Sanggenol F exerts anti-diabetic effects via promoting adipocyte differentiation and modifying adipokines expression

Comparison of changes in adipokine and inflammatory cytokine levels in patients with newly diagnosed type 2 diabetes treated with exenatide, insulin, or pioglitazone: A post-hoc study of the CONFIDENCE trial

Background

Adipokines and inflammatory cytokines (ADICs) play important roles in type 2 diabetes mellitus (T2DM). This study aimed to compare the changes of ADIC levels (ΔADICs) in patients with newly diagnosed T2DM treated with different antihyperglycemic agents, and further investigate the impact of these changes on metabolic indices, β-cell function and insulin resistance (IR).

Methods

Four hundred and sixteen patients with newly diagnosed T2DM from 25 centers in China randomly received 48-week intervention with exenatide, insulin or pioglitazone. Anthropometric and laboratory data, indices of β-cell function and IR, and levels of AIDCs, including interleukin-1 beta (IL-1β), interferon-gamma (IFN-γ), leptin, and fibroblast growth factor 21 (FGF21) were detected at baseline and the end of the study.

Results

In total, 281 participants (68 % male, age: 50.3 ± 9.4 years) completed the study. After 48- week treatment, IL-1β and IFN-γ were significantly decreased with exenatide treatment (P < 0.001 and P = 0.001, respectively), but increased with insulin (P = 0.009 and P = 0.026, respectively). However, pioglitazone treatment had no impact on ADICs. No significant change in leptin or FGF21 was detected with any of the treatments. After adjustment for baseline values and changes of body weight, waist and HbA1c, the between-group differences were found in ΔIL-1β (exenatide vs. insulin: P = 0.048; and exenatide vs. pioglitazone: P = 0.003, respectively) and ΔIFN-γ (exenatide vs. insulin: P = 0.049; and exenatide vs. pioglitazone: P < 0.001, respectively). Multiple linear regression analysis indicated that Δweight was associated with ΔIL-1β (β = 0.753; 95 % CI, 0.137-1.369; P = 0.017). After adjusting for treatment effects, Δweight was also be correlated with ΔFGF21 (β = 1.097; 95%CI, 0.250-1.944; P = 0.012); furthermore, ΔHOMA-IR was correlated with Δleptin (β = 0.078; 95%CI, 0.008-0.147; P = 0.029) as well. However, ΔHOMA-IR was not significantly associated with ΔIL-1β after adjusting for treatment effects (P = 0.513).

Conclusion

Exenatide treatment led to significant changes of inflammatory cytokines levels (IL-1β and IFN-γ), but not adipokines (leptin and FGF21), in newly diagnosed T2DM patients. The exenatide-mediated improvement in weight and IR may be associated with a decrease in inflammatory cytokine levels.

Ameliorating Effect of the Total Flavonoids of Morus nigra L. on Prediabetic Mice Based on Regulation of Inflammation and Insulin Sensitization

Prediabetes is a critical stage characterized by insulin resistance. Morus nigra L., an edible plant, is widely used in food and nutritive supplements and exhibits various pharmacological activities; however, its therapeutic effects and mechanisms on prediabetes have rarely been reported. In this research, the major components of total flavonoids of M. nigra L. (TFM) were identified, and TFM treatment was found to reduce prediabetes progressing to type 2 diabetes mellitus (T2DM) from 93.75 to 18.75%. The microbiota and next-generation sequencing combined with western blotting in vivo and in vitro demonstrated that TFM and its components ameliorated insulin resistance mediated by the suppressor of cytokine signaling and protein tyrosine phosphatase 1B, which benefited by maintaining intestinal homeostasis and restraining plasma levels of inflammatory factors. This study confirmed the T2DM prevention effect of TFM and revealed the underlying mechanism, setting the stage for the design of functional foods for diabetes prevention.

