Method for treatment of mulberry leaves for feeding silkworms in order to obtain a feedstuff for silkworms, doped with at least a metal selected among silver and/or zinc, comprising the steps of: a. preparing a solution comprising water, a photo- reducer agent and a precursor of said at least metal; b. treating said mulberry leaves with said solution; c. exposing said treated mulberry leaves to UV radiation, so that the photo-reduction of said precursor of said at least metal occurs, with the consequent deposition on said leaves of nanoparticles of said at least metal.

The present invention provides methods for inhibiting or preventing cancer cell growth using silver nanoparticles