Effects of lactic acid bacteria fermented feed and three types of lactic acid bacteria (L. plantarum, L. acidophilus, B. animalis) on intestinal microbiota and T cell polarization (Th1, Th2, Th17, Treg) in the intestinal lymph nodes and spleens of rats

OBJECTIVE

In this study, we investigated the effects of Rubus coreanus-derived lactic acid bacteria (LAB) fermented feed (RC-LAB fermented feed) and three types of LAB (Lactobacillus plantarum, Lactobacillus acidophilus, Bifidobacterium animalis) on the expression of transcription factors and cytokines in Th1, Th2, Th17, and Treg cells in the intestinal lymph nodes and spleens of rats. In addition, the effect on intestinal microbiota composition and body weight was investigated.

METHODS

Five-week-old male rats were assigned to five treatments and eight replicates. The expression of transcription factors and cytokines of Th1, Th2, Th17, and Treg cells in the intestinal lymph nodes and spleens was analyzed using real-time reverse transcriptase polymerase chain reaction assays. Intestinal tract microbiota compositions were analyzed by next-generation sequencing and quantitative polymerase chain reaction assays.

RESULTS

RC-LAB fermented feed and three types of LAB increased the expression of transcription factors and cytokines in Th1, Treg cells and Galectin-9, but decreased in Th2 and Th17 cells. In addition, the intestinal microbiota composition changed, the body weight and Firmicutes to Bacteroidetes (F/B) ratio decreased, and the relative abundance of LAB increased.

CONCLUSION

LAB fermented feed and three types of LAB showed an immune modulation effect by inducing T cell polarization and increased LAB in the intestinal microbiota.

Water Extract of Rubus coreanus Prevents Inflammatory Skin Diseases In Vitro Models

Atopic dermatitis (AD) is a chronic inflammatory skin disease caused by immune hypersensitivity reaction. The cause of AD is unclear, but its symptoms have a negative effect on quality of life; various treatment methods to alleviate these symptoms are underway. In the present study, we aimed to evaluate in vitro antioxidant and anti-inflammatory effects of Rubus coreanus water extract (RCW) on AD. Total phenolic compounds and flavonoid content of RCW were 4242.40 ± 54.84 mg GAE/g RCE and 1010.99 ± 14.75 mg CE/g RCW, respectively. RCW reduced intracellular reactive oxygen species level and increased the action of antioxidant enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase in tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-stimulated HaCaT cells. Moreover, mRNA expression of the pro-inflammatory cytokines, including TNF-α, interleukin-1β, and interleukin-6, was downregulated by RCW in the TNF-α/IFN-γ-stimulated cells. The levels of inflammatory chemokines (thymus- and activation-regulated chemokine; eotaxin; macrophage-derived chemokine; regulated on activation, normal T-cell expressed and secreted; and granulocyte-macrophage colony-stimulating factor) and intercellular adhesion molecule-1 were decreased in the TNF-α/IFN-γ-stimulated HaCaT cells after RCW treatment. Additionally, the mRNA expression levels of filaggrin and involucrin, proteins that form the skin, were increased by RCW. Furthermore, RCW inhibited the nuclear factor kappa-light-chain-enhancer of the activated B cells pathway in the TNF-α/IFN-γ-stimulated HaCaT cells. Collectively, the present investigation indicates that RCW is a potent substance that inhibits AD.

Rubi Fructus Water Extract Alleviates LPS-Stimulated Macrophage Activation via an ER Stress-Induced Calcium/CHOP Signaling Pathway

