There's an introduction to NAPRALERT on this www page: http://info.cas.org/support/stngen/dbss/index.html
Mary Lou Quinn, Managing Director, NAPRALERT, states the difference between Medline and Napralert as follows:
"NAPRALERT is and always has been restricted to world literature regarding natural products. Medline is not restricted. Just as one example, if you query NAPRALERT on the key word AMYGDALIN, you will get only that literature pertaining to the compound AMYGDALIN (otherwise known as LAETRILE).
If you query Medline, not only will you get the above, but you will also get lots of articles dealing with the Amygdala of the brain, anatomy, physiology, etc. It has never been NAPRALERT'S goal to be all inclusive regarding medical science. However, if you want the most comprehensive database on Medicinal plants and Natural products, then NAPRALERT is the way to go."
Quoted from the NAPRALERT information package:
"Napralert (NAtural PRoducts ALERT) is a relational database of world literature on the chemical constituents and pharmacology of plant, microbial and animal (primarily marine) extracts.
It's housed and maintained by the Program for Collaborative Research in the Pharmaceutical Sciences, within the Department of Medicinal Chemistry and Pharmacognosy, in the College of Pharmacy of the University of Illinois at Chicago, 833 South Wood Street (M/C 877), Chicago, IL 60612, U.S.A.
Phone (312)-996-2246, Fax (312)-996-7107."
And here is what it'll cost you:
You can access Napralert by paying bulk rate (subscribing) or by paying per question. Annual subscription fee for individual user with no ties to government agencies, small or large businesses, research institutes or libraries: USD 100, of which half gets you manuals, a user ID/password, and limited disk storage space, and the other half gets you answers (at USD 0.75 per reference obtained).
Per question rate: USD 25 + USD 0.75 per reference obtained.
Off-line (snailmail rate): USD 25 + USD 0.75 per reference obtained.
NAPRALERT is also available on-line through STN in the US, Europe and Asia.
You can get free Medline access here http://www4.infotrieve.com/newmedline/adv_search.asp or here: http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed &cmd=search
One has the niftier search engine, while the other will tell you right away if it was 'in vitro' or 'in vivo'. (Why is that important? Section 5.1.8 in this FAQ has a nice introduction to the ins and outs of herbal research.)
There is, of course, a caveat with depending on a (a bit skewed) database like Medline: you won't get much outside of the 'white' world; you won't get much outside of English language, you won't get much of the multitude of (occasionally very useful) far-out research. And it helps to add a keyword like 'herb' or 'plant' to your search. Medline is not made for herbalists, it's made for MDs. Live with it, but learn where to get hands-on information, as well. Like the practitioner-level journals I mention in the 'Good Periodicals' -part of this FAQ (section 6.3.2).
Comment by Mark D. Gold (mgold.holisticmed.com):
"I find it (Medline) a very useful tool. But it is important to realize that there are several articles which warn about the "dangers" of herbs (particularly in JAMA) which are little more than inaccurate hatchet jobs."
IBIDS is a database where you can search for scientific articles on herbs and supplement. From the NIH (National Institute of Health), Office of Dietary Supplements: http://ods.od.nih.gov/Health_Information/ IBIDS.aspx