Alpinetin attenuates inflammatory responses by interfering toll-like receptor 4/nuclear factor kappa B signaling pathway in lipopolysaccharide-induced mastitis in mice

Alpinetin alleviates LPS-induced lung epithelial cell injury by inhibiting p38 and ERK1/2 signaling via aquaporin-1

Alpinetin has been reported to play a protective role in lung diseases, while its special mechanisms remain indistinct. In this study, acute lung injury (ALI) model was constructed by inducing MLE-12 cells with lipopolysaccharide (LPS). Cell activity together with apoptosis was judged employing cell counting kit-8 (CCK-8), flow cytometry along with western blot. Oxidative stress levels were measured by dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining and corresponding kits. In addition, enzyme-linked immunosorbent assay (ELISA) was to examine the levels of inflammatory factors. The protein expressions of aquaporin-1 (AQP1), p38 and extracellular signal-regulated kinase (ERK) 1/2 pathway were estimated utilizing western blot. The data showed that alpinetin increased the viability, reduced the apoptosis, oxidative stress and inflammation and inactivated p38 and ERK1/2 signaling in LPS-induced MLE-12 cells. Moreover, alpinetin also increased AQP1 expression and AQP1 knockdown reversed the impacts of alpinetin on LPS-induced MLE-12 cells. Additionally, AQP1 agonist AqF026 also exerted anti-apoptotic and anti-inflammatory activities in LPS-treated MLE-12 cells. Evidently, alpinetin may exert its protective role in LPS-induced ALI by inactivation of p38 and ERK1/2 signaling through regulating AQP1.

Natural products modulate NLRP3 in ulcerative colitis

Ulcerative colitis (UC) is a clinically common, progressive, devastating, chronic inflammatory disease of the intestine that is recurrent and difficult to treat. Nod-like receptor protein 3 (NLRP3) is a protein complex composed of multiple proteins whose formation activates cysteine aspartate protease-1 (caspase-1) to induce the maturation and secretion of inflammatory mediators such as interleukin (IL)-1β and IL-18, promoting the development of inflammatory responses. Recent studies have shown that NLRP3 is associated with UC susceptibility, and that it maintains a stable intestinal environment by responding to a wide range of pathogenic microorganisms. The mainstay of treatment for UC is to control inflammation and relieve symptoms. Despite a certain curative effect, there are problems such as easy recurrence after drug withdrawal and many side effects associated with long-term medication. NLRP3 serves as a core link in the inflammatory response. If the relationship between NLRP3 and gut microbes and inflammation-associated factors can be analyzed concerning its related inflammatory signaling pathways, its expression status as well as specific mechanism in the course of IBD can be elucidated and further considered for clinical diagnosis and treatment of IBD, it is expected that the development of lead compounds targeting the NLRP3 inflammasome can be developed for the treatment of IBD. Research into the prevention and treatment of UC, which has become a hotbed of research in recent years, has shown that natural products are rich in therapeutic means, and multi-targets, with fewer adverse effects. Natural products have shown promise in treating UC in numerous basic and clinical trials over the past few years. This paper describes the regulatory role of the NLRP3 inflammasome in UC and the mechanism of recent natural products targeting NLRP3 against UC, which provides a reference for the clinical treatment of this disease.

Oxidative stress, hormones, and effects of natural antioxidants on intestinal inflammation in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic, relapsing gastrointestinal (GI) disorder characterized by intestinal inflammation. The etiology of IBD is multifactorial and results from a complex interplay between mucosal immunity, environmental factors, and host genetics. Future therapeutics for GI disorders, including IBD, that are driven by oxidative stress require a greater understanding of the cellular and molecular mechanisms mediated by reactive oxygen species (ROS). In the GI tract, oxidative stressors include infections and pro-inflammatory responses, which boost ROS generation by promoting the production of pro-inflammatory cytokines. Nuclear factor kappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2) represent two important signaling pathways in intestinal immune cells that regulate numerous physiological processes, including anti-inflammatory and antioxidant activities. Natural antioxidant compounds exhibit ROS scavenging and increase antioxidant defense capacity to inhibit pro-oxidative enzymes, which may be useful in IBD treatment. In this review, we discuss various polyphenolic substances (such as resveratrol, curcumin, quercetin, green tea flavonoids, caffeic acid phenethyl ester, luteolin, xanthohumol, genistein, alpinetin, proanthocyanidins, anthocyanins, silymarin), phenolic compounds including thymol, alkaloids such as berberine, storage polysaccharides such as tamarind xyloglucan, and other phytochemicals represented by isothiocyanate sulforaphane and food/spices (such as ginger, flaxseed oil), as well as antioxidant hormones like melatonin that target cellular signaling pathways to reduce intestinal inflammation occurring with IBD.

