Chemical Constituents of the Essential Oil Extracted from Elsholtzia densa and Their Insecticidal Activity against Tribolium castaneum and Lasioderma serricorne.

Storage pests pose a great threat to global food security. Here, we found that the essential oil (EO) extracted from E. densa possesses obvious effects against the insects that threaten stored-products. In this work, we investigated the chemical constituents of the essential oil extracted from Elsholtzia densa, and their insecticidal (contact and fumigant) toxicity against Tribolium castaneum and Lasioderma serricorne. A total of 45 compounds were identified by GC-MS, accounting for 98.74% of the total EO. Meanwhile, 11 compounds were isolated from the EO, including limonene, ß-caryophyllene, ρ-cymene, trans-phytol, α-terpineol, linalool, acetophenone, 1,8-cineole, ρ-cymen-7-ol, 1-O-cerotoylgly-cerol, and palmitic acid. Furthermore, acetophenone, ρ-cymen-7-ol, and 1-O-cerotoylgly-cerol were isolated for the first time from Elsholtzia spp. The results of the bioassays indicated that the EO had the property of insecticidal toxicity against T. castaneum and L. serricorne. All of the compounds showed different levels of insecticidal toxicity against the two species of insects. Among them, 2-ethyl-1H-imidazole had no insecticidal toxicity against T. castaneum, but possessed fumigant and obvious contact toxicity against L. serricorne. ρ-Cymen-7-ol had beneficial insecticidal toxicity against the two species of insects, and fumigant toxicity against L. serricorne. ρ-Cymen-7-ol (LD50 = 13.30 µg/adult), 1-octen-3-ol (LD50 = 13.52 µg/adult), and 3-octanol (LD50 = 17.45 µg/adult) showed significant contact toxicity against T. castaneum. Acetophenone (LD50 = 7.07 µg/adult) and ρ-cymen-7-ol (LD50 = 8.42 µg/adult) showed strong contact toxicity against L. serricorne. ρ-Cymene (LC50 = 10.91 mg/L air) and ρ-cymen-7-ol (LC50 = 10.47 mg/L air) showed powerful fumigant toxicity to T. castaneum. Limonene (LC50 = 5.56 mg/L air), acetophenone (LC50 = 5.47 mg/L air), and 3-octanol (LC50 = 5.05 mg/L air) showed obvious fumigant toxicity against L. serricorne. In addition, the EO and its chemical compounds possessed different levels of repellent activity. This work provides some evidence of the value of exploring these materials for insecticidal activity, for human health purposes. We suggest that the EO extracted from E. densa may have the potential to be developed as an insecticidal agent against stored product insect pests.

Design, synthesis and evaluation of tetrahydrocarbazole derivatives as potential hypoglycemic agents.

Two series of tetrahydrocarbazole derivatives have been designed and synthesized based on ZG02, a promising candidate developed in our previous studies. The newly prepared compounds were screened for glucose consumption activity in HepG2 cell lines. Aza-tetrahydrocarbazole compound 12b showed the most potent hypoglycemic activity with a 45% increase in glucose consumption when compared to the solvent control, which had approximately 1.2-fold higher activity than the positive control compounds (metformin and ZG02). An investigation of the potential mechanism indicated that 12b may exhibit hypoglycemic activity via activation of the AMPK pathway. Metabolic stability assays revealed that 12b showed good stability profiles in both artificial gastrointestinal fluids and blood plasma from SD rats. An oral glucose tolerance test (OGTT) was performed and the results further confirmed that 12b was a potent hypoglycemic agent.

Hyperglycemia decreases anti-cancer efficiency of Adriamycin via AMPK pathway

The authors and journal apologise for an error in the above paper, which appeared in volume 25 part 11, pages 955­966. The error relates to the artwork of Fig. 5 on page 963, in which the blots given in panel E were mistakenly replicated in panel F.

