Lipid peroxidation in liver tissue of ovariectomized and pinealectomized rats: effect of estradiol and progesterone supplementation

The present study aimed to determine the effect of estradiol-progesterone supplementation and pinealectomy on lipid peroxidation of liver tissue in ovariectomized rats. The study was carried out on 36 adult Sprague-Dawley female rats, which weighed 200-250 g. The rats were divided into 6 groups: Group 1: Sham Ovariectomy (Sham-Ovx), Group 2: Ovariectomy (Ovx), Group 3: Ovx + Estradiol-Progesterone supplementation (Ovx + H), Group 4: Sham Pinealectomy and Ovx (Sham Pnx -Ovx), Group 5: Ovx -Pnx, Group 6: Ovx -Pnx + H. Malondialdehyde (MDA), reduced form of glutathione (GSH) and glutathione peroxidase (GSH-Px) levels were determined in liver tissue of rats. The highest MDA levels and the lowest GSH-Px levels were determined in the ovariectomized-pinealectomized group, whereas the lowest MDA was in the Sham-Ovx group, and the highest GSH-Px levels were found in the Sham-Ovx and Ovx + Hormone supplemented group. Furthermore, the highest GSH levels were in group 1 and lowest levels were in group 5. The findings of this study demonstrate that ovariectomy led to lipid peroxidation in liver tissues of rats. Pinealectomy in addition to ovariectomy, increases lipid peroxidation, but, estradiol and progesterone supplementations to the ovariectomized-pinealectomized rats protect against lipid peroxidation to a significant extent.     

Effects of different levels of wheat bran, rice bran and maize powder supplementation with saw dust on the production of shiitake mushroom (Lentinus edodes (Berk.) Singer)

The cultivation of shiitake mushroom (Lentinus edodes) is increasing rapidly in Bangladesh due to its nutritional and medicinal importance with excellent flavor and longer shelf life. With the aim of increased production, we have cultivated L. edodes on saw dust (SD) supplemented with different levels (10%, 15%, 20%, 25%, 30%, 35% and 40%) of wheat bran (WB), rice bran (RB), maize powder (MP) and their combination (WB+RB+MP = 1:1:1) to investigate the growth, yield and quality of this mushroom. Most of the growth, yield and quality parameters varied significantly when mushrooms were cultivated with different levels of supplementation. The yield of mushroom was increased with the level of each supplementation upto a certain level, and then decreased. SD supplemented with 25% WB produced the highest number of fruiting bodies (34.8/500 g packet), highest biological yield (153.3/500 g packet), and biological efficiency (76.6%) of L. edodes. But the yield of the best quality mushroom was observed on SD with 40% WB supplementation; however, the qualities were not always supplementation dose dependent. In this study, we report that 25% WB supplementation with SD may be very effective for higher yield and 40% WB supplementation for better quality of L. edodes.     

Short-term and long-term vitamin C supplementation in humans dose-dependently increases the resistance of plasma to ex vivo lipid peroxidation

To assess the effects of short-term and long-term vitamin C supplementation in humans on plasma antioxidant status and resistance to oxidative stress, plasma was obtained from 20 individuals before and 2h after oral administration of 2g of vitamin C, or from eight subjects enrolled in a vitamin C depletion-repletion study using increasing daily doses of vitamin C from 30 to 2500 mg. Plasma concentrations of ascorbate, but not other physiological antioxidants, increased significantly after short-term supplementation, and increased progressively in the long-term study with increasing vitamin C doses of up to 1000 mg/day. Upon incubation of plasma with a free radical initiator, ascorbate concentrations were positively correlated with the lag phase preceding detectable lipid peroxidation. We conclude that vitamin C supplementation in humans dose-dependently increases plasma ascorbate concentrations and, thus, the resistance of plasma to lipid peroxidation ex vivo. Plasma and body saturation with vitamin C in humans appears desirable to maximize antioxidant protection and lower risk of oxidative damage.     

