Correction to: Eriocalyxin B Inhibits Adipogenesis in 3T3­L1 Adipocytes by Cell Cycle Arrest.

In the original publication of this article, we found an error under the section "Introduction". The first sentence of the fourth paragraph appears incorrectly. The corrected sentence is given below. Eriocalyxin B, isolated and identified in 1982 [1], is the major component in Chinese plant Isodon eriocalyx (Dunn.) Hara (family Lamiaceae) showing many pharmacological activities, such as inhibiting inflammatory response, regulating immune cell differentiation, inhibiting tumor cells proliferation, causing cell cycle arrest affecting angiogenesis and promoting cancer cells apoptosis.

Eriocalyxin B Inhibits Adipogenesis in 3T3-L1 Adipocytes by Cell Cycle Arrest.

Eriocalyxin B, an ent-Kaurene diterpenoid extracted from a traditional Chinese herb Isodon eriocalyx, has been shown to possess multifunctional activities such as anti-cancer and anti-inflammatory. However, the function and mechanism of the compound in adipocyte differentiation is still unknown. Here we reported that eriocalyxin B blunted adipogenesis remarkably by inhibiting the accumulation of lipid droplets, triglycerides and the expressions of adipogenesis-related factors, including C/EBPß, C/EBPα, PPARγ, and FABP4. Moreover, we showed that the inhibition might be the consequence of cell cycle being arrested at the G2/M phase during the mitotic clonal expansion of adipocyte differentiation, most likely by suppressing mRNAs and proteins of CDK1, CDK2, Cyclin A and Cyclin B1. Overall, we conclude that eriocalyxin B is capable of inhibiting adipocyte differentiation at the early stage through downregulating the proteins involved in cell cycle progression.

Clerodane Diterpenoids with Anti-hyperglycemic Activity from Tinospora crispa.

Four new clerodane diterpenoids, tinosporols A-C (2-4) and tinosporoside A (5), together with six known analogues were isolated from the vines of Tinospora crispa. Their structures were established by extensive spectroscopic analysis. The relative configuration at C-12 in the known diterpenoid borapetoside E (1), the major component of the plant, was firstly established with the aid of molecular model. Compound 1 significantly reduced serum glucose levels at dose-dependent manners in alloxan-induced hyperglycemic mice and db/db type 2 diabetic mice.

[A new phenylpropanoid glycoside compound isolated from Karelinia caspia].

To study the constituents of Karelinia caspia(Pall.) Less, three phenylpropanoid derivatives and other compounds were isolated by silica gel, RP-18 chromatographic methods. Compound 1 was a new phenylpropanoid glycoside named as kareline A. Their structures were determined by spectroscopic analysis, including 1D- and 2D-NMR and mass spectrometry.

Structure-Based Optimization and Biological Evaluation of Pancreatic Lipase Inhibitors as Novel Potential Antiobesity Agents.

The unusual fused ß-lactone vibralactone was isolated from cultures of the basidiomycete Boreostereum vibrans and has been shown to significantly inhibit pancreatic lipase. In this study, a structure-based lead optimization of vibralactone resulted in three series of 104 analogs, among which compound C1 exhibited the most potent inhibition of pancreatic lipase, with an IC50 value of 14 nM. This activity is more than 3000-fold higher than that of vibralactone. The effect of compound C1 on obesity was investigated using high-fat diet (HFD)-induced C57BL/6 J obese mice. Treatment with compound C1 at a dose of 100 mg/kg significantly decreased HFD-induced obesity, primarily through the improvement of metabolic parameters, such as triglyceride levels.

[Studies on terpenoids from Zygophyllum fabago].

This study was to investigate the chemical constituents of the aerial part of Zygophyllumfabago, by phytochemical methods. The compounds were isolated by silica gel and Sephadex LH-20 column chromatographies from the EtOAc extract. Their structures were characterized by various spectroscopic data (1H-NMR, 13C-NMR, MS) and comparison with the literature. As a result, thirteen compounds were isolated and their structures were identified as 1-hydroxyhinesol(1), hinesol(2), atractylenolactam(3), beta-eudesmol (4), 5alpha-hydroperoxy-beta-eudesmol(5), 12-hydroxy-valenc-1(10)-en-2-one(6), pubinernoid A(7), (6S,7E)-6-hydroxy-4,7-megastigmadien-3,9-dione(8), 3-hydroxy-5alpha, 6alpha-epoxy-beta-ionone (9), (3S,5R, 6S, 7E)-3, 5, 6-trihydroxy-7-megastigmen-9-one(10), (6R,7E,9R)-9-hydroxy-4,7-megastigmadien-3-one(11), (S)-3-hydroxy-beta-ionone(12), and blumenol A(13). Compounds 1-7 were sesquiterpenoids and 8-13 were megastigmane type norsesquiterpenoids. All the compounds were obtained from Z. fabago for the first time, and compound 1 was a new natural product.