Alpinetin inhibits neuroinflammation and neuronal apoptosis via targeting the JAK2/STAT3 signaling pathway in spinal cord injury

BACKGROUND

A growing body of research shows that drug monomers from traditional Chinese herbal medicines have antineuroinflammatory and neuroprotective effects that can significantly improve the recovery of motor function after spinal cord injury (SCI). Here, we explore the role and molecular mechanisms of Alpinetin on activating microglia-mediated neuroinflammation and neuronal apoptosis after SCI.

METHODS

Stimulation of microglia with lipopolysaccharide (LPS) to simulate neuroinflammation models in vitro, the effect of Alpinetin on the release of pro-inflammatory mediators in LPS-induced microglia and its mechanism were detected. In addition, a co-culture system of microglia and neuronal cells was constructed to assess the effect of Alpinetin on activating microglia-mediated neuronal apoptosis. Finally, rat spinal cord injury models were used to study the effects on inflammation, neuronal apoptosis, axonal regeneration, and motor function recovery in Alpinetin.

RESULTS

Alpinetin inhibits microglia-mediated neuroinflammation and activity of the JAK2/STAT3 pathway. Alpinetin can also reverse activated microglia-mediated reactive oxygen species (ROS) production and decrease of mitochondrial membrane potential (MMP) in PC12 neuronal cells. In addition, in vivo Alpinetin significantly inhibits the inflammatory response and neuronal apoptosis, improves axonal regeneration, and recovery of motor function.

CONCLUSION

Alpinetin can be used to treat neurodegenerative diseases and is a novel drug candidate for the treatment of microglia-mediated neuroinflammation.

The role and mechanism of flavonoid herbal natural products in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestine that presents clinically with abdominal pain, mucopurulent stools, and posterior urgency. The lesions of UC are mainly concentrated in the rectal and colonic mucosa and submucosa. For patients with mild to moderate UC, the best pharmacological treatment includes glucocorticoids, immunosuppressants, antibiotics, and biologics, but the long-term application can have serious toxic side effects. Currently, nearly 40% of UC patients are treated with herbal natural products in combination with traditional medications to reduce the incidence of toxic side effects. Flavonoid herbal natural products are the most widely distributed polyphenols in plants and fruits, which have certain antioxidant and anti-inflammatory activities. Flavonoid herbal natural products have achieved remarkable efficacy in the treatment of UC. The pharmacological mechanisms are related to anti-inflammation, promotion of mucosal healing, maintenance of intestinal immune homeostasis, and regulation of intestinal flora. In this paper, we summarize the flavonoid components of anti-ulcerative colitis and their mechanisms reported in the past 10 years, to provide a basis for rational clinical use and the development of new anti-ulcerative colitis drugs.

A Novel TLR4-SYK Interaction Axis Plays an Essential Role in the Innate Immunity Response in Bovine Mammary Epithelial Cells

Mammary gland epithelium, as the first line of defense for bovine mammary gland immunity, is crucial in the process of mammary glands’ innate immunity, especially that of bovine mammary epithelial cells (bMECs). Our previous studies successfully marked SYK as an important candidate gene for mastitis traits via GWAS and preliminarily confirmed that SYK expression is down-regulated in bMECs with LPS (E. coli) stimulation, but its work mechanism is still unclear. In this study, for the first time, in vivo, TLR4 and SYK were colocalized and had a high correlation in mastitis mammary epithelium; protein−protein interaction results also confirmed that there was a direct interaction between them in mastitis tissue, suggesting that SYK participates in the immune regulation of the TLR4 cascade for bovine mastitis. In vitro, TLR4 also interacts with SYK in LPS (E. coli)-stimulated or GBS (S. agalactiae)-infected bMECs, respectively. Moreover, TLR4 mRNA expression and protein levels were little affected in bMECsSYK- with LPS stimulation or GBS infection, indicating that SYK is an important downstream element of the TLR4 cascade in bMECs. Interestingly, IL-1β, IL-8, NF-κB and NLRP3 expression in LPS-stimulated or GBS-infected bMECsSYK- were significantly higher than in the control group, while AKT1 expression was down-regulated, implying that SYK could inhibit the IL-1β, IL-8, NF-κB and NLRP3 expression and alleviate inflammation in bMECs with LPS and GBS. Taken together, our solid evidence supports that TLR4/SYK/NF-κB signal axis in bMECs regulates the innate immunity response to LPS or GBS.