Hyperglycemia decreases anti-cancer efficiency of Adriamycin via AMPK pathway

Accumulating clinical evidence indicates that diabetic liver cancer patients are less sensitive to intra-arterial chemotherapy than non-diabetic cancer patients. However, the underlying mechanism remains largely uncharacterized. Here, we report that hyperglycemia inhibits AMPK pathway and subsequently reduces ADR induced DNA damage, resulting in decreased chemotherapeutic sensitivity of Adriamycin (ADR). HepG2 and Bel-7402 cells were treated with ADR in various glucose conditions and then subjected to cell proliferation assay and apoptosis. The IC50 of ADR greatly increased with the increasing concentration of glucose (15±4nM to 93±39nM in HepG2, 78±8nM to 1310±155nM in Bel-7402). Both FACs and Western-blot analysis indicated that high concentration of glucose protected cells from ADR induced apoptosis. Mouse hepatoma H22 xenografts were established both in db/db diabetic mice and STZ-induced diabetic mice. The inhibitory effect in tumor growth of ADR was significantly reduced in diabetic mice, which could be recovered by insulin therapy. Hyperglycemia greatly ameliorated AMPK activation and H2AXexpression caused by ADR treatment. Pretreatment with Compound C or AMPK silencing eliminated hyperglycemia reduced cytotoxicity of ADR. However, the impaired cytotoxicity in hyperglycemia was recovered by treatment with AMPK activator AICAR. This study indicates that hyperglycemia impairs the chemotherapeutic sensitivity of ADR by down-regulating AMPK pathway and reducing ADR induced DNA damage.

Discovery of tetrahydrocarbazoles with potent hypoglycemic and hypolipemic activities.

A series of tetrahydrocarbazole derivatives was designed and synthesized on the basis of the AMP-activated protein kinase activator GY3. All the synthesized compounds were screened in HepG2 cell lines for glucose consumption activity and several of them showed potent glucose decreasing activity. In vivo evaluation of the hypoglycemic and hypolipemic effects indicated that 7a exhibited comparable activity with pioglitazone, but with a weaker body-weight increasing effect. The pharmacokinetic profiles of 7a were also investigated.

Oleanolic acid derivative DKS26 exerts antidiabetic and hepatoprotective effects in diabetic mice and promotes glucagon-like peptide-1 secretion and expression in intestinal cells.

BACKGROUND AND PURPOSE: Glucagon-like peptide-1 (GLP-1) is an important target for diabetes therapy based on its key role in maintaining glucose and lipid homeostasis. This study was designed to investigate antidiabetic and hepatoprotective effects of a novel oleanolic acid derivative DKS26 in diabetic mice and elucidate its underlying GLP-1 related antidiabetic mechanisms in vitro and in vivo. EXPERIMENTAL APPROACH: The therapeutic effects of DKS26 were investigated in streptozotocin (STZ)-induced and db/db diabetic mouse models. Levels of plasma glucose, glycosylated serum protein (GSP), lipid profiles, insulin, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), oral glucose tolerance (OGT), pancreatic islets and hepatic histopathological morphology, liver lipid levels and expression of pro-inflammatory cytokines were assessed. Intestinal NCI-H716 cells and diabetic models were used to further validate its potential GLP-1-related antidiabetic mechanisms. KEY RESULTS: DKS26 treatment (100 mg·kg-1 ·day-1 ) decreased plasma levels of glucose, GSP, ALT and AST; ameliorated OGT and plasma lipid profiles; augmented plasma insulin levels; alleviated islets and hepatic pathological morphology; and reduced liver lipid accumulation, inflammation and necrosis in vivo. Furthermore, DKS26 enhanced GLP-1 release and expression, accompanied by elevated levels of cAMP and phosphorylated PKA in vitro and in vivo. CONCLUSION AND IMPLICATIONS: DKS26 exerted hypoglycaemic, hypolipidaemic and islets protective effects, which were associated with an enhanced release and expression of GLP-1 mediated by the activation of the cAMP/PKA signalling pathway, and alleviated hepatic damage by reducing liver lipid levels and inflammation. These findings firmly identified DKS26 as a new viable therapeutic option for diabetes control.

Terpenoids from Curcuma wenyujin increased glucose consumption on HepG2 cells.

Thirty four terpenoids, including two new cadinane-type sesquiterpenoids containing conjugated aromatic-ketone moieties, curcujinone A (1) and curcujinone B (2), were isolated from 95% ethanol extract of the root tubers of Curcuma wenyujin. Their structures were determined by spectroscopic methods, especially 2D NMR and HRMS techniques. The relative and absolute configurations of 1 and 2 were identified by quantum chemical DFT and TDDFT calculations of the 13C NMR chemical shifts, ECD spectra, and specific optical rotations. All compounds and extracts were evaluated for their anti-diabetic activities with a glucose consumption model on HepG2 Cells. The petroleum fraction CWP (10µg/mL) and compounds curcumenol (4), 7α,11α-epoxy-5ß-hydroxy-9-guaiaen-8-one (5), curdione (17), (1S, 4S, 5S 10S)-germacrone (18), zederone (20), a mixture of curcumanolide A (25) and curcumanolide B (26), gajutsulactone B (27), and wenyujinin C (30) showed promising activities with over 45% increasing of glucose consumption at 10µM.

