Atraric Acid Exhibits Anti-Inflammatory Effect in Lipopolysaccharide-Stimulated RAW264.7 Cells and Mouse Models.

Lichens, composite organisms resulting from the symbiotic association between the fungi and algae, produce a variety of secondary metabolites that exhibit pharmacological activities. This study aimed to investigate the anti-inflammatory activities of the secondary metabolite atraric acid produced by Heterodermia hypoleuca. The results confirmed that atraric acid could regulate induced pro-inflammatory cytokine, nitric oxide, prostaglandin E2, induced nitric oxide synthase and cyclooxygenase-2 enzyme expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Meanwhile, atraric acid downregulated the expression of phosphorylated IκB, extracellular signal-regulated kinases (ERK) and nuclear factor kappa B (NFκB) signaling pathway to exhibit anti-inflammatory effects in LPS-stimulated RAW264.7 cells. Based on these results, the anti-inflammatory effect of atraric acid during LPS-induced endotoxin shock in a mouse model was confirmed. In the atraric acid treated-group, cytokine production was decreased in the peritoneum and serum, and each organ damaged by LPS-stimulation was recovered. These results indicate that atraric acid has an anti-inflammatory effect, which may be the underlying molecular mechanism involved in the inactivation of the ERK/NFκB signaling pathway, demonstrating its potential therapeutic value for treating inflammatory diseases.

Protective Effects of 2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-glucoside on Ovariectomy Induced Osteoporosis Mouse Model.

2,3,5,4'-Tetrahydroxystilbene-2-O-ß-d-glucoside (TSG), an active polyphenolic component of Polygonum multiflorum, exhibits many pharmacological activities including antioxidant, anti-inflammation, and anti-aging effects. A previous study demonstrated that TSG protected MC3T3-E1 cells from hydrogen peroxide (H2O2) induced cell damage and the inhibition of osteoblastic differentiation. However, no studies have investigated the prevention of ovariectomy-induced bone loss in mice. Therefore, we investigated the effects of TSG on bone loss in ovariectomized mice (OVX). Treatment with TSG (1 and 3 µg/g; i.p.) for six weeks positively affected body weight, uterine weight, organ weight, bone length, and weight change because of estrogen deficiency. The levels of the serum biochemical markers of calcium (Ca), inorganic phosphorus (IP), alkaline phosphatase (ALP), and total cholesterol (TCHO) decreased in the TSG-treated mice when compared with the OVX mice. Additionally, the serum bone alkaline phosphatase (BALP) levels in the TSG-treated OVX mice were significantly increased compared with the OVX mice, while the tartrate-resistant acid phosphatase (TRAP) activity was significantly reduced. Furthermore, the OVX mice treated with TSG showed a significantly reduced bone loss compared to the untreated OVX mice upon micro-computed tomography (CT) analysis. Consequently, bone destruction in osteoporotic mice as a result of ovariectomy was inhibited by the administration of TSG. These findings indicate that TSG effectively prevents bone loss in OVX mice; therefore, it can be considered as a potential therapeutic for the treatment of postmenopausal osteoporosis.

Saccharomonopyrones A-C, New α-Pyrones from a Marine Sediment-Derived Bacterium Saccharomonospora sp. CNQ-490.

Intensive study of the organic extract of the marine-derived bacterium Saccharomonospora sp. CNQ-490 has yielded three new α-pyrones, saccharomonopyrones A-C (1-3). The chemical structures of these compounds were assigned from the interpretation of 1D, 2D NMR and mass spectrometry data. Saccharomonopyrone A (1) is the first α-pyrone microbial natural product bearing the ethyl-butyl ether chain in the molecule, while saccharomonopyrones B and C possess unusual 3-methyl and a 6-alkyl side-chain within a 3,4,5,6-tetrasubstituted α-pyrone moiety. Saccharomonopyrone A exhibited weak antioxidant activity using a cation radical scavenging activity assay with an IC50 value of 140 µM.

The Protective Effects of Astaxanthin on the OVA-Induced Asthma Mice Model.