Alpinetin: a Dietary Flavonoid with Diverse Anticancer Effects

Cancer is  a global burden and mechanistically complex disease with a plethora of genetic, physiological, metabolic, and environmental alterations. The development of dietary nutraceuticals into cancer chemotherapeutics has emerged as a new paradigm in cancer treatment. Alpinetin (ALPI) is a novel flavonoid component of multiple edible and medicinal plants and possesses a wide range of biological and pharmacological activities including antibacterial, anti-hemostatic, anti-oxidative, anti-hepatotoxic, stomachic, immunosuppressive, and anti-inflammatory. Recently, ALPI has been reported as a bioactive dietary nutraceutical with promising anticancer activity in various human cancers through multiple mechanisms. The purpose of this review is to compile the data on natural sources of ALPI, and its anticancer activity including cellular targets and anticancer mechanism in various human cancers. Moreover, this review will set the stage for further design and conduct pre-clinical and clinical trials to develop ALPI into a lead structure for oncological therapy.

Formononetin Protects LPS-Induced Mastitis Through Suppressing Inflammation and Enhancing Blood-Milk Barrier Integrity via AhR-Induced Src Inactivation

Formononetin (FOR), a natural flavonoid derived from Radix Astragali, has been reported to have anti-inflammatory and anti-oxidative effects. However, its protective mechanism against mastitis is still unknown. Nuclear factor kappa-B (NF-κB) signaling pathway plays an important role in inflammation, especially mastitis. Aryl hydrocarbon receptor (AhR) is involved in inflammatory regulation and defense against diseases. We investigated the protective effect of FOR on LPS-induced mastitis in mice and the effect of Ahr and NF-κB signaling pathways on the development of mastitis. In this study, mastitis model was induced by LPS injection through the nipple duct. Protective effect of FOR on LPS-induced mastitis was assessed by FOR pretreatment. The protective mechanism of FOR against mastitis was further investigated using LPS stimulation on mouse mammary epithelial cells EpH4-Ev. The results showed that LPS-induced mammary histological injury was inhibited by FOR. FOR significantly inhibited LPS-induced MPO activity. FOR administration enhanced the integrity of blood-milk barrier. In vitro and in vivo experiments showed that FOR inhibited LPS-induced NF-κB signaling pathway activation and the production of inflammatory factors TNF-α and IL-1ß. Moreover, FOR increased the expression of tight junction protein and enhanced blood-milk barrier integrity. LPS activated AhR and Src expression. But FOR induced significant increase in AhR inhibited Src phosphorylation to exert anti-inflammatory effects. In addition, AhR antagonist CH223191 reversed the inhibition of FOR on Src expression. And the inhibition of FOR on NF-κB activation and inflammatory cytokine production were reversed by AhR antagonist CH223191. In conclusion, FOR had protective effects against LPS-induced mastitis via suppressing inflammation and enhancing blood-milk barrier integrity via AhR-induced Src inactivation.

Alpinetin: A Review of Its Pharmacology and Pharmacokinetics

Flavonoids isolated from medicinal herbs have been utilized as valuable health-care agents due to their virous biological applications. Alpinetin is a natural flavonoid that emerges in many widely used medicinal plants, and has been frequently applied in Chinese patent drugs. Accumulated evidence has demonstrated that alpinetin possesses a broad range of pharmacological activities such as antitumor, antiinflammation, hepatoprotective, cardiovascular protective, lung protective, antibacterial, antiviral, neuroprotective, and other properties through regulating multiple signaling pathways with low systemic toxicity. However, pharmacokinetic studies have documented that alpinetin may have poor oral bioavailability correlated to its extensive glucuronidation. Currently, the reported pharmacological properties and pharmacokinetics profiles of alpinetin are rare to be scientifically reviewed. In this article, we aimed to highlight the mechanisms of action of alpinetin in various diseases to strongly support its curative potentials for prospective clinical applications. We also summarized the pharmacokinetics properties and proposed some viable strategies to convey an appreciable reference for future advances of alpinetin in drug development.

Alpinetin Protects Chondrocytes and Exhibits Anti-Inflammatory Effects via the NF-κB/ERK Pathway for Alleviating Osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint disease which is greatly affected by the inflammatory response triggered by the NF-κB signaling pathway. Alpinetin (APT) is a natural flavonoid compound, which has been reported to have many important biological activities such as antibacterial, antitumor, and anti-inflammatory. However, the action of its effect on chondrocytes in OA has yet to be elucidated. In this study, we investigated APT's anti-inflammatory action. The effects of APT on cell viability and cytotoxicity of rat chondrocytes was investigated by CCK8. Western blotting, qRT-PCR, and immunofluorescent staining were used to elucidate the molecular mechanisms and signaling pathways of APT mediating anti-inflammatory effects on chondrocytes. An OA model was induced by destabilization of the medial meniscus (DMM) in rats, then APT was injected into the knee articular cavity to examine its anti-inflammatory effects in vivo. These results showed that APT could reduce the TNF-α-induced increase of MMP-13 and ADAMTS-5 and decrease of COL2A1 levels. APT antagonized TNF-α-induced down-regulation of BCL-2 and CDK1. Further studies have shown that APT simultaneously repressed cell nucleus translocation of p65 and the phosphorylation of IκB and activated the phosphorylation of ERK. In vivo, APT suppressed cartilage matrix degradation. In conclusion, APT appears to favorably modulate anti-inflammatory effects in chondrocytes making it a promising compound for OA treatment. Graphical Abstract Inhibitory effects of Alpinetin on TNF-α-induced NF-κB activation resulted in destruction of cartilage in rat OA chondrocytes in vitro. The TNF-α receptor were stimulated by TNF-α, activating the cytoplasmic IκBα kinases(IKKS), then IKKs will be phosphorylated, and subsequently degraded by the ubiquitin-proteasome system. NF-κB transfer to the nucleus and bind various NF-κB regulates the NF-κB recognition site in the promoter region. Which triggers the gene expression of pro-inflammatory and pro-apoptotic. However, Alpinetin could inhibits the NF-κB signaling pathway in different ways: APT inhibits IκBα phosphorylation, preventing phosphorylated ubiquitination of IκBα further. Moreover, APT blocks translocation of the activated NF-κB to the nucleus, to protect the cartilage tissue from damage.

