Pharmacognosy – What’s In A Plant?

Pharmacognosy is the study of medicine derived from natural sources. Most of us think of this field as plant based research. Interestingly, though this field actually includes animal sources (for example cod liver for it’s oil) – which I will not cover. We tend to believe medicinal plants are herbs or seasonings along with spices, but in reality medicinal plants implies a broader reach.  We usually eat the fruit but don’t think much about the rest of the plant when in fact it often is the leaves, flowers, roots, and occasionally the stems and twigs that contain a medicinal property.

Therefore we include vegetables such as broccoli and cauliflower and fruits such as blackberries, raspberries, and blueberries.1 We use carrots and celery to lose weight but…

There is more than meets the eye with celery. Celery contains 786 chemicals and 76 of those active chemicals can help lower blood pressure. If you can eat 8 whole stalks of celery you can lower your blood pressure several points. Who would have given that much thought to eating celery? We all know it is a good food for losing weight but for blood pressure? 2

The number of active chemicals in any given fruit, vegetable or spice is fascinating. Now I understand why it is so important to eat a lot of varied vegetables and fruit. If we had, as a society, stuck to the basics I think we would be a lot better off health wise. Now we eat so much processed foods we have created the health problems many of us suffer from. Even the simple idea of eating chicken is a problem because they are all brined. That means we can’t get away from salt if we wanted to. The “natural” chemicals found in plants are removed or processed in some fashion but it’s those natural chemicals that are healthy.

Every plant contains up to a couple of hundred chemicals. An example: There are 106 compounds found in Lemon balm3,4. You will find that many of the chemical components in one herb will be found in many others, which is why several herbs have similar activities.

However, not every component or constituent will be medicinally active in our bodies. Some compounds will be inert (inactive) but those that are active can and do impact the body in some way. Other examples of the high number of natural chemicals can be seen in: cloves – 351, green tea – 771, and carrots – 419.

One chemical can have many actions, such as Quercetin which has 176 actions and if found in carrots, apples, cloves, fennel, fenugreek, garlic, green tea. Etc.(351 plants in all).  Those 176 actions are the identical in every plant so they all have the potential to work on the same health issues.5.

Another point to ponder – scientists have the habit of testing isolated components in the dish or animals and often the outcome is extrapolated to humans. The herbs tend to work better as a “whole” herb, either the petals, leaves, or roots for example. Taking one chemical out and using it separates it from the milieu and perhaps that in itself will render it inactive or less active.6

Herbalists make decoctions, tinctures, teas, salves, etc., but they don’t separate the components. They may extract the components into the liquid menstrum (which can be water for tea, or oil for slaves, or alcohol for tinctures) but the extraction brings out all the constituents into the liquid so the “whole” milieu is still intact. We don’t extract individual components from fruit so why do it with herbs?



  1. Grover JK, Yadav S, Vats V. Medicinal plants of India with anti-diabetic potential. J Ethnopharmacol. 2002;81(1):81-100. doi:10.1016/S0378-8741(02)00059-4.
  2. Duke J. Apium graveolens – Celery. Accessed July 25, 2017.
  3. Venkatesan R, Ji E, Kim SY. Phytochemicals that regulate neurodegenerative disease by targeting neurotrophins: a comprehensive review. Biomed Res Int. 2015;2015:814068. doi:10.1155/2015/814068.
  4. Natural Standard – Lemon balm. Accessed July 23, 2012.
  5. Duke J. Quercetin. Accessed July 25, 2017.
  6. Chang J. Medicinal herbs: drugs or dietary supplements? Biochem Pharmacol. 2000;59(3):211-219. Accessed July 25, 2017.