Trading itself is the most risky business in the world. And when you are taking loan to trade, you are actually multiplying your risk. Trading should be done with idle money. Money that you can afford to lose. Yes you can trade with other's money on profit sharing basis. But for that first you have to prove your consistency in profit making.
You certainly CANNOT take the risk of borrowing money and then trading with it. Its a disastrous mistake. Trading itself involves a very high risk of losing your capital so why would you want to loose borrowed capital and then pay interest on top of it?