Alpinetin inhibits breast cancer growth by ROS/NF-κB/HIF-1α axis

Alpinetin, the main active ingredient in the Chinese medicinal herb Alpinia katsumadai Hayata, has been found to have anticancer activity. However, the therapeutic efficacy of signalling cascades modulated by alpinetin remains unknown. Here, we showed that alpinetin provoked mitochondria‐associated apoptosis in a dose‐dependent manner in breast cancer cells. Mechanistic investigations revealed that alpinetin dampens hypoxia‐inducible factor‐1α (HIF‐1α) signalling due to a lack of NF‐κB activation through reduced mitochondrial reactive oxygen species (ROS) production, decreasing HIF‐1α transcription. In vivo, we also found alpinetin led to significant tumour regression by inhibiting NF‐κB pathway. Overall, our work uncovers a ROS/NF‐κB/HIF‐1α axis‐dependent mechanism underlying the anticancer effects of alpinetin and suggests that alpinetin could act as a novel therapeutic agent against breast cancer.

Alpinetin Inhibits Oral Squamous Cell Carcinoma Proliferation via miR-211-5p Upregulation and Notch Pathway Deactivation

Background: The effect of alpinetin (ALP) on miR-211-5p level and function in oral squamous cell carcinoma (OSCC) remains unclear.Materials and methods: Human OSCC cell lines (CAL-27 and TCA-8113) and a mouse xenograft model with subcutaneously injected TCA-8113 cells were used. Effect of ALP treatment on cell viability, cell cycle distributions, and p-p53, p21, c-PARP, cyclin D1, NICD, HES1, and miR-211-5p expression levels was analyzed. Influence of ALP on tumor volume and weight was determined.Results: ALP treatment (at doses 400 and 500 µM) significantly decreased the viability of CAL-27 and TCA-8113 cells (P < 0.05). It upregulated the number of cells in G1 phase and miR-211-5p expression, increased p-p53, p21, and c-PARP levels, and decreased cyclin D1 levels. Furthermore, miR-211-5p mimic treatment increased the number of cells in G1 phase, and p53, p21, and c-PARP levels, and decreased cyclin D1 levels. Contrasting effects were observed under anti-miR-211-5p treatment. ALP downregulated NICD and HES1, whereas anti-miR-211-5p increased NICD and HES1 expression. ALP effects were alleviated in both cell lines under Jagged-1 overexpression plasmid treatment. Finally, ALP inhibited tumor growth and increased miR-211-5p expression in vivo.Conclusion: ALP-induced miR-211-5p upregulation and Notch pathway deactivation may be involved in its anti-proliferative effects in OSCC.

Anti-Inflammatory Effect of a TCM Formula Li-Ru-Kang in Rats With Hyperplasia of Mammary Gland and the Underlying Biological Mechanisms

Li-Ru-Kang (LRK), a formula of eight traditional Chinese medicines (TCM), has been used to treat hyperplasia of mammary gland (HMG) in TCM clinics. However, how LRK works in HMG patients is unclear. To explore the possible mechanisms of LRK against HMG, the network pharmacology was used to screen the potential targets and possible pathways that involved in LRK treated HMG. Rat HMG model induced by estrogen and progesterone was used to further verify the effects of the key molecules of LRK selected from the enriched pathways on HMG. Nipple heights and diameters were measured and uterus index was calculated. The histopathological changes of mammary gland tissue were detected by hematoxylin-eosin (H&E) staining. Western blot was used to detect the phosphorylation of ERK, JNK, and P38. And immunohistochemistry staining was performed to evaluate the levels of estrogen receptor α (ERα), progesterone receptor (PR), nuclear factor-(NF-)κB (p65), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), cyclooxygenases 2 (COX-2), inducible nitric oxide synthase (iNOS), 8-hydroxy-2′deoxyguanosine (8-OHdG), and nitrotyrosine (NT). Our results indicate that LRK treatment rescues significantly nipples height and diameter, decreases uterus index and ameliorates HMG. LRK treatment also markedly attenuates the over-expression of IL-1β, TNF-α, COX-2, and iNOS, and suppressed the formation of 8-OHdG and NT. Furthermore, LRK treatment significantly inhibits the phosphorylation of JNK, ERK, and p38 and expression of NF-κB (p65), interestingly, LRK treatment has no effect on the expression of ERα and PR. Our data suggest that the LRK treatment protects the mammary glands from the damage of oxidative stress and inflammation induced by estrogen and progesterone, via suppresses of MAPK/NF-κB signaling pathways without affecting on the expression of ERα and PR.

