Xanthii fructus inhibits inflammatory responses in LPS-stimulated RAW 264.7 macrophages through suppressing NF-κB and JNK/p38 MAPK

Natural product/diet-based regulation of macrophage polarization: Implications in treatment of inflammatory-related diseases and cancer

Macrophages are phagocytic cells with important physiological functions, including the digestion of cellular debris, foreign substances, and microbes, as well as tissue development and homeostasis. The tumor microenvironment (TME) shapes the aggressiveness of cancer, and the biological and cellular interactions in this complicated space can determine carcinogenesis. TME can determine the progression, biological behavior, and therapy resistance of human cancers. The macrophages are among the most abundant cells in the TME, and their functions and secretions can determine tumor progression. The education of macrophages to M2 polarization can accelerate cancer progression, and therefore, the re-education and reprogramming of these cells is promising. Moreover, macrophages can cause inflammation in aggravating pathological events, including cardiovascular diseases, diabetes, and neurological disorders. The natural products are pleiotropic and broad-spectrum functional compounds that have been deployed as ideal alternatives to conventional drugs in the treatment of cancer. The biological and cellular interactions in the TME can be regulated by natural products, and for this purpose, they enhance the M1 polarization of macrophages, and in addition to inhibiting proliferation and invasion, they impair the chemoresistance. Moreover, since macrophages and changes in the molecular pathways in these cells can cause inflammation, the natural products impair the pro-inflammatory function of macrophages to prevent the pathogenesis and progression of diseases. Even a reduction in macrophage-mediated inflammation can prevent organ fibrosis. Therefore, natural product-mediated macrophage targeting can alleviate both cancerous and non-cancerous diseases.

Inhibition of macrophage MAPK/NF-κB pathway and Th2 axis by mangiferin ameliorates MC903-induced atopic dermatitis

Available online Atopic dermatitis (AD) is a chronic, persistent inflammatory skin disease characterized by eczema-like lesions and itching. Although topical steroids have been reported for treating AD, they are associated with adverse effects. Thus, safer medications are needed for those who cannot tolerate these agents for long periods. Mangiferin (MAN) is a flavonoid widely found in many herbs, with significant anti-inflammatory and immunomodulatory activities. However, the potential modulatory effects and mechanisms of MAN in treating Th2 inflammation in AD are unknown. In the present study, we reported that MAN could reduce inflammatory cell infiltration and scratching at the lesion site by decreasing MC903-induced levels of Th2-type cytokines, Histamine, thymic stromal lymphopoietin, Leukotriene B4, and immunoglobulin E. The mechanism may be related to reductions in MAPK and NF-κB-associated protein phosphorylation by macrophages. The results suggested that MAN may be a promising therapeutic agent for AD.

Improved colonic inflammation by nervonic acid via inhibition of NF-κB signaling pathway of DSS-induced colitis mice

BACKGROUND

Nervonic acid (C24:1^∆15, 24:1 ω-9, cis-tetracos-15-enoic acid; NA), a long-chain monounsaturated fatty acid, plays an essential role in prevention of metabolic diseases, and immune regulation, and has anti-inflammatory properties. As a chronic, immune-mediated inflammatory disease, ulcerative colitis (UC) can affect the large intestine. The influences of NA on UC are largely unknown.

PURPOSE

The present study aimed to decipher the anti-UC effect of NA in the mouse colitis model. Specifically, we wanted to explore whether NA can regulate the levels of inflammatory factors in RAW264.7 cells and mouse colitis model.

METHODS

To address the above issues, the RAW264.7 cell inflammation model was established by lipopolysaccharide (LPS), then the inflammatory factors tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-1β (IL-1β), and Interleukin-10 (IL-10) were detected by Enzyme-linked immunosorbent assay (ELISA). The therapeutic effects of NA for UC were evaluated using C57BL/6 mice gavaged dextran sodium sulfate (DSS). Hematoxylin and eosin (H&E) staining, Myeloperoxidase (MPO) kit assay, ELISA, immunofluorescence assay, and LC-MS/MS were used to assess histological changes, MPO levels, inflammatory factors release, expression and distribution of intestinal tight junction (TJ) protein ZO-1, and metabolic pathways, respectively. The levels of proteins involved in the nuclear factor kappa-B (NF-κB) pathway in the UC were investigated by western blotting and RT-qPCR.

RESULTS

In vitro experiments verified that NA could reduce inflammatory response and inhibit the activation of key signal pathways associated with inflammation in LPS-induced RAW264.7 cells. Further, results from the mouse colitis model suggested that NA could restore intestinal barrier function and suppress NF-κB signal pathways to ameliorate DSS-induced colitis. In addition, untargeted metabolomics analysis of NA protection against UC found that NA protected mice from colitis by regulating citrate cycle, amino acid metabolism, pyrimidine and purine metabolism.

CONCLUSION

These results suggested that NA could ameliorate the secretion of inflammatory factors, suppress the NF-κB signaling pathway, and protect the integrity of colon tissue, thereby having a novel role in prevention or treatment therapy for UC. This work for the first time indicated that NA might be a potential functional food ingredient for preventing and treating inflammatory bowel disease (IBD).

Megastigmane glycosides from Streblus ilicifolius (S.Vidal) Corner and their anti-inflammatory activity

Twelve undescribed megastigmane glycosides, streilicifolosides A-L (1-12), together with 8 known analogues (13-21) were isolated from the leaves of Streblus ilicifolius (S.Vidal) Corner. Their plannar structures were elucidated using extensive NMR spectroscopic methods (1D and 2D-NMR spectroscopy), and HRESIMS spectroscopic data analyses. The absolute configurations of the undescribed compounds were determined by the glucose-induced shift-trend, calculated and experimental circular dichroism spectroscopy. All the compounds were tested for inhibitory effects on the production of NO in LPS-treated RAW264.7 cells, and streilicifoloside E and platanionoside D exhibited potent anti-inflammatory activity comparable to that of the positive control, with IC₅₀ values of 26.33 and 21.84 μM, respectively. Furthermore, these two compounds markedly decreased the secretion of PGE2 and TNF-α and inhibited the expression of COX‒2, iNOS and NF-κB/p65 in LPS-induced RAW264.7 cells in a dose-dependent manner. In addition, the structure-activity relationships of the isolates were also discussed. The results suggest that streilicifoloside E and platanionoside D could be used as potential candidates for the development of new anti-inflammatory agents.

Sesquiterpene lactones-enriched fractions from Xanthium mongolicum Kitag alleviate RA by regulating M1 macrophage polarization via NF-κB and MAPK signaling pathway

Introduction: Rheumatoid arthritis (RA) is a chronic autoimmune disease, characterized by activated M1-like macrophage in the joint. Xanthium mongolicum Kitag (X. mongolicum) is a traditional medicinal plant that has long been used to treat RA and other immune diseases in China. Methods: Fractions of X. mongolicum were separated based on polarity. Anti-RA activity of the fractions were screened by LPS-stimulated RAW264.7 macrophage in vitro. The major active compounds were identified by UPLC-MS and quantified by HPLC. The anti-RA effects of the active fraction was evaluated in complete freund's adjuvant (CFA)-induced arthritis and collagen-induced arthritis (CIA) mouse models in vivo and LPS-stimulated macrophage in vitro. Results: Sesquiterpene lactones-enriched fraction from X. mongolicum (SL-XM) exhibited the strongest anti-RA activity among all components in vitro. Five major constituents i.e., Xanthinosin (1), Xanthatin (2), Mogolide D (3), Mogolide E (4), and Mogolide A (5) were identified as major compounds of SL-XM. SL-XM ameliorated symptoms of CFA and CIA induced arthritis mice model. Furthermore, SL-XM treatment inhibited LPS-induced M1 macrophages polarization. In addition, SL-XM inhibited the phosphorylation of NF-κB and MAPK signaling pathways in LPS-induced macrophage and CIA-challenged mice. Discussion: The main anti-RA active fraction of X. mongolicum may be the Sesquiterpene lactones, which includes five key compounds. SL-XM may exert its anti-RA effect by suppressing M1 macrophage polarization via the NF-κB and MAPK signaling pathway.

