security - Watson API access from adobe action script 3

I'm trying to access the Watson Text to Speech API thru an action script 3 flash application. As you known Adobe implement a new security features to restrict the access across domains using a mechanism that use a rules based xml configuration file (crossdomain.xml). In my case the below error is raised when the script is executed:

Source code:

    package
    {
        import flash.net.URLRequest;
        import flash.net.URLRequestHeader;
        import flash.net.URLLoaderDataFormat;
        import flash.net.URLLoader;

        import flash.net.URLVariables;
        import flash.net.URLRequestMethod;
        import flash.events.Event;
        import flash.events.HTTPStatusEvent;
        import flash.events.SecurityErrorEvent;
        import flash.events.IOErrorEvent;

        public class Greeter
        {
        public function sayHello():String

        {

            var params:Object = {user:"John",password:"secret"};

            var request:URLRequest = new URLRequest();
            request.url = "https://watson-api-explorer.mybluemix.net/text-to-speech/api/v1/voices";
            request.contentType = "application/json";
            request.method = URLRequestMethod.POST;

            request.data = JSON.stringify(params);


            var contentTypeHeader:URLRequestHeader = new URLRequestHeader("Content-Type","application/json");
            var acceptHeader:URLRequestHeader = new URLRequestHeader("Accept","application/json");
            var formDataHeader:URLRequestHeader = new URLRequestHeader("Content-Type","application/json");
            var authorizationHeader:URLRequestHeader = new URLRequestHeader("Authorization","Basic YjcxYWUwNTMtZTJmYi00ZmQzLWFiMTctOTRjYTc2MzYzYWE3OlZ5dU9VZ0w3ak1zVw==");

            request.requestHeaders = [acceptHeader,formDataHeader,authorizationHeader,contentTypeHeader];

            var postLoader:URLLoader = new URLLoader();
            postLoader.dataFormat = URLLoaderDataFormat.BINARY;

            postLoader.addEventListener(Event.COMPLETE, loaderCompleteHandler);
            postLoader.addEventListener(HTTPStatusEvent.HTTP_STATUS, httpStatusHandler);
            postLoader.addEventListener(SecurityErrorEvent.SECURITY_ERROR, securityErrorHandler);
            postLoader.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);

            try
            {
            postLoader.load(request);
            }
            catch (error:Error)

            {
            trace("Unable to load post URL");
            }

            var greeting:String;
            greeting = "Prueba de conexión a Watson!";
            return JSON.stringify(request.data);
        }

        private function loaderCompleteHandler(event:Event):void

        {
            trace("loaderCompleteHandler: ");
        }

        private function httpStatusHandler(event:HTTPStatusEvent):void
        {
            trace("httpStatusHandler: ");
        }

        private function securityErrorHandler(event:SecurityErrorEvent):void

        {
            trace("securityErrorHandler: " + event);
        }

        private function ioErrorHandler(event:IOErrorEvent):void
        {
            trace("ioErrorHandler: " + event);
        }
        }
    }

Console output:

[trace] Advertencia: Error al cargar el archivo de política desde https://watson-api-explorer.mybluemix.net/crossdomain.xml
[trace] *** Violación de la seguridad Sandbox ***
[trace] Se ha detenido la conexión con https://watson-api-explorer.mybluemix.net/text-to-speech/api/v1/voices - no se permite desde http://garragames.com/garra-x/Tick.swf

[trace] 05:45:44 PM | err | [SecurityErrorEvent type="securityError" bubbles=false cancelable=false eventPhase=2 text="Error #2170: Security sandbox violation: http://garragames.com/garra-x/Tick.swf cannot send HTTP headers to https://watson-api-explorer.mybluemix.net/text-to-speech/api/v1/voices."]
[trace] Error #2044: Unhandled securityError:. text=Error #2170: Security sandbox violation: http://garragames.com/garra-x/Tick.swf cannot send HTTP headers to https://watson-api-explorer.mybluemix.net/text-to-speech/api/v1/voices.

¿Exist another option to access the API from Action Script Flash App?