Effects of resveratrol on the levels of ATP, 5-HT and GAP-43 in the hippocampus of mice exposed to chronic unpredictable mild stress.

Growing evidence suggested that energy deficiency might be involved in the pathophysiological mechanism of depression. Energy deficiency, mainly results from mitochondrial damage, can lead to the dysfunction of synaptic neurotransmission, and further cause depressive-like behavior. The antidepressant effect of resveratrol had been widely demonstrated in previous studies; however, the underlying mechanism remains poorly understood. The present study aimed to investigate whether the antidepressant effects of resveratrol involved in the energy levels and neurotransmission in the hippocampus. We found that resveratrol and fluoxetine significantly attenuated depressive-like behaviors induced by chronic unpredictable mild stress (CUMS), which evidenced by the increased sucrose preference and the reduced immobility time in a forced swimming test. In addition, resveratrol increased hippocampal ATP levels, decreased Na+-K+-ATPase and pyruvate levels, and upregulated the levels of mitochondrial DNA (mtDNA), mRNA expression of sirtuin (SIRT)1 and peroxisome proliferator-activated receptor γ coactivator (PGC)1α. Furthermore, resveratrol and fluoxetine increased serotonin (5-HT) levels and downregulated the mRNA expression of 5-HT transporter (SERT) in the hippocampus. The decreased protein expression of growth-associated protein (GAP)-43 induced by CUMS was also ameliorated by resveratrol and fluoxetine. These findings demonstrated the antidepressant effects of resveratrol and suggested that resveratrol was able to promote mitochondrial biogenesis, enhance ATP and 5-HT levels, as well as upregulate GAP-43 expression in the hippocampus.

Depressive-like behaviors are induced by chronic liver injury in male and female mice.

Depression is a highly prevalent mental disease and increasingly become a global public health problem. Recent studies have shown that the dysfunction of liver was associated with depression. However, the previous studies have not been fully explained the relationship between depression and liver injury. The present study was aimed to investigate whether chronic liver injury could induce depressive-like behavior. Chronic liver injury was induced by intraperitoneal injection of carbon (CCl4), D-galactosamine (D-GalN) and thioacetamide (TAA), respectively. And the results showed that the serum activities of ALT in CCl4, D-GalN and TAA groups were significantly increased in both male and female mice compared with the control group, while the activities of AST increased only in CCl4 group. Meanwhile, H&E staining showed that CCl4, D-GalN and TAA induced hepatocytes injury in both male and female mice. Moreover, the sucrose preference was significantly decreased and the immobility time in forced swimming test and tail suspension test were significantly prolonged in CCl4 and D-GalN group compared with control group. Our findings demonstrated that chronic liver injury induced by CCl4 and D-GalN could induce depressive-like behaviors in mice.

Transcriptomic analysis reveals the mechanism of sulfasalazine-induced liver injury in mice.

Liver injury is one of the main toxic effect of sulfasalazine (SASP). However, the toxicological mechanism of SASP-induced liver injury remains unclear. In the present study, the liver injury was induced by orally treatment with SASP for 4 weeks in mice. The hepatic mRNA profiles were detected by RNA sequencing and the differentially expressed genes (DEGs) were analyzed by bioinformatics methods. The elevated serum levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP) and total bilirubin (TBIL), combined with the hepatic histopathological features verified that liver injury was successfully caused by SASP. Transcriptomic results showed that 187 genes (fold change > 1.5 and P < 0.05) were differentially expressed, of which 106 genes were up-regulated and 81 genes were down-regulated in SASP-treated group. Moreover, the further analysis showed that these 187 differentially expressed genes (DEGs) were enriched in 123 GO terms, which mainly including oxidation-reduction process, oxidoreductase activity and epoxygenase P450 pathway. KEGG pathway analysis showed 30 pathways including chemical carcinogenesis, retinol metabolism, arachidonic acid metabolism, linoleic acid metabolism and glutathione metabolism. Among these 187 DEGs, the top 22 hub genes were screened from network of protein-protein interaction (PPI) and verified by qRT-PCR. The results showed that the mRNA levels of hepatic drug-metabolizing enzymes, including cyp2b50, cyp2c50, cyp2c39, cyp2c38, cyp2c29, cyp2c54, cyp2c55, cyp2a5, gsta1, gsta2, gstt2, gstm2 and ephx1, were significantly up-regulated, while egfr and egr1 were down-regulated in SASP-treated group. Moreover, the mRNA levels of egfr and cyp2c55 exhibited a dose-dependent changes in SASP groups. Western blotting verified that the changes of protein levels of EGFR and CYP2C55 were consistent with mRNA levels. Considering that egfr has the highest score in PPI degree and cyp2c55 has the largest fold change in qPCR analysis, our present results suggested that the toxicological mechanisms of SASP-induced liver injury might be related to multi-biological processes and pathways, and egfr and cyp2c55 may play important roles in SASP-induced liver injury. The present study would be helpful for better understanding the hepatotoxic mechanism of SASP. However, the precise mechanism still needs further research.