Neohesperidin Exerts Lipid-Regulating Effects in vitro and in vivo via Fibroblast Growth Factor 21 and AMP-Activated Protein Kinase/Sirtuin Type 1/Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1α Signaling Axis.

The purpose of this study is to prove the lipid-regulating effects of neohesperidin (NHP) and explore the potential mechanisms related to fibroblast growth factor 21 (FGF21) and AMP-activated protein kinase (AMPK). Free fatty acids (FFAs)-induced lipid-accumulated HepG2 cells, acutely egg yolk-induced dyslipidemia and chronically diet-induced obese (DIO) model mice were treated with NHP. Biochemical analyses were carried out to determine the lipid profiles. Western blotting and real-time PCR were employed to analyze FGF21, AMPK and the related proteins or mRNA expressions. Body weight and food intake were measured in DIO mice. siRNA or inhibitors of FGF21 or AMPK were utilized in further study. NHP showed potent hypolipidemic effect in HepG2 cells loaded with FFAs and reversed the pathological changes of lipid in the acute or chronic dyslipidemia mouse model. It obviously improved the lipid profiles in plasma, liver and gastrocnemius muscles in DIO mice, and led to a significant body weight loss. Simultaneously, FGF21 protein expression or secretion, and AMPK/sirtuin type 1 (SIRT1)/peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α) axis or related molecules, was improved by NHP in HepG2 cells and/or DIO mice. Furthermore, the siRNA or inhibitor targeting FGF21 or AMPK rejected the triglyceride-lowering effect of NHP. In conclusion, NHP regulates lipid metabolism in vivo and in vitro via FGF21 and AMPK/SIRT1/PGC-1α signaling axis.

Effects and molecular mechanisms of the antidiabetic fraction of Acorus calamus L. on GLP-1 expression and secretion in vivo and in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: The radix of Acorus calamus L. (AC) is widely used in diabetes therapies in traditional folk medicine from America and Indonesia, and we have previously reported that the ethyl acetate fraction of AC (ACE) acts as an antidiabetic through insulin sensitizing, insulin releasing and alpha-glucosidase inhibitory activities. The present study is designed to investigate the effects and molecular mechanisms of ACE on glucagon-like peptide-1 (GLP-1) expression and secretion related to its hypoglycemic effects. MATERIALS AND METHODS: The hypoglycemic effect of ACE (100mg/kg, i.g.) was confirmed by testing blood glucose levels or via oral glucose tolerance test (OGTT) in streptozotocin (STZ) induced hyperglycemic mice, db/db diabetic mice and diet-induced obese (DIO) mice. Plasma insulin, GLP-1 levels and intestinal GLP-1 related gene expression were determined in STZ-induced and db/db diabetic mice. The in vitro effects of ACE (12.5µg/ml) on the expression and secretion of GLP-1 were detected in NCI-H716 intestinal L-cells, and the correlation between ACE and molecules in the Wnt signaling pathway was further explored. RESULTS: ACE (100mg/kg) significantly lowered fasting blood glucose in STZ-induced and db/db diabetic mice and improved the OGTT in DIO mice. Insulin releasing and islet protective effects, along with the increased secretion of GLP-1, were observed. The expression of proglucagon gene (gcg) and post-translational processing gene prohormone convertase 3 (pc3) and the GLP-1 content in the culture medium of L-cells notably increased after the ACE treatment (12.5µg/ml). At the same time, ß-catenin nuclear translocation occurred, and its downstream protein cyclin D1 was activated, showing the involvement of Wnt signaling. CONCLUSIONS: ACE might activate Wnt signaling to increase the gene expression of gcg and pc3 and exert incretin effects, including insulinotropic and islet protection, to lower blood glucose levels via elevated GLP-1 secretion either directly or indirectly.

Design, synthesis and biological evaluation of GY3-based derivatives for anti-type 2 diabetes activity.

A series of indole carboxylic acid derivatives were designed and synthesized. Their anti-type 2 diabetes activity was evaluated in HepG2 cell and db/db mice. The results showed that compounds 8c, 17a, 17b, 15a and 15b could significantly increase glucose consumption in HepG2 cell. Furthermore, compound 8c was able to lower the blood glucose level and induce less weight gain in db/db mice.

