Improving the oxidative stability and lengthening the shelf life of DHA algae oil with composite antioxidants.

Based on various antioxidant mechanisms, four kinds of antioxidants including ascorbyl palmitate (AP), vitamin E (VE), phytic acid (PA) and one of the polyphenols (antioxidant of bamboo leaves, tea polyphenol palmitate or tea polyphenols (TP)) were used in combination to improve oxidative stability of docosahexaenoic acid (DHA) algae oil. To achieve the best effect, the formulations and mixture ratios of the antioxidant combinations were optimized. The effects were monitored by peroxide value, thiobarbituric acid-reactive substances, acid value, free radicals, Rancimat induction time and fatty acid composition of DHA algae oil undergoing accelerated storage. Finally, the DHA algae oil containing 80 mg/kg AP, 80 mg/kg VE, 40 mg/kg PA and 80 mg/kg TP had the highest oxidative stability. Furthermore, the shelf life of DHA algae oil containing the optimum composite antioxidant was predicted by using accelerated shelf life testing coupled with Arrhenius model, which was 3.80-fold longer than the control sample.

Effects of natural phenolics on shelf life and lipid stability of freeze-dried scallop adductor muscle.

Effects of natural phenolics on the shelf life of dried scallop adductor muscle predicted by accelerated shelf life testing (ALST) combined with Arrhenius model were investigated. This allows the food industries to reliably and rapidly determine the shelf life of dried shellfish species treated with antioxidants. The shelf life of dried scallop adductor muscle treated with antioxidants of bamboo leaves (AOB) and tea polyphenols (TP) was more than 1.70-fold that of dried control scallop adductor muscle. Thus, the highly nutritional value of dried scallop adductor muscle, based on its lipid constituents, is maintained during storage. OXITEST method further confirmed the improvement of lipid stability of antioxidant treated dried scallop adductor muscle by protecting polyunsaturated fatty acids, especially eicosapentaenoic and docosahexaenoic acids, against autoxidation. Moreover, the natural phenolics employed effectively limited lipid oxidation by breaking the autoxidative chain reaction and/or inhibiting free radical formation in dried scallop adductor muscle during storage.

Effects of polyprenols from pine needles of Pinus massoniana on ameliorating cognitive impairment in a D-galactose-induced mouse model.

Cognitive deficiency and oxidative stress have been well documented in aging and in neurodegenerative disorders such as Alzheimer's disease. In this study, we assessed the therapeutic effect of polyprenols on D-galactose-induced cognitive impairment in mice by testing on of behavioral and cognitive performance. In order to explore the possible role of polyprenols against D-galactose-induced oxidative damages, we assessed various biochemical indicators. Chronic administration of D-galactose (150 mg/kg·d, s.c.) for 7 weeks significantly impaired cognitive performance (both in step-through passive and active avoidance tests) and locomotor activity (in open-field test) and the ability of spatial learning and memory (in Morris water maze test) compared with the control group. The results revealed that polyprenols treatment for 2 weeks significantly ameliorated model mice's cognitive performance and oxidative defense. All groups of polyprenols enhanced the learning and memory ability in step-through passive and active avoidance tests, locomotor activity in open-field test, and the ability of spatial learning and memory in Morris water maze test. Furthermore, high and middle level of polyprenols significantly increased total antioxidative capacity (T-AOC), glutathione peroxidase (GSH-Px), super oxide dismutase (SOD) activity, neprilysin (NEP), and ß-site AßPP cleaving enzyme 1 (BACE1) expression, while nitric oxide (NO), nitric oxide synthase (NOS) activity, malondialdehyde (MDA) concentration, and the level of Aß1-42 and presenilin 1 (PS1) were decreased. Polyprenols have a significant relieving effect on learning, memory, and spontaneous activities in a D-galactose-induced mouse model and ameliorates cognitive impairment and biochemical dysfunction in mice. In summary, we have demonstrated that polyprenols may ameliorate memory and cognitive impairment via enhancing oxidative defense and affecting generation and dissimilation of Aß-related enzymes, suggesting that polyprenols represent a novel drug for treating Alzheimer's disease.

Effects of dl-praeruptorin A on interleukin-6 level and Fas, bax, bcl-2 protein expression in ischemia-reperfusion myocardium.

AIM: To investigate the effects of dl-praeruptorin (Pd-Ia) on interleukin-6 (IL-6) level and apoptosis-related protein expression in ischemia-reperfusion myocardium. METHODS: Left anterior descending coronary artery was subjected to 30 min ischemia followed by 120 min reperfusion in open-chest anesthetized rats. Serum IL-6 level was measured by radioimmunoassay. Apoptosis-related protein Fas, bax, and bcl-2 expression was detected by immunohistochemistry and computer image analysis system. Infiltration of neutrophils was observed using Hematoxylin-Eosin staining under optical microscope. RESULTS: Pd-Ia 2.0 mg/kg iv lowered serum IL-6 level and Fas, bax, bcl-2 expression under conditions with hypotension and without changes on heart rate, but increased the ratio of bcl-2/bax. There existed a close linearity and positive correlation between IL-6 level and Fas, bax, bcl-2 expression. Whereas, the infiltration of neutrophils was mild. CONCLUSION: Pd-Ia elicits a novel target in the therapeutic prevention of postischemic cardiomyocyte death. The reason might be associated with modulating the expression of some immediate-early genes including IL-6, Fas, bax, and bcl-2 in ischemia-reperfusion myocardium.