Paeoniflorin Ameliorates Fructose-Induced Insulin Resistance and Hepatic Steatosis by Activating LKB1/AMPK and AKT Pathways.

The present study aimed to evaluate the effects of paeoniflorin on insulin resistance and hepatic steatosis induced by fructose. Male Sprague-Dawley rats were fed 20% fructose drink for eight weeks. The insulin sensitivity, serum lipid profiles, and hepatic lipids contents were measured. The results showed that paeoniflorin significantly decreased serum insulin and glucagon levels, improved insulin sensitivity and serum lipids profiles, and alleviated hepatic steatosis in fructose-fed rats. Moreover, paeoniflorin enhanced the phosphorylation level of AMP-activated protein kinase (AMPK) and protein kinase B (PKB/AKT) and inhibited the phosphorylation of acetyl coenzyme A carboxylase (ACC)1 in liver. Paeoniflorin also increased the hepatic carnitine palmitoyltransferase (CPT)-1 mRNA and protein expression and decreased the mRNA expression of sterol regulatory element-binding protein (SREBP)1c, stearyl coenzyme A decarboxylase (SCD)-1 and fatty acid synthetase (FAS). Furthermore, we found that paeoniflorin significantly increased the heptatic protein expression of tumor suppressor serine/threonine kinase (LKB)1 but not Ca2+/CaM-dependent protein kinase kinase (CaMKK)ß. These results suggest that the protective effects of paeoniflorin might be involved in the activation of LKB1/AMPK and insulin signaling, which resulted in the inhibition of lipogenesis, as well as the activation of ß-oxidation and glycogenesis, thus ameliorated the insulin resistance and hepatic steatosis. The present study may provide evidence for the beneficial effects of paeoniflorin in the treatment of insulin resistance and non-alcoholic fatty liver.

Curcumin reverses the depressive-like behavior and insulin resistance induced by chronic mild stress.

Increasing evidence has demonstrated that patients with depression have a higher risk of developing type 2 diabetes. Insulin resistance has been identified as the key mechanism linking depression and diabetes. The present study established a rat model of depression complicated by insulin resistance using a 12-week exposure to chronic mild stress (CMS) and investigated the therapeutic effects of curcumin. Sucrose intake tests were used to evaluate depressive-like behaviors, and oral glucose tolerance tests (OGTT) and intraperitoneal insulin tolerance tests (IPITT) were performed to evaluate insulin sensitivity. Serum parameters were detected using commercial kits. Real-time quantitative PCR was used to examine mRNA expression. CMS rats exhibited reduced sucrose consumption, increased serum glucose, insulin, triglyceride (TG), low density lipoprotein-cholesterol (LDL-C), non-esterified fatty acid (NEFA), glucagon, leptin, and corticosterone levels, as well as impaired insulin sensitivity. Curcumin upregulated the phosphorylation of insulin receptor substrate (IRS)-1 and protein kinase B (Akt) in the liver, enhanced insulin sensitivity, and reversed the metabolic abnormalities and depressive-like behaviors mentioned above. Moreover, curcumin increased the hepatic glycogen content by inhibiting glycogen synthase kinase (GSK)-3ß and prevented gluconeogenesis by inhibiting phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6-phosphatase (G6Pase). These results suggest that curcumin not only exerted antidepressant-like effects, but also reversed the insulin resistance and metabolic abnormalities induced by CMS. These data may provide evidence to support the potential use of curcumin against depression and/or metabolic disorders.

Ferulic acid inhibits neuro-inflammation in mice exposed to chronic unpredictable mild stress.

