The research that is carried out about drugs occurring naturally is called Pharmacognosy. The word pharmacognosy comes from the Greek language- 'Pharmakon' corresponds to drug or medicine and 'gnosis' corresponds to knowledge [1].

Various fields that constitute pharmacognosy are as follows:
• Medical ethnobotany
• Ethnopharmacology
• Phytotherapy
• Phytochemistry
• Zoopharmacognosy
• Marine Pharmacognosy [2]

HISTORY:

Year - Event
• 8000 - 5000 B.C.E. - Some plants were grown that had therapeutic properties- Papaver somniferum, Sambucus nigra, Fumaria officinalis, Menyanthes trifoliata etc.

In ancient Mesopotamia:

• 1700 B.C.E. - Law Code of Hammurabi- A host of plants with medicinal properties were mentioned: Belladonna, Licorice, Mint, Poppy etc.

• 1600 B.C.E. Treatise of Medical Diagnosis and Prognoses

In ancient China:

• 142 - 220 A.D. - Books on Traditional Chinese Medicine- Shang Hang Lun (Treatise on the treatment of Acute diseases caused by cold) along with Chin Kuei Yao Lueh (Prescriptions from the Golden Chamber)

• 492 A.D. - Pen T’sao Jing Ji Zhu (Commentaries on the Herbal Classic)- 730 herbs were divided into 6 sections.

• 589 - 618 A.D. - Zhong Zhi Yue Fa (How to cultivate herbs) and Ru Lin Cai Yue Fa (How to collect herbs in the forest)- Sui dynasty

• 1578 A.D. A path-breaking book Pen T’sao Kan Mu (Herbal with Commentary)- consists of 1892 drugs, with prescriptions exceeding 11,000

In ancient Egypt:

• 1600 B.C.E. - Smith Papyrus - steps to carry out surgeries & cosmetic formulas as well; the document contains herbs such as thyme, pomegranate root, aloe, coriander, garlic, acacia gum etc.

In ancient India:

• 700-600 B.C.E. - 3 major writings in Ayurveda - Caraka Samhita, Susruta Samhita, Astanga Hrdayam Samhita. 3 minor ones- Sarngadhara Samhita, Bhava Prakasa Samhita, Madhava Nidanam Samhita; drugs mentioned in these texts come from both plants and animals

In ancient Greece and Rome:

• 460 - 375 B.C.E. - Hippocrates made use of treatments such as vinegar, herbs etc. to heal patients

• 340 B.C.E. - Two books were written by Theophrastus- De Historia Plantarum and De Causis Plantarum

• 60 A.D. - Natural History by Pliny - biggest collection of information on plants in the Roman era; a number of plants with their therapeutic uses have been noted down i.e. above 1000

In the middle ages:

• 980 - 1037 A.D. - Ibn Sina wrote two books Kitab ash-shifa (Book of Healing) and Canon of Medicine

• 1785 A.D. - Usage of digitalis was discovered by William Withering

• 1820 A.D. Caventou & Pelletier discovered ways to separate quinine and cinchonine from the barks of the cinchona tree [3]


USES OF NATURAL PRODUCTS IN MEDICINE:

A. From plants-

1. Quinine: Quinine is obtained from the bark of the cinchona tree and is used in treating malaria. Many people lose their lives due to malaria each year.

2. Meadow Saffron: The compound that is present in this plant is colchicine; rheumatism & gout have been successfully treated by making use of this compound. It has also been used to stop the spread of some cancers.

3. Khella (Toothpick Weed): This is an herb that is grown in the Mediterranean region. There is an increase in the flow of blood towards the heart as well as an improvement in the air intake of lungs.

4. Madagascar periwinkle: Treatment of diabetes and cancer (acute leukemia) is done using this plant.


5. Coca plant: The drug that is manufactured from this plant is cocaine & is mainly found in South America. One can get easily addicted to this drug; its other uses are as a local anesthetic and for alleviating pain in patients.

6. Rauvolfia: A compound present in this plant, reserpine, is used to reduce the pain and irritation caused due to scorpion stings & snake bites. For treating mental diseases, the original tranquilizer made use of was reserpine. Another application of this compound is in hypertension.

7. Meadowsweet (Mead wort): Its main application is in alleviating pain when a patient suffers from diseases such as rheumatism, headache and arthritis.

8. Opium poppy: Morphine was the drug that was separated from Opium initially in 1806. Some of the important morphine derivatives used as analgesics are heroin & codeine [4].

