From what I know it is inhibiting kreatin kinase and a few others (see http://focusbiomolecules.com/leonurine-neuroinflammation-inhibitor/ )
These kind of "unpopular" natural mind altering substances are usually not tested for their binding affinities, because they are not of much interest pharmacologically. Ergo you won't make money off of them.
So I guess you won't find any credible information soon for the pharmacological action of leonotis leonurua, nepeta cataria, tagetes lucida or any mind altering plants of that sort.
But still I hope that this will change soon and will be happy AF if any new research papers pop up on this topic.