Gondoic acid alleviates LPS‑induced Kupffer cells inflammation by inhibiting ROS production and PKCθ/ERK/STAT3 signaling pathway

Kupffer cells (KCs) is the main macrophage in liver, and its inflammation is related to liver diseases. It has been shown that inflammatory macrophages are accompanied by changes in monounsaturated fatty acid (MUFA) content. However, the effect of gondoic acid (GA) on inflammation and its underlying mechanism have not been described. In the current study, we demonstrated that GA significantly inhibited the expression of pro-inflammatory factors in LPS-exposed KCs. Further research found that GA reduced lipopolysaccharide (LPS)-stimulated reactive oxygen species (ROS) levels and enhanced the expression of antioxidant genes. Meanwhile, GA obviously blocked the LPS-stimulated PKCθ/ERK/STAT3 signaling pathways to alleviate the inflammatory responses. These results demonstrated for the first time that GA improves KCs inflammation through the inhibition of ROS production and PKCθ/ERK/STAT3 signaling pathway, the results assist in the potential development of functional foods or prodrugs based on the GA rich plant oils.

Sesquiterpene lactones from Xanthium sibiricum Patrin alleviate asthma by modulating the Th1/Th2 balance in a murine model

BACKGROUND

Asthma is a complex airway disease involving a variety of cells and cytokines. Xanthium sibiricum Patrin ex Widder (X. sibiricum) is a traditional Chinese medicine for various immune diseases, especially allergic rhinitis and asthma. Sesquiterpene lactones are the main bioactive and most abundant constituent, and are characteristic component of the plant. We explore whether sesquiterpene lactones from X. sibiricum (SL-XS) is the main active constitute for its anti-asthma activity.

PURPOSE

In the present study, SL-XS was isolated, the major compounds were isolated and identified in extract of SL-XS, and the anti-asthma activity of SL-XS was validated in vivo.

METHODS

SL-XS was isolated by a standard phytochemical method. The structures of major sesquiterpene lactones were identified by NMR and LC-MS spectra. The contents of major SL-XS were analyzed by HPLC. The anti-asthma effect of SL-XS was evaluated in a house dust mite (HDM)-induced mouse model.

RESULTS

The sesquiterpene lactones were isolated from X. sibiricum, and five major constituents i.e., 8‑epi-xanthatin-1β, 5β-epoxide (1), tomentosin (2), 8‑epi-xanthatin (3), 2‑epi-xanthumin (4) and sibiriolide B (5) were identified from SL-XS. Oral administration of SL-XS dose-dependently ameliorated airway inflammation and remodeling in HDM-challenged asthma mouse model. Furthermore, SL-XS treatment inhibited the upregulation of proinflammatory and Th2 cytokines, while reversed the downregulation of Th1 related cytokines. In addition, SL-XS regulated the balance between T-bet and GATA-3. Moreover, SL-XS inhibited the upregulation of JAK1, p-JAK1, JAK2, p-JAK2, JAK3, p-JAK3 and p-STAT6 in HDM-challenged mice.

CONCLUSION

The sesquiterpene lactones including five major constituents may be the main anti-asthma active constituent of X. sibiricum. SL-XS exerted its anti-asthma effect by modulating the Th1/Th2 balance via the JAK/STAT signaling pathway.

A Newly Synthesized Flavone from Luteolin Escapes from COMT-Catalyzed Methylation and Inhibits Lipopolysaccharide-Induced Inflammation in RAW264.7 Macrophages via JNK, p38 and NF-κB Signaling Pathways

Luteolin is a common dietary flavone possessing potent anti-inflammatory activities. However, when administrated in vivo, luteolin becomes methylated by catechol-O-methyltransferases (COMT) owing to the catechol ring in the chemical structure, which largely diminishes its anti-inflammatory effect. In this study, we made a modification on luteolin, named LUA, which was generated by the chemical reaction between luteolin and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). Without a catechol ring in the chemical structure, this new flavone could escape from the COMT-catalyzed methylation, thus affording the potential to exert its functions in the original form when administrated in the organism. Moreover, an LPS-stimulated RAW cell model was applied to detect the anti-inflammatory properties. LUA showed much more superior inhibitory effect on LPS-induced production of NO than diosmetin (a major methylated form of luteolin) and significantly suppressed upregulation of iNOS and COX-2 in macrophages. LUA treatment dramatically reduced LPS-stimulated reactive oxygen species (ROS) and mRNA levels of pro-inflammatory mediators such as IL-1β, IL-6, IL-8 and IFN-β. Furthermore, LUA significantly reduced the phosphorylation of JNK and p38 without affecting that of ERK. LUA also inhibited the activation of NF-κB through suppression of p65 phosphorylation and nuclear translocation.

Anti-Inflammatory Activity and Mechanism of Cryptochlorogenic Acid from Ageratina adenophora

Ageratina adenophora is an invasive plant known for its toxicity to livestock. Current research on this plant has shifted from toxicity prevention to the beneficial utilization of plant resources. This study was performed to investigate the effects and mechanisms of cryptochlorogenic acid (CCGA) isolated from Ageratina adenophora on the inflammatory responses induced by lipopolysaccharide (LPS) in RAW264.7 cells. RAW264.7 cells were pretreated with CCGA (200, 100, and 50 μg/mL) and subsequently stimulated with LPS (1 μg/mL) for 16 h. The cytotoxicity of CCGA was tested using the Cell Counting Kit (CCK8). The mechanism of action of CCGA in attenuating inflammation was also identified using enzyme-linked immunosorbent assay (ELISA), quantitative reverse transcription-polymerase chain reaction, and Western blot. The results showed that CCGA had a maximal safe concentration of 200 mg/mL. Moreover, CCGA reduced the level of nitric oxide (NO) and iNOS in LPS-induced RAW264.7 cells (p < 0.01). In addition, CCGA reduced the levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-8) and cyclooxygenase-2 (COX-2) in LPS-induced RAW264.7 cells at both the mRNA and protein levels (p < 0.01). CCGA prevented the activation of nuclear factor-kappa B (NF-kB) in LPS-induced RAW264.7 cells via the inhibition of IKK and IκB phosphorylation and the degradation of IκB proteins (p < 0.01). This finding indicated that CCGA isolated from A. adenophora may be a potential candidate for the treatment of inflammation-related diseases.

Parathyroid hormone promotes the osteogenesis of lipopolysaccharide-induced human bone marrow mesenchymal stem cells through the JNK MAPK pathway

Periodontitis is a series of inflammatory processes caused by bacterial infection. Parathyroid hormone (PTH) plays a critical role in bone remodeling. The present study aimed to investigate the influences of PTH on human bone marrow mesenchymal stem cells (HBMSCs) pretreated with lipopolysaccharide (LPS). The proliferative ability was measured using cell counting kit-8 (CCK-8) and flow cytometry. The optimal concentrations of PTH and LPS were determined using alkaline phosphatase (ALP) activity assay, ALP staining, and Alizarin Red staining. Osteogenic differentiation was further assessed by quantitative reverse-transcription polymerase chain reaction (RT-qPCR), Western blot analysis, and immunofluorescence staining. PTH had no effects on the proliferation of HBMSCs. Also, 100 ng/ml LPS significantly inhibited HBMSC osteogenesis, while 10⁻⁹ mol/l PTH was considered as the optimal concentration to reverse the adverse effects. Mechanistically, c-Jun N-terminal kinase (JNK) phosphorylation was activated by PTH in LPS-induced HBMSCs. SP600125, a selective inhibitor targeting JNK mitogen-activated protein kinase (MAPK) signaling, weakened the effects of PTH. Taken together, the findings revealed the role and mechanism of PTH and JNK pathway in promoting the osteogenic differentiation of LPS-induced HBMSCs, which offered an alternative for treating periodontal diseases.

