1), OVA + coal dust + salbutamol (P2), and OVA + coal dust + EERTL (P3). Eosinophil cells, neutrophils, lymphocytes, epithelial thickness, smooth muscle, fibrosis subepithelial bronchioles, and the number of goblet cells as indicators of anti-inflammatory and anti-remodelling airways.

RESULTS

The number of eosinophils, neutrophils, and lymphocytes cells are given salbutamol or EERTL was significantly lower than the OVA-sensitized and coal dust exposure group only. There are meaningful differences in the average thickness of the epithelium, smooth muscle, and subepithelial fibrosis of bronchiolus. The histopathology picture of goblet cells showed an increase in the number and size (hyperplasia) in OVA-sensitized and coal dust exposure compared to another group.

CONCLUSION

It was concluded that the EERTL nebulizer could reduce inflammatory cells and remodelling process from bronchoalveolar lavage in the mice combination of asthma and coal dust models.

The Gene Regulatory Roles of Herbal Extracts on the Growth, Immune System, and Reproduction of Fish

The crucial need for safe and healthy aquatic animals obligates researchers in aquaculture to investigate alternative and beneficial additives. Medicinal herbals and their extracts are compromised with diverse effects on the performances of aquatic animals. These compounds can affect growth performance and stimulate the immune system when used in fish diet. In addition, the use of medicinal herbs and their extracts can reduce oxidative stress induced by several stressors during fish culture. Correspondingly, aquatic animals could gain increased resistance against infectious pathogens and environmental stressors. Nevertheless, the exact mode of action where these additives can affect aquatic animals' performances is still not well documented. Understanding the mechanistic role of herbal supplements and their derivatives is a vital tool to develop further the strategies and application of these additives for feasible and sustainable aquaculture. Gene-related studies have clarified the detailed information on the herbal supplements' mode of action when administered orally in aquafeed. Several review articles have presented the potential roles of medicinal herbs on the performances of aquatic animals. However, this review article discusses the outputs of studies conducted on aquatic animals fed dietary, medicinal herbs, focusing on the gene expression related to growth and immune performances. Furthermore, a particular focus is directed to the expected influence of herbal supplements on the reproduction of aquatic animals.

Molecular Biology of Atherosclerotic Ischemic Strokes

Among the causes of global death and disability, ischemic stroke (also known as cerebral ischemia) plays a pivotal role, by determining the highest number of worldwide mortality, behind cardiomyopathies, affecting 30 million people. The etiopathogenetic burden of a cerebrovascular accident could be brain ischemia (~80%) or intracranial hemorrhage (~20%). The most common site when ischemia occurs is the one is perfused by middle cerebral arteries. Worse prognosis and disablement consequent to brain damage occur in elderly patients or affected by neurological impairment, hypertension, dyslipidemia, and diabetes. Since, in the coming years, estimates predict an exponential increase of people who have diabetes, the disease mentioned above constitutes together with stroke a severe social and economic burden. In diabetic patients after an ischemic stroke, an exorbitant activation of inflammatory molecular pathways and ongoing inflammation is responsible for more severe brain injury and impairment, promoting the advancement of ischemic stroke and diabetes. Considering that the ominous prognosis of ischemic brain damage could by partially clarified by way of already known risk factors the auspice would be modifying poor outcome in the post-stroke phase detecting novel biomolecules associated with poor prognosis and targeting them for revolutionary therapeutic strategies.

Anti-inflammatory effects of Capparis ecuadorica extract in phthalic-anhydride-induced atopic dermatitis of IL-4/Luc/CNS-1 transgenic mice

CONTEXT

The natural products derived from Capparis ecuadorica H.H. Iltis (Capparaceae) could have great potential for anti-inflammation since they inhibited the inflammatory response in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells.

OBJECT

This study investigated the anti-inflammatory effects and related mechanism of methanol extract of C. ecuadorica leaves (MCE) during atopic dermatitis (AD) responses.

MATERIALS AND METHODS

Alterations in the phenotypical markers for AD, luciferase signal, iNOS-mediated COX-2 induction pathway, and inflammasome activation were analysed in non-Tg (n = 5) and 15% phthalic anhydride (PA) treated IL-4/Luc/CNS-1 transgenic (Tg) HR1 mice (n = 5 per group), subsequent to treatment with acetone-olive oil (AOO), vehicle (DMSO) and two dose MCE (20 and 40 mg/kg) three times a week for 4 weeks.

RESULTS

MCE treatment reduced the intracellular ROS level (48.2%), NO concentration (7.1 mmol/L) and inflammatory cytokine expressions (39.1%) in the LPS-stimulated RAW264.7 cells. A significant decrease was detected for ear thickness (16.9%), weight of lymph node (0.7 mg), IgE concentration (1.9 µg/mL), and epidermal thickness (31.8%) of the PA + MCE treated Tg mice. MCE treatment induced the decrease of luciferase signal derived from the IL-4 promoter and the recovery of the IL-4 downstream regulator cytokines. PA + MCE treated Tg mice showed decreasing infiltration of mast cells (42.5%), iNOS-mediated COX-2 induction pathway, MAPK signalling pathway and inflammasome activation in the ear tissue.

CONCLUSIONS

These findings provide the first evidence that MCE may have great potential to suppress chemical-induced skin inflammation through the suppression of IL-4 cytokine and the iNOS-mediated COX-2 induction pathway, and activation of inflammasome.

Phytochemical, Cytotoxicity, Antioxidant and Anti-Inflammatory Effects of Psilocybe Natalensis Magic Mushroom

Psilocybin-containing mushrooms, commonly known as magic mushrooms, have been used since ancient and recent times for depression and to improve quality of life. However, their anti-inflammatory properties are not known. The study aims at investing cytotoxicity; antioxidant; and, for the first time, anti-inflammatory effects of Psilocybe natalensis, a psilocybin-containing mushroom that grows in South Africa, on lipopolysaccharide-induced RAW 264.7 macrophages. Macrophage cells were stimulated with lipopolysaccharide and treated with different concentrations of Psilocybe natalensis mushroom extracted with boiling hot water, cold water and ethanol over 24 h. Quercetin and N-nitro-L-arginine methyl ester were used as positive controls. Effects of extracts on the lipopolysaccharide-induced nitric oxide, prostaglandin E₂, and cytokine activities were investigated. Phytochemical analysis, and the antioxidant and cytotoxicity of extracts, were determined. Results showed that the three extracts inhibited the lipopolysaccharide-induced nitric oxide, prostaglandin E₂, and interleukin 1β cytokine production significantly in a dose-dependent manner close to that of the positive controls. A study proposed that ethanol and water extracts of Psilocybe natalensis mushroom were safe at concentrations used, and have antioxidant and anti-inflammatory effects. Phytochemical analysis confirmed the presence of natural antioxidant and anti-inflammatory compounds in the mushroom extracts.

