Role of gut-derived bacterial lipopolysaccharide and peripheral TLR4 in immobilization stress-induced itch aggravation in a mouse model of atopic dermatitis.

Psychological stress and intestinal leakage are key factors in atopic dermatitis (AD) recurrence and exacerbation. Here, we demonstrate the mechanism underlying bacterial translocation across intestinal epithelial barrier damaged due to stress and further aggravation of trimellitic anhydride (TMA)-induced itch, which remain unclear, in AD mice. Immobilization (IMO) stress exacerbated scratching bouts and colon histological damage, and increased serum corticosterone and lipopolysaccharide (LPS). Orally administered fluorescein isothiocyanate (FITC)-dextran and surgically injected (into the colon) Cy5.5-conjugated LPS were detected in the serum and skin after IMO stress, respectively. The relative abundance of aerobic or facultative anaerobic bacteria was increased in the colon mucus layer, and Lactobacillus murinus, E. coli, Staphylococcus nepalensis, and several strains of Bacillus sp. were isolated from the spleens and mesenteric lymph nodes. Oral antibiotics or intestinal permeability blockers, such as lubiprostone (Lu), 2,4,6-triaminopyrimidine (TAP) and ML-7, inhibited IMO stress-associated itch; however, it was reinduced through intradermal or i.p. injection of LPS without IMO stress. I.p. injection of TAK-242 (resatorvid), a TLR4 inhibitor, abrogated IMO stress-associated itch, which was also confirmed in TLR4-KO mice. IMO stress alone did not cause itch in naïve mice. IMO stress-induced itch aggravation in TMA-treated AD mice might be attributed to the translocation of gut-derived bacterial cells and LPS, which activates peripheral TLR4 signaling.

An orally active, small-molecule TNF inhibitor that disrupts the homotrimerization interface improves inflammatory arthritis in mice.

Excessive signaling by the proinflammatory cytokine TNF is involved in several autoimmune diseases, including rheumatoid arthritis (RA). However, unlike the approved biologics currently used to treat this and other conditions, commercially available small-molecule inhibitors of TNF trimerization are cytotoxic or exhibit low potency. Here, we report a TNF-inhibitory molecule (TIM) that reduced TNF signaling in vitro and was an effective treatment in a mouse model of RA. The initial lead compound, TIM1, attenuated TNF-induced apoptosis of human and mouse cells by delaying the induction of proinflammatory NF-κB and MAPK signaling and caspase 3- and caspase 8-dependent apoptosis. TIM1 inhibited the secretion of the proinflammatory cytokines IL-6 and IL-8 by disrupting TNF homotrimerization, thereby preventing its association with the TNF receptor. In a mouse model of collagen-induced polyarthritis, the more potent TIM1 analog TIM1c was orally bioavailable and reduced paw swelling, histological indicators of knee joint pathology, inflammatory infiltration of the joint, and the overall arthritis index. Orally delivered TIM1c showed immunological effects similar to those elicited by intraperitoneal injection of the FDA-approved TNF receptor decoy etanercept. Thus, TIM1c is a promising lead compound for the development of small-molecule therapies for the treatment of RA and other TNF-dependent systemic inflammation disorders.

Beneficial role of Boehmeria nivea in health and phytochemical constituents.

The leaf and stem extracts of Boehmeria nivea (BN) collected from three different regions in Korea were screened for their antioxidant, neuroprotective, estrogenic, insulin secretion, and α-glucosidase inhibitory activity. We also examined whether BN extracts regulate cancer cell growth, inflammatory-related gene expression, and lipid accumulation in cellular system. Leaf extracts possessed greater antioxidant, anti-proliferative in cancer cells, neuroprotective, estrogenic activity, and inhibitory effect on pro-inflammatory gene expression than stem extracts. Leaf and stem extracts inhibited lipid accumulation in three T3-L1 adipocytes but did not affect glucose-stimulated insulin secretion in INS-1 cells. We isolated and identified the phytochemical constituents in the n-butanol and ethyl acetate fractions of BN leaves by combining silica gel column chromatography with mass spectrometry and 1 H- and 13 C-NMR analysis. The active compounds (caffeic acid, isoquercitrin, p-coumaric acid, and rutin) exhibited ABTS and DPPH radical scavenging activity, which may contribute to the biological activities of BN leaf extract. An analytical method was developed to quantify marker compounds for the discrimination of BN collected from different regions. Our results support the use of this analysis method for accurate identification and quantification of marker compounds in BN for the development of functional foods. PRACTICAL APPLICATIONS: Boehmeria nivea (BN) has been used as a raw material for the textile industry or traditional herbal medicine. The current study established the biological activities and active components of BN. Our results showed that BN leaf and stem extracts exhibit antioxidant, neuroprotective, and estrogenic activity. BN leaf extract also inhibited cancer cell growth, inflammatory mediators and cytokines production, and lipid accumulation in vitro. Moreover, the bioactive compounds, such as caffeic acid, isoquercitrin, p-coumaric acid, and rutin, exert ABTS and DPPH radical scavenging activities. Therefore, BN could potentially be a promising source of bioactive phytochemicals for the development of functional foods or drugs.