Solanum nigrum Line inhibits osteoclast differentiation and suppresses bone mineral density reduction in the ovariectomy‑induced osteoporosis model

Bone homeostasis is maintained by osteoclasts that absorb bone and osteoblasts that form bone tissue. Menopausal osteoporosis is a disease associated with aging and hormonal changes due to menopause causing abnormal activation of osteoclasts, resulting in a decrease in bone density. Existing treatments for osteoporosis have been reported to have serious side effects, such as jawbone necrosis and breast and uterine cancer; therefore, their use by patients is decreasing, whilst studies focusing on alternative treatments are increasingly popular. Solanum nigrum Line (SL) has been used as a medicinal plant that possesses several pharmacological effects, such as anti‑inflammatory and hepatotoxic protective effects. To the best of our knowledge, however, its effects on osteoporosis and osteoclasts have not been demonstrated previously. In the present study, the anti‑osteoporotic effect of SL was investigated using a postmenopausal model of osteoporosis in which Sprague‑Dawley rat ovaries were extracted. In addition, the inhibitory effects on osteoclast differentiation and function of SL was confirmed using an osteoclast model treated with receptor activator of NF‑κB ligand (RANKL) on murine RAW 264.7 macrophages. In vivo experiments showed that SL reduced the decrease in bone mineral density and improved changes in the morphological index of bone microstructure, such as trabecular number and separation. In addition, the number of tartrate resistant acid phosphatase‑positive cells in the femur and the expression levels of nuclear factor of activated T‑cells cytoplasmic 1 (NFATc1) and cathepsin K protein were inhibited. In vitro, SL suppressed RANKL‑induced osteoclast differentiation and bone resorption ability; this was mediated by NFATc1/c‑Fos, a key transcription factor involved in osteoclast differentiation, ultimately inhibiting expression of various osteoclast‑associated genes. These experimental results show that SL may be an alternative treatment for osteoporosis caused by abnormal activation of osteoclasts in the future.

Ethyl acetate fraction from Nymphaea hybrida Peck modulates inflammatory responses in LPS-stimulated RAW 264.7 cells and acute inflammation murine models

ETHNOPHARMACOLOGICAL RELEVANCE

Nymphaea hybrida Peck is used as a traditional medicinal herb for treating pain and inflammatory diseases, and known for its ornamental value and as a hot drink. However, the effects of N. hybrida polar fractions on lipopolysaccharide (LPS)-induced in vitro inflammation model and acute inflammation murine models have yet to be evaluated.

AIM OF THE STUDY

The aim of this study was to elucidate the anti-inflammatory effects of N. hybrida ethanol extract (NHE) and its polar fractions: petroleum ether (PE), methylene chloride (MC), ethyl acetate (EA), methanol (ME), and water (WA). The underlying molecular mechanisms of active fraction in LPS-stimulated RAW 264.7 murine macrophages were further investigated.

MATERIAL AND METHODS

Fractions with potential anti-inflammatory effects were screened using direct nitric oxide (NO) radical scavenging and cyclooxygenase (COX)-2 inhibition assays in vitro. The anti-inflammatory properties of potential fraction were evaluated in LPS-stimulated RAW264.7 cells, xylene-induced ear edema, carrageenan-induced paw edema and xylene-induced Evans blue exudation of acute inflammation murine models. The regulation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways were investigated using western blotting and immunofluorescence.

RESULTS

Compared to other polar fractions, NHE-EA displayed higher phenol and flavonoid content, and exerted greater activity in direct NO radical scavenging and COX-2 inhibition assay in vitro. NHE-EA markedly decreased the levels of inflammatory mediators, NO and prostaglandin E₂ (PGE₂), by suppressing the over-expression of inducible nitric oxide synthase (iNOS) and COX-2 in LPS-stimulated RAW264.7 cells. The NHE-EA fraction dose-dependently alleviated over-elevation of LPS-associated intracellular calcium and decreased the abnormal secretion of pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and interferon-γ (IFN-γ). The combination with NHE-EA effectively attenuated the activation and nuclear translocation of NF-κB p65, and the phosphorylation of extracellular signal-regulated kinases (ERK), c-Jun N-terminal kinases (JNK), and p38 kinases of MAPK pathways. NHE-EA could significantly ameliorate the degree of swelling of the mice ear and paw, the skin exudation of Evans blue and the excessive secretion of inflammatory cytokines.

CONCLUSION

Our results demonstrated that NHE-EA was the most active polar fraction of N. hybrida extracts. It inhibited the LPS-associated inflammatory response by blocking the activation of NF-κB and MAPKs pathways in RAW264.7 cells. It also effectively alleviated the inflammatory response of acute inflammation. These results indicated the role of NHE-EA as adjuvants and their potential role in alternative strategy for the treatment of inflammatory diseases.

The Adjuvant Effects on Vaccine and the Immunomodulatory Mechanisms of Polysaccharides From Traditional Chinese Medicine

Vaccination is still the most successful strategy to prevent and control the spread of infectious diseases by generating an adequate protective immune response. However, vaccines composed of antigens alone can only stimulate weak immunogenicity to prevent infection in many cases. Adjuvant can enhance the immunogenicity of the antigens. Therefore, adjuvant is urgently needed to strengthen the immune response of the vaccines. An ideal adjuvant should be safe, cheap, biodegradable and biologically inert. In addition to having a long shelf life, it can also promote cellular and humoral immune responses. Traditional Chinese medicine (TCM) has many different ingredients, such as glycosides, polysaccharides, acids, terpenes, polyphenols, flavonoids, alkaloids, and so on. TCM polysaccharides are one of the main types of biologically active substances. They have a large range of pharmacological activities, especially immunomodulatory. TCM polysaccharides can regulate the immune system of animals by binding to multiple receptors on the surface of immune cells and activating different signal pathways. This review focuses on a comprehensive summary of the most recent developments in vaccine adjuvant effects of polysaccharides from many important TCM, such as Artemisia rupestris L., Cistanche deserticola, Pinus massoniana, Chuanminshen violaceum, Astragalus, Ganoderma lucidum, Codonopsis pilosula, Lycium barbarum, Angelica, Epimedium, and Achyranthes bidentata. Moreover, this review also introduces their immunomodulatory effects and the molecular mechanisms of action on animal bodies, which showed that TCM polysaccharides can activate macrophages, the signal pathway of T/B lymphocytes, regulate the signal pathway of natural killer cells, activate the complement system, and so on.

Anti-Inflammatory Effects of a Polyphenol, Catechin-7,4'-O-Digallate, from Woodfordia uniflora by Regulating NF-κB Signaling Pathway in Mouse Macrophages

Inflammation is a defense mechanism that protects the body from infections. However, chronic inflammation causes damage to body tissues. Thus, controlling inflammation and investigating anti-inflammatory mechanisms are keys to preventing and treating inflammatory diseases, such as sepsis and rheumatoid arthritis. In continuation with our work related to the discovery of bioactive natural products, a polyphenol, catechin-7,4′-O-digallate (CDG), was isolated from Woodfordia uniflora, which has been used as a sedative and remedy for skin infections in the Dhofar region of Oman. Thus far, no study has reported the anti-inflammatory compounds derived from W. uniflora and the mechanisms underlying their action. To investigate the effects of CDG on the regulation of inflammation, we measured the reduction in nitric oxide (NO) production following CDG treatment in immortalized mouse Kupffer cells (ImKCs). CDG treatment inhibited NO production through the downregulation of inducible nitric oxide synthase expression in lipopolysaccharide (LPS)-stimulated ImKCs. The anti-inflammatory effects of CDG were mediated via the inhibition of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation, an important inflammatory-response-associated signaling pathway. Moreover, CDG treatment has regulated the expression of pro-inflammatory cytokines, such as IL-6 and IL-1β. These results suggested the anti-inflammatory action of CDG in LPS-stimulated ImKCs.