Triketone-terpene meroterpenoids from the leaves of Rhodomyrtus tomentosa

Eight new meroterpenoids (1-8) featuring β-triketone-conjugated terpenoids, rtomentones A-H, were isolated from the leaves of Rhodomyrtus tomentosa. Structures of the isolates were unambiguously established by a combination of NMR and ECD spectroscopy and X-ray diffraction analysis. Rtomentone C (3) was the first example of aromadendrane-based meroterpenoid containing an oxa-spiro[5.6] ring. Rtomentone D (4) was obtained as a racemic mixture confirmed by chiral HPLC analysis. The cytotoxicity against MDA-MB-231, A549, and DLD-1 cells of all isolates was evaluated.

Dectin-1/Syk signaling triggers neuroinflammation after ischemic stroke in mice

Background

Dendritic cell-associated C-type lectin-1 (Dectin-1) receptor has been reported to be involved in neuroinflammation in Alzheimer’s disease and traumatic brain injury. The present study was designed to investigate the role of Dectin-1 and its downstream target spleen tyrosine kinase (Syk) in early brain injury after ischemic stroke using a focal cortex ischemic stroke model.

Methods

Adult male C57BL/6 J mice were subjected to a cerebral focal ischemia model of ischemic stroke. The neurological score, adhesive removal test, and foot-fault test were evaluated on days 1, 3, 5, and 7 after ischemic stroke. Dectin-1, Syk, phosphorylated (p)-Syk, tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) expression was analyzed via western blotting in ischemic brain tissue after ischemic stroke and in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro. The brain infarct volume and Iba1-positive cells were evaluated using Nissl’s and immunofluorescence staining, respectively. The Dectin-1 antagonist laminarin (LAM) and a selective inhibitor of Syk phosphorylation (piceatannol; PIC) were used for the intervention.

Results

Dectin-1, Syk, and p-Syk expression was significantly enhanced on days 3, 5, and 7 and peaked on day 3 after ischemic stroke. The Dectin-1 antagonist LAM or Syk inhibitor PIC decreased the number of Iba1-positive cells and TNF-α and iNOS expression, decreased the brain infarct volume, and improved neurological functions on day 3 after ischemic stroke. In addition, the in vitro data revealed that Dectin-1, Syk, and p-Syk expression was increased following the 3-h OGD and 0, 3, and 6 h of reperfusion in BV2 microglial cells. LAM and PIC also decreased TNF-α and iNOS expression 3 h after OGD/R induction.

Conclusion

Dectin-1/Syk signaling plays a crucial role in inflammatory activation after ischemic stroke, and further investigation of Dectin-1/Syk signaling in stroke is warranted.

A new triterpenoid from the leaves of Rhodomyrtus tomentosa (Ait.) Hassk

A new triterpenoid, 2α, 3β, 23α, 29-tetrahydroxyolean-11, 13 (18)-dien-28, 19β-olide, named as rhodotomoside A (1), together with six known triterpenoids (2-7), were isolated from the leaves of Rhodomyrtus tomentosa (Ait.) Hassk by column chromatography on silica gel, reversed-phase C₁₈ silica gel and semi-preparative HPLC. Their structures were elucidated on the basis of spectroscopic methods, including extensive 1D NMR, 2D NMR and MS spectra. The inhibition rates of α-glucosidase of compound 1 was 77.82%, and exhibited inhibitory activity against α-glucosidase with IC₅₀ value at 0.213 ± 0.016 mg/mL.

Evaluation of a Rhodomyrtus tomentosa ethanolic extract for its therapeutic potential on Staphylococcus aureus infections using in vitro and in vivo models of mastitis

An ethanolic extract from Rhodomyrtus tomentosa leaves (RTL) was studied as a natural alternative to control Staphylococcus aureus, which is an important pathogen responsible for bovine mastitis. The minimal inhibitory concentrations (MICs) of the RTL extract and of rhodomyrtone, a pure compound isolated from the plant, were determined by a microdilution method. Rhodomyrtone and the RTL extract exhibited antibacterial activity against S. aureus, including its persistent phenotype (SCV: small-colony variant) and a biofilm hyperproducer strain, with MICs of 0.25–0.5 and 8–16 µg/mL, respectively. Time-kill kinetics showed a strong bactericidal activity for both the RTL extract- and rhodomyrtone-treated bacteria at 2 × MIC as early as 4 h post-exposure. An additive effect of the extract at 0.5 × MIC was observed in a combination with oxytetracycline or pirlimycin against S. aureus by showing a 64- to 128-fold reduction in antibiotic MICs. Moreover, the RTL extract significantly decreased the number of intracellular SCVs inside bovine mammary epithelial cells. However, the extract or its combination with pirlimycin only slightly improved the activity of pirlimycin against the bacterial colonization of mouse mammary glands. In vitro MICs determined in the presence of casein indicated that the limited activity of the RTL extract in the murine model of mastitis could be linked to neutralization of active components by milk proteins. While the RTL extract showed interesting antibacterial properties in vitro, to be considered as an alternative to antibiotics in dairy farms, formulation studies are needed to cope with the observed reduction of activity in vivo.

Mycetia cauliflora methanol extract exerts anti-inflammatory activity by directly targeting PDK1 in the NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Mycetia cauliflora Reinw. (Rubiaceae) has been used as a traditional remedy to ameliorate clinical signs of inflammatory diseases, including pain, inflammation, ulcers, and wounds. Among the Mycetia subfamilies, the molecular and cellular mechanisms of Mycetia longifolia (Rubiaceae) have been studied. However, those of Mycetia cauliflora are not clearly understood. Comprehensive investigation of this plant is necessary to evaluate its potential for ethnopharmacological use.

MATERIALS

and methods: The activities of Mycetia cauliflora methanol extract (Mc-ME) on the secretion of inflammatory mediators, the mRNA expression of proinflammatory cytokines, and identification of its molecular targets were elucidated using lipopolysaccharide (LPS)-induced macrophage-like cells. Moreover, the suppressive actions of Mc-ME were examined in an LPS-induced peritonitis mouse model.