9. Cannabis (Marijuana): Glaucoma, sleeping disorders etc have been treated using this plant.

10. English yew (Taxus baccata): Taxols are produced by using the leaves of this plant which is then made use of in treating breast cancer.

11. Daffodils: Alzheimer's disease is treated by using daffodil bulbs that contain Galantamine hydrobromide [5].

12. Dandelion: It is used to enhance bile flow. The extract of this plant can be used as a diuretic and is a very powerful anti-oxidant [6].


B. From animals-

1. Gelatin: The outer covering of medicines i.e. capsules is made up of gelatin, a by-product obtained from animals [7].

2. Decocted Rhinoceros horn: Traditional Chinese Medicine includes decocted rhinoceros horn in treating fever and delirium [8].

3. Heparin: The healthcare industry uses heparin as an anticoagulant which can either be made from beef lung or the intestinal mucosa of pigs [9].

C. From marine sources:

1. A marine organism with tentacles, Bugula neritina, gives out a product Bryostatin 1 that is now studied in Phase 2 cancer trials [10],[11].

2. A colonial tunicate, Ecteinascidia turbinate, gives out a product ET-743 (tetrahydroisoquinolone alkaloid) which is an anti-cancer agent [12].

3. A cone snail, Conus magnus, gives out ?-conotoxin that is used as an analgesic to relieve chronic pain. FDA approved the drug Prialt in 2004.

4. A sea fan, Pseudopterogorgia elisabethae, gives out Pseudopterosin A, which has anti-inflammatory properties and is used in skin care lotions. The drug Resilience was patented in 1989 [11].

5. Fungus Aspergillus ostianus strain TUF 01 F313 exhibited antibacterial properties against R. atlantica- three chlorine containing compounds were found along with penicillic acid (antibiotics) [13].

D. From micro organisms:

Cephalosporins from Cephalosporium acremonium [14].

DRUGS FROM NATURAL SOURCES IN THE PIPELINE:

1. The compound santalol, found in sandalwood oil is in Phase 2 trials for treating warts (Verruca vulgaris) [15].

2. Danshen Dripping pill (Danshen- a Chinese herb that belongs to the Mint family) is in Phase 4 trials for treating Coronary Heart disease [16].

LATEST NEWS:

1. Mistletoe and its therapeutic properties [17].

2. Kratom (Mitragyna speciosa), a relative of the coffee plant, can be used an anti-diarrheal for a short period of time. Its long-term safety is still a controversy [18].


REFERENCES:

1. http://www.pharmacognosy.com/about.htm

2. http://en.wikipedia.org/wiki/Pharmacognosy

3. Nagy M. History of Phytotherapy and Pharmacognosy. Website:
http://www.chem.uwec.edu/chem491_w01/%20Pharmacognosy%20491/
%20%20%20%20%20Med%20Chem%20Lectures/Lecture%20%206/HistoryofPharmacognosy.pdf

4. http://www.factmonster.com/dk/science/encyclopedia/medicinal-plants.html

5. http://www.plantsandus.org.uk/top-10_medicine.htm

6. http://www.mnn.com/health/fitness-well-being/stories/5-medicinal-plants-you-may-have-on-hand

7. http://thechart.blogs.cnn.com/2012/02/27/the-animal-products-in-your-medicine-cabinet/

8. http://advocacy.britannica.com/blog/advocacy/2008/09/traditional-chinese-medicine-and-endangered-animals-2/

9. http://www.npr.org/blogs/health/2013/03/13/174205188/is-your-medicine-vegan-probably-not

10. http://www.noaa.gov/features/economic_0309/medicines.html

11. Dr Calle F. Marine genetic resources: A source of new drugs- the experience of the biotechnology sector. Website:
http://www.iflos.org/media/8841/presentation%20fernando%20de%20la%20calle.pdf

12. Jimeno J, Sousa-Faro J M F, et al. New marine derived anticancer therapeutics- A journey from the sea to clinical trials. Mar Drugs. 2004; 2: 14-29.

13. Aggarwal G V, Doshi G M, et al. Novel antibiotics from marine sources. International Journal of Pharmaceutical Sciences & Nanotechnology. 2011; 4(3): 1446-1461.

14. http://scholar.lib.vt.edu/theses/available/etd-09062007-000547/unrestricted/Thesis-chap_1.pdf

15. http://clinicaltrials.gov/show/NCT01286441

16. http://clinicaltrials.gov/ct2/show/NCT01825759

17. http://med.news.am/eng/news/335/medicinal-features-of-mistletoe.html

18. http://www.foxnews.com/health/2013/12/04/kratom-latest-legal-plant-based-high/


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