Green’s Dictionary of Slang

usu. constr. with if..., phr. used to underline a given statement .

1870		London & Provincial Entr’acte 1 Oct. 6/2: Bruise me if we don’t go and have it out at ‘coddem’.
1901		Sydney Sportsman (Surry Hills, NSW) 25 Sept. 3/2: Oh, bruise me! you should see her / When she’s having things about .