Akebia saponin D attenuates allergic airway inflammation through AMPK activation.

Akebia saponin D (ASD) is a bioactive triterpenoid saponin extracted from Dipsacus asper Wall. ex DC.. This study aimed to investigate the effects of ASD on allergic airway inflammation. Human lung epithelial BEAS-2B cells and bone marrow-derived mast cells (BMMCs) were pretreated with ASD (50, 100 and 200 µΜ) and AMPK activator 5-aminoimidazole-4-carboxamide-1-ß-D-ribofuranoside (AICAR) (1 mM), and then stimulated with lipopolysaccharide (LPS) or IL-33. Pretreatment with ASD and AICAR significantly inhibited TNF-α and IL-6 production from BEAS-2B cells, and IL-13 production from BMMCs. Moreover, pretreatment with ASD and AICAR significantly increased p-AMPK expression in BEAS-2B cells. Inhibition of AMPK by siRNA and compound C partly abrogated the suppression effect of ASD on TNF-α, IL-6, and IL-13 production. Asthma murine model was induced by ovalbumin (OVA) challenge and treated with ASD (150 and 300 mg/kg) or AICAR (100 mg/kg). Infiltration of eosinophils, neutrophils, monocytes, and lymphocytes, and production of TNF-α, IL-6, IL-4, and IL-13 were attenuated in ASD and AICAR treated mice. Lung histopathological changes were also ameliorated after ASD and AICAR treatment. Additionally, it showed that treatment with ASD and AICAR increased p-AMPK expression in the lung tissues. In conclusion, ASD exhibited protective effects on allergic airway inflammation through the induction of AMPK activation.

Curcumin inhibits the formation of atherosclerosis in ApoE-/- mice by suppressing cytomegalovirus activity in endothelial cells.

BACKGROUND: Curcumin (Cur) is a hydrophobic polyphenol compound derived from the rhizome of the herb Curcuma longa. Cur has a wide spectrum of biological and pharmacological activities. It has been shown that human cytomegalovirus (HCMV) infection was an important risk factor for atherosclerosis (AS) and Cur exhibited an outstanding anti-HCMV effect. However, anti-AS effects of Cur remain unclear when HCMV infected endothelial cells. AIMS: This study will investigate the anti-AS activities and mechanism of Cur,when HCMV infected in vivo and in vitro. MATERIALS AND METHODS: Cur (0.5, 1, and 2 µM) was used to explore the anti-AS activities and mechanism after HCMV infected endothelial cells in vitro. ApoE-/- mice were fed a high fat and cholesterol diet (HD) and given 4000,000 copies/mouse MCMV infection by intraperitoneal and treated with ganciclovir (5 mg/kg/d), Cur (25, 15 mg/kg/d) for 10 weeks in vivo. KEY FINDINGS: As our results showed that Cur inhibited CMV replication and proliferation, reduced the intracellular ROS overproduction, decreased the release of inflammatory cytokines, down-regulated the level of HMGB1-TLRS-NF-κB signaling pathway-related proteins in vitro experiments. Cur reduced the serum levels of LDL-C, TC and TG, significantly decreased the formation of atherosclerotic plaque in the aorta, reduced the lipid deposition in liver and inflammatory damage in heart, lung and kidney in vivo experiments. SIGNIFICANCE: This study showed that Cur prevent AS progression by inhibiting CMV activity and CMV-induced HMGB1-TLRS-NF-κB signaling pathway.

Vitamin D supplementation rescues simvastatin induced myopathy in mice via improving mitochondrial cristae shape.

Statin induced myopathy (SIM) is a main deleterious effect leading to the poor treatment compliance, while the preventive or therapeutic treatments are absent. Mounting evidences demonstrated that vitamin D plays a vital role in muscle as a direct modulator. The deficiency of vitamin D was considered as a cause of muscle dysfunction, whereas the supplementation resulted in a remission. However, there is no causal proof that vitamin D supplementation rescues SIM. Here, using the mice model of simvastatin-induced myopathy, we investigated the role of vitamin D supplementation and the mechanisms associated with mitochondria. Results indicated that simvastatin administration (80 mg/kg) impaired skeletal muscle with the increased serum creatine kinase (CK) level and the declined grip strength, which were alleviated by vitamin D supplementation. Moreover, vitamin D supplementation rescued the energy metabolism dysfunction in simvastatin-treated mice gastrocnemius by reducing the abnormal aggregation of muscular glycogen and lactic acid. Mitochondrial homeostasis plays a key role in the process of energy metabolism. Thus, the mitochondrial dysfunction is a mortal damage for the highly energy-requiring tissue. In our study, the mitochondrial cristae observed under transmission electron microscope (TEM) were lytic in simvastatin-treated gastrocnemius. Interestingly, vitamin D supplementation improved the mitochondrial cristae shape by regulating the expression of mitofusin-1/2 (MFN1/2), optic atrophy 1 (OPA1) and dynamin-related protein 1 (Drp1). As expected, the mitochondrial dysfunction and oxidative stress was mitigated by vitamin D supplementation. In conclusion, these findings suggested that moderate vitamin D supplementation rescued simvastatin induced myopathy via improving the mitochondrial cristae shape and function.

Akebia saponin D alleviates hepatic steatosis through BNip3 induced mitophagy.

Akebia Saponin D (ASD) is the most abundant constituent of the rhizome of Dipsacus asper Wall. The prior studies have shown that ASD alleviates hepatic steatosis targeted at the modulation of autophagy and exerts hepatoprotective effects through mitochondria. However, it is still unclear which signal transduction pathway that ASD increase autophagy and protect the mitochondria. The purpose of this paper was to explore the mechanisms through which ASD alleviates hepatic steatosis. ASD significantly reduced lipid accumulation in BRL cells. Furthermore, ASD significantly increased the mitophagy acting as increase the colocalization between mitochondria and punctate EGFP-LC3. ASD treatment increased the expression of BNip3, phospho-AMPK, prevented oleic acid (OA) induced LC3-II and phospho-mTOR expression. These effects were similar to the effects cotreatment with rapamycin. ASD treatment could not attenuate the expression of BNip3 blocked by chloroquine (CQ) or siRNA-mediated knockdown of BNip3. These results suggest that Akebia saponin D alleviates hepatic steatosis targeted at BNip3 mediated mitophagy. Activation of BNip3 via ASD may offer a new strategy for treating NAFLD.

Multi-allergen challenge stimulates steriod-resistant airway inflammation via NF-κB-mediated IL-8 expression.

Neutrophilic airway inflammation associated with multiple allergens has been related to steroid-resistant asthma. However, most animal models use only one allergen, which cannot simulate asthma closely as seen in patients. To determine the mechanism of inflammatory process involved in this severe condition, BALB/c mice were repetitively challenged with the pooled extract of dust mite, ragweed, and Aspergillus species (DRA). We found that DRA increased interleukin (IL)-10 and TGF-ß levels and neutrophil recruitment in bronchial alveolar lavage fluid. We also found that although dexamethasone suppressed the release of these two cytokines, mast cells recruitment, and mucus hypersecretion, it actually increased neutrophil infiltration and the level of keratinocyte-derived chemokine (mKC), a functional homolog of human IL-8. Treatment of human lung alveolar A549 cells with Der p1, an extract of house dust mite Dermatophagoides pteronyssinus, increased the expression of IL-8 and activity of NF-κB. The elevated IL-8 level was suppressed by BAY11-7082, a selective NF-κB inhibitor, but not by dexamethasone. These results suggest that increased IL-8 (mKC) levels may be involved in steroid-resistant neutrophilic airway inflammation through an NF-κB-dependent pathway.