Rutin protects against lipopolysaccharide-induced mastitis by inhibiting the activation of the NF-κB signaling pathway and attenuating endoplasmic reticulum stress

Rutin, found widely in traditional Chinese medicine materials, is used to treat eye swelling and pain, hypertension, and hyperlipidemia. In the present study, a mouse mastitis model induced by lipopolysaccharide (LPS) was established to explore rutin's inhibitory mechanism on mastitis via nuclear factor kappa B (NF-κB) inflammatory signaling and the relationship between NF-κB signaling and endoplasmic reticulum (ER) stress. Mice were divided into six groups: Control group, LPS model group, LPS + rutin (25, 50, and 100 mg/kg) and LPS + dexamethasone (DEX) group. DEX, rutin, and PBS (control and LPS groups) were administered 1 h before and 12 h after perfusion of LPS. After LPS stimulation for 24 h, to evaluate rutin's therapeutic effect on mastitis, the mammary tissues of each group were collected to detect histopathological injury, tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6 mRNA and protein levels; and glucose-regulated protein, 78 kDa (GRP78) protein levels. The protein and mRNA levels of TNF-α, IL-1β, and IL-6 in the LPS + rutin group were significantly lower than those in the LPS model group. Similarly, p50/p105, phosphorylated (p)-p65/p65 and p-inhibitor of nuclear factor kappa b kinase subunit beta (p-IKKβ)/IKKβ ratios in the LPS + rutin group (50 mg/kg) and LPS + rutin group (100 mg/kg) decreased significantly. GRP78 protein expression was significantly higher in LPS + rutin group (100 mg/kg). The structure of mammary tissue became gradually more intact and vacuolization of acini decreased as the rutin concentration increased. The nuclear quantity of p65 in the LPS + rutin group decreased significantly in a rutin dose-dependent manner. Rutin had an anti-inflammatory effect in the LPS-induced mouse mastitis model, manifested by inhibition of NF-κB pathway activation and attenuation of ER stress.

Screening for the anti-inflammation quality markers of Xiaojin Pills based on HPLC-MS/MS method, COX-2 inhibition test and protein interaction network

Nowadays, breast disorders seriously affect women’s health in an increasing number. In China, Xiaojin Pills are commonly used in the treatment of breast diseases. Doctors have concluded that the combined use of Xiaojin Pills with conventional therapy can significantly improve the efficacy with fewer side effects. However, the prescription of Xiaojin Pills is complicated and their quality control methods cannot completely ensure the quality of Xiaojin Pills. On the basis of its mechanism, our study combined chemical evaluation and biological evaluation to identify the anti-inflammatory markers of Xiaojin Pills. In this manuscript, 13 compounds in Xiaojin Pills were quantified. At the same time, the cyclooxygenase-2 inhibition rates of different Xiaojin Pills were measured and the possible markers were screened by spectrum-effect relationship. Further, anti-inflammatory activities of markers were verified and protein interaction network was analyzed, identifying the components of Protocatechuate, Beta-Boswellic acid and Levistilide A as the anti-inflammatory quality markers of Xiaojin Pills. We hope our studies can provide a scientific theoretical basis for accurately quality control of Xiaojin Pills and reasonable suggestions for pharmaceutical companies and new ideas for the quality control of other medicines.

Quercetin decrease somatic cells count in mastitis of dairy cows

Quercetin is a dietary flavonoid which has an effect on inflammation, angiogenesis and vascular inflammation. In several other flavonoids (e.g. kaempferol, astragalin, alpinetin, baicalein, indirubin), anti-inflammatory mechanism was proven by using mice mastitis model. The aim of the current study was pilot analysis of quercetin tolerability and its impact on somatic cells count (SCC) after multiple intramammary treatment on dairy cows with clinical mastitis. Based on SCC and clinical investigation, 9 dairy cows with clinical mastitis of one quarter were selected for the pilot study. Baseline analysis (hematology, TNFα, SCC) was performed every 24h among all cows three days before the first dose (B1-B3). After the baseline monitoring (B1-B3) eight days treatment (D1-D8) was performed with a high and low dose. Selected blood parameters were analyzed. Starting from D1 to D8, a decrease of SCC in relation to baseline was characterized by declining trend. The presented results allowed the confirmation of the significant influence of quercetin on the reduction of SCC in mastitis in dairy cows after 8days of therapy.