RESULTS

At nontoxic concentrations, Mc-ME downregulated the release of nitric oxide (NO), the mRNA expression of inducible nitric oxide synthase (iNOS), and the mRNA expression of interleukin (IL)-1β from LPS-activated RAW264.7 cells. This extract also inhibited the nuclear translocation of p65 and p50 and the phosphorylation of IκBα, IKK, and AKT. Western blot analysis and in vitro kinase assays confirmed that phosphoinositide-dependent kinase-1 (PDK1) is the direct immunopharmacological target of Mc-ME effect. In addition, Mc-ME significantly reduced inflammatory signs in an animal model of acute peritonitis. These effects were associated with decreased NO production and decreased AKT phosphorylation.

CONCLUSION

Our results suggest that Mc-ME displays anti-inflammatory actions in LPS-treated macrophage-like cells and in an animal model of acute inflammatory disease. These actions are preferentially managed by targeting PDK1 in the nuclear factor (NF)-κB signaling pathway.

Syk: a new target for attenuation of Helicobacter pylori-induced gastric mucosal inflammatory responses

The magnitude of gastric mucosal inflammatory response to H. pylori relies primarily on the extent of its key endotoxin, LPS, engagement of Toll-like receptor-4 (TLR4) and the initiation of signal transduction events converging on mitogen-activated protein kinase (MAPK) and IκB complex (IKK) cascades. These cascades, in turn, exert their control over the assembly of transcription factors, NFκB and AP1, implicated in the induction of the expression of iNOS and COX-2 proinflammatory genes. The LPS-induced TLR4 activation and the ensuing phosphorylation of its intracellular tyrosine domain by Src-family kinases not only leads to recruitment to the cytoplasmic domain of TLR4 of adaptor molecules directly involved in propagation of the signaling cascades converging on MAPK and IKK, but also provides a propitious docking site for a non-receptor tyrosine kinase, spleen tyrosine kinase (Syk), the activation of which apparently leads to upregulation in the expression of proinflammatory genes. Here, we review the pathways engaged by H. pylori in the recruitment and interaction of Syk with TLR4 in gastric mucosa, and discuss the cascades involved in Syk-mediated amplification in proinflammatory signaling. We focus, moreover, on the potential role of drugs targeting Syk and TLR4 in the treatment of H. pylori-related gastric disease.

The Health Beneficial Properties of Rhodomyrtus tomentosa as Potential Functional Food

Rhodomyrtus tomentosa (Aiton) Hassk. is a flowering plant belonging to the family Myrtaceae, native to southern and southeastern Asia. It has been used in traditional Vietnamese, Chinese, and Malaysian medicine for a long time for the treatment of diarrhea, dysentery, gynecopathy, stomachache, and wound healing. Moreover, R. tomentosa is used to make various food products such as wine, tea, and jam. Notably, R. tomentosa has been known to contain structurally diverse and biologically active metabolites, thus serving as a potential resource for exploring novel functional agents. Up to now, numerous phenolic and terpenoid compounds from the leaves, root, or fruits of R. tomentosa have been identified, and their biological activities such as antioxidant, antibacterial, anti-inflammatory, and anticancer have been evidenced. In this contribution, an overview of R. tomentosa and its health beneficial properties was focused on and emphasized.

Structures and Bioactive Properties of Myrtucommulones and Related Acylphloroglucinols from Myrtaceae

Myrtaceae are a group of plants that include a number of renowned species used in ethnomedicine in many areas worldwide. Their valuable therapeutic properties have stimulated a fruitful research activity addressed to the identification of the bioactive components of their extracts yielding a great diversity of terpenes; polyphenols; and other exclusive products. Among the latter, starting with the discovery of myrtucommulone A from myrtle (Myrtus communis), a series of structurally-related acylphloroglucinol compounds have been characterized from several species that represent the basic active principles to be considered in view of possible drug development. Aspects concerning chemical and biological properties of these products are reviewed in the present paper.

Anti-allergic Inflammatory Effects of the Essential Oil From Fruits of Zanthoxylum coreanum Nakai

Zanthoxylum coreanum Nakai is a rare shrub which grows in Korea and China. Pericarp of Z. coreanum has been used as a crude medicine, but there are few researches about the pharmacologic activities. The present study was designed to investigate the anti-allergic inflammatory activities of the essential oil from fruits of Zanthoxylum coreanum Nakai (ZCO). Our findings showed that ZCO inhibited both the IgE-antigen complex or PMA/A23187-induced β-hexosaminidase release and IL-4 production dose-dependently in RBL-2H3 mast cells, and confirmed that ZCO at the tested concentrations did not show cytotoxicity to RBL-2H3 cells by MTS assay. Additionally, we found that ZCO showed the significant inhibition on LPS-induced overproduction of TNF-α, IL-6 and NO. Consistently, the protein levels of iNOS and COX-2 were also remarkably decreased by ZCO treatment. Herein, Our mechanistic studies revealed that ZCO significantly suppressed the activation of transcription factor NF-κB in PMA-activated 293T cells, and further inhibited NF-κB p65 translocation into the nucleus in LPS-stimulated RAW264.7 cells. Further investigation identified that ZCO down-regulated LPS-induced phosphorylation of MAPK (JNK, ERK, and p38) signal pathway. For incremental research, we established an DNCB-induced atopic dermatitis model in BALB/c mice, and found that ZCO remarkably inhibited DNCB-induced ear swelling and AD-like symptoms. Based on these findings, ZCO is suggested to have a therapeutic potential for the allergic inflammatory diseases.

Cytotoxic and anti-inflammatory active phloroglucinol derivatives from Rhodomyrtus tomentosa

Seven undescribed phloroglucinol derivatives, tomentodiones N-T, and eleven known ones were isolated from Rhodomyrtus tomentosa. Tomentodione N is the first example of a β-triketone unit coupled with an isoamyl alcohol through a furan fused-ring, and tomentodiones N, S, T were three racemates. The undescribed structures were elucidated by means of spectroscopic, X-ray diffraction, electronic circular dichroism calculation, and chemical methods. In addition, the isolated compounds were determined for the cytotoxic activities on HeLa cells and anti-inflammatory activities in LPS-stimulated RAW 264.7 cells.