Anti-inflammatory effects of Fritillaria thunbergii Miquel extracts in LPS-stimulated murine macrophage RAW 264.7 cells

The aim of the present study was to demonstrate that Fritillaria thunbergii Miquel extract exerts anti-inflammatory and antioxidant effects on lipopolysaccharide-stimulated RAW 264.7 cells. To confirm the inhibitory effect of ethyl acetate fraction of FTM (EAFM) on inflammation, the expression of nitric oxide (NO) and inflammatory cytokines was assessed by performing ELISA. Expression of intracellular mRNA and protein was confirmed by reverse transcription PCR and western blotting. In addition, the anti-inflammatory and anti-oxidant mechanisms of NF-κB, MAPK and heme oxygenase-1 (HO-1) were also investigated. EAFM significantly inhibited the expression of inflammatory factors including NO, IL-6 and TNF-α at non-toxic concentrations. EAFM also inhibited the mRNA and protein expression of inducible nitric oxide synthase in a concentration-dependent manner, but did not alter the expression of cyclooxygenase-2. Pre-treatment with EAFM inhibited the nuclear translocation of NF-κB, and suppressed the phosphorylation of ERK and JNK. In addition, EAFM induced 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity and an increase in the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and HO-1. The results indicated that EAFM inhibited the expression of pro-inflammatory cytokines by inhibiting ERK/JNK phosphorylation and NF-κB translocation. EAFM also exerted antioxidant effects via Nrf2/HO-1 stimulation. Collectively, the results of the present study indicated that EAFM may be a valuable alternative for the treatment of a variety of inflammatory diseases.

Effects of edpetiline from Fritillaria on inflammation and oxidative stress induced by LPS stimulation in RAW264.7 macrophages

The dry bulbs of Fritillaria cirrhosa species can help resolve phlegm, soothe cough, clear heat, and moisten the lung, and the main active components responsible for these effect are its alkaloids. However, it is unclear whether or how edpetiline in Fritillaria can inhibit the excessive inflammatory response and oxidative stress. In this research, we aimed to examine this aspect using lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages as an inflammatory model. The quantitative real-time polymerase chain reaction and western blot analysis results showed that edpetiline significantly inhibited the content and mRNA expression levels of proinflammatory cytokines (TNF-α and IL-6) in LPS-induced RAW264.7 cells, significantly increased the mRNA expression of IL-4 (anti-inflammatory cytokine), and markedly downregulated the inflammatory mediators inductible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) mRNA and protein expression levels. The oxidative stress induced by LPS was also inhibited by edpetiline, as the level of intracellular reactive oxygen species decreased notably. Edpetiline may exert anti-inflammatory and antioxidant effects through inhibiting the phosphorylation of IκB and the nuclear transcription of nuclear transcription factor-κB p65 and decreasing the phosphorylation of p38 and ERK in the mitogen-activated protein kinase signaling pathway, without activating the JNK/mitogen-activated protein kinase signaling pathway. These findings suggest that edpetiline may be a potential therapeutic agent for the prevention or treatment of inflammation- and oxidative stress-related pathophysiological processes and diseases.

Dehydroepiandrosterone attenuates LPS-induced inflammatory responses via activation of Nrf2 in RAW264.7 macrophages

Dehydroepiandrosterone (DHEA) is the major steroid hormone in humans and animals, which can regulate the body's inflammatory responses. However, the detail mechanism of this beneficial function is still poorly understood. The present study aimed to explore the anti-inflammation effect of DHEA and its underlying molecular mechanism in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The findings showed that DHEA significantly inhibited the inflammation-related mediators production and pro-inflammatory cytokines expression level. Further research found that DHEA obviously blocked the LPS-stimulated PI3K/AKT, MAPK and NF-κB activation in RAW 264.7 cells. Meanwhile, DHEA enhanced the autophagy-dependent Keap1 protein degradation, subsequently activated the Nrf2 pathway to alleviate the redox imbalance and inflammatory responses. In conclusion, our data demonstrated that DHEA suppresses inflammatory responses through the activation of Nrf2 and inhibition of NF-κB in LPS-stimulated macrophages.

Anti-Inflammatory Activity of Extracts and Pure Compounds Derived from Plants via Modulation of Signaling Pathways, Especially PI3K/AKT in Macrophages

The plant kingdom is a source of important therapeutic agents. Therefore, in this review, we focus on natural compounds that exhibit efficient anti-inflammatory activity via modulation signaling transduction pathways in macrophage cells. Both extracts and pure chemicals from different species and parts of plants such as leaves, roots, flowers, barks, rhizomes, and seeds rich in secondary metabolites from various groups such as terpenes or polyphenols were included. Selected extracts and phytochemicals control macrophages biology via modulation signaling molecules including NF-κB, MAPKs, AP-1, STAT1, STAT6, IRF-4, IRF-5, PPARγ, KLF4 and especially PI3K/AKT. Macrophages are important immune effector cells that take part in antigen presentation, phagocytosis, and immunomodulation. The M1 and M2 phenotypes are related to the production of pro- and anti-inflammatory agents, respectively. The successful resolution of inflammation mediated by M2, or failed resolution mediated by M1, may lead to tissue repair or chronic inflammation. Chronic inflammation is strictly related to several disorders. Thus, compounds of plant origin targeting inflammatory response may constitute promising therapeutic strategies.

Two new ent-kaurane glucosides from the fruits of Xanthium strumarium subsp. sibiricum

The chemical investigation of the fruits of Xanthium strumarium (Asteraceae) led to the isolation of two new ent-kauranoid glucosides named 2-O-(6-O-isocaleryl-β-D-glucopyranosyl) atractyligenin (1) and 2-O-(2-O-isovaleryl-β-D-glucopyranosyl) atractyligenin (2), together with one known compound. Their structures were established by comprehensive spectroscopic analysis coupled with single-crystal X-ray diffraction and electronic circular dichroism data. All compounds and their aglycone were evaluated for their anti-proliferative activities in vitro against three human cancer cell lines.

Anti-Toxoplasma activity and chemical compositions of aquatic extract of Mentha pulegium L. and Rubus idaeus L.: An in vitro study

This study aimed to determine the chemical compositions of crude aquatic extracts of M. pulegium L. and R. idaeus L., and their anti-Toxoplasma activity. Crude aquatic extraction of aerial parts of R. idaeus L. and M. pulegium L. was performed. GC-MS and HTPLC analyses were carried out. MTT assay was performed on Vero cells treated by different concentrations (Log -10 from 10-1 to 10-6) of the extracts. The anti-Toxoplasma activity of the concentrations was investigated using vital staining. Menthol (99.23%) and limonene (0.227%) were the major compounds of the aquatic extract of M. pulegium L. Phytochemical compositions of R. idaeus L. were terpenoids, esterols, and flavonoids. The cell toxicity of M. pulegium L. was lower than R. idaeus L. (CC50 > 10-2 versus. ≥ 10-4). Aquatic extract of M. pulegium L. showed higher anti-Toxoplasma activity (LC50 ≥ 10-6) than R. idaeus L. (LC50 ≥ 10-5). Statistically significant cell toxicity and anti-Toxoplasma activity (p < .05) were seen regarding the different concentrations of R. idaeus L. and M. pulegium L. Both R. idaeus L. and M. pulegium L. revealed anti-Toxoplasma activities. Cell toxicity of R. idaeus L. was significantly higher than M. pulegium L. M. pulegium L. extract could be more applicable due to its lower cell toxicity.