Effects of Alpinetin on Intestinal Barrier Function, Inflammation and Oxidative Stress in Dextran Sulfate Sodium-Induced Ulcerative Colitis Mice

BACKGROUND

Alpinetin is a flavonoid isolated from Alpinia katsumadai Hayata that has demonstrated anti-inflammatory, antibacterial and anti-tumor activities. However, alpinetin has not been widely studied in amelioration of inflammatory bowel disease. The study aimed to investigate the role of alpinetin on intestinal epithelial tight junctions, oxidative stress and Nrf2/HO-1 signaling pathway in dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice.

METHODS

A total of 40 mice were divided into 5 groups (n = 8/group): control group, DSS group (received 3% DSS), and low, medium and high-dose treatment groups (3% DSS + alpinetin 25, 50 and 100mg/kg). The disease activity index (DAI), histological scores, epithelial tight junctions, oxidative stress factors, and Nrf2/HO-1 signaling pathway in the colon were determined.

RESULTS

Alpinetin improved DAI, colonic shortening, histological scores and myeloperoxidase activity compared with the DSS group. The expression of occludin and zonula occludens-1 were upregulated by alpinetin, whereas the expression of claudin-2 was reduced. Moreover, alpinetin inhibited the level of malondialdehyde, and increased the level of superoxide dismutase. Nrf2/HO-1 signaling pathways were also found to be activated.

CONCLUSION

Alpinetin is associated with decreased intestinal inflammation and oxidative stress dose-dependently, and also regulated the expression of tight junctions between cells in UC mice. The findings of our study may shed light on the use of alpinetin in the treatment of UC.

Quantification and pharmacokinetics of alpinetin in rat plasma by UHPLC-MS/MS using protein precipitation coupled with dilution approach to eliminate matrix effects

Alpinetin, a bioactive flavonoid, has attracted great attention due to its diverse therapeutic effects, namely anti-oxidant, anti-tumor and anti-inflammatory effects with low systemic toxicity. Various determination methods have been developed in quality control and plant chemistry areas. However, quantification and pharmacokinetics of alpinetin in biological matrix have not been studied. In the present research, a sensitive, efficient and reliable ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the determination of alpinetin in rat plasma was developed and validated. Plasma samples were processed with protein precipitation (PP) followed by a 5-fold acetonitrile/water (50:50, v/v) dilution to significantly decrease matrix effect which exited in one step PP method. Determination of alpinetin was conducted using positive electrospray ionization tandem mass spectrometry in multiple reaction monitoring mode. Results demonstrated that the method was precise (3.3%-12.3%), accurate (-5.8% to 10.8%) and linear in the range of 1-1000 ng/mL. The new developed method was subsequently applied to a pharmacokinetic research of alpinetin following oral and intravenous dosing to healthy Sprague-Dawley rats. Alpinetin was demonstrated rapid absorption after oral administration with an absolute bioavailability of ∼15.1% and extensive distribution after dosing.

Alpinetin attenuates inflammatory responses by suppressing TLR4 and NLRP3 signaling pathways in DSS-induced acute colitis

Alpinetin, a composition of Alpinia katsumadai Hayata, has been reported to have a number of biological properties, such as antibacterial, antitumor and other important therapeutic activities. However, the effect of alpinetin on inflammatory bowel disease (IBD) has not yet been reported. The purpose of this study was to investigate the anti-inflammatory effect and mechanism of alpinetin on dextran sulfate sodium (DSS)-induced colitis in mice. In vivo, DSS-induced mice colitis model was established by giving mice drinking water containing 5% (w/v) DSS for 7 days. Alpinetin (25, 50 and 100 mg/kg) were administered once a day by intraperitoneal injection 3 days before DSS treatment. In vitro, phorbol myristate acetate (PMA)-differentiated monocytic THP-1 macrophages were treated with alpinetin and stimulated by lipopolysaccharide (LPS). The results showed that alpinetin significantly attenuated diarrhea, colonic shortening, histological injury, myeloperoxidase (MPO) activity and the expressions of tumor necrosis factor (TNF-α) and interleukin (IL-1β) production in mice. In vitro, alpinetin markedly inhibited LPS-induced TNF-α and IL-1β production, as well as Toll-like receptor 4 (TLR4) mediated nuclear transcription factor-kappaB (NF-κB) and NOD-like receptor protein 3 (NLRP3) inflammasome activation. In conclusion, this study demonstrated that alpinetin had protective effects on DSS-induced colitis and may be a promising therapeutic reagent for colitis treatment.