Immune-related gene expression and physiological responses in rainbow trout (Oncorhynchus mykiss) after intraperitoneal administration of Rhodomyrtus tomentosa leaf extract: A potent phytoimmunostimulant

The immunostimulatory effects of Rhodomyrtus tomentosa leaf extract were evaluated in rainbow trout through changes in expression profile of genes involved in innate immune and antioxidant response, hematology and stress indicators. The concentrations of R. tomentosa at 10 and 100 μg per fish were administrated by intraperitoneal injection, alone or in combination with LPS. After 6 h of administration, the gene expression was measured in head kidney, spleen, and intestine. Results indicated that R. tomentosa exerted immunostimulatory effects by inducing the expression of il10, saa, hepcidin, and sod in head kidney and the expression of il10, tgfβ, and inos in intestine. In combination with LPS, the plant suppressed the expression of pro-inflammtory cytokine il1β, il8 and other consisting of saa and gpx1 in head kidney and il1β in spleen, pointing out its anti-inflammatory activities. Furthermore, the plant did not exert any impact on hematological parameters, but it was able to reduce cortisol levels when co-administered with LPS, indicating that R. tomentosa could attenuate stress response in rainbow trout. Our observations suggest that R. tomentosa induced the expression of genes involved in cytokine and innate immune response and modulated the physiological stress response as indicated by the suppressed cortisol in rainbow trout.

Evaluation of the anti-inflammatory activity of Tinospora cordifolia (Willd.) Miers chloroform extract – a preclinical study

Objectives

Tinospora cordifolia (Willd.) Miers is an inevitable ingredient of Ayurvedic rasayanas for the treatment of disorders with unregulated inflammation. However, studies regarding the mechanism of anti-inflammatory potential of this plant at the molecular level are lacking.

Methods

In vitro evaluations were conducted in RAW264.7 macrophages which were preincubated with chloroform extract of T. cordifolia (CETC) and subsequently stimulated with LPS. The expressions of COX-2, TNF-α and iNOS genes were analysed by SQRT-PCR and Western blot, cytokines (IL-6, IL-1β and PGE2) levels by ELISA, NF-κB activation and p38 MAPK phosphorylation by Immunoblot and confocal imaging. Anti-inflammatory potential of CETC was validated further in a rat model of carrageenan-induced hind paw edema. Phytochemical characterisation was carried out using the HPLC technique.

Key findings

The LPS-induced upregulation of proinflammatory biomarkers was significantly prevented by CETC, without inhibiting COX-1. CETC- and LPS-incubated cells showed reduced phosphorylated p38 MAPK levels, and higher levels NF-κB were retained in cytoplasm. Rats pretreated with CETC showed a statistically significant decrease in paw oedema (P ≤ 0.05), and HPLC characterisation detected stigmasterol and β-sitosterol. The LD50 of CETC lies above 2000 mg/Kg body weight.

Conclusions

These findings encourage us strongly to focus on CETC to develop anti-inflammatory drugs with lower degree of inhibition to the constitutively expressing COX-1.

Immunomodulatory effects of Rhodomyrtus tomentosa leaf extract and its derivative compound, rhodomyrtone, on head kidney macrophages of rainbow trout (Oncorhynchus mykiss)

Rhodomyrtus tomentosa is a medicinal plant that shows biological effects including immunomodulatory activity on human and other mammals but not in fish. In this study, we evaluated the in vitro immunomodulatory effects of R. tomentosa leaf extract and its active compound, rhodomyrtone, on the immune responses, using rainbow trout (Oncorhynchus mykiss) head kidney (HK) macrophages as a model. The tested immune functions included the expression of genes involved in innate immune and inflammatory responses and the production of reactive oxygen species (ROS). Gene expression was evaluated after exposure to 10 μg mL^-1 of R. tomentosa and 1 μg mL^-1 of rhodomyrtone for 4 and 24 h. R. tomentosa and rhodomyrtone induced changes in the expression of pro-inflammatory cytokines (il1β, il8, and tnfα), anti-inflammatory cytokines (il10 and tgfβ), inducible enzymes (inos, cox2, and arginase), and an antioxidant enzyme (gpx1). Co-exposure of R. tomentosa with LPS resulted in a prominent reduction in the expression of genes related to an inflammatory process (il1β, il8, tnfα, inos, saa, hepcidin, and gpx1), suggesting anti-inflammatory effects. Similarly, co-exposure of rhodomyrtone with LPS led to a downregulation of inflammation-related genes (il1β, inos, saa, and hepcidin). In addition, exposure to both natural plant products caused a reduction in cellular ROS levels by HK macrophages. The present results indicate that R. tomentosa and rhodomyrtone exerted immunostimulatory and anti-inflammatory effects on fish macrophages, thus opening up the possibility of using these natural products to further develop immunostimulants for health management in aquaculture.

Momordica charantia Inhibits Inflammatory Responses in Murine Macrophages via Suppression of TAK1

Momordica charantia known as bitter melon is a representative medicinal plant reported to exhibit numerous pharmacological activities such as antibacterial, antidiabetic, anti-inflammatory, anti-oxidant, antitumor, and hypoglycemic actions. Although this plant has high ethnopharmacological value for treating inflammatory diseases, the molecular mechanisms by which it inhibits the inflammatory response are not fully understood. In this study, we aim to identify the anti-inflammatory mechanism of this plant. To this end, we studied the effects of its methanol extract (Mc-ME) on lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Specifically, we evaluated nitric oxide (NO) production, mRNA expression of inflammatory genes, luciferase reporter gene activity, and putative molecular targets. Mc-ME blocked NO production in a dose-dependent manner in RAW264.7 cells; importantly, no cytotoxicity was observed. Moreover, the mRNA expression levels of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 were decreased by Mc-ME treatment in a dose-dependent manner. Luciferase assays and nuclear lysate immunoblotting analyses strongly indicated that Mc-ME decreases the levels of p65 [a nuclear factor (NF)-[Formula: see text]B subunit] and c-Fos [an activator protein (AP)-1 subunit]. Whole lysate immunoblotting assays, luciferase assays, and overexpression experiments suggested that transforming growth factor [Formula: see text]-activated kinase 1 (TAK1) is targeted by Mc-ME, thereby suppressing NF-[Formula: see text]B and AP-1 activity via downregulation of extracellular signal-regulated kinases (ERKs) and AKT. These results strongly suggest that Mc-ME exerts its anti-inflammatory activity by reducing the action of TAK1, which also affects the activation of NF-[Formula: see text]B and AP-1.

