Inhibition of immediate-type allergic reaction by Rosa davurica Pall. in a murine model

The impact of atmospheric ultrafine particulate matter on IgE-mediated type 1 hypersensitivity reaction

The effect of atmospheric ultrafine particulate matter (UPM) on respiratory allergic diseases has been investigated for decades; however, the precise molecular mechanisms underlying these effects remain poorly understood. In this study, we used a simulated UPM (sUPM) generated via the spark discharge method to refine black carbon, a core particle that closely mimics real-world UPM, including the size (i.e., size of agglomerates: 165 nm) and organic carbon/elemental carbon ratio (i.e., 2.62). When 25 μg/mouse of dispersed sUPM was instilled into the lungs of mice, it promoted the infiltration and degranulation response of pulmonary mast cells, and exposure to sUPM in an immunoglobulin E (IgE)-mediated passive anaphylaxis model intensified the degranulation response of peripheral mast cells. These effects of sUPM were demonstrated to amplify the downstream signaling mechanism of the high-affinity IgE receptor (FcεRI) mediated by IgE when tested using rat basophil leukemia (RBL)-2H3 and mouse bone marrow-derived mast cells (BMMCs) collected from the bone marrow of BALB/c mice. These results indicate that airborne UPM can exacerbate type 1 hypersensitivity reactions by enhancing the IgE-mediated signaling pathways within mast cells. Furthermore, this study provided mechanistic evidence on exacerbated allergic pulmonary diseases induced by UPM inhalation.

Therapeutic Potential of Rosa davurica Pall. Root Extract as an Antidiabetic Agent: A Comprehensive Analysis from Molecular Mechanisms to In Vivo Efficacy

Rosa davurica Pall. is widely used in traditional oriental herbal therapy, but its components and molecular mechanisms of action remain unclear. This study investigates the antidiabetic potential of Rosa davurica Pall. root extract (RDR) and elucidates its underlying molecular mechanisms with in vitro and in vivo models. Data from the current study show that RDR exhibits strong antioxidant activity and glucose homeostasis regulatory effects. It significantly impacts glucose homeostasis in C2C12 skeletal muscle cells by inhibiting α-glucosidase activity. Further molecular mechanistic studies revealed that RDR promoted glucose uptake by phosphorylation of AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC), but not Phosphatidylinositol 3-kinase (PI 3-kinase)/Akt in C2C12 skeletal muscle cells. These actions increased the expression and translocation of glucose transporter type 4 (GLUT4) to the plasma membrane. In addition, RDR treatment in the STZ-induced diabetic rats remarkably improved the low body weight, polydipsia, polyphagia, hyperglycemia, and islet architecture and increased the insulin/glucose ratio. The liver (ALT and AST) and kidney marker enzyme (BUN and creatinine) levels were restored by RDR treatment as well. Phytochemical analysis identified eight major constituents in RDR, crucial for its antioxidant and antidiabetic activity. Through the molecular docking of representative glucose transporter GLUT4 with these compounds, it was confirmed that the components of RDR had a significantly high binding score in terms of structural binding. These findings from the current study highlight the antidiabetic effects of RDR. Collectively, our data suggest that RDR might be a potential pharmaceutical natural product for diabetic patients.

The first chloroplast sequence of Rosa davurica Pall. var. Davurica

Rosa davurica Pall. var. davurica is a member of the plant family Rosaceae. Although R. davurica has high application value, its chloroplast genome sequence has not been reported. This study aims to reveal the genetic characteristics of the chloroplast genome of Rosa roxburghii. The length of its total chloroplast DNA is 156,971 bp, with 37.22% G/C content. Its chloroplast genome has two inverted repeat (IRa and IRb) regions totaling 26,051 bp which are separated by a large single copy (LSC) region of 86,032 bp and a small single copy (SSC) region of 18,837 bp. The genome contains 131 independent genes (86 protein-coding, 37 tRNA, and 8 rRNA), and there are 18 repeated genes within the IR region. Among these genes, 17 genes contained one or two introns. The phylogenetic analysis showed that R. davurica was relatively close to other Rosa species, such as the Rosa hybrid.

Rosa davurica inhibits skin photoaging via regulating MAPK/AP-1, NF-κB, and Nrf2/HO-1 signaling in UVB-irradiated HaCaTs