The effects of Brazilian propolis on etiological agents of mastitis and the viability of bovine mammary gland explants

The objective of this study was to evaluate in vitro the antimicrobial activity of Brazilian propolis from Urupema, São Joaquim, and Agua Doce (Santa Catarina State) and green propolis from Minas Gerais State, and the effects of propolis on bovine mammary gland explant viability. The propolis samples differed in flavonoid content and antioxidant activity. Green propolis showed the highest content of flavonoids, followed by the sample from São Joaquim. The propolis from Urupema showed the lowest flavonoid content along with the lowest antioxidant activity. The total phenolics were similar across all studied samples. Despite phytochemical differences, the propolis samples from Minas Gerais, São Joaquim, and Urupema presented the same level of antimicrobial activity against Staphylococcus aureus strains. The reduction in S. aureus growth was, on average, 1.5 and 4 log10 times at 200 and 500 μg/mL, respectively. At concentrations of 1,000 μg/mL, all propolis reduced bacterial growth to zero. On the other hand, when the propolis were tested against strains of Escherichia coli, the samples presented weak antimicrobial activity. Mammary explants were maintained in culture for 96h without a loss in viability, demonstrating the applicability of the model in evaluating the toxicity of propolis. The origin and chemical composition of the propolis had an effect on mammary explant viability. We encountered inhibitory concentrations of 272.4, 171.8, 63.85, and 13.26 μg/mL for the propolis from Água Doce, Urupema, São Joaquim, and Mina Gerais, respectively. A clear association between greater antimicrobial activity and toxicity for mammary explants was observed. Of all propolis tested, the Urupema sample was noteworthy, as it showed antimicrobial activity at less toxic concentrations than the other samples, reducing bacterial growth to an average of 9.3 × 10(2) cfu/mL after 6h of contact using 200 μg/mL of extract. The results demonstrate the potential for Brazilian propolis in the treatment of mastitis, although effectiveness is dependent on geographical origin and concentration. The results from the mammary gland explant assays are promising for the investigation of other natural products with antimicrobial and anti-inflammatory properties that can be used in the intramammary treatment of subclinical mastitis and during dry cow therapy.

Mouse models of mastitis - how physiological are they?

Lactation mastitis is a common, but poorly understood, inflammatory breast disease that is a significant health burden. A better understanding of the aetiology of mastitis is urgently required, and will assist in the development of improved prevention and treatment strategies in both human and animal species. Studies in mice have the potential to greatly assist in identifying new drug candidates for clinical trials, and in developing a better understanding of the disease. Mouse models of mastitis involve administration of a mastitis-inducing agent to the mammary gland usually during lactation to examine the host immune response, and progression through to resolution of the disease. There are important variations in the protocols of these mouse models that critically affect the conclusions that can be drawn from the research. Some protocols involve weaning of offspring at the time of mastitis induction, and there are variations in the mastitis-inducing agent and its carrier. Induction of mammary gland involution through weaning of offspring limits the capacity to study the disease in the context of a lactating mammary gland. Administration of live bacteria in an aqueous carrier can cause sepsis, restricting the physiological relevance of the model. Mouse model research should employ appropriately designed controls and closely monitor the health of the mice. In this commentary, we discuss the advantages and study design limitations of each mouse model, and highlight the potential for further development of physiologically relevant mouse models of mastitis.

Anti-hyperplasia effects of Rosa rugosa polyphenols in rats with hyperplasia of mammary gland

Rosa rugosa (Thunb.) is used in Chinese traditional medicine with the functions of promoting blood circulation, relieving the depressed liver and attenuating breast disorders. This study was to investigate the anti-hyperplasia effects of the polyphenols-rich fraction from R. rugosa (FRR) in rat. Rat model of hyperplasia of mammary gland (HMG) was induced by intramuscularly injected with estrogen (0.5mg/kg/d) for 25 days, and followed with progestogen (5mg/kg/d) for another 5 days. Meanwhile, FRR was orally given for 30 days. Then, the levels of estradiol and oxidative stress were assessed. The mammary expressions of AKT and JNK were evaluated by Western blot analysis. The expressions of NFκB-p65, COX-2 and VEGF were measured by immunohistochemical analysis. The whole results indicated that FRR could exert anti-hyperplasia effects in rat via modulating the mammary expression of JNK and AKT, as well as alleviating the NFκB related oxidative stress and inflammatory responses.