Syk - GTP RAC-1 mediated immune-stimulatory effect of Cuscuta epithymum, Ipomoea batata and Euphorbia hirta plant extracts

Polymorphonuclear neutrophils (PMNn) are the pivotal mediators of phagocytosis. In addition to neutropenia, impaired neutrophilic function is associated with pathological conditions and immuno-deficiencies. Henceforth, Immuno-stimulatory strategies targeting neutrophilic function are indeed powerful tools in combating obstinate infections. In appreciation towards the usefulness of herbal medicines in therapeutic scenario, the present study was carried out to analyse the immuno-stimulatory effect of Cuscuta epithymum, Ipomoea batata and Euphorbia hirta using in-vitro and in-vivo rodent experimental models. Throughout the experimentation, phagocytosis was studied and expressed as phagocytotic index and percentage phagocytosis. Different extracts of these plants were initially screened for their potency to induce phagocytosis in PMNn and the methanolic fractions, which are effective, were considered for further experimentation.The phagocytosis stimulation by the methanolic extracts was compared with the standard Granulocyte Macrophage - Colony Stimulating Factor (GM-CSF) at a dose of 65ng/ml. Immunoblotting analysis shown that the methanolic extracts induce the phosphorylation of Syk which in turn phosphorylates GDP-RAC-1, hinting the possible mechanism of action. Following these in vitro investigations, the potency of methanolic extracts was assessed using rat model by performing carbon clearance assay, Delayed Type Hypersensitivity and antibody titre.The phosphorylation status of Syk and GDP-RAC-1 was also assessed in the edematous fluid collected from the right hind paw. In vivo findings were in agreement with the in vitro findings by presenting an improved immune response and increased phosphorylation of Syk and GDP-RAC-1. Conclusively, this study provides the initial insights into the therapeutic implications of the tropical plants in inducing phagocytosis.

Rhodomyrtus tomentosa Leaf Extract Inhibits Methicillin-Resistant Staphylococcus aureus Adhesion, Invasion, and Intracellular Survival in Human HaCaT Keratinocytes

Methicillin-resistant Staphylococcus aureus (MRSA) has an ability to invade nonprofessional phagocytic cells, resulting in persistent infections and most likely host cell death. Series of our studies have claimed pronounced antibacterial efficacy of Rhodomyrtus tomentosa leaf extract. This study was to further investigate potency of the extract in intracellular killing of human HaCaT keratinocytes. Pretreatment of MRSA with the extract resulted in a remarkable reduction in the bacterial adhesion to HaCaT keratinocytes, compared with untreated control (p < 0.001). In addition, at least 60% inhibition of the bacterial invasion into HaCaT cells was observed. Intracellular killing assay demonstrated that the extract exhibited strong antibacterial activity against intracellular MRSA at nontoxic concentrations (128 mg/L), which may have resulted from the increase in bactericidal activity under phagolysosomal pH. Transmission electron microscopy displayed the effects of the extract on alterations in the bacterial cell morphology with cell lysis. Fluorescence microscopy revealed that the extract decreased MRSA-induced apoptosis in HaCaT cells. In addition, cytotoxicity of HaCaT cells caused by MRSA supernatant was reduced at least 50% by the extract. The potential activities of R. tomentosa extract may be useful in an alternative treatment of MRSA infections in slight acidic compartments, particularly skin infections.

Watsonianone A from Rhodomyrtus tomentosa Fruit Attenuates Respiratory-Syncytial-Virus-Induced Inflammation In Vitro

Respiratory syncytial virus (RSV) is one of the most common respiratory pathogens. Immoderate inflammation plays a great role in causing RSV-induced diseases. In the present study, watsonianone A, isolated from the fruit of Rhodomyrtus tomentosa (Ait.) Hassk, was found to show a good inhibitory effect on RSV-induced NO production, with a half-maximal inhibitory concentration of 37.2 ± 1.6 μM. Enzyme-linked immunosorbent assay and fluorescence quantitative polymerase chain reaction analyses indicated that watsonianone A markedly reduced both mRNA and protein levels of tumor necrosis factor α, interleukin 6, and monocyte chemoattractant protein 1 in RSV-infected RAW264.7 cells. Mechanistically, watsonianone A inhibited nuclear factor κB (NF-κB) activation by suppressing IκBα phosphorylation. Further analysis revealed that watsonianone A activated the thioredoxin system and decreased intracellular reactive oxygen species (ROS) levels, which are closely associated with NF-κB activation in RSV-infected cells. These results reveal that watsonianone A can attenuate RSV-induced inflammation via the suppression of ROS-sensitive inflammatory signaling.

In vitro and in vivo assessments of Rhodomyrtus tomentosa leaf extract as an alternative anti-streptococcal agent in Nile tilapia (Oreochromis niloticus L.)

PURPOSE

Rhodomyrtustomentosa is a Thai medicinal plant that has been attracting attention for its remarkable antibacterial properties against Gram-positive pathogenic bacteria. The purpose of this study was to evaluate the antibacterial properties of R. tomentosa leaf extract against Streptococcus agalactiae and Streptococcus iniae isolated from infected tilapia.

METHODOLOGY

The anti-streptococcal activity of R. tomentosa was determined using broth microdilution assays.

RESULTS

The extract demonstrated strong antibacterial activity against the fish pathogens, with minimum inhibitory concentrations (MICs) ranging from 7.8‒62.5 µg ml-1. It was found to possess a dose-dependent bacteriostatic effect on this organism. Scanning electron microscopy revealed irregular and long chains of swollen cells, as well as corkscrew shapes andincomplete separation of cell division of S. agalactiae cells following the treatment at sub-MIC. Moreover, S. agalactiae cells pre-treated with the extract became more sensitive to oxidative stress induced by H2O2 than the untreated cells. Based on the mortality of Nile tilapia after intraperitoneal infection of S. agalactiae at median lethal dose (LD50), the pre-treated cells caused a significant (P<0.01) reduction in mortality of S. agalactiae-infected Nile tilapia.

CONCLUSION

The results suggested that R. tomentosa could be further developed as a simple and effective agent for the treatment of streptococcosis in Nile tilapia.

