Sodium Butyrate Supplementation Inhibits Hepatic Steatosis by Stimulating Liver Kinase B1 and Insulin-Induced Gene.

BACKGROUND AND AIMS: Butyric acid is an intestinal microbiota-produced short-chain fatty acid, which exerts salutary effects on alleviating nonalcoholic fatty liver disease (NAFLD). However, the underlying mechanism of butyrate on regulating hepatic lipid metabolism is largely unexplored. METHODS: A mouse model of NAFLD was induced with high-fat diet feeding, and sodium butyrate (NaB) intervention was initiated at the eighth week and lasted for 8 weeks. Hepatic steatosis was evaluated and metabolic pathways concerning lipid homeostasis were analyzed. RESULTS: Here, we report that administration of NaB by gavage once daily for 8 weeks causes an augmentation of insulin-induced gene (Insig) activity and inhibition of lipogenic gene in mice fed with high-fat diet. Mechanistically, NaB is sufficient to enhance the interaction between Insig and its upstream kinase AMP-activated protein kinase (AMPK). The stimulatory effects of NaB on Insig-1 activity are abolished in AMPKα1/α2 double knockout (AMPK-/-) mouse primary hepatocytes. Moreover, AMPK activation by NaB is mediated by LKB1, as evidenced by the observations showing NaB-mediated induction of phosphorylation of AMPK, and its downstream target acetyl-CoA carboxylase is diminished in LKB1-/- mouse embryonic fibroblasts. CONCLUSIONS: These studies indicate that NaB serves as a negative regulator of hepatic lipogenesis in NAFLD and that NaB attenuates hepatic steatosis and improves lipid profile and liver function largely through the activation of LKB1-AMPK-Insig signaling pathway. Therefore, NaB has therapeutic potential for treating NAFLD and related metabolic diseases.

Plumbagin inhibits cell proliferation and promotes apoptosis in multiple myeloma cells through inhibition of the PI3K/Akt-mTOR pathway.

Plumbagin is the primary component of the traditional Chinese medicine Baihua Dan, and possesses anti-infection and anticancer effects with the ability to enhance the sensitivity of tumor cells to radiation therapy. The present study aimed to investigate the potential anticancer effect and mechanism of plumbagin on multiple myeloma (MM) cells. Human MM OPM1 cells were treated with plumbagin, and its impact on cell viability, cytotoxicity, apoptosis and caspase-3 activity was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, lactate dehydrogenase leakage, flow cytometry and colorimetric assays. In addition, the protein expression levels of phosphoinositide 3-kinase, phosphorylated (p)-Akt and p-mammalian target of rapamycin (mTOR) in OPM1 cells were analyzed by western blotting. The results demonstrated that plumbagin treatment inhibited cell viability, increased cell cytotoxicity, activated cell apoptosis and promoted caspase-3 activity in the OPM1 cells. Furthermore, pretreatment of plumbagin significantly suppressed PI3K, p-Akt and p-mTOR protein expression levels in the OPM1 cells. In conclusion, the present study indicates that plumbagin inhibits cell proliferation and promotes apoptosis in MM cells through inhibition of PI3K/Akt-mTOR expression.

From the Cover: Zinc Deficiency Worsens and Supplementation Prevents High-Fat Diet Induced Vascular Inflammation, Oxidative Stress, and Pathological Remodeling.

Obesity has become a common public health problem in the world and raises the risk of various cardiovascular diseases. Zinc is essential for multiple organs in terms of normal structure and function. The present study investigated the effects of high fat diet (HFD) induced obesity on the aorta in mice, and evaluated whether it can be affected by zinc deficiency or supplementation. Four-week-old male C57BL/6J mice were fed HFD with varied amounts of zinc (deficiency, adequate and supplementation) for 3 and 6 months. Results showed that HFD feeding induced a time-dependent aortic remodeling, demonstrated by increased vessel wall thickness, tunica cell proliferation and fibrotic responses, and inflammatory response, reflected by increased expression of inflammatory cytokines (tumor necrosis factor-α and vascular cell adhesion molecule 1). HFD feeding also caused aortic oxidative damage, reflected by 3-nitrotyrosine and 4-hydroxy-2-nonenal accumulation, and down-regulated nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression and function, shown by down-regulation of its downstream antioxidants, catalase, NAD(P)H dehydrogenase (quinone 1), and metallothionein expression. The vascular effects of obesity-induced by HFD was exacerbated by zinc deficiency but significantly improved by zinc supplementation. In addition, down-regulation of Nrf2 function and associated antioxidants expression were also worsened by zinc deficiency but improved by zinc supplementation. These results suggest that HFD induces aortic remodeling, which can be exacerbated by zinc deficiency and improved by zinc supplementation.

Effects of Proanthocyanidins on Intestinal Motility Disturbance Following Intestinal Ischemia/Reperfusion.

PURPOSE: To investigate the potential protective effects of Proanthocyanidins(PAs) on intestinal motility disturbance following intestinal ischemia/reperfusion (I/R). MATERIALS AND METHODS: Male rats were divided into four groups: Sham, I/R, I/R+PA100 and I/R+PA200. Sham group underwent laparotomy without ligation, the others were subjected to intestinal ischemia for 1 h and reperfusion 4 h. Rats in the I/R+PA100 group received PAs (100 mg/kg/d) for 5 days prior to I/R, while rats in the I/R+PA200 group received PAs (200 mg/kg/d). After reperfusion, using an electrophysiology instrument measured ileal slow wave. Ileal specimens were obtained to determine contractility, tissue levels of Bax, Bcl-2, and Caspase-3 and evaluate histopathological changes. In addition, blood sample was obtained to determine serum superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels. RESULTS: Intestinal I/R caused severe histopathological injury including mucosal erosions, inflammatory cell infiltration, necrosis, and hemorrhage. Both PAs treatment decreased mucosal pathological impairment in comparison with the I/R group (p < .05) in light microscopic evaluations. In both PAs-treated groups, Bax and Caspase-3 expression were decreased compared to I/R group, while the Bcl-2 expression increased (p < .05), which was similarly the case for serum SOD activity demonstrated significant enhance (p < .05) and decline in MDA levels in comparison with I/R group (both p < .05). Moreover, PAs treatment was more efficient in attenuating serum MDA levels of intestinal I/R (both p < .05). And the contractile amplitude and frequency of slow wave in I/R+PA100 and I/R+PA200 groups were higher than I/R group (both p < .05). CONCLUSIONS: PAs improve intestinal motility disturbance following intestinal I/R by alleviating oxidative stress and apoptosis.