  We consider the scalar-tensor theories of gravity extended by the
pseudoscalar couplings to matter and gauge fields and derive constraints on the
CP-odd combinations of scalar and pseudoscalar couplings from laboratory spin
precession experiments and from the evolution of photon polarization over
cosmological distances. We show the complimentary character of local and
cosmological constraints, and derive novel bounds on the pseudoscalar couplings
to photons from the laboratory experiments. It is also shown that the more
accurate treatment of the spin content of nuclei used in the spin precession
experiments allows to tighten bounds on Lorentz-violating backgrounds coupled
to the proton spin.
