I assume that you do not want to deserialize this XML entity to an object.
The best is then to use xpath
MEL XPath expressions in your JDBC outbound endpoint query.
MEL Xpath documentation: http://www.mulesoft.org/documentation/display/current/Mule+Expression+Language+Reference#MuleExpressionLanguageReference-XpathandRegex
JDBC outbound endpoint documentation showing old-style expressions in the query: http://www.mulesoft.org/documentation/display/current/JDBC+Transport+Reference#JDBCTransportReference-BasicInsert/Update/DeleteStatements
Just use MEL instead of the old style the MuleSoft doc shows.