The mistake is to think that gambling is a sure thing to pursue as a money maker. I don't know how much more money he has to sacrifice just to raise capital and then start a business in another field.
The most sensible solution is to find a number of investors to finance your friend's business, but there must be a portfolio of businesses that he has successfully run so that investors will be happy to help him.
Hopefully that way your friend can develop better, and the most important thing is to stop gambling using money and important assets.