Diastereoselective Synthesis of Chromeno[3,2-d]isoxazoles via Brønsted Acid Catalyzed Tandem 1,6-Addition/Double Annulations of o-Hydroxyl Propargylic Alcohols

A Brønsted acid catalyzed tandem process to access densely functionalized chromeno[3,2-d]isoxazoles with good to excellent yields and diastereoselectivities was disclosed. The procedure is proposed to involve a 1,6-conjugate addition/electrophilic addition/double annulations process of alkynyl o-quinone methides (o-AQMs) in situ generated from o-hydroxyl propargylic alcohols with nitrones. Mild conditions, good functional group compatibility, easy scale-up of the reaction, and further product transformation demonstrated its potential application.

Combined treatment with FABP4 inhibitor ameliorates rosiglitazone-induced liver steatosis in obese diabetic db/db mice

Rosiglitazone has been reported to exert dual effects on liver steatosis, and it could exacerbate liver steatosis in obese animal models, which was suggested to be closely related to the elevated hepatic expression of FABP4. This study aimed to investigate whether combined treatment with FABP4 inhibitor I-9 could alleviate rosiglitazone-induced liver steatosis in obese diabetic db/db mice. Male C57BL/KsJ-db/db mice were orally treated with rosiglitazone, rosiglitazone combined with I-9 daily for 8 weeks. The liver steatosis was evaluated by triglyceride content and H&E staining. The expression of hepatic lipogenic genes or proteins in liver tissue or in FFA-treated hepatocytes and PMA-stimulated macrophages were determined by real-time quantitative polymerase chain reaction (RT-qPCR) or western blotting. Results showed that combined treatment with I-9 decreased rosiglitazone-induced increase in serum FABP4 level and expression of lipogenic genes in liver, especially FABP4, and ameliorated liver steatosis in db/db mice. Rosiglitazone-induced intracellular TG accumulation and increased expression of FABP4 in the cultured hepatocytes and macrophages were also suppressed by combined treatment. We concluded that combined treatment with FABP4 inhibitor I-9 could ameliorate rosiglitazone-exacerbated elevated serum FABP4 level and ectopic liver fat accumulation in obese diabetic db/db mice without affecting its anti-diabetic efficacy.

A novel low systemic diacylglycerol acyltransferase 1 inhibitor, Yhhu2407, improves lipid metabolism

Diacylglycerol acyltransferase 1 (DGAT1) plays a pivotal role in lipid metabolism by catalyzing the committed step in triglyceride (TG) synthesis and has been considered as a potential therapeutic target of multiple metabolic diseases, including dyslipidemia, obesity and type 2 diabetes. Here we report a novel DGAT1 inhibitor, Yhhu2407, which showed a stronger DGAT1 inhibitory activity (IC₅₀ = 18.24 ± 4.72 nM) than LCQ908 (IC₅₀ = 78.24 ± 8.16 nM) in an enzymatic assay and led to a significant reduction in plasma TG after an acute lipid challenge in mice. Pharmacokinetic studies illustrated that Yhhu2407 displayed a low systemic, liver- and intestine-targeted distribution pattern, which is consistent with the preferential tissue expression pattern of DGAT1 and therefore might help to maximize the beneficial pharmacological effects and prevent the occurrence of side effects. Cell-based investigations demonstrated that Yhhu2407 inhibited free fatty acid (FFA)-induced TG accumulation and apolipoprotein B (ApoB)-100 secretion in HepG2 cells. In vivo study also disclosed that Yhhu2407 exerted a beneficial effect on regulating plasma TG and lipoprotein levels in rats, and effectively ameliorated high-fat diet (HFD)-induced dyslipidemia in hamsters. In conclusion, we identified Yhhu2407 as a novel DGAT1 inhibitor with potent efficacy on improving lipid metabolism in rats and HFD-fed hamsters without causing obvious adverse effects.