Although astaxanthin has a variety of biological activities such as anti-oxidant effects, inhibitory effects on skin deterioration and anti-inflammatory effects, its effect on asthma has not been studied. In this paper, the inhibitory effect of astaxanthin on airway inflammation in a mouse model of ovalbumin (OVA)-induced asthma was investigated. We evaluated the number of total cells, Th1/2 mediated inflammatory cytokines in bronchoalveolar lavage fluid (BALF) and airway hyperresponsiveness as well as histological structure. The level of total IgE, IgG1, IgG2a, OVA-specific IgG1, and OVA-specific IgG2a were also examined. The oral administration of 50 mg/mL astaxanthin inhibited the respiratory system resistance, elastance, newtonian resistance, tissue damping, and tissue elastance. Also, astaxanthin suppressed the total cell number, IL-4, and IL-5, and increased the IFN-γ in the BALF. In the sera, total IgE, IgG1, and OVA-specific IgG1 were reduced by astaxanthin exposure and IgG2a and OVA-specific IgG2a were enhanced via oral administration of astaxanthin. Infiltration of inflammatory cells in the lung, production of mucus, lung fibrosis, and expression of caspase-1 or caspase-3 were suppressed in OVA-induced asthmatic animal treated with astaxanthin. These results suggest that astaxanthin may have therapeutic potential for treating asthma via inhibiting Th2-mediated cytokine and enhancing Th1-mediated cytokine.

Anti-adipogenic and anti-diabetic effects of cis-3',4'-diisovalerylkhellactone isolated from Peucedanum japonicum Thunb leaves in vitro.

Peucedanum japonicum Thunb is a medicinal plant belonging to the family Umbelliferae. This study evaluated the anti-diabetic and anti-obesity effects of cis-3',4'-diisovalerylkhellactone (cDIVK) isolated from Peucedanum japonicum Thunb leaves. cDIVK (30 and 50µM) effectively inhibited adipocyte differentiation and fat accumulation, whereas it stimulated glucose uptake compared with the control in 3T3-L1 cells. cDIVK significantly increased AMPK activation and suppressed protein and mRNA expression of major adipogenic transcriptional factors such as C/EBPα, PPARγ and SREBP-1c in 3T3-L1 cells. In addition, cDIVK had potential α-glucosidase inhibitory activity. These results indicated that cDIVK may act as a natural dual therapeutic agent for diabetes and obesity.

Herbal preparation (HemoHIM) enhanced functional maturation of bone marrow-derived dendritic cells mediated toll-like receptor 4.

BACKGROUND: HemoHIM, which is an herbal preparation of three edible herbs (Angelicam gigas Nakai, Cnidium offinale Makino, and Peaonia japonica Miyabe), is known to have various biological and immunological activities, but the modulatory effects of this preparation on dendritic cells (DCs)-mediated immune responses have not been examined previously. DCs are a unique group of white blood cells that initiate primary immune responses by capturing, processing, and presenting antigens to T cells. RESULTS: In the present study, we investigated the effect of HemoHIM on the functional and phenotypic maturation of murine bone marrow-derived dendritic cells (BMDCs) both in vitro and in vivo. The expression of co-stimulatory molecules (CD40, CD80, CD86, MHC I, and MHC II) and the production of cytokines (IL-1ß, IL-6, IL-12p70, and TNF-α) were increased by HemoHIM in BMDCs. Furthermore, the antigen-uptake ability of BMDCs was decreased by HemoHIM, and the antigen-presenting ability of HemoHIM-treated mature BMDCs increased TLR4-dependent CD4(+) and CD8(+) T cell responses. CONCLUSIONS: Our findings demonstrated that HemoHIM induces TLR4-mediated BMDCs functional and phenotypic maturation through in vivo and in vitro. And our study showed the antigen-presenting ability that HemoHIM-treated mature BMDCs increase CD4(+) and CD8(+) T cell responses by in vitro. These results suggest that HemoHIM has the potential to mediate DC immune responses.

The Protective Effects of Alisol A 24-Acetate from Alisma canaliculatum on Ovariectomy Induced Bone Loss in Vivo.

Alisma canaliculatum is a herb commonly used in traditional Korean medicine, and has been shown in scientific studies to have antitumor, diuretic hepatoprotective, and antibacterial effects. Recently, the anti-osteoclastogenesis of alisol A 24-acetate from Alisma canaliculatum was investigated in vitro. However, the influence of alisol A 24-acetate on osteoporosis in animals has not been investigated. The present study was undertaken to investigate the anti-osteoporotic effect of alisol A 24-acetate on bone mass in ovariectomized (OVX) mice and to identify the mechanism responsible for its effects. OVX mice were treated daily with 0.5 or 2 µg/g of alisol A 24-acetate for a period of six weeks. It was found that these administrations significantly suppressed osteoporosis in OVX mice and improved bone morphometric parameters. The serum estradiol, bone alkaline phosphatase levels, regulatory T/Th17 cell numbers were significantly increased by alisol A 24-acetate as compared with untreated OVX mice. In addition, TRAP activity was inhibited by alisol A 24-acetate in OVX mice. These results suggest alisol A 24-acetate effectively prevents bone loss in OVX mice, and that it can be considered a potential therapeutic for the treatment of postmenopausal osteoporosis.