Bioactive sulfur-containing compounds from Xanthium sibiricum, including a revision of the structure of xanthiazinone

Seven previously undescribed sulfur-containing compounds, (+)- and (-)-xanthiazinone A, (+)- and (-)-xanthiazinone B, (+)- and (-)-xanthiazinone C and xanthiazinone D, and four known thiazinedione derivatives, together with three thiophene derivatives were isolated from the fruits of Xanthium sibiricum. Racemic xanthiazinones A-C were separated by chiral HPLC columns. Their chemical structures were elucidated based on extensive spectroscopic analyses, ECD calculations, and single crystal X-ray diffractions. The X-ray crystallographic analyses for xanthiazinones A-C represent the first example described for the structure elucidation of the thiazinedione with the five-membered lactone ring attached via an oxygen atom. Accordingly, the previously proposed structure for xanthiazinone was revised. The anti-inflammatory and cytotoxic activities were evaluated for all the isolated compounds. (+)-xanthiazinone B and 2-hydroxy-xanthiazone exhibited potent inhibitory effects against nitric oxide production in lipopolysaccharide-activated RAW 264.7 mouse macrophage cells with IC₅₀ values of 8.75 and 10.90 μM, respectively. All compounds obviously were inactive for three human tumor cell lines (HepG2, MCF-7, and A549) with IC₅₀ values more than 10 μM.

Anti-Inflammatory Effects of Neochlorogenic Acid Extract from Mulberry Leaf (Morus alba L.) Against LPS-Stimulated Inflammatory Response through Mediating the AMPK/Nrf2 Signaling Pathway in A549 Cells

Neochlorogenic acid (nCGA) is a phenolic compound isolated from mulberry leaf (Morus alba L.), which possesses multiple pharmacological activities containing antioxidant and anti-inflammatory effects. However, the role of nCGA in the treatment of acute pneumonia and the underlying molecular mechanism are still unclear. Hence, the aim of study is to investigate the anti-inflammatory properties of nCGA on LPS-stimulated inflammation in A549 cells. In the present study, results reported that nCGA without cytotoxicity significantly reduced the production of TNF-α, IL-6, and NO, and further suppressed the proteins of iNOS, COX2, TNF-α, IL-6 expression. Furthermore, nCGA also inhibited NF-κB activation and blocked MAPKs signaling pathway phosphorylation. In addition, we found nCGA significantly increased the expression of HO-1 via activating the AMPK/Nrf2 signaling pathway to attenuate the inflammatory response, whereas this protective effect of nCGA was reversed by pre-treatment with compound C (C.C, an AMPK inhibitor). Therefore, all these results indicated that nCGA might act as a natural anti-inflammatory agent for the treatment of acute pneumonia.

Discovery and evaluation of novel synthetic 5-alkyl-4-oxo-4,5-dihydro-[1,2,4]triazolo[4,3-a]quinoxaline-1-carbox-amide derivatives as anti-inflammatory agents

To develop novel anti-inflammatory agents, a series of 5-alkyl-4-oxo-4,5-dihydro-[1, 2, 4]triazolo[4,3-a]quinoxaline-1-carboxamide derivatives were designed, synthesised, and evaluated for anti-inflammatory effects using RAW264.7 cells. Structures of the synthesised compounds were determined using ¹H NMR, ¹³C NMR, and HRMS. All the compounds were screened for anti-inflammatory activity based on their inhibitory effects against LPS-induced NO release. Among them, 5-(3,4,5-trimethoxybenzyl)-4-oxo-4,5-dihydro-[1, 2, 4]triazolo[4,3-a]quinoxaline-1-carboxamide (6p) showed the highest anti-inflammatory activity and inhibited NO release more potently than the lead compound D1. Further studies revealed that compound 6p reduced the levels of NO, TNF-α, and IL-6, and that its anti-inflammatory activity involves the inhibition of COX-2 and iNOS and downregulation of the mitogen-activated protein kinases (MAPK) signal pathway. Notably, compound 6p displayed more prominent anti-inflammatory activity than D1 and the positive control ibuprofen in the in vivo acute inflammatory model. Overall, these findings indicate that compound 6p is a therapeutic candidate for the treatment of inflammation.

Simultaneous quantification of atractyloside and carboxyatractyloside in rat plasma by LC-MS/MS: Application to a pharmacokinetic study after oral administration of Xanthii Fructus extract

Xanthii Fructus is extensively used as an herbal medicine. Ingestion of this herb is associated with severe hepatotoxicity and nephrotoxicity. Atractyloside and carboxyatractyloside are two dominative toxic constituents in Xanthii Fructus. However, their pharmacokinetic study is lacking. In this study, a novel high-performance liquid chromatography-tandem mass spectrometry method was developed to simultaneously quantify the rat plasma concentrations of atractyloside and carboxyatractyloside. After protein precipitation, the analytes were chromatographic separated on a ZORBAX Eclipse Plus column (2.1 × 150 mm id, 5 µm) under gradient elute. In the negative electrospray ionization mode, the transitions at m/z 725.3→645.4 for atractyloside, m/z 769.3→689.4 for carboxyatractyloside, and m/z 479.2→121.1 for paeoniflorin (the internal standard) were acquired by multiple reaction monitoring. This analytical method showed good linearity over 1-500 ng/mL for atractyloside and 2-500 ng/mL for carboxyatractyloside with acceptable precision and accuracy. No matrix effect, instability and carryover occurred in the analysis procedure. The extraction recoveries were greater than 85.0%. This method was applied to a preliminary pharmacokinetic study by orally administering Xanthii Fructus extract (9 g/kg) to rats, which was useful to evaluate the role of these two compounds in Xanthii Fructus-induced toxicity.

Chondroprotective and antiarthritic effects of Daphnetin used in vitro and in vivo osteoarthritis models

AIMS

Daphnetin (DAP) is a traditional Chinese drug usually used to treat cardiovascular diseases. Studies have confirmed the anti-inflammatory, antioxidant, anti-bacterial and insecticidal, anti-tumor and neuro-protective effects of DAP. However, its anti-arthritic potential remains unexplored. The aim of this study is to investigate the in vitro and in vivo chondroprotective effects of DAP.

MAIN METHODS

The effect of DAP on primary rabbit chondrocytes was examined using recombinant human IL-1β for 24 h. For the in vivo studies, rabbits were randomly divided into groups: a normal control group and osteoarthritis (OA) groups. The OA groups received three different doses of DAP for 4 or 8 weeks. The anti-arthritic effect of DAP was assessed using histopathological examinations, qRT-PCR, western blotting and immunohistochemical analysis.

KEY FINDINGS

Both in vitro and in vivo results indicate that DAP exerts a protective effect against IL-1β in chondrocytes. In vitro, DAP inhibits the expression of IL-6, IL-12, MMP-3, MMP-9 and MMP-13, induced by IL-1β in rabbit chondrocytes, and stimulates the production of IL-10. The inhibitory effect of DAP on the MMPs is partially regulated by the inhibition of the PI3K/AKT, MAPK and NF-κB signaling pathways. The effect of DAP on OA may be attributed to the suppression of inflammatory factor secretion, chondrocyte apoptosis observed by the decrease in pro-apoptotic Caspase-3 and BAX, and the activation of anti-apoptotic BCL-2.

SIGNIFICANCE

DAP has a broad range of prospects in the treatment of OA, which provides a novel therapeutic strategy for OA.

Effects of berberine on the growth performance, antioxidative capacity and immune response to lipopolysaccharide challenge in broilers

This study evaluated the effects of berberine on growth performance, immunity, haematological parameters, antioxidant capacity, and the expression of immune response-related genes in lipopolysaccharide (LPS)-challenged broilers. We assigned 120 one-day-old male broilers (Ross 308) to two treatment groups; each group included two subgroups, each of which included six replicates of five birds per replicate. The experiment used a 2 × 2 factorial arrangement with berberine treatment (0 or 60 mg/kg dietary) and challenge status [injection of saline (9 g/L w/v) or LPS (1.5 mg/kg body weight)] as the main factors. On days 14, 16, 18 and 20, broilers were intraperitoneally injected with LPS or physiological saline. Blood and liver samples were collected on day 21. Dietary berberine supplementation significantly alleviated the compromised average daily gain and average daily feed intake (p < 0.05) caused by LPS. The LPS challenge led to increased lymphocyte and white blood cell (WBC) counts, malondialdehyde (serum and liver) content, and immunoglobulin G and M, tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) expression (p < 0.05) and significantly reduced serum total superoxide dismutase (T-SOD) activity (p < 0.05). Dietary berberine significantly mitigated the LPS-induced decreases in the mRNA expression of nuclear factor-kappa B (NF-κB), TNF-α, IL-1β, inducible nitrite synthase and cyclooxygenase-2 (p < 0.05) in the liver. In conclusion, berberine supplementation has a positive effect on LPS challenge, which may be related to the increase in antioxidant enzyme activity and inhibition of both NF-κB signalling and the expression of inflammatory mediators.