Synthesis and biological evaluation of novel benzyl-substituted (S)-phenylalanine derivatives as potent dipeptidyl peptidase 4 inhibitors.

A series of novel benzyl-substituted (S)-phenylalanine derivatives were synthesized and evaluated for their dipeptidyl peptidase 4 (DPP-4) inhibitory activity and selectivity. It was found that most synthesized target compounds were potent DPP-4 inhibitors with IC50 values in 3.79-25.52 nM, which were significantly superior to that of the marketed drug sitagliptin. Furthermore, the 4-fluorobenzyl substituted phenylalanine derivative 6g not only displayed the potent DPP-4 inhibition with an IC50 value of 3.79 nM, but also showed better selectivity against DPP-4 over other related enzymes including DPP-7, DPP-8, and DPP-9. In an oral glucose tolerance test (OGTT) in normal Sprague Dawley rats, compound 6g reduced blood glucose excursion in a dose-dependent manner.

Design, synthesis, biological evaluation, and docking studies of (s)-phenylalanine derivatives with a 2-cyanopyrrolidine moiety as potent dipeptidyl peptidase 4 inhibitors.

A novel series of (S)-phenylalanine derivatives with a 2-cyanopyrrolidine moiety were designed and synthesized through a rational drug design strategy. Biological evaluation revealed that most tested compounds were potent dipeptidyl peptidase 4 (DPP-4) inhibitors; among them, the cyclopropyl-substituted phenylalanine derivative 11h displayed the most potent DPP-4 inhibitory activity with an IC50 value of 0.247 µm. In addition, molecular docking analysis of the representative compounds 11h, 11k, and 15a were performed, which not only revealed the impact of binding modes on DPP-4 inhibitory activity but also provided additional methodological values for design and optimization.

A novel indole derivative compound GY3 improves glucose and lipid metabolism via activation of AMP-activated protein kinase pathway.

The AMP-activated protein kinase (AMPK) is a ubiquitously expressed serine/threonine protein kinase that functions as an intracellular fuel sensor. It has been demonstrated to mediate the activities of a number of pharmacological and physiological factors that exert beneficial effects on type2 diabetes mellitus. GY3 is a novel synthesized indole compound derived from indomethacin, a non-steroid anti-inflammatory drug. In a previous study, we found that GY3 could improve insulin resistance and lower glucose levels in db/db mice, although its mechanism of action is not yet clear. In this study, we demonstrate that in vivo administration of GY3 improved serum triglyceride levels and decreased lipid accumulation in the livers of db/db mice. In vitro studies show that GY3 increased glucose consumption in HepG2 cells and 3T3-L1 adipocytes, decreased free fatty acid (FFA)-induced lipid accumulation in HepG2 cells and lipid accumulation in 3T3-L1 adipocytes. In vitro studies further show that GY3 improved glucose and lipid metabolism through an AMPK-dependent pathway but not the PI3K pathway. These findings suggest that GY3 is an effective agent for the improvement of glucose and lipid metabolism through AMPK pathway activation.

Design, synthesis and biological evaluation of novel imidazolone derivatives as dipeptidyl peptidase 4 inhibitors.

A series of novel imidazolone derivatives were designed and synthesized via a rational drug design strategy. These compounds were obtained from 3-substituted imidazolidine-2,4-dione through alkylation, formylation, dehydration, and amination. The structures were characterized by (1)H NMR, (13)C NMR, and MS. All target compounds were screened for their DPP-4 inhibitory activity in vitro. The results revealed that some imidazolone derivatives showed potent DPP-4 inhibition. Compound 5b had an IC50 value of 2.21 µM inhibitory activity against DPP-4. As a promising lead compound, compound 5b with DPP-4 binding mode was further studied by docking analysis. The expected interaction mode was obtained.

Insulin releasing and alpha-glucosidase inhibitory activity of ethyl acetate fraction of Acorus calamus in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: The radix of Acorus calamus L. (AC) is widely used in the therapy of diabetes in traditional folk medicine of America and Indonesia, and we previously reported the insulin sensitizing activity of the ethyl acetate fraction of AC (ACE). AIM OF THE STUDY: To investigate the insulin releasing and alpha-glucosidase inhibitory activity of ACE in vitro and in vivo. MATERIALS AND METHODS: Insulin releasing and alpha-glucosidase inhibitory effects of different fractions from AC were detected in vitro using HIT-T15 cell line and alpha-glucosidase enzyme. Furthermore, effects of ACE orally on serum glucose were detected in fasted and glucose/amylum challenged normal mice. RESULTS: AC and ACE increased insulin secretion in HIT-T15 cells as gliclazide did. As in vivo results, ACE (400 and 800 mg/kg) significantly decreased fasting serum glucose, and suppressed the increase of blood glucose levels after 2g/kg glucose loading in normal mice. In addition, ACE as a mixed-type inhibitor inhibited alpha-glucosidase activity in vitro with an IC(50) of 0.41 microg/ml, and 100mg/kg of it clearly reduced the increase of blood glucose levels after 5 g/kg amylum loading in normal mice. CONCLUSIONS: Apart from its insulin sensitizing effect, ACE may have hypoglycemic effects via mechanisms of insulin releasing and alpha-glucosidase inhibition, and thus improves postprandial hyperglycemia and cardiovascular complications.

