No, generally Henna Hair Dye will only darken hair. Henna works like layers of paint, meaning it will coat your hair's natural base color, rather than bleach it. The end result, then, is a combination of your hair's base color and the dyes color.
Natural lighteners, such as lemon juice and honey, can help lighten chemically dyed or previously henna'd hair. For more tips, check out our blog on how to lighten hair naturally.
Using MM Light Blonde Henna on brown or black hair may product subtle blonde streaks but will generally have no effect.