Chemical constituents and anti-inflammatory activities of Maqian (Zanthoxylum myriacanthum var. pubescens) bark extracts

In this study, 44 compounds in the petroleum ether extract of Maqian (Zanthoxylum myriacanthum var. pubescens) bark, a traditional Dai herbal medicine, were identified by GC-MS. Major components included 3(2H)-benzofuranone, asarinin and (dimethoxymethyl)-3-methoxy-benzene. A total of 18 compounds were isolated from the ethyl acetate extracts of Maqian bark by column chromatography and identified by chemical and spectral analyses. Rhoifoline B, zanthoxyline dimethoxy derivative, N-nortidine, nitidine, decarine are the major alkaloids. Both the petroleum ether and ethyl acetate extracts showed significant inhibition on NO production, which imply anti-inflammatory activity, in lipopolysaccharide-induced RAW 264.7 cells without cell toxicity. Decarine is the major anti-inflammatory constituent with NO IC₅₀ values of 48.43 μM on RAW264.7 cells. The petroleum ether extract, the ethyl acetate extract and decarine showed anti-inflammatory activities through inhibiting TNF-α and IL-1β production in lipopolysaccharide-stimulated THP-1 cells without cell toxicity too. Decarine showed anti-inflammatory activity on human colon cells by reducing IL-6 and IL-8 production in TNF-α+IL-1β-induced Caco-2 cells. These results support the use of Maqian bark as a remedy for enteritis and colitis recorded by Dai medicine in China, and elucidate the major pharmacological compounds in Maqian bark.

The dichloromethane fraction from Mahonia bealei (Fort.) Carr. leaves exerts an anti-inflammatory effect both in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Mahonia bealei has a long history of medical use in traditional Chinese medicine for the treatment of inflammatory-associated diseases. Despite numerous phytochemical and pharmacological studies, there is a lack of systematic studies to understand the cellular and molecular mechanisms of the anti-inflammatory activity of this plant.

AIM OF STUDY

This study aimed to evaluate the anti-inflammatory activity of the dichloromethane fraction from M. bealei leaves (MBL-CH).

MATERIALS AND METHODS

RAW 264.7 cells were pretreated with different concentrations of MBL-CH for 30min prior to treatment with 1μg/ml of lipopolysaccharide (LPS). The nuclear factor κB (NF-κB) pathway and subsequent production of inflammatory mediators, such as nitric oxide (NO), prostaglandin E2 (PGE2), and tumour necrosis factor (TNF)-α were investigated. Furthermore, the in vivo mouse model of LPS-induced acute lung injury (ALI) was employed to study the anti-inflammatory effects of MBL-CH.

RESULTS

Pre-treatment with MBL-CH significantly inhibited the LPS-stimulated secretion of NO, PGE2, and TNF-α into the culture medium, as well as the mRNA levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and TNF-α, which were associated with a reduction in the phosphorylation of IκBα, Akt, and PI3K and inhibition of the transcriptional activity of NF-κB. Furthermore, in vivo experiments revealed that MBL-CH attenuated LPS-stimulated lung inflammation in mice.

CONCLUSION

Taken together, our findings indicate that MBL-CH attenuates LPS-stimulated inflammatory responses in macrophages by blocking NF-κB activation through interference with activation of the PI3K/Akt pathway, providing scientific evidence that the plant can be employed in traditional remedies.

Flavonoids as Cytokine Modulators: A Possible Therapy for Inflammation-Related Diseases

High levels of cytokines, such as interleukin (IL)-1β, tumor necrosis factor (TNF)-α and IL-6, are associated with chronic diseases like rheumatoid arthritis, asthma, atherosclerosis, Alzheimer's disease and cancer; therefore cytokine inhibition might be an important target for the treatment of these diseases. Most drugs used to alleviate some inflammation-related symptoms act by inhibiting cyclooxygenases activity or by blocking cytokine receptors. Nevertheless, these drugs have secondary effects when used on a long-term basis. It has been mentioned that flavonoids, namely quercetin, apigenin and luteolin, reduce cytokine expression and secretion. In this regard, flavonoids may have therapeutical potential in the treatment of inflammation-related diseases as cytokine modulators. This review is focused on current research about the effect of flavonoids on cytokine modulation and the description of the way these compounds exert their effect.

Effects of Rhodomyrtus tomentosa Leaf Extract on Staphylococcal Adhesion and Invasion in Bovine Udder Epidermal Tissue Model

Bovine mastitis is one of the most important infectious diseases in dairy herds, and staphylococci are the most important etiologic agents of this disease. Antibiotics and chemical agents used in livestock for prevention and cure of the disease can accumulate in milk and give rise to food safety concerns. Rhodomyrtus tomentosa leaf extract was studied as an alternative approach to reduce the bacterial infections. The ethanolic extract of this plant demonstrated antibacterial activity with minimum inhibitory concentration (MIC) values as low as 16–64 μg/mL against staphylococcal isolates. In addition, the extract had an effect on the bacterial cell surface properties by increasing its hydrophobicity in a concentration dependent manner. To further extend the antibacterial efficacy, silver nanoparticles synthesized with the extract, a pure rhodomyrtone, and liposomal encapsulated rhodomyrtone were applied and their inhibitory effects on bacterial adhesion and invasion were determined by ex vivo study in a bovine udder epidermal tissue model. These agents exerted remarkable antibacterial activity against staphylococci and decreased the adhesion of the bacterial cells to the tissues. These results supported that R. tomentosa ethanolic extract could be applied as an alternative agent for bovine udder care in dairy farms.

The Syk Inhibitor Fostamatinib Decreases the Severity of Colonic Mucosal Damage in a Rodent Model of Colitis

BACKGROUND AND AIMS

Inflammatory bowel disease is a chronic inflammatory disease of the gastrointestinal system. In some cases, current medications used for inflammatory bowel disease may not be enough for remission, creating a need for more potent and reliable medications. There is no study showing the efficacy of fostamatinib, with proven effects on some inflammatory diseases, on ulcerative colitis. In our study we planned to research the efficacy of fostamatinib, a spleen tyrosine kinase inhibitor, on acetic acid-induced colitis.

METHODS

The study included 28 male Sprague-Dawley rats, randomly divided into control group, fostamatinib group, colitis group and fostamatinib + colitis group, each containing seven rats. Colitis induction was performed with 4% acetic acid. Colonic inflammation was assessed with disease activity index, macroscopic and histological damage scores, colonic myeloperoxidase, malondialdehyde and superoxide dismutase activity, and tumour necrosis factor alpha [TNFα], CD3, Syk, and phospho-Syk expression.

