Nandini P. Shetty

Dietary iron supplements and Moringa oleifera leaves influence the liver hepcidin messenger RNA expression and biochemical indices of iron status in rats

In this study, the effects of iron depletion and repletion on biochemical and molecular indices of iron status were investigated in growing male Wistar rats. We hypothesized that iron from Moringa leaves could overcome the effects of iron deficiency and modulate the expression of iron-responsive genes better than conventional iron supplements. Iron deficiency was induced by feeding rats an iron-deficient diet for 10 weeks, whereas control rats were maintained on an iron-sufficient diet (35.0-mg Fe/kg diet). After the depletion period, animals were repleted with different source of iron, in combination with ascorbic acid. Iron deficiency caused a significant (P < .05) decrease in serum iron and ferritin levels by 57% and 40%, respectively, as compared with nondepleted control animals. Significant changes in the expression (0.5- to100-fold) of liver hepcidin (HAMP), transferrin, transferrin receptor-2, hemochromatosis type 2, ferroportin 1, ceruloplasmin, and ferritin-H were recorded in iron-depleted and iron-repleted rats, as compared with nondepleted rats (P < .05). Dietary iron from Moringa leaf was found to be superior compared with ferric citrate in overcoming the effects of iron deficiency in rats. These results suggest that changes in the relative expression of liver hepcidin messenger RNA can be used as a sensitive molecular marker for iron deficiency.

Effect of different drying methods on chlorophyll, ascorbic acid and antioxidant compounds retention of leaves of Hibiscus sabdariffa L.

BACKGROUND Use of the indigenous, easily accessible leafy vegetable roselle (Hibiscus sabdariffa L.) for value addition is gaining impetus as its nutritive and nutraceutical compounds are exposed by investigations. Being a perishable, storage is challenging, hence different methods of drying have been an attractive alternative for its postharvest usage in foods without much compromising its quality and antioxidant potential. RESULTS Room- and freeze-dried samples were found to have best quality in terms of colour, total flavonoid content (18.53 ± 2.39 and 18.66 ± 1.06 g kg(-1) respectively), total phenolic content (17.76 ± 1.93 and 18.91 ± 0.48 g kg(-1)), chlorophyll content (1.59 ± 0.001 and 1.55 ± 0.001 g kg(-1)) and ascorbic acid content (11.11 ± 1.04 and 8.92 ± 0.94 g kg(-1)) compared with those subjected to infrared, crossflow, microwave, oven or sun drying. Samples treated by room and freeze drying retained maximum antioxidant potential as shown by the phosphomolybdate method and the 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging activity and ferric-reducing antioxidant power assays. Cold water and hot water extracts showed significantly higher total phenolic content and total antioxidant activity owing to the greater solubility of phenolics and destruction of cellular components in polar solvents than in organic solvents. CONCLUSION The data obtained show the potential for retaining quality parameters of roselle leaf under suitable drying methods.