Design, synthesis and insulin-sensitizing activity of indomethacin and diclofenac derivatives.

A series of aromatic acetic acid compounds were designed and synthesized on the basis of Non-steroidal anti-inflammatory drugs indomethacin and diclofenac. Compounds 5a, 7a, 5h, 7h and 17 could strongly promote insulin-regulated differentiation of 3T3-L1 cells in vitro. They acted as full or partial PPARgamma agonist, or improved insulin resistance through non-PPARgamma pathway.

Insulin sensitizing activity of ethyl acetate fraction of Acorus calamus L. in vitro and in vivo.

UNLABELLED: Acorus calamus L. (AC), family Araceae, have been used in the Indian and Chinese systems of medicine for hundreds of years. The radix of AC is widely used in the therapy of diabetes in traditional folk medicine of America and Indonesia. AIM OF THE STUDY: To investigate the insulin sensitizing activity and antidiabetic effects of the ethyl acetate fraction of AC (ACE). MATERIALS AND METHODS: Glucose consumption mediated by insulin was detected in L6 rat skeletal muscle cells. Diabetes and its complications related indexes were monitored after orally administrating to genetically obese diabetic C57BL/Ks db/db mice daily for 3 weeks. RESULTS: ACE (12.5 and 25 microg/ml) increased glucose consumption mediated by insulin in L6 cells (p<0.05 and p<0.01). In db/db mice, ACE (100 mg/kg) significantly reduced serum glucose, triglyceride, reinforce the decrease of total cholesterol caused by rosiglitazone (at least p<0.05), and markedly reduced free fatty acid (FFA) levels and increased adiponectin levels (p<0.01 and p<0.05) as rosiglitazone did (p<0.05 and p<0.001). Serum insulin was decreased but not significantly. In addition, ACE decreased the intake of food and water, and did not increase body weight gain whereas rosiglitazone did. CONCLUSIONS: Owing to the ability of insulin sensitizing, ACE has the potential to be useful for the treatment of diabetes and cardiovascular complications without body weight gain.

Expression of extracellular superoxide dismutase during adipose differentiation in 3T3-L1 cells.

Obesity is known to be the primary causal component in metabolic syndrome. Adipocytes in obese patients exhibit increased oxidative stress via the activation of reactive oxygen species (ROS)-producing systems and inactivation of antioxidant enzymes. Extracellular superoxide dismutase (EC-SOD) is an anti-inflammatory enzyme that protects cells from the damaging effects of ROS. An earlier report showed that plasma EC-SOD levels in type 2 diabetic patients were significantly and inversely related to body mass index and homeostasis model assessment-insulin resistance index. Moreover, the administration of pioglitazone, an antidiabetic agent, significantly increased the plasma level of EC-SOD. In this report, the expression of EC-SOD was compared to other adipocytokines in mice 3T3-L1 pre-adipocytes. EC-SOD expression levels were increased after the induction of differentiation and then declined, which was similar to adiponectin and transcription factors such as peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and CCAAT/enhancer-binding protein-alpha (C/EBP-alpha). On the other hand, the expression levels of pro-inflammatory adipocytokines, such as tumor necrosis factor-alpha (TNF-alpha) and monocyte chemo-attractant protein-1 (MCP-1), increased markedly in the development stage of cells. It was observed that the expression of EC-SOD in differentiated 3T3-L1 cells co-cultured with LPS-stimulated J774 macrophages was up-regulated, while the addition of TNF-alpha down-regulated EC-SOD and adiponectin expression in adipocytes. It is known that infiltrated and activated macrophages produce extracellular ROS at high levels in adipose tissue. It is possible that the expression of EC-SOD in adipocytes was stimulated to protect them from oxidative stress in the co-culture system.