Despite the availability of antibiotics and vaccines, many intractable infectious diseases still threaten human health across the globe. Uncontrolled infections can lead to systemic inflammatory response syndrome and the excessive production of inflammatory cytokines, known as a cytokine storm. As cytokines also play necessary and positive roles in fighting infections, it is important to identify nontoxic and anti-inflammatory natural products that can modulate cytokine production caused by infections. Rubi Fructus, the unripe fruits of Rubus coreanus Miquel, are known to possess antioxidative properties. In this study, the effect of the water extract of Rubi Fructus (RF) on the lipopolysaccharide (LPS)-induced inflammatory response in RAW 264.7 macrophages was investigated using biochemical and cell biology techniques. Our data indicated that RF inhibits p38 phosphorylation, intracellular calcium release, and the production of nitric oxide (NO), interleukin (IL)-6, monocyte chemotactic activating factor (MCP)-1, tumor necrosis factor (TNF)-α, leukemia inhibitory factor (LIF), lipopolysaccharide-induced CXC chemokine (LIX), granulocyte-colony stimulating factor (G-CSF), granulocyte macrophage colony-stimulating factor (GM-CSF), vascular endothelial growth factor (VEGF), macrophage colony-stimulating factor (M-CSF), macrophage inflammatory protein (MIP)-1α, MIP-1β, MIP-2, and regulated on activation, normal T cell expressed and secreted (RANTES) in LPS-treated macrophages. In addition, we observed decreasing mRNA expression of Chop, Camk2a, Stat1, Stat3, Jak2, Fas, c-Jun, c-Fos, Nos2, and Ptgs2 without cytotoxic effects. We concluded that RF demonstrated immunoregulatory activity on LPS-stimulated macrophages via an endoplasmic reticulum (ER) stress-induced calcium/CCAAT-enhancer-binding protein homologous protein (CHOP) pathway and the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway.

The cholesterol-lowering effect of unripe Rubus coreanus is associated with decreased oxidized LDL and apolipoprotein B levels in subjects with borderline-high cholesterol levels: a randomized controlled trial

BACKGROUND

Rubus coreanus (R. coreanus) possesses properties that may decrease cholesterol levels.

METHODS

The effects of unripe R. coreanus (uRC) consumption on low-density lipoprotein (LDL) and total cholesterol levels related to decreased circulating apolipoprotein (Apo) B and oxidized LDL levels were evaluated. This randomized, double-blind, placebo-controlled study included subjects with borderline-high cholesterol levels (between 200 and 239 mg/dL) who consumed one capsule daily containing 600 mg of freeze-dried uRC extract (n = 39) or the placebo (n = 38).

RESULTS

After 12 weeks, the uRC group showed reductions of 21.23 ± 4.36 mg/dL in total cholesterol levels (P = 0.007) and 15.61 ± 4.16 mg/dL in LDL cholesterol levels (P = 0.032). In addition, significantly greater reductions in Apo B levels were observed in the uRC group (- 3.48 ± 3.40 mg/dL), but Apo B levels were increased in the placebo group (6.21 ± 2.84 mg/dL; P = 0.032). Furthermore, a remarkably lower oxidized LDL level was detected in the uRC group (57.76 ± 2.07 U/L) than in the placebo group (66.09 ± 3.47 U/L) after 12 weeks of consumption (P = 0.044).

CONCLUSIONS

Because of its cholesterol-lowering effect, uRC shows great promise as a therapeutic agent for subjects with borderline-high total blood cholesterol levels.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03649620 (8/28/2018, retrospectively registered).

Free and bound volatile compounds in the Rubus coreanus fruits of different ripening stages

The aim of the present study was to investigate the free and bound volatiles in the Rubus coreanus (RC) fruits of different ripening stages. Thirty-seven free volatiles and 28 bound volatiles were identified in RC fruit for the first time. The contents of free (E)-2-hexen-1-ol, 1-hexanol, 2-heptanol, β-myrcene, (E), (Z)-β-ocimene, allo-ocimene, linalool, cosmene, α-terpineol, methyl salicylate, eugenol, and β-damascenone remain high, and increased with the ripening of RC fruit. The contents of 11 bound volatiles decreased during the ripening, and became lower than the contents of their free volatiles in the ripe fruit. The ripe black fruit is closely correlated to the free nonanal, sulcatone, (E)-2-hexen-1-ol, 1-hexanol, 2-heptanol, 1-heptanol, 1-nonanol, (E)-linalool oxide (furanoid), and β-damascenone, and bound (E)-2-hexen-1-ol and (E)- β-ocimene. The ripe RC fruit is more fruity and floral than unripe fruit. The gradually hydrolyzed bound volatiles can enhance the fruity, floral, and herbaceous odors. PRACTICAL APPLICATIONS: Rubus coreanus (RC) fruit is a functional natural fruit. Both fresh and processed Rubus coreanus fruits including jams, confitures, wine, yogurt, vinegar, and beverages, as well as ingredients in functional foods or cosmetics have been extensively consumed. However, the free and bound aroma compounds in RC fruit have not been well understood. This work illustrates the contributions of free and bound volatiles to the flavor of RC fruit.