Supplemental selenium and coenzyme Q10 reduce glycation along with cardiovascular mortality in an elderly population with low selenium status – A four-year,prospective, randomised,double-blind placebo-controlled trial

BackgroundA low intake of selenium has been shown to increase the risk of cardiovascular mortality, and supplementation of selenium and coenzyme Q10 influences this. The mechanism behind is unclear although effects on inflammation, oxidative stress and microRNA expression have been reported.Fructosamine, a marker of long-term glycaemic control, is also a marker of increased risk of heart disease and death, even in non-diabetics.ObjectiveTo analyse the impact of selenium and coenzyme Q10 supplementation on the concentration of fructosamine. Also, the relation between pre-intervention serum selenium concentration and the effect on fructosamine of the intervention was studied.MethodsFructosamine plasma concentration was determined in 219 participants after six and 42 months of intervention with selenium yeast (200 μg/day) and coenzyme Q10 (200 mg/ day) (n = 118 of which 20 had diabetes at inclusion), or placebo (n = 101 of which 18 had diabetes at inclusion). Pre-intervention, the serum selenium levels were 67 μg/L (active treatment group: 66.6 μg/L; placebo group: 67.4 μg/L), corresponding to an estimated intake of 35 μg/day. Changes in concentrations of fructosamine following intervention were assessed by the use of T-tests, repeated measures of variance, and ANCOVA analyses.ResultsPost-intervention selenium concentrations were 210 μg/L in the active group and 72 μg/L in the placebo group. A lower concentration of fructosamine could be seen as a result of the intervention in the total population (P = 0.001) in both the males (P = 0.04) and in the females (P = 0.01) in the non-diabetic population (P = 0.002), and in both the younger (<76 years) (P = 0.01) and the older (≥76 years) participants (P = 0.03). No difference could be demonstrated in fructosamine concentration in the diabetic patients, but the total sample was small (n = 38). In subjects with a low pre-intervention level of serum selenium the intervention gave a more pronounced decrease in fructosamine compared with those with a higher baseline selenium level.ConclusionA significantly lower concentration of fructosamine was observed in the elderly community-living participants supplemented with selenium and coenzyme Q10 for 42 months compared to those on the placebo. As oxidative mechanisms are involved in the glycation of proteins, less glycoxidation could be a result of the supplementation of selenium and coenzyme Q10, which could have contributed to lower cardiac mortality and less inflammation, as has earlier been reported.This study was registered at Clinicaltrials.gov, and has the identifier NCT01443780.     

The impact of vitamin D3 supplementation on muscle function among HIV-infected children and young adults: a randomized controlled trial

Objectives:

We tested the hypothesis that daily vitD₃ supplementation increases neuromuscular motor skills, jump power, jump energy, muscular force, and muscular strength.

Methods:

This was a secondary analysis of a randomized controlled trial of 12-months of oral 7,000 IU/day vitD₃ supplementation or placebo among 56 persons living with HIV aged 9-25 years. Neuromuscular motor skills were quantified using the Bruininks-Oseretsky Test of Motor Proficiency. Power was quantified using peak jump power, and energy was quantified using peak jump height. Muscular force was quantified using isometric ankle plantar- and dorsiflexion, isokinetic knee flexion and extension. Muscular strength was quantified using isometric handgrip strength.

Results:

After 12-months, serum 25-hydroxyvitamin D [25(OH)D] was higher with supplementation versus placebo (β=12.1 ng/mL; P<0.001). In intention-to-treat analyses, supplementation improved neuromuscular motor skills versus placebo (β=1.14; P=0.041). We observed no effect of supplementation on jump power, jump energy, muscular force, or muscular strength outcomes versus placebo.

Conclusions:

Among HIV-infected children and young adults supplementation with daily high-dose vitD₃ increased concentration of serum 25(OH)D and improved neuromuscular motor skills versus placebo.     

