Hi,
Never heard of it before, but read about it just now on wiki, web MD, a couple of other sites and this study:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2410097/
It looks interesting, with comparable effects to metformin for lowering BG.
And (curiously) similar effects on the guts - although these pass within 1 month.
Dosage seems difficult to decide. The study showing lowered BG levels only ran for 3 months, so no data on long term treatment. Also, a herbalist once told me that no herb retains its efficacy if used for too long (over 5 months or so). She suggested that all herbs be used for 3-4 months with a 3 month resting period before recommending use. No idea if other herbalists advise the same...
Also, I would be wary of its anti-biotic effect. Would need far more info on what types of bugs it kills... Might destroy the friendly ones in the gut.
Thanks for bringing it to my attention though.
Certainly one to watch.