Effects of Rubus coreanus byproducts on intestinal microbiota and the immune modulation

Objective

Although the efficacy of Rubus coreanus (RC) byproducts as a feed additive has been recognized, its effects on intestinal microorganisms and the immune system are still unknown.

Methods

Six-week-old male rats were treated with 0.5% RC (T1), 1.0% RC (T2), and 1.5% RC (T3) for 4 weeks.

Results

We found that treatment with RC byproducts significantly increased the daily gain of body weight and feed intake. Treg-cell differentiation was enhanced in the mesenteric lymph nodes and spleen from the rats fed with RC byproducts. Illumina sequencing showed that bacteria in the phylum Firmicutes decreased and while those in the phylum Bacteroidetes increased in RC-treated groups. Particularly, the pathogenic microorganisms in the family Peptococcaceae decreased, and the non-pathogenic families Lachnospiraceae and S24-7 increased. Quantitative polymerase chain reaction analysis showed that the RC byproducts increased the lactic acid bacteria Bifidobacterium spp., Oscillospira spp., Leuconostoc citreum, and Weissella cibaria in a concentration-dependent manner.

Conclusion

RC byproducts may be effective in immunomodulation by affecting intestinal microorganisms.

Antiviral Effects of Black Raspberry (Rubus coreanus) Seed and Its Gallic Acid against Influenza Virus Infection

Influenza is a serious public health concern worldwide, as it causes significant morbidity and mortality. The emergence of drug-resistant viral strains requires new approaches for the treatment of influenza. In this study, Rubus coreanus seed (RCS) that is left over from the production of wine or juice was found to show antiviral activities against influenza type A and B viruses. Using the time-of-addition plaque assay, viral replication was almost completely abolished by simultaneous treatment with the RCS fraction of less than a 1-kDa molecular weight (RCSF1). One of the polyphenols derived from RCSF1, gallic acid (GA), identified by liquid chromatography-tandem mass spectrometry, showed inhibitory effects against both influenza type A and B viruses, albeit at relatively high concentrations. RCSF1 was bound to hemagglutinin protein, inhibited hemagglutination significantly and disrupted viral particles, whereas GA was found to only disrupt the viral particles by using transmission electron microscopy. In BALB/c mice infected with influenza virus, oral administration of RCSF1 significantly improved the survival rate and reduced the viral titers in the lungs. Our results demonstrate that RCSF1 and GA show potent and broad antiviral activity against influenza A and B type viruses and are promising sources of agents that target virus particles.

Stimulation of cannabinoid receptors by using Rubus coreanus extracts to control osteoporosis in aged male rats

A substantial proportion of men with prostatic disease have an increased risk of bone loss. In the present study, we investigated the effects of Rubus coreanus Miquel (RCM) extracts on osteoporosis that occurs with N-methyl-N-nitrosourea (MNU)-induced prostatic hyperplasia. The rats used in this study were categorized into groups of healthy controls, rats treated with MNU, and rats treated with MNU and RCM. The rats were sacrificed after 10 weeks of RCM treatment, after which ultrasonography, serum biochemical tests, histopathological examinations, immunohistochemical analysis, and semi-quantitative reverse-transcription polymerase chain reaction analysis were performed. There were no marked differences in body weight gain and the size and weight of the prostate gland between the MNU group and the MNU and RCM group. However, treatment with RCM inhibited osteoclastic osteolysis and reduced dysplastic progress in the prostate gland, as observed by histopathological evaluation and by analyzing changes in the levels of bone regulatory factors. In addition, the group treated with MNU and RCM had higher expression levels of cannabinoid receptors-1, -2, and osteoprotegerin. These results indicate that the anti-osteoporotic effect of RCM in prostatic hyperplasia is attributable to the cannabinoid receptor-related upregulation of osteoblastogenesis and inhibition of prostatic hyperplasia. The results of the present study suggest that treatment with RCM may benefit osteoporotic patients with prostatic disease by simultaneously altering the activation of osteoblasts and osteoclasts.