KR-12-a5 Reverses Adverse Effects of Lipopolysaccharides on HBMSC Osteogenic Differentiation by Influencing BMP/Smad and P38 MAPK Signaling Pathways

KR-12-a5 is an analogue of the antimicrobial peptide KR-12. Both of these two agents can play key effects in the treatment of infections such as osteomyelitis. Our previous work demonstrated that the osteogenic differentiation of human bone marrow mesenchymal stem cells (HBMSCs) can be enhanced by KR-12. The present study investigated if KR-12-a5 could reverse the adverse effects of lipopolysaccharides (LPS) on HBMSC osteogenesis and the involved molecular mechanisms. We observed the proliferation, cell cycle, and apoptosis of HBMSCs in the presence of KR-12-a5 by a cell counting kit-8 assay and flow cytometry. The osteogenic differentiation of HBMSCs was studied by alkaline phosphatase, Alizarin Red staining, and quantitative assays. Osteogenic differentiation marker levels were detected using real-time quantitative PCR analysis, which demonstrated that KR-12-a5 treatment reversed the inhibition of osteogenesis. Western blot analysis indicated that LPS-activated P38 mitogen-activated protein kinase (MAPK) signaling was inhibited and BMP/Smad pathway was reactivated after KR-12-a5 treatment under induced osteogenic conditions. Furthermore, flow cytometry results demonstrated that KR-12-a5 relieved LPS-induced oxidative stress. Combining the LPS-treated mouse model results, we proved that KR-12-a5 reversed the adverse effects of LPS on HBMSC osteogenic differentiation by influencing the BMP/Smad and P38 MAPK signaling pathways.

Anti-inflammatory effects of paeoniflorin from Paeonia lactiflora Pall. on human corneal epithelial cells and a mouse model of dry eye disease

Dry eye disease (DED) is characterized by increased osmolality of tears due to a lack of production or increased evaporation of tears. Hyperosmolarity is involved in DED pathogenesis, which damages ocular surface cells and leads to inflammation of the ocular surface. We investigated the anti-inflammatory effect of paeoniflorin (PF) from Paeonia lactiflora Pall. on human corneal epithelial (HCE) cells and its molecular mechanisms, and its therapeutic effects on a mouse model of experimental dry eye (EDE). HCE cells were treated with PF-1 (PF prepared in vitro; 0.01%, 0.1% and 1.0%). Protein production/activity was determined by Western blotting, RT-PCR and immunofluorescent staining. Meanwhile, eye drops containing 0.01%, 0.1% and 1.0% of PF-2 (PF prepared in vivo) were applied to the EDE, and the tear volume, corneal fluorescein-staining score, detachment of the corneal epithelium, and immunohistochemical staining were measured after 28 days of treatment. PF reduced expression of proinflammatory factors such as interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α in HCE cells, and significantly improved dry-eye signs, including tear volume, desquamation of the corneal epithelium and ocular surface inflammation in mice treated with 1.0% PF-2. Further study showed that PF improved EDE by inhibiting mitogen-activated protein kinase (MAPK), phosphorylated (p)-c-Jun N-terminal kinase (JNK) and pp-38, and nuclear factor kappa B (NF-κB) signaling pathways. These data suggest that PF can improve dry-eye symptoms and reduce expression of proinflammatory mediators. Hence, eye drops containing PF could be used as an adjunctive treatment for DED.

JAX2, an ethanol extract of Hyssopus cuspidatus Boriss, can prevent bronchial asthma by inhibiting MAPK/NF-κB inflammatory signaling

BACKGROUND

Hyssopus cuspidatus Boriss has been used to treat bronchial asthma for many years in Uighur medicine. JAX2, an ethanol extract from this plant, has effectiveness against bronchial asthma. However, the molecular basis for the anti-inflammatory effects of JAX2 remains unclear.

PURPOSE

This study aimed to evaluate the mechanism of JAX2 against bronchial asthma.

METHODS

We established an asthma model in rats using ovalbumin (OVA), and an inflammatory model in RAW264.7 cells using lipopolysaccharide (LPS) stimulation. To evaluate the anti-inflammatory effects of JAX2, the concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-6, IL-17, eotaxin and immunoglobulin (Ig)E were measured by enzyme-linked immunosorbent assay (ELISA). Cell viability was investigated by the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)2H-tetrazolium, inner salt (MTS) assay. Further, nitric oxide (NO) and reactive oxygen species (ROS) were determined using Griess reagent and 2,7-dichlorofluorescein diacetate. The phosphorylation of p-extracellular signal-regulated kinase (ERK), p-Jun-NH2-terminal kinase (JNK), p38 kinases (p38) and p-inhibitor of nuclear factor kappa-B kinase (IKK), and nuclear translocation of p-p65 kinases (p-p65) were determined by immunofluorescence to uncover the effects of JAX2 on the Mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways.

RESULTS

After JAX2 administration to rats, Interferon (IFN)-γ concentrations in BALF increased significantly. Further, the concentrations of TNF-α, IL-4, IL-6, IL-17 and eotaxin in BALF, and IgE in serum decreased. JAX2 decreased TNF-α, IL-6 and NO in cell supernatant, and reduced ROS intracellularly. Concurrently, IFN-γ concentrations increased in cell supernatant significantly. In LPS-induced RAW264.7 cells, JAX2 inhibited phosphorylation of p-ERK, p-JNK and p-38 MAPK. The subsequent phosphorylation of p-IKK and nuclear translocation of the p-p65 subunit of NF-κB were also suppressed.

CONCLUSION

Based on these findings, we believe that JAX2 has both preventive and treatment effects in bronchial asthma. Furthermore, in the RAW264.7 cell inflammatory model, JAX2 also inhibited NF-κB and MAPK signaling pathways.

Ginkgo biloba sarcotesta polysaccharide inhibits inflammatory responses through suppressing both NF-κB and MAPK signaling pathway

BACKGROUND

Polysaccharides, common components of natural products extensively studied as dietary supplements and functional foods, have been found to have various activities. In the present study, a water-soluble polysaccharide, namely GBSP3a, was isolated and purified from G. biloba sarcotesta. The anti-inflammatory activity of GBSP3a in lipopolysaccharide (LPS)-induced RAW264.7 macrophages and the potential underlying molecular mechanisms were then assessed.

RESULTS

GBSP3a exerted its anti-inflammatory effect by remarkably inhibiting the secretion of pro-inflammatory mediators and cytokines, including nitric oxide (NO), prostaglandin E₂ (PGE₂ ), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in LPS-stimulated RAW264.7 macrophages. Excessive mRNA and protein expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were dose-dependently inhibited by GBSP3a in LPS-stimulated RAW264.7 cells. Further research suggested that the anti-inflammatory effect of GBSP3a can be attributed to the modulation of the NF-κB and MAPK signaling pathways.

CONCLUSION

GBSP3a exhibits anti-inflammatory activity and exerts its anti-inflammatory effect probably through suppressing both NF-κB and MAPK signaling pathway, indicating that GBSP3a could be used for the development of anti-inflammatory agent or nutraceuticals. © 2018 Society of Chemical Industry.

Discovery of anti-inflammatory terpenoids from Mallotus conspurcatus croizat

ETHNOPHARMACOLOGICAL RELEVANCE

Mallotus conspurcatus croizat (Euphorbiaceae), a plant native to Jinxiu in Guangxi, is popularly used in folk medicine to treat pelvic inflammatory disease. The anti-inflammatory activities of the compounds obtained from M. conspurcatus root were evaluated in this study.

AIM OF THE STUDY

This study explored the major anti-inflammatory components of this plant.

