Disclosed is a novel class of substituted imidazole compounds, pharmaceutical compositions containing them and uses of these compounds in the treatment and/or prevention of diseases and disorders related to the histamine H3 receptor. More particularly, these compounds are useful for the treatment and/or prevention of diseases and disorders in which an interaction with the histamine H3 receptor is beneficial. These imidazoles compounds have the formula I
wherein R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, A, X, Y and Z are as defined in the specification.
The present invention encompasses compounds of general formula (1)
wherein
R
1
, R
2
and R
3
are defined as in claim
1
, which are suitable for the treatment of diseases characterised by excessive or abnormal cell proliferation, and their use for preparing a pharmaceutical composition having the above-mentioned properties.