Rosa davurica is widely used to treat various kinds of diseases because of its high antioxidant, antiviral and anti-inflammatory activities. This use of plant-based materials as medicine is called phytomedicine and has been widely practiced since time immemorial. However, the pharmacological mechanism of R. davurica in skin photoaging is not yet fully understood. Therefore, this study was carried out to evaluate the recovery effects of R. davurica leaf extracts (RDE) in UVB-irradiated human skin keratinocytes (HaCaTs) and investigate whether RDE is a potential therapeutic agent against skin photoaging. The expression of aging-related markers including mitogen-activated protein kinases/activator protein 1 (MAPK/AP-1), nuclear factor-κB (NF-κB), and nuclear factor E2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) was evaluated using Western blot analysis. The reactive oxygen species (ROS) was also used by FACS in HaCaTs. Findings indicated that RDE is efficient in scavenging free radicals and dose-dependently reducing ROS generation. Furthermore, RDE notably decreased UVB-induced matrix metalloproteinase-1 (MMP-1) expression through inhibition of MAPK/AP-1 and NF-κB signaling pathways as well as induced blocking of extracellular matrix (ECM) degradation in UVB-irradiated HaCaTs. In addition, RDE improved Nrf2/HO-1 signaling that increases oxidative defense capacity and enhances transforming growth factor-beta (TGF-β) signaling activation to promote procollagen type I synthesis, relieving UVB-induced skin cell damage. In conclusion, the protective effects of RDE on skin cellular components suggest that it has a high biological potential for skin protection from UVB-induced skin photoaging and is a good candidate for drug and cosmetic application.

Flavonoids from Rosa davurica Pall. fruits prevent high-fat diet-induced obesity and liver injury via modulation of the gut microbiota in mice

Rosa davurica Pall. (RDP) fruits are popularly consumed as beverages and healthy food in China because of their various beneficial activities. In particular, flavonoids are one of the major active ingredients of RDP fruits with predominant pharmacological effects. However, the anti-obesity activities of flavonoids from RDP fruits and their regulation effect on the gut microbiota have not been determined. In the present study, the flavonoid-rich extracts (RDPF) were isolated from RDP fruits and their anti-obesity effects were investigated using a high-fat diet (HFD)-induced obese mouse model. The results showed that RDPF intervention significantly inhibited the body weight, liver weight, kidney weight and epididymal adipose tissue weight of HFD-fed mice without affecting the calorie intake. Plasma lipid levels were also significantly lowered by RDPF treatment. Histological examination showed that RDPF supplementation partially recovered HFD-induced hepatic steatosis in the liver. RDPF also prevented oxidative injury of the liver, as evidenced by the altered superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) levels. The expression levels of CCAAT/enhancer binding protein α (C/EBPα), sterol regulatory element binding protein-1C (SREBP-1C), fatty acid synthase (FAS), acyl-coenzyme A oxidase 1 (ACOX1), peroxisome proliferator-activated receptor (PPARα) and CAT mRNA in the livers of mice were also regulated by RDPF administration. 16S rRNA gene sequence data further indicated that RDPF addition increased the microbial diversity and reshaped the community composition. Intriguingly, RDPF intervention did not exhibit inhibitory tendency toward the ratio of Firmicutes to Bacteroidetes, but markedly decreased the relative abundance of Erysipelotrichaceae. This study provided novel insights into the application of RDPF in the food industry.

Rosa davurica Pall. improves DNCB-induced atopic dermatitis in mice and regulated TNF-Alpa/IFN-gamma-induced skin inflammatory responses in HaCaT cells

PURPOSE

Rosa davurica Pall., is mainly distributed in Korea, Japan, northeastern China, southeastern Siberia, and eastern Asia. It has been extensively used to treat various kinds of diseases by reason of the significant antioxidant, antiviral and anti-inflammatory activities. However, the pharmacological mechanism of Rosa davurica Pall. in atopic dermatitis (AD) is still ill defined and poorly understood. This study was to examine the anti-inflammatory effects and its mechanism on AD of Rosa davurica Pall. leaves (RDL).

METHODS

To evaluate the therapeutic potential of RDL against AD, we have investigated the effects of RDL on the inflammatory reactions and the productions of inflammatory chemokines and cytokines that were induced by tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ) in HaCaT cells. Futhermore, we examined the effects of RDL on the signaling pathways of mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB). For the in-vivo studies, RDL extract was topically applied to the dinitrochlorobenzene (DNCB)-induced AD mice, then its therapeutic effect was evaluated physiologically and morphologically.

RESULTS

After the stimulation of HaCaT cells with TNF-α/IFN-γ, RDL considerably reduced the release of inflammatory mediators such as nitric oxide (NO), PEG₂ and other cytokines. RDL also reduced the phosphorylations of MAPK and NF-κB in TNF-α/IFN-γ-stimulated HaCaT cells. In vivo topical application of RDL to DNCB-induced AD mice significantly reduced the dorsal skin and ear thickness, clinical dermatitis severity, and mast cells. Treatment with RDL also markedly decreased the levels of serum IgE, IL-6 and the number of WBCs in the blood.

CONCLUSION

Our studies indicate that RDL inhibits the AD-like skin lesions by modulating skin inflammation. Consequently, these results suggest that RDL may be served as a possible alternative therapeutic treatment for skin disorder such as AD.

