Beneficial effect of modified egg on serum T3, T4 and dyslipidaemia following dietary Zn-supplementation in Wistar rat.

A fall in serum T3 and T4 along with increase in serum cholesterol, triglycerides, LDL-c and VLDL-c and decrease in HDL-c was observed in albino Wistar rats when fed on semi-synthetic diet containing either 40 or 80mg Zn/kg diet. Zn concentrations were observed to increase with decreased concentration of Cu and Mg in their tissues. On including modified egg (Indian Patent Application No. 2264\Del\2005) in the Zn supplement diet, the levels of T3 and T4, lipid profile in serum and mineral status approached closer to control group-I. The data suggest that hypothyroidism and dyslipidaemia caused by excessive Zn in diet can be ameliorated on consuming these modified eggs due to restoration of mineral status in the body.

Effect of modified egg* on developmental defects in neonates of NIDDM induced Wistar rats.

Maternal Zn deficiency has been suggested as the contributing factor for all congenital malformations during pregnancy particularly in diabetes. Maternal Zn-supplementation, therefore, was suggested as one possible nutrition intervention during pregnancy to improve its outcome. But a number of trials with Zn-supplementation are not consistent and discourage the use of excessive Zn-supplementation during pregnancy. Instead a multivitamin/ mineral supplement to them has been suggested to reduce its complication. Accordingly, the poultry egg was modified for trace elements, vitamin-E and omega-3 fatty acids so as to use it as a dietary supplement for diabetics to reduce their complications during the pregnancy. The results showed that NIDDM induced rats fed either on 40 or 80 mg Zn/kg diet delivered less number of pups/litter and their body weight was higher at birth as compared to control group fed 20 mg Zn/kg diet. During the weaning period, some abnormalities characterized by restricted movements of the hind legs, curl toes of limbs, eye opening problems, less hair on the body and more head to body ratio were observed. Whereas number of pups delivered per litter were more with higher body weights without abnormalities in the pups in NIDDM groups fed egg mixed diet. Further Zn, Cu and Mg concentrations were significantly less in the liver, hair and abdominal muscles in pups in NIDDM groups but their concentrations were restored approaching closer to control in pups in groups fed egg mixed diet estimated on 18th day of weaning period. The excretion of these trace elements increased in the urine of dams fed Zn supplemented diet but decreased in the dams fed egg mixed diet on 15th day of their suckling period. The data suggest that if these modified eggs are included in the regular diet during pregnancy, they may protect the neonates in womb against the damaging effect of imbalances of physiologically important nutrients due to diabetes or environmental contamination.

Long term excessive Zn-supplementation promotes metabolic syndrome-X in Wistar rats fed sucrose and fat rich semisynthetic diet.

During the last two decades Zinc (Zn) as a micronutrient is being used indiscriminately in agricultural and husbandry practices and also in baby foods and multivitamin supplements with a view that Zn is non-toxic and promotes linear growth and body weight in the consumers. The long-term effect of increasing Zn load in the body has not been worked out so far. In this study, three groups of rats were fed on a semi-synthetic diet containing 20 mg (control, group-I), 40 mg (group-II) and 80 mg Zn /kg (group-III) diet respectively for 6 months. The results revealed that the gain in body weight increased in rats in Zn-concentration dependent manner. The urine examined on weekly basis showed glucosuria in group-II on week 10 and in group-III on week 8 and thereafter. The arterial blood pressure was significantly higher in group-II and III than their control counter parts on monthly basis. Histochemical examination of skin revealed an increase in the number of adipocytes filled with triglycerides making a subcutaneous fatty tissue thicker in group-II and group-III than that of control group. The blood profile after 180 days of dietary treatment, displayed a significant rise in glucose, total lipids, cholesterol, triglycerides, LDL-cholesterol, VLDL-cholesterol, insulin, cortisol and aldosterone whereas HDL-cholesterol, T3, T4 and TSH showed a reduction in their levels in the blood serum. The tissue metal status showed an increase of Zn, Cu and Mg in the serum, a rise in Zn in liver, hair and abdominal muscles and fall in Cu and Mg concentrations in liver, hair and abdominal muscles. This data suggest that Zn in excess in diet when fed for longer periods of time induces metabolic syndrome-X.

Influence of low cholesterol eggs enriched with vitamin-E and omega-3 fatty acid on blood lipid profile of Wistar rats.

In the recent past, low cholesterol eggs enriched with vitamin-E and omega-3 fatty acid have been developed and are marketed under different brands claiming them as heart friendly. The influence of these eggs (smart eggs) on lipid profile of rats was evaluated in comparison to that of the standard eggs. Data of 4 week dietary treatment revealed that total plasma cholesterol, low density lipoprotein (LDL) and very low density lipoprotein (VLDL) cholesterol increased only 22% in rats fed on diet containing 4 smart eggs per kg of semi-synthetic diet in contrast to the increase of more than 100 % when fed on diet containing standard eggs. The results suggest that it is not the low cholesterol content alone but also vitamin E and omega-3 fatty acids present in smart eggs that act synergically to prevent a substantial change in blood lipid profile and impose no serious risk to the health of the consumers.

Pathology of ovary, uterus, vagina and gonadotrophs of female mice fed on Zn-deficient diet.

Dietary Zn-deficiency in mature female mice for 6 weeks caused a retardation of ovarian growth characterized by lack of vesicular and Grafian follicles, degenerated corpus luteum, distorted cell membranes of granulosa cells with pycnotic nuclei, poor development of theca interna, inordinate accumulation of sudanophilic granules in theca interna and interstitial cells. The vagina and uterus did not exhibit cyclic changes in their cytoarchitecture as a result of the cessation of estrous cycle after 6 weeks of dietary treatment. They displayed wide spread degenerative changes in their myometrial and endometrial layers. The uterine glands appeared collapsed with little or no secretion. The vagina lacked cornification. Their gonadotrophs reacted positive to PAS, identical to the control group observed at diestrous stage. However, they did not display a negative reaction, characteristic of the gonadotrophs at estrous stage of the control group, examined even at an interval of 1 day for 6 days in succession. These results point towards the suspension of steroidogenesis inspite of intact gonadotrophs under Zn-deficiency condition.