beta-carotene and proanthocyanidin

The impact of lotus seedpod proanthocyanidin (LSPC) on the functional properties of β-carotene-loaded whey-protein stabilized nanoemulsions was investigated. LSPC was selected because it is known to exhibit strong antioxidant activity, as well as having various health benefits. Physically stable nanoemulsions containing small anionic droplets (d < 0.15 μm; ζ = -27 mV) could be formed at pH 6.5 using whey protein-LSPC complexes as natural emulsifiers. The physical and chemical stabilities of the nanoemulsions were then measured when they were incubated at different pH values. LSPC addition promoted droplet aggregation at pH 4, but not at pH 3, 6.5, or 8, which was mainly attributed to its ability to reduce the electrostatic repulsion between the lipid droplets at pH 4. LSPC was shown to have stronger antioxidant activity than catechin and epicatechin. Our results show that the chemical stability of β-carotene nanoemulsions could be considerably improved by adding LSPC. We believe that LSPC-whey protein complexes can be used as effective emulsifiers and antioxidants in nutraceutical-loaded nanoemulsions, which may be useful for developing more efficacious functional foods and beverages.

Topics: Antioxidants; beta Carotene; Emulsifying Agents; Emulsions; Lotus; Nanostructures; Proanthocyanidins; Whey Proteins

To select rabbiteye blueberry leaves from an appropriate harvest season to develop functional foods, this paper studied the bioactive secondary metabolites and the antioxidant capacity of rabbiteye blueberry leaves from May, September, and November. The results showed the leaves from May had the highest content of total flavonoids (114.21 mg/g) and the leaves from November had the highest content of total polyphenols and proanthocyanidins (425.24 and 243.29 mg/g, respectively). It was further found that blueberry leaves from different seasons have similar bioactive constituents, but their contents are obviously different by HPLC. The rabbiteye blueberry leaves from November had the highest antioxidant capacity, which was well correlated with their highest proanthocyanidin content. The results clarify that the blueberry leaves from different seasons have different contents of bioactive secondary metabolites and different antioxidant activities, which implied that leaves from November should be selected first for utilization in functional foods.

Topics: Antioxidants; beta Carotene; Blueberry Plants; Chromatography, High Pressure Liquid; Flavonoids; Free Radical Scavengers; Plant Extracts; Plant Leaves; Polyphenols; Proanthocyanidins; Seasons; Secondary Metabolism

Free radicals have been implicated in over a hundred disease conditions in humans, including arthritis, hemorrhagic shock, atherosclerosis, advancing age, ischemia and reperfusion injury of many organs, Alzheimer and Parkinson's disease, gastrointestinal dysfunctions, tumor promotion and carcinogenesis, and AIDS. Antioxidants are potent scavengers of free radicals and serve as inhibitors of neoplastic processes. A large number of synthetic and natural antioxidants have been demonstrated to induce beneficial effects on human health and disease prevention. However, the structure-activity relationship, bioavailability and therapeutic efficacy of the antioxidants differ extensively. Oligomeric proanthocyanidins, naturally occurring antioxidants widely available in fruits, vegetables, nuts, seeds, flowers and bark, have been reported to possess a broad spectrum of biological, pharmacological and therapeutic activities against free radicals and oxidative stress. We have assessed the concentration- or dose-dependent free radical scavenging ability of a novel IH636 grape seed proanthocyanidin extract (GSPE) both in vitro and in vivo models, and compared the free radical scavenging ability of GSPE with vitamins C, E and beta-carotene. These experiments demonstrated that GSPE is highly bioavailable and provides significantly greater protection against free radicals and free radical-induced lipid peroxidation and DNA damage than vitamins C, E and beta-carotene. GSPE was also shown to demonstrate cytotoxicity towards human breast, lung and gastric adenocarcinoma cells, while enhancing the growth and viability of normal human gastric mucosal cells. The comparative protective effects of GSPE, vitamins C and E were examined on tobacco-induced oxidative stress and apoptotic cell death in human oral keratinocytes. Oxidative tissue damage was determined by lipid peroxidation and DNA fragmentation, while apoptotic cell death was assessed by flow cytometry. GSPE provided significantly better protection as compared to vitamins C and E, singly and in combination. GSPE also demonstrated excellent protection against acetaminophen overdose-induced liver and kidney damage by regulating bcl-X(L) gene, DNA damage and presumably by reducing oxidative stress. GSPE demonstrated excellent protection against myocardial ischemia-reperfusion injury and myocardial infarction in rats. GSPE was also shown to upregulate bcl(2) gene and downregulate the oncogene c-myc. Topical application of GS

Topics: Animals; Anthocyanins; Antioxidants; Apoptosis; Ascorbic Acid; beta Carotene; Biological Availability; Cardiovascular Diseases; Dose-Response Relationship, Drug; Flow Cytometry; Free Radical Scavengers; Free Radicals; Humans; Keratinocytes; Kidney Diseases; Liver Diseases; Neoplasms; Plant Extracts; Proanthocyanidins; Seeds; Vitamin E