Increased Accumulation of Ginsenosides in Panax ginseng Sprouts Cultivated with Kelp Fermentates.

Currently, new agri-tech has been developed and adapted for the cultivation of crops using smart farming technologies, e.g., plant factories and hydroponics. Kelp (Laminaria japonica), which has a high industrial value, was considered as an alternative to chemicals for its eco-friendly and sustainably wide use in crop cultivation. In this study, a fermented kelp (FK) was developed for use in hydroponics. The FK contained various free and protein-bound amino acid compositions produced by fermenting the kelp with Saccharomyces cerevisiae. Supplementing FK as an aeroponic medium when cultivating ginseng sprouts (GSs) elevated the total phenolic and flavonoid contents. Additionally, seven ginsenosides (Rg1, Re, Rb1, Rc, Rg2, Rb2, and Rd) in GSs cultivated with FK in a smart-farm system were identified and quantified by a high-performance liquid chromatography-evaporative light scattering detector/mass spectrometry analysis. Administering FK significantly increased the ginsenosides in the GSs compared to the control group, which was cultivated with tap water. These results indicate the FK administration contributed to the increased accumulation of ginsenosides in the GSs. Overall, this study suggests that FK, which contains abundant nutrients for plant growth, can be used as a novel nutrient solution to enhance the ginsenoside content in GSs during hydroponic cultivation.

Comparative Study on Phenolic Compounds and Antioxidant Activities of Hop (Humulus lupulus L.) Strobile Extracts.

In this study, we investigated the phenolic compounds in hop strobile extracts and evaluated their antioxidant property using DPPH and ABTS assay. The total phenolic compound (TPC) and total flavonoid compound (TFC) estimated in two different solvent extracts considerably varied depending on the extraction solvent. The most abundant phenolic compound in hop strobile was humulones (α-acid) with levels ranging from 50.44 to 193.25 µg/g. El Dorado accession revealed higher antioxidant activity in ethanol extracts (DPPH: IC50 124.3 µg/mL; ABTS: IC50 95.4 µg/mL) when compared with that of the other accessions. Correlations between DPPH (IC50) scavenging TFC in ethanol extract (TFC_E, -0.941), and TPC_E (-0.901), and between ABTS (IC50) scavenging TFC_E (-0.853), and TPC_E (-0.826), were statistically significant at p < 0.01 level, whereas no significant correlation was observed between antioxidant activities, TPC and TFC in water extract. This study is the first to report that variations in the level of phenolic contents and antioxidant activity of various hop cultivars depended on the type of extraction solvent used and the cultivation regions. These results could provide valuable information on developing hop products.

Changes in Functionality of Tenebrio molitor Larvae Fermented by Cordyceps militaris Mycelia.

The Food and Agriculture Organization (FAO) has been estimating the potential of insects as human food since 2010, and for this reason, Tenebrio molitor larvae, also called mealworms, have been explored as an alternative protein source for various foods. In this study, in order to increase nutrient contents and improve preference as an alternative protein source, we fermented the T. molitor larvae by Cordyceps militaris mycelia. T. molitor larvae were prepared at optimal conditions for fermentation and fermented with C. militaris mycelia, and we analyzed T. molitor larvae change in functionality with proximate composition, ß-glucan, cordycepin, adenosine, and free amino acids content. T. molitor larvae fermented by C. militaris mycelia showed higher total protein, total fiber, and ß-glucan content than the unfermented larvae. In addition, the highest cordycepin content (13.75 mg/g) was observed in shaded dried T. molitor larvae fermented by C. militaris mycelia. Additionally, the isolated cordycepin from fermented T. molitor larvae showed similar cytotoxicity as standard cordycepin when treated with PC-9 cells. Therefore, we report that the optimized methods of T. molitor larvae fermented by C. militaris mycelia increase total protein, total fiber, ß-glucan and produce the amount of cordycepin content, which can be contributed to healthy food and increase T. molitor larvae utilization.