MATERIALS AND METHODS

The ethyl acetate fraction of the ethanol extract from M. conspurcatus was separated using chromatographic techniques. The structures of the isolates were elucidated from NMR, MS and X-ray data as well as from ECD. The anti-inflammatory activities of the isolates from M. conspurcatus were evaluated using LPS-stimulated RAW 264.7 cell models. The production of NO, TNF-α and PGE-2 was determined by ELISA and Griess tests. The expression levels of COX-2, NF-κB/p65 and iNOS were measured by western blotting.

RESULTS

Two new diterpenoids, malloconspur A (1) and malloconspur B (2), and sixteen known terpenoids (3-18) were identified by comprehensive spectroscopic analyses and comparison with literature data. Malloconspur B (2) and 17-hydroxycleistantha-12,15-dien-3-one (3) substantially inhibited the release of NO with IC₅₀ values of 10.47 μM and 9.32 μM, respectively. Compounds 1, 2 and 3 markedly decreased the secretion of PGE₂ and TNF-α (P < 0.01) by LPS-induced RAW264.7 cells. Compounds 2 and 3 markedly decreased iNOS, NF-κB/p65 and COX-2 protein expression.

CONCLUSIONS

Our identification of these diterpenoids provides strong evidence for the use of M. conspurcatus among the Yao people as a medicinal plant for the treatment of inflammation. The dramatic differences in the chemical structures of the active diterpenoids of this plant from those on the market suggest these compounds have potential as anti-inflammatory lead compounds for follow-up research.

Traditional Uses, Botany, Phytochemistry, Pharmacology, Pharmacokinetics and Toxicology of Xanthium strumarium L.: A Review

Xanthium strumarium L. (Asteraceae) is a common and well-known traditional Chinese herbal medicine usually named Cang-Er-Zi, and has been used for thousands of years in China. The purpose of this paper is to summarize the progress of modern research, and provide a systematic review on the traditional usages, botany, phytochemistry, pharmacology, pharmacokinetics, and toxicology of the X. strumarium. Moreover, an in-depth discussion of some valuable issues and possible development for future research on this plant is also given. X. strumarium, as a traditional herbal medicine, has been extensively applied to treat many diseases, such as rhinitis, nasal sinusitis, headache, gastric ulcer, urticaria, rheumatism bacterial, fungal infections and arthritis. Up to now, more than 170 chemical constituents have been isolated and identified from X. strumarium, including sesquiterpenoids, phenylpropenoids, lignanoids, coumarins, steroids, glycosides, flavonoids, thiazides, anthraquinones, naphthoquinones and other compounds. Modern research shows that the extracts and compounds from X. strumarium possess wide-ranging pharmacological effects, including anti- allergic rhinitis (AR) effects, anti-tumor effects, anti-inflammatory and analgesic effects, insecticide and antiparasitic effects, antioxidant effects, antibacterial and antifungal effects, antidiabetic effects, antilipidemic effects and antiviral effects. However, further research should focus on investigating bioactive compounds and demonstrate the mechanism of its detoxification, and more reasonable quality control standards for X. strumarium should also be established.

Esculentoside B inhibits inflammatory response through JNK and downstream NF-κB signaling pathway in LPS-triggered murine macrophage RAW 264.7 cells

Natural compound esculentoside B (EsB), (2S,4aR,6aR,6aS,6bR,8aR,9R,10R,11S,12aR,14bS)-11-hydroxy-9-(hydroxymethyl)-2 methoxycarbonyl-2,6a,6b,9,12a-pentamethyl-10-[(2S,3R,4S,5R)-3,4,5-trihydroxyoxan-2-yl]oxy-1,3,4,5,6,6a,7,8,8a,10,11,12,13,14b-tetradecahydropicene-4a-carboxylic acid with molecular weight of 664.833, isolated from roots of Phytolacca acinosa Roxb has been widely used as a constituent of traditional Chinese medicine (TCM). However, the anti-inflammatory capacity of EsB has not been reported yet. Therefore, the objective of this study was to investigate anti-inflammatory activities of EsB in LPS-treated macrophage RAW 264.7 cells. EsB could inhibit nitric oxide (NO) production. EsB also suppressed gene and protein expression levels of inducible isoform of NO synthase (NOS) and cyclooxygenase-2 in a dose-dependent manner. In addition, EsB decreased gene expression and protein secretion levels of pro-inflammatory cytokines such as IL-1β, TNF-α, and IL-6. EsB remarkably suppressed nuclear translocation of nuclear factor kappa-B (NF-κB) from cytosolic space. Phosphorylation of IκB was also inhibited by EsB. Moreover, EsB specifically down-regulated phospho-c-Jun N-terminal kinase (p-JNK), but not p-p38 or phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2). Taken together, these results suggest that EsB has inhibitory effect on inflammatory response by inactivating NF-κB and p-JNK. It could be used as a new modulatory drug for effective treatment of inflammation-related diseases.

Isolation and identification of peptides from simulated gastrointestinal digestion of preserved egg white and their anti-inflammatory activity in TNF-α-induced Caco-2 cells

Simulated gastrointestinal digestion of preserved egg white (SGD-PEW) exerts anti-inflammatory effects on Caco-2 cells and a mouse model of DSS-induced colitis. Here, we aimed to separate peptides derived from SGD-PEW and evaluate their anti-inflammatory effects using an in vitro inflammatory model. Six peptides were isolated and identified. DEDTQAMPFR (DR-10), DEDTQAMPF (DF-9), MLGATSL (ML-7) and MSYSAGF (MF-7) significantly inhibited IL-8 secretion and markedly decreased gene expression, including TNF-α, IL-8, IL-6, IL-1β and IL-12 and promoted IL-10 gene expression in Caco-2 cells. DR-10, DF-9, ML-7 and MF-7 significantly inhibited the phosphorylation of JNK. In the meantime, DR-10 and DF-9 significantly reduced the phosphorylation of IκB and p38. These results indicated that ML-7 and MF-7 exerted their anti-inflammatory activity through the MAPK signaling pathway in TNF-α-induced Caco-2 cells. Whereas, DR-10 and DF-9 inhibited the NF-κB and MAPK signaling pathways. The results suggested that DR-10, DF-9, ML-7 and MF-7 derived from SGD-PEW may be a new type of prophylactic food for the treatment of inflammation.

Anti-inflammatory lignans and phenylethanoid glycosides from the root of Isodon ternifolius (D.Don) Kudô

Five undescribed lignans, three undescribed phenylethanoid glycosides and eight known compounds were isolated from the root of Isodon ternifolius (D.Don) Kudô (Lamiaceae). The structures of all of the isolated constituents were characterized by physical data analyses including NMR, MS and ECD. The anti-inflammatory activities of the isolates were evaluated based on their ability to inhibit NO, PGE2 and TNF-α production in LPS-induced RAW 264.7 macrophage cells. Six phenyl-naphthalene lignans, ternifoliuslignan A, ternifoliuslignan B, ternifoliuslignan C, ternifoliuslignan D, ternifoliuslignan E and 3-carboxy-6,7-dihydroxy-1-(3',4'-dihydroxyphenyl) -naphthalene, can substantially inhibit the release of NO with IC₅₀ values in the range of 9.98-29.14 μM, which are better than the positive reference. These phenyl-naphthalene lignans could markedly decrease the secretions of PGE2 and TNF-α in LPS-induced RAW264.7 cells. Ternifoliuslignan C and ternifoliuslignan D decreased iNOS, COX-2 and NF-κB/p65 protein expression. A preliminary structure-activity relationship among the phenyl-naphthalene lignans for the anti-inflammatory activity was discussed.

