Tokyo stocks fell moderately on Wednesday on caution ahead of the release of key U.S. inflation data later in the day. The 225-issue Nikkei Stock Average ended down 191.32 points, or 0.48 percent, from Tuesday at 39,581.81. The broader Topix index finished 11.90 points, or 0.43 percent, lower at 2,742.79. On the top-tier Prime Market, decliners were led by insurance, pharmaceutical and consumer credit issues. The U.S. dollar moved little in the upper 151 yen range as investors refrained from active trading ahead of the U.S. consumer price index data for March, dealers said. Stocks were in nega…