Therapeutic effects of α-iso-cubebenol, a natural compound isolated from the Schisandra chinensis fruit, against sepsis

IM156, a new AMPK activator, protects against polymicrobial sepsis

IM156, a novel biguanide with higher potency of AMP‐activated protein kinase activation than metformin, has inhibitory activity against angiogenesis and cancer. In this study, we investigated effects of IM156 against polymicrobial sepsis. Administration of IM156 significantly increased survival rate against caecal ligation and puncture (CLP)‐induced sepsis. Mechanistically, IM156 markedly reduced viable bacterial burden in the peritoneal fluid and peripheral blood and attenuated organ damage in a CLP‐induced sepsis model. IM156 also inhibited the apoptosis of splenocytes and the production of inflammatory cytokines including IL‐1β, IL‐6 and IL‐10 in CLP mice. Moreover, IM156 strongly inhibited the generation of reactive oxygen species and subsequent formation of neutrophil extracellular traps in response to lipopolysaccharide in neutrophils. Taken together, these results show that IM156 can inhibit inflammatory response and protect against polymicrobial sepsis, suggesting that IM156 might be a new treatment for sepsis.

Anti-Obesity Effect of α-Cubebenol Isolated from Schisandra chinensis in 3T3-L1 Adipocytes

The efficacy of α-cubebenol isolated from Schisandra chinensis has been studied in several diseases, including cecal ligation, puncture challenge-induced sepsis, and degranulation of neutrophils. To identify the novel functions of α-cubebenol on lipid metabolism, alterations on the regulation of lipogenesis, lipolysis, and inflammatory response were observed in 3T3-L1 adipocytes treated with α-cubebenol. Most lipogenic targets, including lipid accumulation, level of lipogenic transcription factors, and expression of lipogenic regulators, were suppressed in MDI (3-isobutyl-1-methylxanthine, dexamethasone, and insulin)-stimulated 3T3-L1 adipocytes treated with α-cubebenol without significant cytotoxicity. In addition, similar inhibition effects were observed in the iNOS-induced COX-2 mediated pathway and NLRP3 inflammasome pathway of MDI-stimulated 3T3-L1 cells treated with α-cubebenol. Lipolytic targets, such as cAMP concentration, expression of adenylyl cyclase and PDE4, and their downstream signaling pathway, in MDI-stimulated 3T3-L1 cells were stimulated by the α-cubebenol treatment. The levels of transcription factors and related proteins for β-oxidation were significantly higher in the MDI + α-cubebenol treated group than in the MDI + Vehicle treated group. These results show that α-cubebenol has a novel role as a lipogenesis inhibitor, lipolysis and β-oxidation stimulator, and inflammasome suppressor in MDI-stimulated 3T3-L1 adipocytes.

Exercise Attenuates High-Fat Diet-induced Disease Progression in 3xTg-AD Mice

PURPOSE

Little is known regarding the therapeutic role of exercise against the risk of a high-fat diet (HFD) for Alzheimer's disease (AD) and AD-like cognitive deficits. This study aimed to investigate the therapeutic effect of treadmill running against HFD-induced progression in AD neuropathology and cognitive impairments in the triple-transgenic AD (3xTg-AD) mice.

METHODS

The 3xTg-AD mice were assigned to a chow diet (control, n = 10), an HFD (n = 10), or an HFD combined with exercise (HFD + EX, n = 10) group. Mice in the HFD were fed with a 60% fat diet for 20 wk. The HFD + EX mice were additionally subjected to treadmill running.

RESULTS

Compared with the control mice, the HFD mice had impaired brain insulin signaling, exacerbated AD neuropathology, defects in synaptic stability/plasticity, and apoptotic neuronal cell death in conjunction with exacerbated cognitive deficits in the affected brain regions, which were all significantly alleviated in the HFD + EX mice.

CONCLUSION

The current findings suggest that treadmill running protects against AD-like disease progression and cognitive deficits caused by an HFD in the 3xTg-AD mice.