Adenine suppresses IgE-mediated mast cell activation

Nucleobase adenine is produced by dividing human lymphoblasts mainly from polyamine synthesis and inhibits immunological functions of lymphocytes. We investigated the anti-allergic effect of adenine on IgE-mediated mast cell activation in vitro and passive cutaneous anaphylaxis (PCA) in mice. Intraperitoneal injection of adenine to IgE-sensitized mice attenuated IgE-mediated PCA reaction in a dose dependent manner, resulting in a median effective concentration of 4.21 mg/kg. In mast cell cultures, only adenine among cytosine, adenine, adenosine, ADP and ATP dose-dependently suppressed FcɛRI (a high affinity receptor for IgE)-mediated degranulation with a median inhibitory concentration of 1.6mM. It also blocked the production of LTB4, an inflammatory lipid mediator, and inflammatory cytokines TNF-α and IL-4. In addition, adenine blocked thapsigargin-induced degranulation which is FcɛRI-independent but shares FcɛRI-dependent signaling events. Adenine inhibited the phosphorylation of signaling molecules important to FcɛRI-mediated allergic reactions such as Syk, PLCγ2, Gab2, Akt, and mitogen activated protein kinases ERK and JNK. From this result, we report for the first time that adenine inhibits PCA in mice and allergic reaction by inhibiting FcɛRI-mediated signaling events in mast cells. Therefore, adenine may be useful for the treatment of mast cell-mediated allergic diseases. Also, the upregulation of adenine production may provide another mechanism for suppressing mast cell activity especially at inflammatory sites.

Anti-allergic action of aged black garlic extract in RBL-2H3 cells and passive cutaneous anaphylaxis reaction in mice

Garlic (Allium sativum) has been used as a food as well as a component of traditional medicine. Aged black garlic (ABG) is known to have various bioactivities. However, the effect of ABG on allergic response is almost unknown. In the present study, we investigated whether ABG can inhibit immunoglobulin E-mediated allergic response in RBL-2H3 cells as well as in vivo passive cutaneous anaphylaxis (PCA). In in vitro tests, ethyl acetate extract (EBG) of ABG significantly inhibited the release of β-hexosaminidase (IC₅₀, 1.53 mg/mL) and TNF-α (IC₅₀, 0.98 mg/mL). Moreover, BG10, an active fraction of EBG, dramatically suppressed the release of β-hexosaminidase (IC₅₀, 53.60 μg/mL) and TNF-α (IC₅₀, 27.80 μg/mL). In addition, BG10 completely blocked the formation of prostaglandin E₂ and leukotriene B₄ at ≥25 μg/mL. When the effect of BG10 on FcɛRI receptor cascade was investigated, BG10 significantly inhibited the phosphorylation of Syk, but not Lyn. Furthermore, BG10 dose dependently decreased the phosphorylation of cytosolic phospholipase A₂ (cPLA₂) and 5-lipoxygenase (5-LO) as well as the expression of cyclooxygenase-2 (COX-2). Consistent with what has been mentioned earlier, BG10 also significantly inhibited the PCA reaction in mice. In conclusion, these results indicate that ABG suppresses the allergic response, and the mechanism for its anti-allergic action may involve suppressions of Syk, cPLA₂, 5-LO, and COX-2. The anti-allergic actions of ABG, EBG, or BG10 suggest that they may be useful as functional foods for allergic diseases.

[6]-Shogaol inhibits the production of proinflammatory cytokines via regulation of NF-κB and phosphorylation of JNK in HMC-1 cells

[6]-Shogaol is a major bioactive component of Zingiber officinale. Although [6]-shogaol has a number of pharmacological activities including antipyretic, analgesic, antitussive and anti-inflammatory effects, the specific mechanisms of its anti-allergic effects have not been studied. In this study, we present the effects of [6]-shogaol on mast cell-mediated allergic reactions in vivo and in vitro. Sprague-Dawley rats received intradermal injections of anti-DNP IgE was injected into dorsal skin sites. After 48 h, [6]-shogaol was administered orally 1 h prior to challenge with DNP-HSA in saline containing 4% Evans blue through the dorsal vein of the penis. In addition, rat peritoneal mast cells (RPMCs) were cultured and purified to investigate histamine release. In vitro, we evaluated the regulatory effects of [6]-shogaol on the level of inflammatory mediators in phorbol 12-myristate 13-acetate plus calcium ionomycin A23187-stimulated human mast cells (HMC-1). [6]-Shogaol reduced the passive cutaneous anaphylaxis reaction compared to the control group, and histamine release decreased significantly following the treatment of RPMCs with [6]-shogaol. In HMC-1 cells, [6]-shogaol inhibited the production of TNF-α, IL-6 and IL-8, as well as the activation of nuclear factor-κB (NF-κB) and phosphorylation of JNK in compound 48/80-induced HMC-1 cells. [6]-shogaol inhibited mast cell-mediated allergic reactions by inhibiting the release of histamine and the production of proinflammatory cytokines with the involvement of regulation of NF-κB and phosphorylation of JNK.