The rupee appreciated by 23 paise to 51.17 against the US dollar in early trade today on the Interbank Foreign Exchange market as the American currency fell against the euro and other currencies overseas. Dealers said that besides gains in euro and other currencies against the US dollar, a higher opening in the equity market and dollar selling by exporters supported the rupee . The rupee had plunged by 62 paise to close at almost 11-week low of 51.40 rupees in yesterday's trade against the dollar on sustained demand for the US currency from importers.