Dramatic Increase in Content of Diverse Flavonoids Accompanied with Down-Regulation of F-Box Genes in a Chrysanthemum (Chrysanthemum × morifolium (Ramat.) Hemsl.) Mutant Cultivar Producing Dark-Purple Ray Florets.

Anthocyanins (a subclass of flavonoids) and flavonoids are crucial determinants of flower color and substances of pharmacological efficacy, respectively, in chrysanthemum. However, metabolic and transcriptomic profiling regarding flavonoid accumulation has not been performed simultaneously, thus the understanding of mechanisms gained has been limited. We performed HPLC-DAD-ESI-MS (high-performance liquid chromatography coupled with photodiode array detection and electrospray ionization mass spectrometry) and transcriptome analyses using "ARTI-Dark Chocolate" (AD), which is a chrysanthemum mutant cultivar producing dark-purple ray florets, and the parental cultivar "Noble Wine" for metabolic characterization and elucidation of the genetic mechanism determining flavonoid content. Among 26 phenolic compounds identified, three cyanidins and eight other flavonoids were detected only in AD. The total amounts of diverse flavonoids were 8.0 to 10.3 times higher in AD. Transcriptome analysis showed that genes in the flavonoid biosynthetic pathway were not up-regulated in AD at the early flower stage, implying that the transcriptional regulation of the pathway did not cause flavonoid accumulation. However, genes encoding post-translational regulation-related proteins, especially F-box genes in the mutated gene, were enriched among down-regulated genes in AD. From the combination of metabolic and transcriptomic data, we suggest that the suppression of post-translational regulation is a possible mechanism for flavonoid accumulation in AD. These results will contribute to research on the regulation and manipulation of flavonoid biosynthesis in chrysanthemum.

Defatted Tenebrio molitor Larva Fermentation Extract Modifies Steatosis, Inflammation and Intestinal Microflora in Chronic Alcohol-Fed Rats.

This study examined the effects of defatted mealworm fermentation extract (MWF) on alcoholic liver injury in rats. The rats were fed either a Lieber-DeCarli control (Con) or alcohol liquid diet (EtOH). The alcohol-fed rats were administered MWF (50, 100, or 200 mg/kg/day) and silymarin (200 mg/kg/day) orally for eight weeks. MWF prevented alcohol-induced hepatocellular damage by decreasing their serum aspartate transaminase, alanine transaminase, and gamma-glutamyl transpeptidase levels significantly compared to the EtOH group. MWF effectively reduced the relative hepatic weight, lipid contents, and fat deposition, along with the down-regulation of transcriptional factors and genes involved in lipogenesis compared to the EtOH group. It also enhanced the antioxidant defense system by elevating the glutathione level and glutathione reductase activity. MWF attenuated the alcohol-induced inflammatory response by down-regulating hepatic inflammation-associated proteins expression, such as phosphorylated-inhibitor of nuclear factor-kappa B-alpha and tumor necrosis factor-alpha, in chronic alcohol-fed rats. Furthermore, sequencing analysis in the colonic microbiota showed that MWF tended to increase Lactobacillus johnsonii reduced by chronic alcohol consumption. These findings suggest that MWF can attenuate alcoholic liver injury by regulating the lipogenic and inflammatory pathway and antioxidant defense system, as well as by partially altering the microbial composition.

Enhanced anti-tumor immunotherapy by silica-coated magnetic nanoparticles conjugated with ovalbumin.

BACKGROUND: The effective induction of an antigen-specific T cell immune response through dendritic cell activation is one of the key goals of tumor immunotherapy. METHODS: In this study, efficient antigen-delivery carriers using silica-coated magnetic nanoparticles were designed and, their antigen-specific T cell immune response through dendritic cell activation investigated. RESULTS: The results showed that the silica-coated magnetic nanoparticles with conjugated ovalbumin enhanced the production of cytokines and antigen uptake in bone marrow-derived dendritic cells. Also, this induced an antigen-specific cytotoxic T lymphocyte (CTL) immune response and activated antigen-specific Th1 cell responses, including IL-2 and IFN-γ production and proliferation. We proved that the immune-stimulatory effects of silica-coated magnetic nanoparticles with conjugated ovalbumin were efficient in inhibiting of tumor growth in EG7-OVA (mouse lymphoma-expressing ovalbumin tumor-bearing mice model). CONCLUSION: Therefore, the silica-coated magnetic nanoparticles with conjugated ovalbumin are expected to be useful as efficient anti-cancer immunotherapy agents.

