Metabolic effects of high sucrose and saturated oil feeding on insulin resistance in Sprague-Dawley rats.

In this study, we explored the effects of long-term consumption of a high-sugar high-fat diet on glucose tolerance and insulin resistance in rats. Rats were fed with either standard rat chow diet (NC group) or high-sugar high-fat diet (HSHF group) for 16 weeks. The HSHF group showed significantly higher fasting insulin level than NC group. Following intraperitoneal glucose challenge, blood glucose and insulin levels in the NC and HSHF groups increased. However, the magnitude of the response in NC group was low compared to HSHF group. Insulin resistance was higher in HSHF group and insulin sensitivity decreased significantly (P < 0.05) in HSHF group in contrast to NC group. Low-density lipoprotein-cholesterol (LDL-C) and triglyceride (TG)/high-density lipoprotein-cholesterol (HDL-C) levels showed significant increase in HSHF group, while triglyceride and total cholesterol levels did not show any difference. The study demonstrated that feeding high-sugar high-fat diet to the experimental Sprague-Dawley rats for 16 weeks increased possibility of insulin resistance in them but did not turn them hyperglycemic or diabetic. Thus, they prove to be a suitable animal model to explore various aspects of insulin resistance.

Sargassum polycystum reduces hyperglycaemia, dyslipidaemia and oxidative stress via increasing insulin sensitivity in a rat model of type 2 diabetes.

BACKGROUND: Sargassum polycystum, a brown seaweed, contains various nutrients and bioactive compounds that have antioxidant and healing properties. The research hypothesises that antioxidants and pigments in dietary S. polycystum extracts can improve insulin sensitivity, blood sugar levels and blood lipid levels in a rat model of type 2 diabetes. The diabetes was induced by a high-sugar, high-fat diet for 16 weeks to enhance insulin resistance, followed by a low-dose intraperitoneal injection of streptozotocin (35 mg kg(-1) body weight). The doses of S. polycystum tested on diabetic rats were 150 and 300 mg kg(-1) body weight for the ethanolic extract or 150 and 300 mg kg(-1) for the water extract. Normal rats, untreated diabetic and metformin-treated diabetic rats (n = 6) were used as control. RESULTS: Both doses of the alcohol extract of S. polycystum and the 300 mg kg(-1) water extract, significantly reduced blood glucose and glycosylated haemoglobin (HbA1C ) levels. Serum total cholesterol, triglyceride levels and plasma atherogenic index were significantly decreased after 22 days treatment in all seaweed groups. Unlike metformin, S. polycystum did not significantly change plasma insulin in the rats, but increased the response to insulin. CONCLUSION: The consumption of either ethanolic or water extracts of S. polycystum dose dependently reduced dyslipidaemia in type 2 diabetic rats. S. polycystum is a potential insulin sensitiser, for a comestible complementary therapy in the management of type 2 diabetes which can help reduce atherogenic risk.

Non-transferrin bound iron.

Non-transferrin-bound iron (NTBI) is an important biomarker related to the iron loading status of patients with certain diseases. NTBI is a highly toxic form of iron capable of generating free radicals and can lead to oxidative damage of various tissues. It is critical to quantify NTBI in blood to ensure personalised patient chelation management and to prevent high iron concentrations that can lead to toxicity and organ failure. Different analytical methods for the direct quantification of NTBI are described in the literature, but none have been translated for use in clinical laboratories. This review provides a critical discussion on the recent breakthroughs and remaining challenges for the direct quantification of NTBI. Most of the developed methods involve lengthy and complex sample preparation, use of expensive reagents and equipment while lacking the required accuracy and reproducibility. Collectively, these factors have limited the clinical translation of the developed methods, and therefore, the need for a reliable and widely accepted analytical method to quantify NTBI remains. Finally, this review explores the potential of rapid and accurate electrochemical techniques that have been demonstrated for environmental samples but are yet to be applied to detect NTBI in human blood plasma/serum and translation to widespread routine clinical use.

Electrochemical Methods for the Analysis of Milk.