Ferulic acid is a hydroxycinnamic acid that widely presents in plant cell wall components. It has been demonstrated that ferulic acid can attenuate depressive-like behaviors in both forced swimming test and tail suspension test. Considering that depression is an inflammatory related mental disease, our present study was aimed to investigate the role of ferulic acid in the regulation of microglia activation, pro-inflammatory cytokines, nuclear factor kappa B (NF-κB) and nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in mice exposed to chronic unpredictable mild stress (CUMS). Our results firstly showed that decreased sucrose preference and increased immobility time were completely reversed by administration with ferulic acid and fluoxetine for four weeks. Then, we found that CUMS significantly caused interleukin-1ß (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) up-regulation, microglia, NF-κB signaling and NLRP3 inflammasome activation in the prefrontal cortex. On the contrary, these activated inflammatory response induced by CUMS were reversed by ferulic acid and fluoxetine as well, suggesting that anti-inflammatory related mechanism was involved in the antidepressant-like effects of ferulic acid in stressed mice.

Elevation of synaptic protein is associated with the antidepressant-like effects of ferulic acid in a chronic model of depression.

Ferulic acid is a hydroxycinnamic acid that widely presents in plant cell wall components. It has been demonstrated that ferulic acid can reverse depressive-like behaviors in both forced swimming test and tail suspension test. However, it is unclear whether chronic ferulic acid treatment can ameliorate the depressive-like behaviors in chronic unpredictable mild stress (CUMS). Because of the putative relationship between neurotrophic system and antidepressant-like activity, we also investigated the effects of chronic ferulic acid on the brain-derived neurotrophic factor (BDNF), postsynaptic protein PSD95, presynaptic protein synapsin I in both prefrontal cortex and hippocampus. The results showed that ferulic acid significantly alleviated CUMS-induced depressive-like behaviors in sucrose preference test and forced swimming test. In addition, ferulic acid significantly up-regulated the levels of BDNF, PSD95 and synapsin I in the prefrontal cortex and hippocampus. The present data indicated that ferulic acid exerted the antidepressant-like effects on behaviors by increasing neurotrophin-related synaptic protein levels in CUMS mice.

Resveratrol Ameliorates the Depressive-Like Behaviors and Metabolic Abnormalities Induced by Chronic Corticosterone Injection.

Chronic glucocorticoid exposure is known to cause depression and metabolic disorders. It is critical to improve abnormal metabolic status as well as depressive-like behaviors in patients with long-term glucocorticoid therapy. This study aimed to investigate the effects of resveratrol on the depressive-like behaviors and metabolic abnormalities induced by chronic corticosterone injection. Male ICR mice were administrated corticosterone (40 mg/kg) by subcutaneous injection for three weeks. Resveratrol (50 and 100 mg/kg), fluoxetine (20 mg/kg) and pioglitazone (10 mg/kg) were given by oral gavage 30 min prior to corticosterone administration. The behavioral tests showed that resveratrol significantly reversed the depressive-like behaviors induced by corticosterone, including the reduced sucrose preference and increased immobility time in the forced swimming test. Moreover, resveratrol also increased the secretion of insulin, reduced serum level of glucose and improved blood lipid profiles in corticosterone-treated mice without affecting normal mice. However, fluoxetine only reverse depressive-like behaviors, and pioglitazone only prevent the dyslipidemia induced by corticosterone. Furthermore, resveratrol and pioglitazone decreased serum level of glucagon and corticosterone. The present results indicated that resveratrol can ameliorate depressive-like behaviors and metabolic abnormalities induced by corticosterone, which suggested that the multiple effects of resveratrol could be beneficial for patients with depression and/or metabolic syndrome associated with long-term glucocorticoid therapy.

Berberine up-regulates the BDNF expression in hippocampus and attenuates corticosterone-induced depressive-like behavior in mice.

Depression is increasingly become a global public healthy problem. This study was to investigate whether berberine could attenuate the depressive-like behavior induced by repeated corticosterone injection and explore the possible mechanisms. The present results showed that exogenous corticosterone injection caused depressive-like behaviors in mice, such as decreased sucrose intake in sucrose preference test (SPT) and increased immobility time in forced swimming test (FST). These behavioral alterations were accompanying with the decreased BDNF mRNA and protein levels in hippocampus and the elevated serum corticosterone levels. Treatment with berberine prevented these changes above. Our findings confirmed the antidepressant-like effect of berberine and suggested its mechanisms might be partially mediated by up-regulation of BDNF in hippocampus.

