Diabetic encephalopathy: beneficial effects of supplementation with fatty acids ω3 and nordihydroguaiaretic acid in a spontaneous diabetes rat model.

BACKGROUND: Diabetic encephalopathy is a chronic complications of diabetes mellitus that affects the central nervous system. We evaluated the effect of ω3 and ω6 polyunsaturated fatty acids (PUFAs) supplementation plus the antioxidant agent nordihydroguaiaretic acid (NDGA) on the etiopathology of diabetic encephalopathy in eSS rats, a spontaneous model of type 2 diabetes. METHODS: One hundred twenty spontaneous diabetic eSS male rats and 38 non-diabetic Wistar, used as healthy control, received monthly by intraperitoneal route, ω3 or ω6 PUFA (6.25 mg/kg) alone or plus NDGA (1.19 mg/kg) for 12 months. Diabetic rats had a worse performance in behavioural Hole-Board test. Histopathological analysis confirmed lesions in diabetic rats brain tissues. We also detected low expression of synaptophysin, a protein linked to release of neurotransmitters, by immunohistochemically techniques in eSS rats brain. Biochemical and histopathological studies of brain were performed at 12th month. Biochemical analysis showed altered parameters related to metabolism. High levels of markers of oxidative stress and inflammation were detected in plasma and brain tissues. Data were analysed by ANOVA test and paired t test was used by comparison of measurements of the same parameter at different times. RESULTS: The data obtained in this work showed that behavioural, biochemical and morphological alterations observed in eSS rats are compatible with previously reported indices in diabetic encephalopathy and are associated with increased glucolipotoxicity, chronic low-grade inflammation and oxidative stress burden. Experimental treatments assayed modulated the values of studied parameters. CONCLUSIONS: The treatments tested with ω3 or ω3 plus NDGA showed improvement in the values of the studied parameters in eSS diabetic rats. These observations may form the basis to help in prevent and manage the diabetic encephalopathy.

Subchronic toxicological evaluation of brea gum (Parkinsonia preacox) as a food additive in BALB/c mice.

Brea gum is a phloematic exudate from Parkinsonia praecox, an autoctonous tree that grows in the arid areas of Argentina. In this work, we propose its potential as a food additive. However, as no toxicological safety evaluation of brea gum has yet been reported, this preliminary study was conducted to evaluate its long-term toxicity over a 120-day period in BALB/c mice fed with brea gum at various levels in the diet. The results showed that animals on diets containing up to 5% brea gum were healthy, exhibiting growth curves similar to controls for both males (P = 0.9138) and females (P = 0.9459), thereby indicating that feed intake and utilization was not affected. A histopathological examination and weight recording of liver, kidneys, and intestine did not reveal any microscopic abnormalities or adverse toxicological effect (weights respect to control: P > 0.1). Moreover, hematological parameters and enzyme activities were within the normal values previously reported for mice. Our findings suggest that feeding brea gum at levels up to 5% to BALB/c mice do not exert any toxicological effects, supporting its potential use as a food additive for human consumption.

Conjugated linoleic acid (CLA) versus saturated fats/cholesterol: their proportion in fatty and lean meats may affect the risk of developing colon cancer.

In spite of the considerable amount of experimental, clinical and epidemiological research about the consumption of red meat, total fats, saturated/unsaturated fatty acids and cholesterol with regard to the risk of developing colorectal cancer (CRC), the issue remains controversial. The general belief is a reduction of red meat intake, and subsequent nutritional advice usually strongly recommends this. Paradoxically, beef together with whole milk and dairy derivatives, are almost the only sources for conjugated linoleic acid (CLAs) family. Furthermore CLAs are the only natural fatty acids accepted by the National Academy of Sciences of USA as exhibiting consistent antitumor properties at levels as low as 0.25-1.0 per cent of total fats. Beside CLA, other polyunsaturated fatty acids (PUFA) belonging to the essential fatty acid (EFA) n-3 family, whose main source are fish and seafood, are generally believed to be antipromoters for several cancers. The purpose of this work is to critically analyze the epidemiological and experimental evidence by tentatively assuming that the reciprocal proportions of saturated fats (SA) plus cholesterol (CH) versus CLAs levels in fatty or lean beef may play an antagonistic role underlying the contradictory effects reported for red meats consumption and CRC risk. Recent results about meat intake and risk for CRC in Argentina have shown an unexpected dual behaviour related to the type of meats. Fatty meat derivatives, such as cold cuts and sausages, mainly prepared from fatty beef (up to 37% fat) were associated with higher risk, whereas high consumption of lean beef (< 15% fat) behaved as a protective dietary habit. CLA is located in the interstitial, non-visible, fat evenly distributed along muscle fibres as well as in subcutaneous depots. Visible fat may be easily discarded during the meal, whereas interstitial fats will be eaten. The remaining intramuscular fat in lean meats range from 25 to 50 g/Kg (2.5 to 5%). The proportion of CLA/SA+CH for lean beef eaters is 0.09 and the fatty meats 0.007 (g/100 g). As a consequence, the beneficial effects of minor amounts of CLA may be relatively enhanced in lean meat compared to fatty meat sub-products which contain a substantial amount of saturated fatty acids and cholesterol, as in cold cuts and cow viscera.