RESULTS

There was a significant difference between the colitis and control groups in terms of all parameters. The disease activity index, macroscopic and microscopic damage scores, immunohistochemical TNFα, CD3, Syk, and phospho-Syk expression, and tissue myeloperoxidase activity were found to be significantly lower in the colitis + fostamatinib group compared with the colitis group. There was no significant difference between the two groups in terms of myeloperoxidase and malondialdehyde activity.

CONCLUSIONS

Fostamatinib reduced the inflammatory damage in the experimental colitis. This effect may be due to suppression of TNFα, T-lymphocytes, and neutrophils in colonic mucosa via suppression of Syk. Fostamatinib may be an appropriate treatment alternative for ulcerative colitis. Further clinical studies are required to support this.

Potential Bio-Control Agent from Rhodomyrtus tomentosa against Listeria monocytogenes

Listeria monocytogenes is an important foodborne pathogen implicated in many outbreaks of listeriosis. This study aimed at screening for the potential use of Rhodomyrtus tomentosa ethanolic leaf extract as a bio-control agent against L. monocytogenes. Twenty-two L. monocytogenes isolates were checked with 16 commercial antibiotics and isolates displayed resistance to 10 antibiotics. All the tested isolates were sensitive to the extract with inhibition zones ranging from 14 to 16 mm. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranged from 16 to 32 µg/mL and 128 to 512 µg/mL, respectively. Time-kill assay showed that the extract had remarkable bactericidal effects on L. monocytogenes. The extract at a concentration of 16 µg/mL reduced tolerance to 10% NaCl in L. monocytogenes in 4 h. Stationary phase L. monocytogenes cells were rapidly inactivated by greater than 3-log units within 30 min of contact time with R. tomentosa extract at 128 µg/mL. Electron microscopy revealed fragmentary bacteria with changes in the physical and morphological properties. Our study demonstrates the potential of the extract for further development into a bio-control agent in food to prevent the incidence of L. monocytogenes contamination.

Fisetin Suppresses Macrophage-Mediated Inflammatory Responses by Blockade of Src and Syk

Flavonoids, such as fisetin (3,7,3′,4′-tetrahydroxyflavone), are plant secondary metabolites. It has been reported that fisetin is able to perform numerous pharmacological roles including anti-inflammatory, anti-microbial, and anti-cancer activities; however, the exact anti-inflammatory mechanism of fisetin is not understood. In this study, the pharmacological action modes of fisetin in lipopolysaccharide (LPS)-stimulated macrophage-like cells were elucidated by using immunoblotting analysis, kinase assays, and an overexpression strategy. Fisetin diminished the release of nitric oxide (NO) and reduced the mRNA levels of inducible NO synthase (iNOS), tumor necrosis factor (TNF)-α, and cyclooxygenase (COX)-2 in LPS-stimulated RAW264.7 cells without displaying cytotoxicity. This compound also blocked the nuclear translocation of p65/nuclear factor (NF)-κB. In agreement, the upstream phosphorylation events for NF-κB activation, composed of Src, Syk, and IκBα, were also reduced by fisetin. The phospho-Src level, triggered by overexpression of wild-type Src, was also inhibited by fisetin. Therefore, these results strongly suggest that fisetin can be considered a bioactive immunomodulatory compound with anti-inflammatory properties through suppression of Src and Syk activities.

Scutellarein Reduces Inflammatory Responses by Inhibiting Src Kinase Activity

Flavonoids are plant pigments that have been demonstrated to exert various pharmacological effects including anti-cancer, anti-diabetic, anti-atherosclerotic, anti-bacterial, and anti-inflammatory activities. However, the molecular mechanisms in terms of exact target proteins of flavonoids are not fully elucidated yet. In this study, we aimed to evaluate the anti-inflammatory mechanism of scutellarein (SCT), a flavonoid isolated from Erigeron breviscapus, Clerodendrum phlomidis and Oroxylum indicum Vent that have been traditionally used to treat various inflammatory diseases in China and Brazil. For this purpose, a nitric oxide (NO) assay, polymerase chain reaction (PCR), nuclear fractionation, immunoblot analysis, a kinase assay, and an overexpression strategy were employed. Scutellarein significantly inhibited NO production in a dose-dependent manner and reduced the mRNA expression levels of inducible NO synthase (iNOS) and tumor necrosis factor (TNF)-α in lipopolysaccharide (LPS)-activated RAW264.7 cells. In addition, SCT also dampened nuclear factor (NF)-κB-driven expression of a luciferase reporter gene upon transfection of a TIR-domain-containing adapter-inducing interferon-β (TRIF) construct into Human embryonic kidney 293 (HEK 293) cells; similarly, NF-κ B nuclear translocation was inhibited by SCT. Moreover, the phosphorylation levels of various upstream signaling enzymes involved in NF-κB activation were decreased by SCT treatment in LPS-treated RAW264.7 cells. Finally, SCT strongly inhibited Src kinase activity and also inhibited the autophosphorylation of overexpressed Src. Therefore, our data suggest that SCT can block the inflammatory response by directly inhibiting Src kinase activity linked to NF-κB activation.

Antileishmanial activity of essential oil and 6,7-dehydroroyleanone isolated from Tetradenia riparia

Tetradenia riparia plant is used as a traditional medicine in Africa for the treatment of inflammatory and infectious diseases as like parasitic. Therapy for leishmaniasis caused by Leishmania (Leishmania) amazonensis specie often fails, and the conventional drugs are toxic, expensive, require a long period of treatment, and adverse effects are common. The alternative therapies using natural products are inexpensive and have few or any adverse reaction. These reasons are sufficient to investigate the new natural therapeutic for leishmaniasis. We evaluated the potential of the essential oil (TrEO) and 6,7-dehydroroyleanone (TrROY) isolated from T. riparia on L. (L.) amazonensis promastigote and amastigote forms, cytotoxicity on human erythrocytes and murine macrophages, nitric production and inducible nitric oxide synthase (iNOS) mRNA expression. TrEO was the most effective to promote the Leishmania promastigote death. After 72 h incubation, the lethal dose of TrEO and TrROY that promoted 50% Leishmania death (LD50) were 0.8 μg/mL and 3 μg/mL, respectively. TrEO and TrROY were not cytotoxic to human erythrocytes, but TrROY was toxic to murine macrophages resulting in a low selectivity index. The transmission electronic microscopy showed that TrEO (0.03 μg/mL) was able to modify the promastigote ultrastructures suggesting autophagy as chromatin condensation, blebbing, membranous profiles and nuclear fragmentation. Infected-macrophages treated with TrEO (0.03 μg/mL) or TrROY (10 μg/mL) had an infection index decreased in 65 and 48%. TrEO did not induce iNOS mRNA expression or nitrite production in macrophages infected with Leishmania. TrROY and mainly TrEO promoted the Leishmania death, and TrROY showed loss toxicity to erythrocytes cells. Other compounds derived from T. riparia and the essential oil could be explored to develop a new alternative treatment for leishmaniasis.

