  A new mechanism having as an origin the space-time noncommutativity has been
shown to generate anisotropy and axial-like interaction giving rise to a
leptonic asymmetry for fermionic particles propagating in a curved
noncommutative $FRW$ universe. As a by-product, for ultra-relativistic
particles like neutrinos, an analytical expression of this asymmetry is derived
explicitly. Constraints and bounds from the cosmological parameters are also
discussed.
