Chemical composition and inhibitory activities on dipeptidyl peptidase IV and pancreatic lipase of two underutilized species from the Brazilian Savannah: Oxalis cordata A.St.-Hil. and Xylopia aromatica (Lam.) Mart.

Brazil has the greatest vegetal biodiversity in the world, but products derived from native species are not optimally utilized. Oxalis cordata and Xylopia aromatica are two underutilized species whose leaves and fruits, respectively, have been used as food in the 19th century. In this study, we used chemical and in vitro assays to evaluate the potential of these species as functional foods. The inhibitory activity on pancreatic lipase and DPP-IV were evaluated using the crude extracts and fractions ethyl acetate, butanol and water of these two species. For polyphenols determination, samples were prepared with different solvents and these were analysed by chromatographic and spectroscopic methods. Finally, fatty acids profile was determinated by gas chromatography. The crude extract (IC50=0.84mg/ml), ethyl acetate extract (IC50=0.88mg/ml) an aqueous fraction (IC50=0.63mg/ml) of C. cordata were inhibitory on pancreatic lipase but inactive against dipeptidyl peptidase IV (DPP-IV). Extracts from X. aromatica were inactive against the lipase pancreatic enzyme, but a butanolic fraction inhibited DPP-IV (IC50=0.71±0.05mg/ml). The phenolic acids orientin/isorientin, chlorogenic acid (0.32g/100g) and the flavonoid derivatives rutin (0.27g/100g), quercetin and luteolin were observed in all products. Additionally, fatty acid quantification showed that oleic (7.5g/100g) and linoleic acid (6.5g/100g) were predominant in X. aromatica fruit. This study confirms the potential for the use of both plants as functional foods due to their nutritional value, biological activity and important phytochemical content.

Antioxidant films based on cross-linked methyl cellulose and native Chilean berry for food packaging applications.

Development of antioxidant and antimicrobial active food packaging materials based on biodegradable polymer and natural plant extracts has numerous advantages as reduction of synthetic additives into the food, reduction of plastic waste, and food protection against microorganisms and oxidation reactions. In this way, active films based on methylcellulose (MC) and maqui (Aristotelia chilensis) berry fruit extract, as a source of antioxidants agents, were studied. On the other hand, due to the high water affinity of MC, this polymer was firstly cross-linked with glutaraldehyde (GA) at different concentrations. The results showed that the addition of GA decreased water solubility, swelling, water vapor permeability of MC films, and the release of antioxidant substances from the active materials increased with the concentration of GA. Natural extract and active cross-linked films were characterized in order to obtain the optimal formulation with the highest antioxidant activity and the best physical properties for latter active food packaging application.

Structural characterization of a rhamnogalacturonan I-arabinan-type I arabinogalactan macromolecule from starfruit (Averrhoa carambola L.).

A structural characterization of polysaccharides obtained from edible tropical fruit named starfruit (Averrhoa carambola L.) was carried out. After fractionation by freeze-thaw and Fehling precipitation, a pectic polysaccharide was obtained. It was composed of rhamnose, arabinose, galactose and uronic acid in the 5.0:72.5:12.1:10.4 molar ratios, respectively. A combination of monosaccharide, GPC, methylation and NMR analysis and enzymatic hydrolysis with endo-ß-(1→4)-D-galactanase showed the presence of a rhamnogalacturonan I to which a branched arabinan and a type I arabinogalactan are attached. The arabinan moiety was formed by (1→5)-linked α-L-Araf units in the backbone, branched only at O-3 by (1→2)- and (1→3)-linked α-L-Araf units, while the type I arabinogalactan was formed by (1→4)- and (1→4,6)-linked ß-D-Galp units in the backbone with (1→5)-, (1→3,5)- and (1→3)-linked α-L-Araf units as side chains.

Ethnoecology of Oxalis adenophylla Gillies ex Hook. & Arn.

ETHNOPHARMACOLOGICAL RELEVANCE: We studied the ethnoecological knowledge of medicinal Oxalis adenophylla in 3 rural villages of north Patagonia, Argentina. To evaluate links between use frequency, ethnoecological knowledge, sociocultural variables and the conservation status of this plant. MATERIALS AND METHOD: Forty informants were interviewed in relation to their knowledge, use, perception and the ecology of Oxalis adenophylla. Sociocultural variables were also documented, such as age, gender, size of family group living in the house, economic activities and ethnic self-determination. The abundance and availability of these plants were estimated in two villages, by measuring the number of plants per area, their weight and the relation between time invested and biomass collected. We tested frequency of use and age with Spearman׳s rank correlation coefficient. The relation between use frequency and gender, family group, economic activities, and ethnic self-determination of the informants was tested with the Mann Whitney non parametric test. An index of ethnoecological knowledge was constructed and correlated with use frequency through Spearman׳s rank correlation. To estimate conservation status we established a local risk index, taking both intrinsic and extrinsic parameters for this species into account. RESULTS: Regionally, Oxalis adenophylla is a plant known for its medicinal, alimentary and ornamental properties, but it has been poorly studied from a pharmacological point of view. Locally, the leaves of the plant are harvested for the preparation of "tortillas", which are stored and consumed in the cold months of the year for the treatment of flu fevers (95% of informants). Informants know the value of its root as a nutrient source and 35.8% reported its consumption. Use is sporadic and involves the harvesting of a mean of one root per year, which is eaten raw in-situ. Only 12% of informants mentioned the plant׳s ornamental feature. The ethnoecological knowledge of Oxalis adenophylla included references to specific environments where the plant grows, its phenology and morphological and organoleptic characteristics, appropriate times for harvesting, and animals that forage for this species. The informants with the greatest ethnoecological knowledge harvested leaves and roots most frequently. The frequency of use did not differ in relation to age or gender. In contrast, frequency of use was the highest when the informant lived with several generations at home, maintained traditional animal husbandry practices and when they considered themselves as belonging to the Mapuche people. Informants perceived low abundance and availability of the plant in the environment, restricted by the great distances involved in obtaining them, seasonality, and in particular, difficulty in finding the roots. Informants believe that the plant is sensitive and it should be harvested in such a way as to ensure no damage to the whole plant, allowing resprouting. Our ecological measurements agreed with this perception. The local risk index for the plant was medium. CONCLUSION: In Patagonian Argentina, Oxalis adenophylla is a multipurpose species widely used for its medicinal properties but less for its edible roots and ornamental features. In the rural communities where we worked, frequency of use seems to depend on individual ethnoecological knowledge, the practice of indigenous worldview, living in households interacting with other generations and maintaining the activity of cattle raising. Locally, the main risk for the plant is the particular environment where it grows, characterized by slopes vulnerable to erosion. The human practice of local use could promote the conservation of this species through the understanding of its sensitivity to harvesting, and its insipient cultivation. This research shows the importance of obtaining a general overview of useful wild species used by local people.