There's been some discussions on possible Dagga actives. Possible GABA / Adenosine / glutamte NMDA stuff going on?
en.wikipedia.org
I've been poking around, and I dont have much time but I found quite a few studies on Wild dagga(leonotus Leonurus) itself, and one if it's diterpenoids: Marrubiin.
So, here we can see that Wild Dagga can block convulsions caused by both NMDA and assorted GABA antagonists:
http://www.ncbi.nlm.nih.gov/pubmed/12046862
However, it seems apparent that whatever is binding to GABA does not have a higher affinity than Bicuculine.
Here we see the analgesic properties of Marrubiin:
http://www.ncbi.nlm.nih.gov/pubmed/10839213
This study suggests that analgesia is not due to mu-opioid...