OBJECTIVETo study the protein tyrosine phosphatase-1B (PTP1B) inhibitory activity of natural products from algae aiming at searching for new way for the treatment of type 2 diabetes mellitus (T2DM) and obesity.

METHODBromophenols derivatives from algae were screened against the PTP1B by the colorimetric assay with GST/PTP1B fusion protein. The Me2SO was distributed as the full enzyme activity, and Na3VO4 (IC50 2 micromol L(-1)) was distributed as the positive control. Inhibition rate was assayed and IC50 were calculated by LOGIT method.

RESULTThree bromophenols from Rhodomela confervoides and Leathesia nana, 3, 4-dibromo-5-(methoxymethyl)-1, 2-benzenediol (1), 2-methyl-3-(2, 3-dibromo4, 5-dihydroxy)-propylaldehyde (2) and 3-(2, 3-dibromo-4, 5-dihydroxy-phenyl)-4-bromo-5, 6-dihydroxy-1, 3-dihydroiso-benzofuran (3) showed significant inhibitory activity against PTP1B. IC50 values were 3.4 +/- micromol L(-1), 4.5 micromol L(-1) and 2.8 micromol L(-1), respectively.

CONCLUSIONThe results prove that three bromophenol derivatives from algae with significant inhibitory activity against PTP1B were potential and effective therapeutic agents for treatment of T2DM and obesity.

Diabetes Mellitus, Type 2 ; drug therapy ; metabolism ; Eukaryota ; chemistry ; Phaeophyta ; chemistry ; Phenols ; chemistry ; therapeutic use ; Protein Tyrosine Phosphatase, Non-Receptor Type 1 ; antagonists & inhibitors ; Rhodophyta ; chemistry

In Korea, the use of herbal remedies is a common cause of drug-induced liver injury. However, the occurrence of both acute pancreatitis and acute hepatitis after taking herbal remedies has rarely been reported. Herein, we report a case of concurrent acute pancreatitis and acute hepatitis associated with Ceramium kondoi ingestion. A 58-year-old woman was diagnosed with advanced gastric cancer 7 months ago. Total gastrectomy and adjuvant chemotherapy was performed without complications. The patient had been well until recently, when she presented with severe abdominal pain after ingestion of Ceramium kondoi for 4 weeks. The laboratory findings demonstrated elevated liver enzymes and lipase, and abdominal computed tomography revealed pancreas swelling with fat infiltration. The diagnosis was made based on the diagnostic criteria for drug induced pancreatitis and the Russel Uclaf Causality Assessment Method scale for drug-induced liver injury. After cessation of Ceramium kondoi, she showed clinical and biochemical improvement.
Abdominal Pain/etiology ; Acute Disease ; Drug-Induced Liver Injury/*diagnosis/enzymology ; Female ; Humans ; Lipase/metabolism ; Liver/*drug effects ; Middle Aged ; Pancreas/*drug effects ; Pancreatitis/*chemically induced/*diagnosis ; Plant Extracts/chemistry/*toxicity ; Rhodophyta/chemistry/metabolism ; Tomography, X-Ray Computed

The present study was designed to observe the protection of Grateloupia filicina polysaccharide (GFP) against hepatotoxicity induced by Dioscorea bulbifera L in mice and its underlying mechanism. GFP was intragastrically (ig) given to mice at various doses. After 6 days, the mice were treated with ethyl acetate extract of Dioscorea bulbifera L (EF, ig). Serum levels of alanine/aspartate aminotransferase (ALT/AST), alkaline phosphatase (ALP), total bilirubin (TB) were measured, and liver histological evaluation was conducted. Furthermore, reductions of liver glutathione (GSH) amount and glutamate cysteine ligase (GCL) activity were tested. The expressions of GCL-c, GCL-m, and HO-1 (heme oxygenase-1) in liver were observed by Western-blot. The results showed that GFP (600 mg x kg(-1)) decreased EF-induced the increase of serum ALT, AST and TB, and GFP (400, 600 mg x kg(-1)) inhibited EF-induced the increase of serum ALP. Liver histological evaluation showed that the liver injury induced by EF was relieved after treated with GFP. GFP further increased liver GSH amount and reversed EF-induced the decrease of GCL activity. The Western-blot result showed that GFP augmented EF-induced the increase of HO-1, and reversed EF-induced the decrease of GCL-c. In conclusion, GFP can act against the oxidative stress liver injury induced by Dioscorea bulbifera L in mice.
Alanine Transaminase ; blood ; Alkaline Phosphatase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Bilirubin ; blood ; Chemical and Drug Induced Liver Injury ; blood ; metabolism ; Dioscorea ; toxicity ; Glutamate-Cysteine Ligase ; metabolism ; Glutathione ; metabolism ; Heme Oxygenase-1 ; metabolism ; Heterocyclic Compounds, 4 or More Rings ; antagonists & inhibitors ; isolation & purification ; toxicity ; Liver ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred ICR ; Oxidative Stress ; drug effects ; Plants, Medicinal ; chemistry ; Polysaccharides ; isolation & purification ; pharmacology ; Random Allocation ; Rhodophyta ; chemistry