Heshouwu (Polygonum multiflorum Thunb.) Extract Attenuates Bone Loss in Diabetic Mice.

This study investigated the effects and mechanism of Heshouwu (Polygonum multiflorum Thunb.) water extract (HSW) on diabetes-related bone loss in mice. HSW was orally administered (300 mg/kg body weight) to high-fat diet and streptozotocin-induced diabetic mice for 10 weeks. HSW significantly alleviated mouse body weight loss and hyperglycemia compared with the control group, and elevated serum levels of insulin, osteocalcin, and bone-alkaline phosphatase. HSW supplementation also significantly increased the bone volume/tissue volume ratio and trabecular thickness and number, and decreased the bone surface/bone volume ratio and trabecular structure model index in the femur and tibia. Moreover, HSW significantly increased femoral bone mineral density. In addition, HSW down-regulated osteoclastogenic genes, such as nuclear factor of activated T-cells, cytoplasmic 1 and tartrate-resistant acid phosphatase 5 (TRAP), in both the femur and tibia tissue, and reduced serum TRAP level compare to those of control mice. These results indicate that HSW might relieve diabetes-related bone disorders through regulating osteoclast-related genes, suggesting HSW may be used as a preventive agent for diabetes-induced bone loss.

Enhanced anti-tumor immunotherapy by dissolving microneedle patch loaded ovalbumin.

The skin is a very suitable organ for the induction of immune responses to vaccine antigens. Antigen delivery systems to the skin by needle and syringe directly deposit the antigen into the epidermal-dermal compartment, one of the most immunocompetent sites due to the presence of professional antigen-presenting cells aimed at the induction of antigen-specific T cells. In this study, we analyzed the amount of ovalbumin as an antigen delivered to the skin by a microneedle. When ovalbumin protein as an antigen was delivered to the skin of mice using a dissolving microneedle, it induced an immune response through the enhanced proliferation and cytokines production by the splenocytes and lymph nodes. Also, it effectively increased the ovalbumin-specific CD8+ T cell and CD4+ T cell population and induced an ovalbumin-specific CTL response against the graft of ovalbumin-expressing EG7 tumor cells in the immunized mice. Also, we identified the inhibition of tumor growth and prevention of tumor formation in the context of the therapeutic and prophylactic vaccine, respectively through EG-7 tumor mouse model. Finally, these data show the potential of patches as attractive antigen delivery vehicles.

Verification of the Functional Antioxidant Activity and Antimelanogenic Properties of Extracts of Poria cocos Mycelium Fermented with Freeze-Dried Plum Powder.

Here we examine the effects of extracts of Poria cocos mycelium fermented with freeze-dried plum powder (PPE) on the α-melanocyte stimulating hormone (α-MSH)-stimulated melanogenesis in cultured murine B16 melanoma cells (B16 cells), relative to the effects of Prunus extract. We found that an extract of Prunus fermentation showed significant inhibition of melanogenesis and tyrosinase activity with no effect on cell proliferation and was more active compared to Prunus extract alone. Furthermore, we confirmed that medium containing 3% Prunus was the optimal culture substrate for fermentation with Poria cocos. These results provide evidence that Prunus fermentation extract affects skin whiting in murine B16 melanoma cells (B16 cells). Prunus contains rutin, oxalic acid, succinic acid, and fumaric acid, which help in digestion and fatigue recovery. The rutin of Prunus mume is reported to have antioxidant and anti-inflammatory effects. Also, Prunus extract has a tyrosinase inhibitory activity for skin whiting through its antioxidant activity. Therefore, we believe the Prunus extract for Poria cocos fermentation can be provided as a potential mediator to induce skin whiting.

Heshouwu (Polygonum multiflorum Thunb.) ethanol extract suppresses pre-adipocytes differentiation in 3T3-L1 cells and adiposity in obese mice.

This study investigated whether Heshouwu (Polygonum multiflorum Thunb.) root ethanol extract (PME) has anti-obesity activity using 3T3-L1 cells and high-fat diet (HFD)-induced obese mice. Treatment with PME (5 and 10 µg/mL) dose-dependently suppressed 3T3-L1 pre-adipocyte differentiation to adipocytes and cellular triglyceride contents. In addition, PME inhibited mRNA and protein expression of adipogenic transcription factors such as CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ), which led to down-regulation of fatty acid synthase gene expression. After feeding mice PME (0.05%) with HFD for 12 weeks, their visceral fat mass, size and body weight were significantly reduced compared with the HFD group. Furthermore, PME supplementation significantly up-regulated the PPARα, CPT1, CPT2, UCP1 and HSL mRNA levels compared with the HFD group, whereas it down-regulated expression of the PPARγ and DGAT2 genes. Finally, HFD increased serum leptin, insulin, glucose and insulin and glucose levels; however, PME reversed these changes. These results demonstrated that PME might relieve obesity that occurs via inhibition of adipogenesis and lipogenesis as well as through lipolysis and fatty acid oxidation in 3T3-L1 cells and HFD-induced obese mice.