Ginsenoside Rk1 suppresses pro-inflammatory responses in lipopolysaccharide-stimulated RAW264.7 cells by inhibiting the Jak2/Stat3 pathway

The saponin ginsenoside Rk1 is a major compound isolated from ginseng. Ginsenoside Rk1 has been reported to have anti-inflammatory and anti-tumor properties and to be involved in the regulation of metabolism. However, the effect and mechanism of anti-inflammatory action of ginsenoside Rk1 has not been fully clarified. We investigated whether ginsenoside Rk1 could suppress the inflammatory response in lipopolysaccharide-stimulated RAW264.7 macrophages and to explore its mechanism of the action. RAW264.7 cells were treated with LPS (1 μg·mL^-1) in the absence or the presence of Ginsenoside Rk1 (10, 20, and 40 μmol·L^-1). Then the inflammatory factors were tested with Griess reagents, ELISA, and RT-PCR. The proteins were analyzed by Western blotting. Ginsenoside Rk1 inhibited lipopolysaccharide-induced expression of nitric oxide (NO), interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, and monocyte chemotactic protein (MCP)-1. Ginsenoside Rk1 inhibited the lipopolysaccharide-stimulated phosphorylation of NF-κB and janus kinase (Jak)2 and signal transducer and activator of transcription (Stat)3 at Ser727 and Tyr705. These data suggested that ginsenoside Rk1 could inhibit expression of inflammatory mediators and suppress inflammation further by blocking activation of NF-κB and the Jak2/Stat3 pathway in LPS-stimulated RAW264.7 cells.

Anti-inflammatory activities of essential oil isolated from the calyx of Hibiscus sabdariffa L

Hibiscus sabdariffa Linn., belonging to the family of Malvaceae, is considered to be a plant with health care applications in China. The main purpose of this study was to analyze the composition of its essential oil and assess its potential therapeutic effect on anti-inflammatory activity. A water steam distillation method was used to extract the essential oil from H. Sabdariffa. The essential oil components were determined by gas chromatography/mass spectrometry (GC-MS) analysis and a total of 18 volatile constituents were identified, the majority of which were fatty acids and ester compounds. Biological activity showed that the essential oil extracted from H. Sabdariffa exhibited excellent anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated macrophage RAW 264.7 cells. The nitric oxide (NO) inhibition rate reached 67.46% when the concentration of the essential oil was 200 μg mL^-1. Further analysis showed that the anti-inflammatory activity of the essential oil extracted from H. Sabdariffa might be exerted through inhibiting the activation of NF-κB and MAPK (JNK and ERK1/2) signaling pathways to decrease NO and pro-inflammatory cytokine (IL-1, IL-6, TNF-α, COX-2, and iNOS) production. Thus, the essential oil extracted from H. Sabdariffa is a good source of a natural product with a beneficial effect against inflammation, and it may be applied as a food supplement and/or functional ingredient.

Enhancement of Anti-Inflammatory Properties of Nobiletin in Macrophages by a Nano-Emulsion Preparation

Lots of active substances are hydrophobic materials at ambient and body temperatures, decreasing their bioavailability and posing great challenges to successful incorporation into medication and functional foods. The goal of this research was to develop a nanoemulsion delivery system containing a hydrophobic crystalline bioactive component (nobiletin) to improve the anti-inflammatory activity. Nobiletin was incorporated into the oily phase, and the nanoemulsions were fabricated using high-speed and high-pressure homogenization. Particle size, polydispersity index (PDI), and zeta potential were evaluated by a commercial laser light scattering instrument. The anti-inflammatory activities were performed in LPS-stimulated RAW 264.7 cells. The developed nobiletin nanoemulsion had an average droplet size of 168.6 ± 3.8 nm and a PDI of 0.168, while the average diameter of the blank nanoemulsion was 157.3 ± 1.9 nm and its PDI was 0.161. The zeta potential values of nobiletin nanoemulsion and blank nanoemulsion were -68.45 ± 0.64 and -62.75 ± 0.21 mV, respectively. All obtained nanoemulsions kept physically stable during storage at 4, 25, and 37 °C. A nobiletin-loaded nanoemulsion showed an enhanced anti-inflammatory activity in LPS-induced macrophages, with a decrease in pro-inflammatory mediators and cytokines. The findings suggested that the nanoemulsion would be used as an effective delivery system for nobiletin to improve its anti-inflammatory activity.

Protective effect of TM6 on LPS-induced acute lung injury in mice

Acute lung injury (ALI) is an acute failure of the respiratory system for which effective treatment is urgently necessary. Previous studies found that several peptides potently inhibited the production of cytokines induced by lipopolysaccharide (LPS). In this study, we synthetized a cell-permeable TIR domain-derived decoy peptide (TM6) and examined its substance for the ability to inhibit TLR signaling in the model of ALI induced by LPS. We demonstrated that TM6 (2.5, 5 and 10 nmol/g) alleviated the histological changes in the lung tissues as well as myeloperoxtidase (MPO) activity, lung W/D ratio, the production of TNF-α, IL-1β and IL-6 induced by LPS. Furthermore, the numbers of total cells, neutrophils and macrophages in the BALF were suppressed by TM6. In vitro, TM6 (5, 10 and 20 µM) inhibited the production of TNF-α, IL-1β and IL-6 in LPS-stimulated alveolar macrophages. Moreover, the activation of Nuclear factor-kappaB (NF-κB) and Mitogen activated protein kinases (MAPK) signaling pathways induced by LPS were also inhibited by TM6. Collectively, our results suggested that TM6 was an effective inhibitor of ALI induced by LPS, and this peptide may very well serve as a future treatment for ALI.

Tonggyu-tang, a traditional Korean medicine, suppresses pro-inflammatory cytokine production through inhibition of MAPK and NF-κB activation in human mast cells and keratinocytes

Background

Allergic diseases including allergic rhinitis, asthma, and atopic dermatitis are increasing worldwide. Common medications used to treat these inflammatory disorders are anti-histamines and corticosteroids, but they have their own limitations such as short duration and severe side effects. Thus, interest in complementary and alternative medicine is continually growing. Here, we investigate the anti-inflammatory mechanisms of Tonggyu-tang (TGT), a traditional Korean medicine that has been used to treat patients with allergic nasal disorders.

Methods

We measured mRNA expressions and production of pro-inflammatory cytokines such as interleukin (IL)-4, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α) by RT-PCR and ELISA assays in HMC-1 (human mast cell line-1) and HaCaT cells, immortalized human keratinocytes. Moreover, we evaluated the effect of TGT on two major inflammation-related pathways, mitogen activated protein kinase (MAPK) and NF-κB signaling pathway in these two cells.

Results

Our results revealed that that TGT significantly reduced the expression and production of inflammatory cytokines such as IL-4, IL-6, IL-8, and TNF-α in the agonist-treated HMC-1 and HaCaT cells. We also found that TGT suppressed MAPK signaling pathway including extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (p38), and c-Jun N-terminal kinase (JNK) as well as NF-κB pathway, which are known to regulate inflammatory cytokine expression.

Conclusion

Taken together, our results demonstrate that TGT inhibits expression of pro-inflammatory cytokines by suppressing MAPK and NF-kB pathway in both mast cells and keratinocytes, suggesting the potential use of TGT in treating allergic inflammatory diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1704-5) contains supplementary material, which is available to authorized users.

Solving the puzzle: What is behind our forefathers' anti-inflammatory remedies?

Inflammation is a ubiquitous host response in charge of restoring normal tissue structure and function but is a double-edged sword, as the uncontrolled or excessive process can lead to the injury of host cells, chronic inflammation, chronic diseases, and also neoplastic transformation. Throughout history, a wide range of species has been claimed to have anti-inflammatory effects worldwide. Among them, Angelica sinensis, Tropaeolum majus, Castilleja tenuiflora, Biophytum umbraculum, to name just a few, have attracted the scientific and general public attention in the last years. Efforts have been made to assess their relevance through a scientific method. However, inflammation is a complex interdependent process, and phytomedicines are complex mixtures of compounds with multiple mechanisms of biological actions, which restricts systematic explanation. For this purpose, the omics techniques could prove extremely useful. They provide tools for interpreting and integrating results from both the classical medical tradition and modern science. As a result, the concept of network pharmacology applied to phytomedicines emerged. All of this is a step toward personalized therapy.