Today's research into carbolines was the most exciting by far, and will not likely be repeated. It has brought together insights into smoking, and more besides, that ties up so much of what I have researched previously. The importance of these findings and analysis is quite breathtaking. The details may be somewhat fuzzy but the overall scheme is well-defined. So here is a brief summary.
Carbolines are a type of alkaloid with psychoactive, and other, properties that are fairly widespread in nature. Some of the beta carbolines, in particular, have been found to have a bariety of beneficial therapeutic effects. Psychoactively, while some tend to hallucinatory effects, others, and this would include thse in tobacco, have a calming effects similar to opiates (and affecting some of the same receptor sites).
The beta carbolines in tobacco, possibly in conjunction with other alkaloids, particularly those also with MAOI activity, play a role that is both supporting of the activity of nicotine (via MAOI activity), and possibly a secondary more direct role on their own. Together, the synergy of MAOIs plus nicotine, plus additional mild, opiate-like activity, provide the unique features of tobacco smoke on human psychology (mild alertness coupled with mild relaxation).
Previous research, mostly un-noted, suggests that beta carbolines are likely the key alkaloids responsible for the 'something missing' experienced with nicotine alone. Others' extractions of beta carbolines from beta carboline rich sources is a strong indicator that this is indeed on the right lines, given the similarity of color of that extraction with the recent tobacco extraction noted in this thread.
Clues led to the nature of harmful toxins called heterocyclic amines (HCAs) in cooked and processed foods. These are created by the action of heat on micxtures of carbohydrates and proteins/dehydrated proteins. One type of HCA is carbolines. While some of the carbolines will be beta carbolines, others will be toxic alpha carbolines. In general most HCAs are bad news. The levels in cooked foods can be far higher than even those found in cigarette smoke (cigarette smoke contains many other toxins too though).
Nevertheless, the existence of some beta carbolines among the generally toxic HCAs is quite likely a reason why there is an 'addiction' to processed and fast foods beyond ease and sweet taste. From a health perspective, an 'addiction' to food that contains high levels of HCAs (and other similar heat induced toxins), and that are also often devoid of significant nutritional value, is serious matter, whose effects are becoming ever clearer.
Ethanol is primarily a 'downer', with the 'high' attributed to preferential slowing of the frontal cortex creating lowered social inhibitions. But there is likely more to it than that, and once again beta carolines might play a key role.
Indeed, I am proposing that beta carbolines play a key role in a broad range of pharmacologically mediated 'addictictiveness', primarily through a mild stimulation of the opiate mediated reward system, and particularly strongly when combined with nicotine and other MAOIs in smoking, with an endorphin release also involved.
In the context of smoking, the inclusion of beta carbolines - and indeed, the whole family of alkaloids found in tobacco - will ensure the best possible efficacy for smoking replacement products. It is almost impossible to over-stress the importance of this point.
