Carrageenan analysis. Part 3: Quantification in swine plasma.

Development and validation of this method was conducted to support a 28-day piglet feeding study of swine-adapted infant formulations stabilised with carrageenan. The validation was performed in accordance with USFDA Good Laboratory Practice (GLP) Regulations and associated current bioanalytical guidelines. Separation of carrageenan from plasma protein was unsuccessful using saturated sodium chloride due to the extremely strong cross-linking interactions between carrageenan and protein. Poligeenan is the deliberately acid-hydrolysed low molecular weight polygalactan non-food product produced from carrageenan. Poligeenan molecules are nearly identical to carrageenan molecules with respect to molecular structure, the primary difference being molecular weight. These poligeenan molecules have similar molecular weight when compared with the lowest molecular weight fraction of carrageenan called the low molecular-weight tail (LMT). Poligeenan was separated from plasma protein using the salting procedure, this being due to the significantly weaker interaction with protein caused by its shorter molecular chain length. Thus, poligeenan was applied as a chemical analyte surrogate for the LMT of carrageenan solely for the development and validation of the method. This method was used to try to detect the LMT of the carrageenan test material during the 28-day piglet feeding study, and if such was absorbed into the bloodstream. Successful development and validation of the method was achieved using LC-MS/MS coupled with ESI in negative-ion mode. A standard curve of instrument response versus poligeenan concentration was developed using swine plasma spiked with a range of poligeenan concentrations. The lower level of quantification (LLOQ) of poligeenan was 10.0 µg ml⁻¹, and the quantification range was 10.0-100.0 µg ml⁻¹. No animals were fed poligeenan.

AMP-activated protein kinase and ATP-citrate lyase are two distinct molecular targets for ETC-1002, a novel small molecule regulator of lipid and carbohydrate metabolism.

ETC-1002 (8-hydroxy-2,2,14,14-tetramethylpentadecanedioic acid) is a novel investigational drug being developed for the treatment of dyslipidemia and other cardio-metabolic risk factors. The hypolipidemic, anti-atherosclerotic, anti-obesity, and glucose-lowering properties of ETC-1002, characterized in preclinical disease models, are believed to be due to dual inhibition of sterol and fatty acid synthesis and enhanced mitochondrial long-chain fatty acid ß-oxidation. However, the molecular mechanism(s) mediating these activities remained undefined. Studies described here show that ETC-1002 free acid activates AMP-activated protein kinase in a Ca(2+)/calmodulin-dependent kinase ß-independent and liver kinase ß 1-dependent manner, without detectable changes in adenylate energy charge. Furthermore, ETC-1002 is shown to rapidly form a CoA thioester in liver, which directly inhibits ATP-citrate lyase. These distinct molecular mechanisms are complementary in their beneficial effects on lipid and carbohydrate metabolism in vitro and in vivo. Consistent with these mechanisms, ETC-1002 treatment reduced circulating proatherogenic lipoproteins, hepatic lipids, and body weight in a hamster model of hyperlipidemia, and it reduced body weight and improved glycemic control in a mouse model of diet-induced obesity. ETC-1002 offers promise as a novel therapeutic approach to improve multiple risk factors associated with metabolic syndrome and benefit patients with cardiovascular disease.