In vivo and in vitro anti-inflammatory activities of Persicaria chinensis methanolic extract targeting Src/Syk/NF-κB

ETHNOPHARMACOLOGIC RELEVANCE

Persicaria chinensis L. (Polygonaceae) [also synonym as Polygonum chimnense L.] has been used as Chinese traditional medicine to treat ulcer, eczema, stomach ache, and various inflammatory skin diseases. Due to no molecular pharmacological evidence of this anti-inflammatory herbal plant, we investigated the inhibitory mechanisms and target proteins contributing to the anti-inflammatory responses of the plant by using its methanolic extract (Pc-ME).

MATERIALS AND METHODS

We used lipopolysaccharide (LPS)-treated macrophages and a murine HCl/EtOH-induced gastritis model to evaluate the anti-inflammatory activity of Pc-ME. HPLC analysis was employed to identify potential active components of this extract. Molecular approaches including kinase assays, reporter gene assays, immunoprecipitation analysis, and overexpression of target enzymes were used to confirm target enzymes.

RESULTS

Pc-ME inhibited LPS-induced nitric oxide and prostaglandin E2 release by RAW264.7 macrophages and ameliorated HCl/EtOH-induced gastric ulcers in mice. The nuclear translocation of NF-κB (p65 and p50) was suppressed by Pc-ME. Phosphorylation of Src and Syk, their kinase activities, and formation of the signaling complex of these proteins were repressed by Pc-ME. Phosphorylation of p85 and Akt induced by Src or Syk overexpression was blocked by Pc-ME. In the mouse gastritis model, orally administered Pc-ME suppressed the increased phosphorylation of IκBα, Αkt, Src, and Syk. Caffeic acid, kaempferol, and quercetin, identified as major anti-inflammatory components of Pc-ME by HPLC, displayed strong nitric oxide inhibitory activity in LPS-treated macrophages.

CONCLUSION

Pc-ME might play a pivotal ethnopharmacologic role as an anti-inflammatory herbal medicine by targeting Syk and Src kinases and their downstream transcription factor NF-κB.

Rhodomyrtone modulates innate immune responses of THP-1 monocytes to assist in clearing methicillin-resistant Staphylococcus aureus

BACKGROUND

The increasing resistance of Staphylococcus aureus to conventional antibiotics poses a major health problem. Moreover, S. aureus can survive within phagocytes, thus evading some antibiotics and the innate immune response. Rhodomyrtone, a bioactive compound from the leaves of Rhodomyrtus tomentosa, possesses potent antibacterial activity against methicillin-resistant S. aureus (MRSA). This study was to investigate the immunomodulatory effects of rhodomyrtone on THP-1 monocytes in response to MRSA.

METHODS

THP-1 monocytes were stimulated with heat-killed MRSA, followed by treatment with rhodomyrtone. The cell pellets were prepared to detect pro-inflammatory molecules using real-time PCR. The supernatants were collected to assess nitric oxide production using Griess assay. Assays for phagocytosis and bacterial killing by THP-1 monocytes were performed to determine if they were affected by rhodomyrtone.

RESULTS

Expression of pro-inflammatory molecules including IL-1β, TNF-α, IL-6, and iNOS was enhanced in THP-1 monocytes stimulated with high doses of heat-killed MRSA (108 to 109 cfu/ml). In contrast, monocytes stimulated with MRSA at lower doses (106 to 107 cfu/ml) did not induce the expression of these cytokines. However, rhodomyrtone significantly increased the expression of pro-inflammatory mediators, IL-6 and iNOS in monocytes stimulated with heat-killed MRSA at low doses, and displayed some anti-inflammatory activity by reducing TNF-α expression in monocytes stimulated with heat-killed MRSA at high doses. Treatment with rhodomyrtone also significantly up-regulated the expression of the key pattern recognition receptors, TLR2 and CD14, in THP-1 monocytes stimulated with heat-killed MRSA at 106 to 109 cfu/ml, while heat-killed MRSA alone did not induce the expression of these molecules. The ability of rhodomyrtone to eliminate MRSA from the monocytes was observed within 24 h after treatment.

CONCLUSION

Rhodomyrtone enhanced the expression of pattern recognition receptors by monocytes in response to MRSA. Increased expression of these receptors might improve MRSA clearance by modulating pro- and anti-inflammatory cytokine responses.

HS-23, Lonicera japonica extract, attenuates septic injury by suppressing toll-like receptor 4 signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Lonicera japonica Thunberg is a traditional herbal medicine widely used in East Asia as an anti-bacterial, anti-inflammatory, and antiviral agent. This study was designed to investigate the effects of HS-23, ethanol extract of the dried flower buds of Lonicera japonica, in experimental models of sepsis and elucidate the mechanisms of action of HS-23.

MATERIALS AND METHODS

Male ICR mice were intravenously administered HS-23 (20 and 40 mg/kg) for 0 (immediately) and 24 h after cecal ligation and puncture (CLP) for survival tests, and HS-23 (40 mg/kg) immediately after CLP for biochemical assays.

RESULTS

HS-23 improved sepsis-induced mortality, enhanced bacterial clearance, and attenuated multiple organ failure. The mechanisms of action of HS-23 included attenuation of increased toll-like receptor (TLR)4 protein and mRNA expression. HS-23 suppressed sepsis-induced increases in protein expression of myeloid differentiation primary response protein 88, p38 and c-Jun N-terminal kinase in both liver and lung, as well as TIR-domain-containing adapter-inducing interferon-β and interferon regulatory transcription factor 3 protein expression in liver.

CONCLUSION

The results of this study revealed that HS-23 attenuated sepsis through suppression of TLR signaling pathways. Therefore, our findings suggest that HS-23 might be useful as a potential therapeutic agent for treatment of sepsis.