Anti-inflammatory effect of a standardized triterpenoid-rich fraction isolated from Rubus coreanus on dextran sodium sulfate-induced acute colitis in mice and LPS-induced macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Rubus coreanus Miquel (Rosaceae), the Korean black raspberry, has traditionally been used to treat inflammatory diseases including diarrhea, asthma, stomach ailment, and cancer. Although previous studies showed that the 19α-hydroxyursane-type triterpenoids isolated from Rubus coreanus exerted anti-inflammatory activities, their effects on ulcerative colitis and mode of action have not been explored. This study was designed to assess the anti-inflammatory effects and the molecular mechanisms involving19α-hydroxyursane-type triterpenoid-rich fraction from Rubus coreanus (TFRC) on a mice model of colitis and lipopolysaccharide (LPS)-induced RAW 264.7 macrophages.

MATERIALS AND METHODS

Experimental colitis was induced by DSS for 7 days in ICR mice. Disease activity indices (DAI) took into account body weight, stool consistency, and gross bleeding. Histological changes and macrophage accumulation were observed by immunohistochemical analysis. Pro-inflammatory markers were determined using immunoassays, RT-PCR, and real time PCR. Signaling pathway involving nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) activation was determined by luciferase assay and Western blotting.

RESULTS

In DSS-induced colitis mice, TFRC improved DAIs and pathological characteristics including colon shortening and colonic epithelium injury. TFRC suppressed tissue levels of pro-inflammatory cytokines and reduced macrophage infiltration into colonic tissues. In LPS-induced RAW 264.7 macrophages, TFRC inhibited the production of NO, PGE2, and pro-inflammatory cytokines by down-regulating the activation of NF-κB and p38 MAPK signaling.

CONCLUSION

The study demonstrates that TFRC has potent anti-inflammatory effects on DSS-induced colonic injury and LPS-induced macrophage activation, and supports its possible therapeutic and preventive roles in colitis.

Effect of the combinatory mixture of Rubus coreanus Miquel and Astragalus membranaceus Bunge extracts on ovariectomy-induced osteoporosis in mice and anti-RANK signaling effect

ETHNOPHARMACOLOGICAL RELEVANCE

Postmenopausal osteoporosis is one of the most common disorders in women after menopause, which is linked to an estrogen deficiency and characterized by an excessive loss of trabecular bone. Rubus coreanus and Astragalus membranaceus have been used for their various pharmacological properties in Asia as a traditional medicine. The present study evaluated the anti-osteoporotic effects of the optimal combination of Rubus coreanus and Astragalus membranaceus in 7:3 mixture (RAM) in ovariectomized (OVX) mice by investigating bone biomechanical properties and the serum levels of TNF-α, osteocalcin, RANKL, OPG, and RANK-RANKL signal-related osteoclast differentiation markers.

MATERIALS AND METHODS

A total of 36 mature female outbred ICR (Institute of cancer research) strain mice (7 weeks) were divided into 6 groups with 7 mice in each group as follows: (1) Sham-operated control mice (Sham) received daily oral phosphate-buffered-saline (PBS) of equal volumes through gavage. (2) OVX mice received a daily oral gavage of PBS (OVX). (3) OVX mice were treated daily with 50mg/kgb.w./day of RAM (4) with 100mg/kgb.w./day of RAM or (5) with 200mg/kgb.w./day of RAM via oral gavage. (6) OVX mice received i.p. injections of 17β-estradiol (E2) (0.1mg/kgb.w./day) three times per week for 12 weeks.

RESULTS

Micro-CT images showed that oral administration of RAM to OVX mice prevented tibial bone loss, preserved trabecular bone microarchitecture, and improved bone biomechanical properties. RAM administration also showed recovery effects on the levels of TNF-α, OPG and RANKL concentration in OVX-states. Additionally, we found that the mechanism by which RAM elicited anti-osteoporotic effects was by down-regulating the expression of TRAF6 and NFATc1 in RANKL-RANK pathway, a route of osteoclast differentiation, followed by reducing the production of osteoclast differentiation factors, calcitonin receptors and cathepsin K.

