A rumen unprotected conjugated linoleic acid supplement inhibits milk fat synthesis and improves energy balance in lactating goats.

Feeding trans-10, cis-12 CLA supplements in a rumen-protected form has been shown to cause milk fat depression (MFD) in cows, ewes, and goats. Methyl esters of CLA were shown to be as effective as FFA in inducing MFD when infused postruminally, but their efficacy as a feed supplement has not been addressed in studies with lactating ruminants. In the present study, we investigated the effects of an unprotected trans-10, cis-12 CLA supplement as methyl esters on performance, milk composition, and energy status of dairy goats. Eighteen multiparous Toggenburg goats were randomly assigned to dietary treatments in a crossover experimental design (14 d treatment periods separated by a 7 d washout interval): 30 g/d of calcium salts of fatty acids (Control) or 30 g/d of a rumen unprotected CLA supplement containing 29.9% of trans-10, cis-12 CLA as methyl esters (CLA). Lipid supplements were mixed into a concentrate and fed individually to animals 3 times a day as a total mixed ration component. The DMI, milk yield, milk protein and lactose content and secretion, and somatic cell count were unaffected by CLA treatment. On the other hand, milk fat content and yield were reduced by 19.9 and 17.9% in CLA-fed goats. Reduced milk fat yield in CLA-fed goats was a consequence of a lower secretion of both preformed and de novo synthesized fatty acids. The CLA treatment also changed the milk fatty acid profile, which included a reduction in the concentration of SFA (2.5%), increased MUFA and PUFA (5.6 and 5.4%, respectively), and a pronounced increase (1576%) in milk fat trans-10, cis-12 CLA. Consistent with the high milk fat trans-10, cis-12 CLA content, all desaturase indexes were reduced in milk fat from CLA-fed goats. The MFD induced by CLA reduced the energy required for milk production by 22%, which was accompanied by an improvement in the estimated energy balance (P < 0.001), greater blood glucose concentration (P < 0.05), and a trend for increased BW (P = 0.08). Approximately 7.2% of trans-10, cis-12 CLA was estimated to escape from rumen biohydrogenation and indirect comparisons with data obtained from other studies suggest equivalent MFD between dietary CLA in the methyl ester form and rumen protected sources. Thus, despite the apparent low degree of rumen protection, our results suggest that methyl esters of CLA could be an alternative to rumen protected CLA supplements due to manufacturing and cost advantages.

Staining tumor cells with biotinylated ACL-I, a lectin isolated from the marine sponge, Axinella corrugata.

Axinella corrugata lectin 1 (ACL-1) was purified from aqueous extracts of the marine sponge, Axinella corrugata. ACL-1 strongly agglutinates native rabbit erythrocytes. The hemagglutination is inhibited by N-acetyl derivatives, particularly N, N', N"-triacetylchitotriose, N-acetyl-D-glucosamine, N-acetyl-D-mannosamine and N-acetyl-D-galactosamine. We investigated the capacity of biotinylated ACL-1 to stain several transformed cell lines including breast (T-47D, MCF7), colon (HT-29), lung (H460), ovary (OVCAR-3) and bladder (T24). ACL-I may bind to both monosaccharides and oligosaccharides of tumor cells, N-acetyl-D-galactosamine, and N-acetyl-D- glucosamine glycan types. The lectins are useful, not only as markers and diagnostic parameters, but also for tissue mapping in suspicious neoplasms. In addition, they provide a better understanding of neoplasms at the cytological and molecular levels. Furthermore, the use of potential metastatic markers such as lectins is crucial for developing successful tools for therapy against cancer. We observed that biotinylated ACL-I stains tumor cells and may hold potential as a probe for identifying transformed cells and for studying glycan structures synthesized by such cells.

Detecção de atividade lectínica e atividade hemolítica em extratos de esponjas (Porifera) nativas da costa atlântica do Brasil / Detection of lectinic activity and hemolytic activity in extracts of native sponges (Porifera) of atlantic coast of Brazil

Extratos aquosos de vinte espécies de esponjas da costa Atlântica brasileira foram testados para verificação da presença de atividade lectínica e atividade hemolítica. Hemaglutinação para eritrócitos humanos e de distintos animais foi evidenciada em 12 dos 20 extratos testados. Os extratos das espécies Axinella corrugata, Chondrilla nucula, Chondrosia collectrix, Cinachyrella alloclada e Guitarra sp1. foram os que apresentaram maior atividade hemaglutinante. Dos doze extratos com atividade hemaglutinante dez tiveram a atividade inibida por um ou mais açúcares e/ou glicoproteínas. A lectina do extrato de Chondrilla nucula foi resistente à desnaturação térmica quando aquecida a 100 ºC por 60 minutos. Atividade hemolítica foi encontrada apenas nos extratos de Petromica citrina e Acervochalina sp. As espécies que apresentaram maior potencial para futuros estudos de suas lectinas foram Axinella corrugata, Chondrilla nucula e Chondrosia collectrix, em vista da maior atividade hemaglutinante apresentada por seus extratos, aliada à maior atividade específica.

Aqueous extracts of twenty species of sea sponges of the Brazilian Atlantic coast were tested with the aim of searching the presence of lectinic and hemolytic activity. Hemagglutinating activity for human erythrocytes and for distinct animals were found in 12 of the 20 tested extracts. The extracts of Axinella corrugata, Chondrilla nucula, Chondrosia collectrix, Cinachyrella alloclada and Guitarra sp1. were the ones that presented highest hemagglutinating activity. Ten of the 12 hemagglutinating extracts had the activity inhibited by one or more sugars or glycoproteins. The lectin from Chondrilla nucula was resistant to thermal denaturation when heated up to 100 ºC for 60 minutes. Hemolytic activity was only found in the extracts from Petromica citrina and Acervochalina sp. The species of sea sponges that showed major potential for futures studies of their lectins were Axinella corrugata, Chondrilla nucula and Chondrosia collectrix, due to the highest hemagglutinating activity presented by their extracts, allied to the highest specific activity.