Nigella sativa extract as a potent antioxidant for petrochemical-induced oxidative stress.

Various beneficial properties has been attributed to Nigella sativa, including its antioxidant potential. Previously, it was reported that supercritical fluid extraction (SFE) could be used to obtain N. sativa extract rich in antioxidants. In the present study, N. sativa extracts prepared using the previously optimized SFE as well as the traditional Soxhlet extraction approaches were analyzed for various known antioxidants. N. sativa extracts were found to prevent protein carbonyl formation as well as depletion of intracellular glutathione (GSH) in fibroblasts exposed to toluene. Furthermore, partially purified SFE and Soxhlet fractions could prevent loss of hepatic GSH in toluene-induced oxidative stressed Wistar rats as well as in L929 fibroblasts. The results showed that SFE-produced N. sativa extract is richer in antioxidants than the Soxhlet approach. It was also shown using preparative silica gel and reverse phase chromatography that different fractions of SFE-extracted or Soxhlet-extracted N. sativa had different levels of protective effects with regards to GSH depletion in vivo as well as in cell culture. Although fractions rich in thymoquinone were found to be most potent in terms of antioxidant capacity, the data indicates that the protective effects of N. sativa may not only be due to thymoquinone, but perhaps other antioxidants.

Assessment of vitamin D and vitamin A intake by female students at the United Arab Emirates University based on self-reported dietary and selected fortified food consumption.

In the United Arab Emirates (UAE), many adolescent girls and women (especially the UAE citizens) are not adequately exposed to sunlight and their dietary intake of vitamin D is insufficient to fulfill the required recommended daily allowance of the vitamin. In the present study, the problem of vitamin D and vitamin A insufficiency in female students of UAE University was investigated through a dietary intake assessment of the vitamins. Results indicated that over 70% of female students constituting the survey population did not consume enough milk and other vitamin-D-rich foods, and many showed poor food habits. Prevalence of vitamin D insufficiency among the population studied indicated that 37% of the total population was considered vitamin D insufficient and 40% of the female students residing in the hostels also had vitamin D insufficiency ( < 5 µg/day) based on self-reported dietary and selected fortified food consumption.

A study on vitamin D and vitamin A in milk and edible oils available in the United Arab Emirates.

Two high-performance liquid chromatography methods have been validated for the determination of vitamin D and vitamin A in milk and edible oils. The percentage recovery of vitamin D added to milk ranged from 89% to 105%, with the repeatability relative standard deviation ranging from 2.78% to 6.11%. Its recovery in oil samples ranged from 90% to 102%, with the repeatability relative standard deviation ranging from 3.97% to 7.54%. The average recovery of vitamin A added to milk was found to be 98.7%. Analytical data for vitamin D in different brands of milk and milk products in the market samples of the United Arab Emirates indicate that 87% of samples contain vitamin D with 39% of samples within the acceptable range (0.8-1.2 microg/100 ml), where as 31% were found to be under-fortified and 30% were over-fortified. Analytical data for vitamin D in edible oils confirm a large variation. All milk samples analyzed contain less than 55 microg/100 ml vitamin A.