CONCLUSIONS

Our research strongly suggests that RAM can be clinically used in the prevention and treatment of postmenopausal osteoporosis.

Immature Rubus coreanus Shows a Free Radical-Scavenging Effect and Inhibits Cholesterol Synthesis and Secretion in Liver Cells

Rubus coreanus fruits have been employed as a traditional medicine for centuries in the Asia-Pacific region. Its pharmacological action differs according to the different extraction methods utilized and the degree of fruit ripening. In this study, we determined the cellular effect of different ethanol extracts of mature and immature Rubus coreanus fruits in human hepatic cell line, HepG2 cells. The antioxidant activity, effect on superoxide dismutase activity and cholesterol biosynthesis efficiency was also evaluated. Immature Rubus coreanus extract showed higher antioxidant capability, compared with that of its mature fractions. Cellular antioxidant proteins including HO-1, Cu/Zn-superoxide dismutase and catalase were highly expressed in the presence of Rubus coreanus. Cholesterol levels in HepG2 cells treated with the water fraction of immature Rubus coreanus were significantly reduced. This antihyperlipidaemic action of Rubus coreanus is a consequence of cholesterol biosynthesis and extracellular secretion in HepG2 cells. These results indicate that among different ethanol fraction of mature and immature Rubus coreanus fruit extracts, water extract of immature fruit extract shows higher antioxidant as well as higher antihyperlipidaemic action.

Antioxidative and aldose reductase-inhibitory effects of a fermentation filtrate of Rubus coreanus

Antioxidative and aldose reductase (AR)-inhibitory effects of a fermentation filtrate of Rubus coreanus (FRC) were investigated using corneal/retinal homogenate and lens cytosol, respectively. Rat corneal/retinal homogenate was treated with 50 µM FeCl₃ in the presence of FRC (3.2-100 µg/mL) for 30 min at 37℃, and thiobarbituric acid-reactive substances (TBARS) was quantified as a lipid peroxidation parameter. FRC markedly suppressed the TBARS production in a concentration-dependent manner, leading to 50% (IC₅₀) and 100% (IC₁₀₀) inhibitory concentrations of 20 and 95 µg/mL, respectively, which was similar to the effect of butylated hydroxyanisole. Activity of AR from rat lens was assayed in the presence of FRC (1-31.6 µg/mL) at 25℃ using glyceraldehyde as a substrate. FRC inhibited lens AR by 50% (IC₅₀) and 90% (IC₉₀) at approximately 2 and 31.6 µg/mL, respectively, comparable to the effect of quercetin. The results indicate that ERC could be a promising candidate for the improvement of eye injury and visual dysfunction of dry eye and diabetic patients.

Protective actions of Rubus coreanus ethanol extract on collagenous extracellular matrix in ultraviolet-B irradiation-induced human dermal fibroblasts

Solar ultraviolet (UV) irradiation leads to distinct changes in the skin connective tissues by degradation of collagen, which is a major structural component in the extracellular matrix. UV irradiation induces the production of matrix metalloproteinases (MMP) capable of attacking native fibrillar collagen and responsible for inhibiting the construction of collagenous extracellular matrix. In this study, we attempted to investigate the protective actions of Rubus coreanus ethanol extract (RCE) on the MMP production and the consequent procollagen/collagen degradation in UV-B-irradiated human dermal fibroblasts. The analytical data showed that Rubus coreanus ethanol extract was mostly comprised of cyanidin 3-rutinoside. Pre-treatment of fibroblasts with this extract inhibited UV-B-induced production of MMP-1, MMP-8 and MMP-13 in dose-dependent manners. In addition, Western blot analysis and immunocytochemical staining assay revealed that RCE markedly augmented the cellular levels of procollagen/collagen declined in UV-B-exposed dermal fibroblasts. These results demonstrate that RCE blocks UV-B-induced increase of the collagen degradation by inhibiting MMP production. Thus, RCE may act as an agent inhibiting excessive dermal collagen degradation leading to the skin photoaging.