The inventors have observed that aqueous mustard seed extract appears to be cytotoxic to fibroblast cells. The cytotoxicity of the aqueous mustard seed extract appears to abate when the extract is heat treated at 120°C for 15 minutes. The heat treated aqueous mustard seed extract when combined with exogenous myrosinase is not cytotoxic but can induce a modest increase in HO-1 content in cultured fibroblasts and thus would be expected to be useful in a topical composition for treating/ preventing itchy skin, particularly the scalp. This invention thus relates to the provision of a topical composition for treating / preventing itchy skin, particularly the scalp.