Long-term administration of red ginseng non-saponin fraction rescues the loss of skeletal muscle mass and strength associated with aging in mice.

Background: Sarcopenia is a new and emerging risk factor aggravating the quality of life of elderly population. Because Korean Red Ginseng (RG) is known to have a great effect on relieving fatigue and enhancing physical performance, it is invaluable to examine its potential as an anti-sarcopenic drug. Methods: Anti-sarcopenic effect of non-saponin fraction of Korean Red Ginseng (RGNS) was evaluated in C2C12 myoblasts treated with C2-ceramide to induce senescence phenotypes, and 22-month-old mice fed with chow diet containing 2% RGNS (w/w) for 4 further months. Results: The RGNS treatment significantly alleviated cellular senescence indicated by intracellular lipid accumulation, increased amount of lysosomal ß-galactosidase, and reduced proliferative capacity in C2C12 myoblasts. This effect was not observed with saponin fraction. In an aged mouse, the 4-month-RGNS diet significantly improved aging-associated loss of muscle mass and strength, assessed by the weights of hindlimb skeletal muscles such as tibialis anterior (TA), extensor digitorum longus (EDL), gastrocnemius (GN) and soleus (SOL), and the cross-sectional area (CSA) of SOL muscle, and the behaviors in grip strength and hanging wire tests, respectively. During the same period, an aging-associated shift of fast-to slow-twitch muscle in SOL muscle was also retarded by the RGNS treatment. Conclusions: These findings suggested that the long-term diet of RGNS significantly prevented aging-associated muscle atrophy and reduced physical performance, and thus RGNS has a strong potential to be developed as a drug that prevents or improves sarcopenia.

Menaquinone-7 ameliorates cerebrovascular calcification-associated memory decline in aged mice.

Menaquinone (MK)-7 is a vitamin K2 analog that functions as a cofactor of γ-glutamyl carboxylase involved in the activation of vitamin K (VK)-dependent proteins. The present study aimed to evaluate the effect of MK-7 on memory and cognitive function in aged C57BL/6 mice. Eighteen-month-old mice were raised for a further 4 months, fed on a standard or calcium-rich diet (3 % [w/w]), and were orally given MK-7 (40 and 400 µg/day/mouse) five times per week during the same period. The Morris water maze (MWM) test was performed at 19 and 22 months. The aged mice showed noticeable memory declines in the MWM test at all time points compared with 6-week-old mice, and this memory loss was significantly restored by the daily administration of high-dose MK-7 for 4 months. MK-7 administration also improved micro-computed tomography-based cerebrovascular calcification and aging-associated declines in growth arrest-specific 6, total and carboxylated matrix Gla proteins, and ganglioside levels in the brain of aged mice. It serologically reduced phosphorous levels in the blood, but not the urea, cholesterol, and calcium. Taken together, the long-term administration of MK-7 significantly improved age-related memory and cognitive impairments, possibly through inhibition of cerebrovascular calcification in aged mice, indicating that it can be used to develop new drugs for improving memory and cognitive function in older adults.

Bee venom phospholipase A2 alleviates collagen-induced polyarthritis by inducing Foxp3+ regulatory T cell polarization in mice.

The mechanism underlying bee venom (BV) therapy is still controversial, with opinions ranging from constituent-based pharmacological action to homeopathic-like activity. The purpose of this study was to examine whether BV phospholipase A2 (bvPLA2), an enzymatic component of BV, is a novel anti-inflammatory and anti-arthritic mediator capable of stimulating CD25+ Foxp3+ regulatory T cell (Treg) polarization in a mouse model of human rheumatoid arthritis (RA). An experimental model of RA was established in male DBA/1 mouse by 2-week-interval injections of 100 µg type II collagen emulsified in complete (first injection) or incomplete Freund's adjuvant (second injection) at the base of the tail. During arthritis development, bvPLA2 (0.1, 0.5, 1.0 mg/kg) and/or Treg inhibitors such as anti-CD25 antibodies and peptide 60 (P60) were injected intraperitoneally for 5 weeks. Arthritic symptoms and the expansion of Tregs were then assessed by behavioral assessments, histological and micro-CT imaging, and flow cytometry. bvPLA2 injections significantly alleviated arthritic behaviors such as squeaking and joint swelling, consistent with changes seen on both histological and micro-CT images. The anti-arthritic effects of bvPLA2 were blocked by intraperitoneal injections of 0.25 mg/kg anti-CD25 antibody and 10 µg/kg P60, as determined by behavioral assessments. Flow cytometric analysis of dendritic cells, B cells, and major T cell subsets from spleens revealed a significant depletion of Tregs following anti-CD25 antibody, but not P60, treatment. bvPLA2 treatment exerted significant anti-inflammatory and anti-arthritic activities in a mouse model of RA via the induction of Tregs.