Inflammatory mediators in mastitis and lactation insufficiency

Mastitis is a common inflammatory disease during lactation that causes reduced milk supply. A growing body of evidence challenges the central role of pathogenic bacteria in mastitis, with disease severity associated with markers of inflammation rather than infection. Inflammation in the mammary gland may be triggered by microbe-associated molecular patterns (MAMPs) as well as danger-associated molecular patterns (DAMPs) binding to pattern recognition receptors such as the toll-like receptors (TLRs) on the surface of mammary epithelial cells and local immune cell populations. Activation of the TLR4 signalling pathway and downstream nuclear factor kappa B (NFkB) is critical to mediating local mammary gland inflammation and systemic immune responses in mouse models of mastitis. However, activation of NFkB also induces epithelial cell apoptosis and reduced milk protein synthesis, suggesting that inflammatory mediators activated during mastitis promote partial involution. Perturbed milk flow, maternal stress and genetic predisposition are significant risk factors for mastitis, and could lead to a heightened TLR4-mediated inflammatory response, resulting in increased susceptibility and severity of mastitis disease in the context of low MAMP abundance. Therefore, heightened host inflammatory signalling may act in concert with pathogenic or commensal bacterial species to cause both the inflammation associated with mastitis and lactation insufficiency. Here, we present an alternate paradigm to the widely held notion that breast inflammation is driven principally by infectious bacterial pathogens, and suggest there may be other therapeutic strategies, apart from the currently utilised antimicrobial agents, that could be employed to prevent and treat mastitis in women.

The chalcones cardamonin and flavokawain B inhibit the differentiation of preadipocytes to adipocytes by activating ERK

AIM

We searched for polyphenols capable of inhibiting the lipid accumulation in 3T3-L1 cells, and investigated the mechanisms of two effective chalcones cardamonin and flavokawain B on differentiation of preadipocytes.

METHOD AND RESULTS

We treated 3T3-L1 cells with a panel of 46 polyphenols and measured intracellular lipid accumulation by Sudan II staining. Four of them, including cardamonin and flavokawain B, inhibited lipid accumulation. In the further study, cardamonin and flavokawain B inhibited lipid accumulation by downregulating the expression of CCAAT/enhancer binding protein (C/EBP)-β, C/EBPα, and peroxisome proliferator-activated receptor-γ (PPARγ) at both mRNA and protein levels. Cardamonin and flavokawain B also increased phosphorylation of extracellular signal-regulated kinase (ERK) in the early phase of adipocyte differentiation. PD98059, an ERK inhibitor, restored C/EBPβ, PPARγ expression and intracellular lipid accumulation in adipocytes. Moreover, cardamonin and flavokawain B also modulated the secretion of C-reactive protein, dipeptidyl peptidase IV, interleukin-6, tumor necrosis factor-α and fibroblast growth factor-21 in mature adipocytes.

CONCLUSIONS

These results indicate that ERK activation and consequent downregulation of adipocyte-specific transcription factors are involved in the inhibitory effects of the chalcones cardamonin and flavokawain B on adipocyte differentiation. Moreover, cardamonin and flavokawain B are able to modulate secretion of adipokines in mature adipocytes.

Mammary inflammation around parturition appeared to be attenuated by consumption of fish oil rich in n-3 polyunsaturated fatty acids

Background

Mastitis endangers the health of domestic animals and humans, and may cause problems concerning food safety. It is documented that n-3 polyunsaturated fatty acids (PUFA) play significant roles in attenuating saturated fatty acids (SFA)-induced inflammation. This study was therefore conducted to determine whether mammary inflammation could be affected by consumption of diets rich in n-3 PUFA.

Methods

Forty-eight rats after mating began to receive diets supplemented with 5% fish oil (FO) or 7% soybean oil (SO). Blood and mammary tissue samples (n = 6) at day 0 and 14 of gestation and day 3 postpartum were collected 9 hours after intramammary infusion of saline or lipopolysaccharide (LPS) to determine free fatty acids (FFA) concentration and FA composition in plasma and inflammation mediators in mammary tissues.

Results

At day 14 of gestation and day 3 postpartum, the FO-fed rats had lower plasma concentrations of C18:2n6, C20:4n6, total n-6 PUFA and SFA, and higher plasma concentrations of C20:5n3 and total n-3 PUFA than the SO-fed rats. Plasma C22:6n3 concentration was also higher in the FO-fed than in the SO-fed rats at day 3 postpartum. Compared with the SO-fed rats, the FO-fed rats had lower mammary mRNA abundance of xanthine oxidoreductase (XOR) and protein level of tumor necrosis factor (TNF)-α, but had higher mammary mRNA abundances of interleukin (IL)-10 and peroxisome proliferator-activated receptor (PPAR)-γ at day 14 of gestation. Following LPS infusion at day 3 postpartum, the SO-fed rats had increased plasma concentrations of FFA, C18:1n9, C18:3n3, C18:2n6 and total n-6 PUFA, higher mammary mRNA abundances of IL-1β, TNF-α and XOR but lower mammary mRNA abundance of IL-10 than the FO-fed rats.

Conclusions

Mammary inflammation around parturition appeared to be attenuated by consumption of a diet rich in n-3 PUFA, which was associated with up-regulated expression of IL-10 and PPAR-γ.