Antidepressant effects of the water extract from Taraxacum officinale leaves and roots in mice.

CONTEXT: The leaves and roots of the Taraxacum officinale F. (Asteraceae) is widely used as traditional medicinal herb in Eastern Asian countries. OBJECTIVE: In the present study, the antidepressant-like effects of the water extract of T. officinale (WETO) leaves and roots were investigated in mice using forced swimming test (FST), tail suspension test (TST) and open field test (OFT). MATERIALS AND METHODS: Effects of acute (1-day) and chronic treatments (14-days) with WETO (50, 100 and 200 mg/kg) on the behavioral changes in FST, TST and OFT, and the serum corticotrophin releasing factor (CRF), adrenocorticotropic hormone (ACTH) and corticosterone concentration were assessed in mice. RESULTS: Chronic treatment (14-days) with WETO at the doses of 50, 100 and 200 mg/kg significantly decreased the immobility time in both FST (92.6, 85.1 and 77.4 s) and TST (84.8, 72.1 and 56.9 s). Acute treatment (1-day) with WETO at a dose of 200 mg/kg also markedly decreased the immobility time in both FST (81.7 s) and TST (73.2 s). However, all treatments did not affect the locomotor activity in the OFT. Moreover, FST induced a significant increase in serum CRF (5.8 ng/ml), ACTH (104.7 pg/ml) and corticosterone levels (37.3 ng/ml). Chronic treatment (14-days) with WETO decreased the serum CRF (200 mg/kg: 3.9 ng/ml) and corticosterone (50 mg/kg: 29.9 ng/ml; 100 mg/kg: 22.5 ng/ml; 200 mg/kg: 19.8 ng/ml) levels. DISCUSSION AND CONCLUSION: These results clearly demonstrated the antidepressant effects of WETO in animal models of behavioral despair and suggested the mechanism involved in the neuroendocrine system.

Chronic treatment with baicalin prevents the chronic mild stress-induced depressive-like behavior: involving the inhibition of cyclooxygenase-2 in rat brain.

Baicalin, a major constituent of flavonoids isolated from Scutellariae Radix, has been previously confirmed to decrease the duration of immobility in mice exposed to the forced swimming test (FST) and tail suspension test (TST). However, its antidepressant effects and mechanisms are still seldom studied in chronic mild stress (CMS) model of depression. In the present study, we attempted to investigate the effects of baicalin on the depressive-like behavior, the mRNA expression and activity of cyclooxygenase-2 (COX-2), as well as prostaglandin E(2) (PGE(2)) levels in the frontal cortex and hippocampus. Moreover, the serum corticosterone levels were also examined. We found that CMS procedure not only decreased the sucrose preference and increased serum corticosterone levels, but also elevated the activity and mRNA expression of COX-2, and increased PGE(2) levels in rat brain regions. Treatment with baicalin (10, 20, 40 mg/kg) prevented these abnormalities induced by CMS. These results confirmed that baicalin exerted antidepressant-like effects, and suggested its mechanisms at least partially related to decease COX-2 activity and expression, subsequently resulted in reduction of PGE(2) levels in brain. Our findings may provide a new aspect to understand the antidepressant action of baicalin, which is targeted on the COX-2 system in brain.

HPV16 CTL epitope peptide-activated dendritic cell and natural killer co-culture for therapy of cervical cancer in an animal model.

There is increasing evidence that natural killer (NK) cells play an important role in antitumor immunity following dendritic cell (DC) vaccination. Little is known, however, about the optimal stimulation of DCs by epitopes and NK interactions for cytotoxicity in tumors. In this study, DC cells activated by the HPV16E7.49-57 epitope and LPS were co-cultured with NK cells in vitro, and then used ot immunize mice to study CTL activity of TC-1, which constitutively expresses HPV16E6E7, with an LDH release assay. Cytotoxicity in mice immunized with DC loaded with epitope HPVE7.49-57 vaccine co-cultured with NK was enhanced significantly (p<0.01). In conclusion, talk-across between DC and NK cells enhances their functions, also improving cytotoxicity againsttumor cells, suggesting that activated DC-NK by epitopes has potential application for cancer-specific immuno-cellular therapy.