In vitro rats of overall proteolysis and the activities of four different proteolytic pathways (lysosomal, Ca2+ dependent, ATP dependent, and ATP independent), as well as rates of protein synthesis, were measured in soleus and extensor digitorum longus (EDL) muscles from streptozotocin-diabetic rats. In the acute phase (1-3 days) of diabetes, there was an increase in overall proteolysis that coincided with an increased activity of the Ca(2+)-dependent pathway in both soleus and EDL and of the ATP-dependent pathway in EDL. After longer periods (5-10 days) of diabetes, the overall rate of protein degradation decreased and reached values similar to or even lower than those of controls as a result of a reduction in the activities of Ca(2+)-dependent and ATP-dependent pathways. No change was detected at any time interval in the activity of the intralysosomal proteolytic system in muscles from diabetic animals. Rates of protein synthesis were already reduced 24 h after diabetes induction and decreased further thereafter. Insulin treatment restored to normal the activities of the proteolytic pathways and rates of protein synthesis.

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We investigated the effects of prolonged treatment of diabetic rats with curcumin-supplemented yoghurt on the physiological and biochemical changes associated with diabetes mellitus. An established metabolic cage model was used to assess these changes in three groups of streptozotocin-diabetic rats which had been administered, by gavage, curcumin blended into yoghurt in the doses of 30, 60 and 90 mg/kg body weight (BW) per d (groups DC 30 , DC 60 , DC 90 ) for 31 d. One group of non-diabetic rats was also treated with 90 mg/kg BW per d curcumin (NDC90). Three control groups of diabetic animals received water (DW), yoghurt (DY) and insulin at 27·78 mmol/d by subcutaneous injection (DI). Also, two groups of non-diabetic animals received water (NDW) and yoghurt (NDY). Groups DI and DC90 exhibited significant falls, relative to DW and DY, in food and water intake, urine volume, glycaemia, urinary urea and glucose, proteinuria, serum TAG and activities of aspartate and alanine aminotransferases, and higher hepatic glycogen and BW. These improvements were greater in DI than in DC90. No difference was observed in the serum levels of total cholesterol or HDL-cholesterol, or in the masses of adipose and muscular tissues, between DC90 and DW or DY. Moreover, the improvements in curcumin-treated rats, relative to DW and DY, were significant and dose-dependent. The NDC90 group also showed no difference from the NDW or NDY groups, in any of the markers for diabetes. In conclusion, curcumin mixed into yoghurt at the highest dose tested exhibited anti-diabetic activity, improving significantly most of the markers assessed in this study.Key words: Functional food: Glycaemia: Proteinuria: Body weight Diabetes mellitus (DM) is a group of metabolic disorders characterised by high levels of glucose in the blood (hyperglycaemia), arising from deficient secretion and/or inefficient action of the hormone insulin, which leads to changes in the metabolism of carbohydrates, lipids and proteins. Apart from hyperglycaemia, these changes typically result in: loss of weight, despite the increased hunger inducing a higher rate of eating, increased water intake and urinary volume, glycosuria, proteinuria and a raised level of urinary urea (1) . A recent study on the prevalence of DM among adults (aged 20 -79 years) in ninety-one countries showed that it would affect 285 million adults (6·4 %) in 2010 and this would increase to 439 million (7·7 %) by 2030. This study also showed that, between 2010 and 2030, the numbers of adults in developing countries with DM will rise by 69 %, while in developed countries the increase will be 20 % (2) .Current developments in pharmaceutical technology are directed not only at the discovery of new drugs, but also at new ways of administering them. Around the world, there is a trend towards the use of functional foods, namely items of food that afford physiological or metabolic health benefits, besides their ordinary nutritional value (3) . Yoghurt is a popular, tasty and healthy milk product, produced ...