Oxidized quercetin reacts with thiols rather than with ascorbate: implication for quercetin supplementation

When an antioxidant scavenges a reactive species, i.e., when it exerts its antioxidant activity, the antioxidant is converted into potentially harmful oxidation products. In this way, the antioxidant quercetin might yield an ortho-quinone, denoted as QQ, which has four tautomeric forms, i.e., the ortho-quinone and three quinonmethides. We evaluated the interaction of QQ with ascorbate or glutathione (GSH). Ascorbate recycles QQ to the parent compound quercetin, while GSH forms two adducts with QQ, i.e., 6-GSQ and 8-GSQ. When both GSH and ascorbate are present, QQ is converted exclusively into GSQ. In the absence of GSH, protein thiols will be arylated by QQ. This protein arylation is not prevented by ascorbate. Thiol arylation by quinones and quinonmethides can impair several vital enzymes. This implies that the product formed when quercetin displays its antioxidant scavenging effect is toxic in the absence of GSH. Therefore, an adequate GSH level should be maintained when quercetin is supplemented.     

Evaluation of the solubility of a range of copper sources and the effects of iron & sulphur on copper solubility under rumen simulated conditions

BackgroundAntagonisms exist in vivo which inhibit copper bioavailability in ruminants. Although the antagonism between iron, sulphur and copper has been well observed in vivo in practice the mechanism by which it acts has not yet been elucidated, nor the compound it creates identified. This results in problems when trying to optimise supplementation to prevent the interaction from occurring or provide a copper source which is able to negate its effects. This work aims to establish if the antagonism between sulphur, iron and copper could be elicited under in vitro rumen replicated conditions and using a range of copper sources to investigate any differences in their participation in the interaction.MethodsRumen simulated conditions were used to test solubility as a proxy for bioavailability of different copper sources. Sources from ionic, hydroxy and organic compounds were tested in de-ionised water and warmed, strained rumen fluid which mimicked duration, agitation, temperature and pH of the rumen.ResultsAll copper sources were less soluble in rumen fluid than in de-ionised water. The addition of sulphide, alone or as part of a sulphur mix with sulphate produced a pronounced reduction in solubility on each of the copper sources. The most soluble were the greatest affected.ConclusionThere was no indication that an in insoluble compound containing copper and iron was formed under these conditions. The intricacy of the in vivo rumen is required to elicit the reaction between copper, iron and sulphur.     

Dose-dependent response of serum lutein and macular pigment optical density to supplementation with lutein esters

We conducted a study to determine the effect of different doses of a lutein supplement on serum lutein concentration and macular pigment optical density (MPOD). Lutein is one of the major components of human macular pigment. Eighty-seven subjects received daily doses of 5, 10, or 20 mg of lutein, or a placebo, over a 140 day period. Serum lutein concentration was determined by HPLC and MPOD by heterochromatic flicker photometry (HFP). Serum lutein responded positively, except in the placebo group, reaching a plateau that, averaged for each dosage group, was linearly dependent on dose. Likewise MPOD, on average, increased at a rate that varied linearly with dose. For subjects deemed more proficient at HFP, approximately 29% of the variability in MPOD response could be attributed to a linear dependence on the fractional change in serum lutein concentration. We did not detect any significant influence of age on serum lutein uptake or MPOD response.     

Silkworm Growth and Silk Yield on Selected Supplemented/ Un-supplemented Mulberry Varieties

ABSTRACT Sericulture has been on developing foot hills till today in Pakistan. It is for the past few years that this industry has received recognition through greater research on the nutritional aspects. Various experiments i.e., nutritional supplementation and searching alternate food plants have been on way with varying degree of success. The present approach includes the very much neglected aspect of trying mulberry varieties and working out their impact on the silkworm growth/ development and silk yield. In Pakistan three varieties of mulberry Morus alba, M. nigra and M. indica are commonly found, these were selected for the present studies and the already established mineral dose 0.2 %N +0.1%P+0.3%K+0.1%Ca+0.15%Mg+0.15%Mn was supplemented to them through dipping method. Amongst the so designed nine treatments those in which the silkworm larvae were fed on M. nigra leaves in any form /combinati-yielded best results, as the larvae in these treatments consumed more food (73.71 gm/10 larvae) and converted maximum (77.22%) of it into body matter. This improved silkworm growth, a primary parameter for increasing the over all production and resulted in better cocoon size which weighed heavier (2.43 gm/cocoon and 1.10 gm/shell) as compared to rest of the test treatments (0.67 and 0.70 gm/shell on M. alba and M. indica , respectively).