In Vitro and In Vivo Effects of Gracilaria verrucosa Extracts on Osteoclast Differentiation.

Bone remodeling, a physiological process characterized by bone formation by osteoblasts and bone resorption by osteoclasts, is important for the maintenance of healthy bone in adult humans. Osteoclasts play a critical role in bone erosion and osteoporosis and are bone-specific multinucleated cells generated through differentiation of monocyte/macrophage lineage precursors. Receptor activator of NF-κB ligand (RANKL) has been reported to induce osteoclast differentiation. In this study, we explored whether Gracilaria verrucosa extracts (GE) could affect RANKL-mediated osteoclast differentiation. GE significantly inhibited RANKL-activated osteoclast differentiation by inhibiting protein expression of c-fos and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1), vital factors in RANKL-mediated osteoclastogenesis. In addition, GE attenuated ovariectomy-induced bone loss in mice. In summary, GE can prevent osteoclastogenesis and hormone-related bone loss via blockage of c-fos-NFATc1 signaling. Our results suggest that GE may have therapeutic potential in the treatment of postmenopausal osteoporosis.

Immunosuppressive Effects of Bryoria sp. (Lichen-Forming Fungus) Extracts via Inhibition of CD8+ T-Cell Proliferation and IL-2 Production in CD4+ T Cells.

Lichen-forming fungi are known to have various biological activities, such as antioxidant, antimicrobial, antitumor, antiviral, anti-inflammation, and anti proliferative effects. However, the immunosuppressive effects of Bryoria sp. extract (BSE) have not previously been investigated. In this study, the inhibitory activity of BSE on the proliferation of CD8+ T cells and the mixed lymphocytes reaction (MLR) was evaluated in vitro. BSE was non-toxic in spleen cells and suppressed the growth of splenocytes induced by anti-CD3. The suppressed cell population in spleen cells consisted of CD8+ T cells and their proliferation was inhibited by the treatment with BSE. This extract significantly suppressed the IL-2 associated with T cell growth and IFN-γ as the CD8+ T cell marker. Furthermore, BSE reduced the expression of the IL-2 receptor alpha chain (IL-2Rα) on CD8+ T cells and CD86 on dendritic cells by acting as antigen-presenting cells. Finally, the MLR produced by the co-culture of C57BL/6 and MMC-treated BALB/c was suppressed by BSE. IL-2, IFN-γ, and CD69 on CD8+ T cells in MLR condition were inhibited by BSE. These results indicate that BSE inhibits the MLR via the suppression of IL-2Rα expression in CD8+ T cells. BSE has the potential to be developed as an anti-immunosuppression agent for organ transplants.

Antitumor Effect of KML-B-Treated Dendritic Cells via Induction of Lymphocyte Activation.

Lectins are carbohydrate-binding proteins with various biological activities, such as antitumor and immunomodulatory effects. Although lectins have various biological activities, they are still limited by cytotoxicity in normal cells. To overcome this problem, we used the noncytotoxic part of Korean mistletoe lectin B-chain (KML-B) to induce maturation of dendritic cells (DCs). A previous study reported that KML-B induces DC maturation by triggering TLR-4, including expression of costimulatory molecules (CD40, CD80, and CD86), MHC II, and secretion of cytokines in DCs. Additionally, matured DCs by KML-B induced T helper (Th) cell activation and differentiation toward Th1 cells. However, the interaction of KML-B-treated DCs with CD8+ T cells is still poorly understood. In this study, we confirmed the ability of matured DCs by KML-B to stimulate cytotoxic T cells using OT-1 mouse-derived CD8+ T cells. KML-B induced MHC I expression in DCs, stimulation of CD8+ T cell activation and proliferation, and IFN-γ secretion. Moreover, tumor sizes were reduced by KML-B treatment during vaccination of OVA257-264-pulsed DCs. Here, we confirmed induction of CD8+ T cell activation and the antitumor effect of KML-B treatment in DCs.