Effect of the chloro-substitution on lowering diabetic hyperglycemia of vanadium complexes with their permeability and cytotoxicity.

The effect of the chloro-substitution of dinuclear vanadium (V) complexes on lowering diabetic hyperglycemia was evaluated. The in vivo tests for hypoglycemic activity show that complex 2 at the dose of 10.0 and 20.0 mg V kg(-1), could significantly decrease the blood glucose level. Importantly, our results the chloro substituent increased the insulin-enhancing properties of the complex 2. The two vanadium compounds had permeability above 10(-5) cm/s. It suggested that two complexes permeate via a passive diffusion mechanism. It was also suggested that two complexes has better good lipophilic properties. The cytotoxicity of two complexes on Caco-2 cells suggested the chlorine atom at C4 of complex 2 increased cytotoxicity for vanadium complexes.

A new insulin-enhancing agent: [N,N'-bis(4-hydroxysalicylidene)-o-phenylene-diamine]oxovanadium(IV) and its permeability and cytotoxicity.

A new insulin-enhancing agent: [N,N'-bis(4-hydroxysalicylidene)-o-phenylene-diamine] oxovanadium(IV) (BPOV) was synthesized and characterized by X-ray crystallography. BPOV was administered intragastrically to STZ-diabetic rats for 4 weeks. The results showed that BPOV could significantly decrease the blood glucose level and ameliorated impaired glucose tolerance in STZ-diabetic rats. BPOV has been further tested on insulin, glycogen and serum lipid studies. The results suggested BPOV has glucose-lowering activity in diabetic rats, as well as improved the disorder of lipid metabolism in diabetes. BPOV had permeability above 10(-5) cm s(-1). It was suggested good lipophilic properties. The cytotoxicity of BPOV on Caco-2 cells was measured by MTT assay which suggested BPOV have higher effect on impairment of cellular associated with lower level capacity of cellular accumulation.

Bis(alpha-furancarboxylato)oxovanadium(IV) prevents and improves dexamethasone-induced insulin resistance in 3T3-L1 adipocytes.

Previous studies showed that bis(alpha-furancarboxylato)oxovanadium(IV) (BFOV), an orally active anti-diabetic organic vanadium complex, could improve insulin resistance in animals with type 2 diabetes. The present study has been carried out to evaluate the effects of BFOV on insulin-resistant glucose metabolism using dexamethasone-treated 3T3-L1 adipocytes as an in-vitro model of insulin resistance. The results showed that BFOV, similar to vanadyl sulfate and rosiglitazone, caused a concentration-dependent increase in glucose consumption by insulin-resistant adipocytes. Moreover, BFOV enhanced the action of insulin and completely prevented the development of insulin resistance induced by dexamethasone, leading to glucose consumption equal to that by normal cells. In addition, dexamethasone reduced the mRNA expression of insulin receptor substrate 1 (IRS-1) and glucose transporter 4 (GLUT4) in 3T3-L1 adipocytes, while BFOV normalized the expression of IRS-1 and GLUT4. These findings suggest that BFOV prevents and improves dexamethasone-induced insulin resistance in 3T3-L1 adipocytes by enhancing expression of IRS-1 and GLUT4 mRNA.

[Insulino-mimetic effects of bis (alpha-furancarboxylato) oxovanadium (IV) in vitro].

To study insulino-mimetic effects of bis(alpha-furancarboxylato) oxovanadium (IV) (BFOV), a orally active antidiabetic vanadyl complex, on glucose uptake and lipogenesis in isolated rat adipocytes were determined by using 2-deoxy-D-[3H]-glucose and D-[3H]-glucose, respectively. Lipolysis was assayed by free fatty acids (FFA) released from isolated rat adipocytes treated with epinephrine. The results showed that BFOV, similar to insulin, concentration-dependently significantly enhanced the uptake of 2-deoxy-D-[3H]-glucose and the transformation from D-[3H]-glucose to lipid in isolated rat adipocytes, with the EC50 values of (0.31 +/- 0.08) mmol L(-1) and (0.49 +/- 0.12) mmol L(-1), respectively. Moreover, BFOV markedly inhibited FFA release from isolated rat adipocytes treated with epinephrine, and the IC50 value was (0.30 +/- 0.20) mmol L(-1). BFOV had insulino-mimetic effects such as enhancing glucose uptake and lipogenesis, as well as inhibiting lipolysis.