Antioxidant extraction

With regard to chemical analysis, literature data may underestimate phytochemical antioxidant contents, because studies generally focus only on antioxidants extracted by aqueous-organic solvents without taking antioxidants linked to DF into account (P6rez-Jim6nez and Saura-Calixto 2005 Saura-Calixto and others 2007). 

This assay has been used by some authors to evaluate the in vitro effects of antioxidant extracts on LDL oxidation (Viana and others 1996 Cirico and Omaye 2006 Kedage and others 2007 Vayalil 2002 Garcfa-Alonso and others 2004 Tarwadi and Agte 2005). Oboh and others (2007) confirmed that hot pepper prevents in vitro lipid peroxidation in brain tissues. Indeed, Bub and others (2000) demonstrated that a moderate intervention with vegetable products rich in carotenoids reduces lipid peroxidation in men. Nicolle and others (2003) evaluated the effect of carrot intake on antioxidant status in cholesterol-fed rats. Later on, they showed that lettuce consumption improves cholesterol metabolism and antioxidant status in rats (Nicole and others 2004). 

Therefore inorganic sunscreens commonly used in cosmetic industry should be carefully tested for their photoactivity and phototoxicity. Sunscreens based on titanium and zinc oxides should contain additional antioxidants, eg a-tocopherol or j5-carotene. Even more efficient protection against unwanted ROSs can be achieved by a smart titanium dioxide modification that would block its photocatalytic activity. Recently Lee et al. described a hydrophobic multicomponent polymer coating for nanocrystalline Ti02 containing natural antioxidants extracted from grape seeds... 

Chung H. Ji X. Canning C. Sun S. Zhou K. 2010. Comparison of different strategies for soybean antioxidant extraction. J. Agric. Food Chem. 58 4508-4512. 

Since the ancient times, spices have been added to different types of food to improve their flavor and to enhance their storage stability. The intake of herbs and spices is regulated by themselves by means of the flavor intensity of the essential oil. However, antioxidant extracts with high contents of phenolic diterpenes do not necessarily contain essential oils. Particularly, plant material from essential oil production for cosmetic or pharmaceutical products is an interesting side product to be used for the preparation of antioxidative extracts. However, data published by Richheimer et al. (1996) indicated that the deoiled biomass contains markedly less camosic acid than the dried, nondeoiled plant material. 

Of particular relevance for the application of antioxidant extracts from rosemary and sage, are meat products. 

For powdered sage, antilisterial effects were at a concentration of 0.7-1%, resulting in a strong decrease of the population within 1 to 14 days at 4°C in broth (Hefnawy et al., 1993 Ting and Deibel, 1992). The highest antilisterial activities were found for rosemary among 18 spices. Antioxidant extracts of rosemary (0.3-0.5%) were effective, whereas 1% oil was ineffective (Pandit and Shelef, 1994). 

Several methods can be found in the literature to extract antioxidants from aromatic plants among them, SFE and SWE use environmentally friendly solvents (19-24). Only two works have been published dealing with the extraction of antioxidant compounds from plants 24, 25). In our research group we studied the extraction of antioxidants from rosemary leaves using SWE (24) SWE is based on the extraction with hot water under a pressure sufficient to maintain water in the liquid state. In our previous work (24), the possibility of tuning the selectivity for antioxidant extraction by changing water temperature from 100 to 200°C was demonstrated. 

In the present work an attempt has been made to optimize the parameters related to the extraction of antioxidants (with ASE) from Spirulina platensis using only environmentally clean solvents such as water, ethanol and mixtures. Thus, as a first approach, a study about different sample pre-treatments and how these affect both, the extraction yield and the final antioxidant activity has been performed. Moreover, a relationship between the efficient concentration (ECso) and the final composition of the solvent (as a function of the dielectric constant) has been studied and a preliminary characterization of the chemical composition of one of the best antioxidant extract has been done using an optimised CE-DAD method. 

From the anti-inflammatory, antipyretic, analgesic, and antioxidant extract of Kageneckia oblonga, Delporte et al. [13] isolated two cucurbitacins which were assayed as potential antioxidants and also as inhibitors of enzymes implicated in inflammatory reactions. Isolated compounds, 23,24-dihydrocucurbitacin F and 3P-( 3-D-glucosyloxy)-16a,23a-epoxy-cucurbitan-5,24-diene-ll-one, Fig. (11), inhibited the production of superoxide anion as well as elastase release in stimulated human neutrophils. In addition, the compounds inhibited both nitrite and... 

Apocynin and spinach leaf antioxidant extract Grape seed proanthocyanidin extract... 

Hettiarachchy, N. S., Glenn, K. C., Gnanasambandan, R., and Johnson, M. G. (1996). Natural antioxidant extract from fenugreek (Trigonelh foenumgraecum) for ground beef patties. /. Food Sci. 61,516-519. 

Harris R, Lecumberri E, Mateos-Aparicio 1, Menglbar M, Heras A. Chitosan nanoparticles and microspheres for the encapsulation of natural antioxidants extracted from Ilex paraguariensis. Carbohydr Polym. 2011 84(2) 803-806. 

Table 5.1 In vivo studies of antioxidant extracts from some fermented plant foods... 

Extract in 2 vol of extraction solvent. Extraction solvent = ethyl acetateimethyl acetate 8 1 + 50 pg/mL butylated hydroxytoluene as an antioxidant. Extract for 20 min while continuously mixing on a vibromax. 

Chitosan NPs and microspheres For the encapsulation of natural antioxidants extracted from Ilex paraguariensis [299]... 

Auerbach, R. H. and D. A. Gray. 1999. Oat antioxidant extraction and measurement— Towards a commercial process./. Sci. Food Agric. 79 385-389. 

Todd, P (1991) Stable alkaline Labiatae antioxidant extracts. US Patent 5,023,017. 

Camosol (Figure 4), a phenolic antioxidant extracted from the herb rosemary, exhibits anticancer activity in animal model for both breast and skin tumorigenesis (68,69). Camosol induced apoptosis accompanied by a dismption of the mitochondrial membrane potential (70). Further analysis revealed that camosol treatment down-regulated the anti-apoptotic protein Bcl-2 in leukemia cell lines and this reduction of Bcl-2 may contribute to the apoptotic effects of cmiosol. Recently we demonstrated that camosol suppresses inducible nitric oxide synthase through down-regulating NFkB in mouse macrophages (77). 

Laroze, L., Soto, C., Ziifliga, M.E., 2010. Phenolic antioxidants extraction from raspberry wastes assisted by-enzymes. Electronic Journal of Biotechnology 13 (6), 11-12. 

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