Activation of transient receptor potential vanilloid 3 by the methanolic extract of Schisandra chinensis fruit and its chemical constituent γ-schisandrin

Transient receptor potential vanilloid 3 (TRPV3) is a non-selective cation channel with modest permeability to calcium ions. It is involved in intracellular calcium signaling and is therefore important in processes such as thermal sensation, skin barrier formation, and wound healing. TRPV3 was initially proposed as a warm temperature sensor. It is activated by synthetic small-molecule chemicals and plant-derived natural compounds such as camphor and eugenol. Schisandra chinensis (Turcz.) Baill (SC) has diverse pharmacological properties including antiallergic, anti-inflammatory, and wound healing activities. It is extensively used as an oriental herbal medicine for the treatment of various diseases. In this study, we investigated whether SC fruit extracts and seed oil, as well as four compounds isolated from the fruit can activate the TRPV3 channel. By performing whole-cell patch clamp recording in HEK293T cells overexpressing TRPV3, we found that the methanolic extract of SC fruit has an agonistic effect on the TRPV3 channel. Furthermore, electrophysiological analysis revealed that γ-schisandrin, one of the isolated compounds, activated TRPV3 at a concentration of 30 µM. In addition, γ-schisandrin (~100 µM) increased cytoplasmic Ca²⁺ concentrations by approximately 20% in response to TRPV3 activation. This is the first report to indicate that SC extract and γ-schisandrin can modulate the TRPV3 channel. This report also suggests a mechanism by which γ-schisandrin acts as a therapeutic agent against TRPV3-related diseases.

Antimicrobial properties of K alanchoe blossfeldiana: a focus on drug resistance with particular reference to quorum sensing-mediated bacterial biofilm formation

Objectives

This study attempts to investigate the antimicrobial properties of Kalanchoe blossfeldiana with a particular reference to quorum sensing (QS)-mediated biofilm formation.

Methods

The methanol extract of K. blossfeldiana leaves (MEKB) was evaluated for antimicrobial properties including QS-controlled production of biofilm (including virulence factor, motility and lactone formation) in Pseudomonas aeruginosa. Methanol extract of K. blossfeldiana was also evaluated for anti-cytokine (tumour necrosis factor-alpha, interleukin-6 and interleukin-1 beta) properties in peripheral blood mononuclear cells (PBMC).

Key findings

Methanol extract of K. blossfeldiana exhibited antimicrobial effect on clinical isolates, as well as standard reference strains. Pseudomonas aeruginosa exposed to MEKB (subminimum inhibitory concentration (MIC)) displayed reduced biofilm formation, whereas supra-MIC produced destruction of preformed biofilms. Methanol extract of K. blossfeldiana reduced the secretion of virulence factors (protease and pyoverdin) along with generation of acyl homoserine lactone (AHL). Confocal laser scanning microscopy images indicate reduction of biofilm thickness. The extract also reduced cytokine formation in lipopolysaccharide-stimulated PBMC.

Conclusions

K alanchoe blossfeldiana was found to interfere with AHL production, which in turn may be responsible for downregulating QS-mediated production of biofilm and virulence. This first report on the antibiofilm and anticytokine properties of this plant may open up new vistas for future exploration of this plant for combating biofilm-related resistant infections.

Identification of a novel anti-inflammatory compound, α-cubebenoate from Schisandra chinensis

AIMS OF THE STUDY

Extracts of Schisandra chinensis have been used as an anti-fatigue and tonic agent. Because chronic fatigue syndrome is related to inflammatory and oxidative stress, we assessed whether Schisandra chinensis has anti-inflammatory constituents and studied the effect of a novel α-cubebenoate isolated from Schisandra chinensis.

MATERIALS AND METHODS

α-Cubebenoate was isolated from an extract of Schisandra chinensis fruits. The inductions of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) by lipopolysaccharide (LPS) were quantified by RT-PCR and Western blotting in mouse peritoneal macrophages. Nitric oxide (NO) and prostaglandin E2 (PGE2) were also measured in the media by Griess reagent and EIA method. A mouse model of LPS-induced peritonitis was used to test the in vivo efficacy of α-cubebenoate.

RESULTS

α-Cubebenoate (5-10μg/ml) inhibited the inductions of iNOS and COX-2 in mouse peritoneal macrophages at the mRNA and protein levels. LPS-induced productions of NO and PGE2 were inhibited by α-cubebenoate (5-10μg/ml). In addition, α-cubebenoate inhibited the LPS-induced activation of JNK, but not those of ERK and p38 MAPK in mouse peritoneal macrophages. Furthermore, in the LPS-induced in vivo peritonitis model, α-cubebenoate (1mg/kg) strongly inhibited the accumulation of polymorph nuclear lymphocytes in the peritoneal cavity.

CONCLUSION

α-Cubebenoate inhibited LPS-induced expression of iNOS and COX-2 in a concentration-dependent manner, thereby suppressing productions of NO and PGE2 in vitro in peritoneal macrophages. α-Cubebenoate also inhibited LPS-induced accumulation of polymorph nuclear lymphocytes in LPS-induced peritonitis model in vivo. α-Cubebenoate may act as an anti-fatigue constituent of Schisandra chinensis through anti-inflammation and could be of therapeutic use as a treatment for inflammatory diseases.