Have you (and perhaps together with brothers and sisters if any) thought about taking out a mortgage on your parent's house to, say 50% of it's value? That way the money stays in the family and no greedy money lender is going to get their paws on the fruits of your parents' labour. If you're alone and can't afford that, an 'interest only' mortgage may be an option.
According what you write on your parents' situation, the eventual interest paid will be a lot less than the amount that will be lost in the end.
It is sad that there are not more considerate persons like you, who wish their parents to at least enjoy some of their money while they can. Good luck.