Update MySQL table & Regexp

I have a MySQL table with 4 millions of records having a field like "hello@xyz22-03-2015". Concatenated date is not fixed for all 4 million records. I am wondering how can I remove the numbers or any string after @xyz using mysql. One possible solution must be somehow with Regular expression and I know that Mysql does not allow replace using regex, so I am wondering how this particular task can be completed. I want to remove everything after @xyz.com

Many thanks