The Bombay Stock Exchange benchmark Sensex lost over 225 points in opening trade today.The sensex was trading at 16,229, down by over 240 points when reports last came in. Similarly, Nifty of national stocks exchange was down by over 74 points at 4869.Stock brokers said trading sentiment was dampened after selling by funds and retailers.The selling was triggered by a steep fall in the US and Asian bourses following Europe's deteriorating debt crisis.The US Dow Jones Industrial Average ended 1.24 per cent lower in yesterday's trade. In Asisan Markets, Japan's Nikkei was down 2.37 per cent and Hong Kong's Hang Seng fell 2.02 per cent in morning trade today