The milk and dairy industries are some of the most profitable sectors in many countries. This business requires close control of product quality and continuous testing to ensure the safety of the consumers. The potential risk of contaminants or degradation products and undesirable chemicals necessitates the use of fast, reliable detection tools to make immediate production decisions. This review covers studies on the application of electrochemical methods to milk (i.e., voltammetric and amperometric) to quantify different analytes, as reported over the last 10 to 15 years. The review covers a wide range of analytes, including allergens, antioxidants, organic compounds, nitrogen- and aldehyde containing compounds, biochemicals, heavy metals, hydrogen peroxide, nitrite, and endocrine disruptors. The review also examines pretreatment procedures applied to milk samples and the use of novel sensor materials. Final perspectives are provided on the future of cost-effective and easy-to-use electrochemical sensors and their advantages over conventional methods.

Electrochemical Preparation of Poly(3,4-Ethylenedioxythiophene) Layers on Gold Microelectrodes for Uric Acid-Sensing Applications.

Two different methods for the synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) on gold electrodes are described, using electropolymerization of 3,4-ethylenedioxythiophene (EDOT) monomer in an aqueous and an organic solution. Cyclic voltammetry (CV) was used in the synthesis of PEDOT thin layers. Lithium perchlorate (LiClO4) was used as a dopant in both aqueous (aqueous/acetonitrile (ACN)) and organic (propylene carbonate (PC)) solvent systems. After the PEDOT layer was created in the organic system, the electrode surface was acclimatized by successive cycling in an aqueous solution for use as a sensor for aqueous samples. The use of an aqueous-based electropolymerization method has the potential benefit of removing the acclimatization step to have a shorter sensor preparation time. Although the aqueous method is more economical and environmentally friendly than the organic solvent method, superior PEDOT formation is obtained in the organic solution. The resulting PEDOT electrode surfaces were characterized by scanning electron microscopy (SEM), which showed the constant growth of PEDOT during electropolymerization from the organic PC solution, with rapid fractal-type growth on gold (Au) microelectrodes.

Application of cyclic voltammetry to analyse uric acid and reducing agents in commercial milks.

Cyclic voltammetry (CV) and high performance liquid chromatography (HPLC), were compared to quantify uric acid and antioxidant reducing agents in 36 milk samples. The enzymes uricase and ascorbate oxidase were used to remove uric and ascorbic acids and showed that the peaks obtained by CV and HPLC did not contain contributions from other unknown compounds. The levels of uric acid obtained by CV compared well to those determined using HPLC, with only a few exceptions, and the average difference was around 6%. CV measurements were made using the main anodic peak seen at approximately 330 mV (Ag/AgCl), while a later oxidation peak at approximately 650 mV can be associated with further reducing agents present in milk. The electrochemical method was quicker to apply than HPLC that included a pre-treatment step, and provides an inexpensive and simple method for the reliable analysis of uric acid in milk.

Effects of Brown Seaweed (Sargassum polycystum) Extracts on Kidney, Liver, and Pancreas of Type 2 Diabetic Rat Model.

The edible seaweed Sargassum polycystum (SP) is traditionally used against several human diseases. This investigation evaluated the effects of two dietary doses of SP ethanolic and aqueous extracts on the pancreatic, hepatic, and renal morphology of type 2 diabetic rats (T2DM). T2DM was induced by feeding rats on high calorie diet followed by a low dose streptozotocin. Changes in the diabetic rat organs in SP treated groups with different doses of extracts were compared with normal rats, diabetic control rats, and metformin treated rats. After 22 days of treatment, the pathological lesions of the livers and kidneys in the diabetic rats were quantitatively and qualitatively alleviated (P < 0.05) by both the SP extracts at 150 mg/kg body weight and by metformin. All the treated diabetic groups revealed marked improvement in the histopathology of the pancreas compared with the control diabetic group. Oral administration of 300 mg/kg body weight of aqueous and ethanolic extracts of SP and metformin revealed pancreas protective or restorative effects. The seaweed extracts at 150 mg/kg body weight reduced the liver and kidney damages in the diabetic rats and may exert tissue repair or restoration of the pancreatic islets in experimentally induced diabetes to produce the beneficial homeostatic effects.