  We present new estimates of AGN accretion and star-formation luminosity in
galaxies obtained for the local 12-$\mu$m sample of Seyfert galaxies (12MGS),
by performing a detailed broad-band spectral energy distribution (SED)
decomposition including the emission of stars, dust heated by star formation
and a possible AGN dusty torus. Thanks to the availability of data from the
X-rays to the sub-millimetre, we constrain and test the contribution of the
stellar, AGN and star-formation components to the SEDs. The availability of
Spitzer-IRS low resolution mid-infrared (mid-IR) spectra is crucial to
constrain the dusty torus component at its peak wavelengths. The results of
SED-fitting are also tested against the available information in other bands:
the reconstructed AGN bolometric luminosity is compared to those derived from
X-rays and from the high excitation IR lines tracing AGN activity like [Ne V]
and [O IV]. The IR luminosity due to star-formation (SF) and the intrinsic AGN
bolometric luminosity are shown to be strongly related to the IR line
luminosity. Variations of these relations with different AGN fractions are
investigated, showing that the relation dispersions are mainly due to different
AGN relative contribution within the galaxy. Extrapolating these local
relations between line and SF or AGN luminosities to higher redshifts, by means
of recent Herschel galaxy evolution results, we then obtain mid- and far-IR
line luminosity functions useful to estimate how many star-forming galaxies and
AGN we expect to detect in the different lines at different redshifts and
luminosities with future IR facilities (e.g., JWST, SPICA).