Sanggenol L promotes apoptotic cell death in melanoma skin cancer cells through activation of caspase cascades and apoptosis-inducing factor

Sanggenol L is one component of root bark of Morus alba. The molecular and cellular mechanisms of sanggenol L effects on melanoma cells are not well known. Recently, melanoma is the most common skin cancer with a high mortality rate not only in United States, but also in East Asia. Therefore, safe and effective treatments for melanoma treatment are required. In this study, we investigated whether or not sanggenol L possesses anti-cancer activity in human and mouse melanoma skin cancer cells. Sanggenol L treatment exerted significant cell growth inhibitory effects and inhibited colony formation capacity against B16, SK-MEL-2, and SK-MEL-28 melanoma skin cancer cells, whereas HaCaT human epithelial keratinocyte cells was unaffected by sanggenol L treatment. Sanggenol L treatment resulted in apoptotic cell death in melanoma skin cancer cells, which was characterized by accumulation of apoptotic cells, nuclear condensation, and apoptotic bodies. We also showed that sanggenol L treatment induced caspase-dependent apoptosis (up-regulation of Bax and cleaved-PARP or down-regulation of Bid, Bcl-2, procaspse-3, -8, and -9), induction of caspase-independent apoptosis (up-regulation of AIF and Endo G on cytosol) in melanoma skin cancer cells. These results suggest that sanggenol L induces caspase-dependent and -independent apoptosis in melanoma skin cancer cells.

Metabolic effects of antidiabetic drugs on adipocytes and adipokine expression

Several classes of antidiabetic agents have been developed that achieve their hypoglycemic outcomes via various molecular mechanisms. Adipose tissue is a major metabolic and energy-storing tissue and plays an important role in many metabolic pathways, including insulin signaling and insulin sensitivity. Adipose tissue monitors and regulates whole body homeostasis via production and release of potent proteins, such as adipokine and adiponectin, into the circulation. Therefore, any agent that can modulate adipocyte metabolism can, in turn, affect metabolic and glucose homeostatic pathways. Antidiabetic drugs are not only recognized primarily as hypoglycemic agents but may also alter adipose tissue itself, as well as adipocyte-derived adipokine expression and secretion. In the current review, we present the major evidence concerning routinely used antidiabetic agents on adipocyte metabolism and adipokine expression.

Chalcone derivatives from the root bark of Morus alba L. act as inhibitors of PTP1B and α-glucosidase

As part of our continuing research to obtain pharmacologically active compounds from Morus alba L. (Moraceae), four Diels-Alder type adducts (DAs) [morusalbins A-D], one isoprenylated flavonoid [albanin T], together with twenty-one known phenolic compounds were isolated from its root bark. The chemical structures were established using NMR, MS, and ECD spectra. The DAs including morusalbins A-D, albasin B, macrourin G, yunanensin A, mulberrofuran G and K, and albanol B exhibited strong inhibitory activities against both protein tyrosine phosphatase 1B (PTP1B) (IC₅₀, 1.90-9.67 μM) and α-glucosidase (IC₅₀, 2.29-5.91 μM). In the kinetic study, morusalbin D, albasin B, and macrourin G showed noncompetitive PTP1B inhibition, with K_i values of 0.33, 1.00, and 1.09 μM, respectively. In contrast, these DAs together with yunanensin A produced competitive inhibition of α-glucosidase, with K_i values of 0.64, 0.42, 2.42, and 1.19 μM, respectively. Furthermore, molecular docking studies revealed that these active DAs have high affinity and tight binding capacity towards the active site of PTP1B and α-glucosidase.

New Cytotoxic Alkylated Chalcones from Fatoua villosa

Three new alkylated chalcones, villosins A - C (1 - 3), five known analogues, together with ten known coumarins, were isolated from Fatoua villosa. The structures of the new compounds were elucidated by extensive spectroscopic analysis, including 1D-, 2D-NMR, and MS data. Compounds 1 - 3 showed cytotoxicity against five kinds of human tumor cell lines (NB4, A549, SHSY5Y, PC3, and MCF7) with IC₅₀ values ranging from 1.4 ± 0.1 to 5.7 ± 0.3 μm.