Pharmshala

Discover the art of Pharmacy

Introduction to pharmacognosy

  • Initially was known as ‘ material medica ’
  • ‘ Pharmakon ’ – ‘drug’ + ‘gignoso ‘ – to acquire knowledge of ‘= ‘pharmacognosy ‘ – knowledge or science of drugs [ latin]
  • ‘Pharmacognosy’ coined by C.A. Seydler [ later found J.A. Schmidt used the term before ]

Definition :

Pharmacognosy is the study of medicinal uses of various naturally occurring drugs its history sources , distributions ,  methods of cultivation , active constituents , medicinal uses identification test preservation methods substituents and adulterants.

History

[Shang dynasty ] (1766-1122BC)

  • Inscription on oracle bones discovered in illness medicine and medical treatment 
  • Earliest medical treatment existing in China – Silk banners and bamboo slips.
  • Most important clinical manual of traditional Chinese medicines – Shang Hang Lun ( treatment on the treatment of Acute diseases caused by cold) – written by Chang-Chug-Ching
  • It has a companion book ‘ Chin Kuli yao Lue’

(Prescription from the golden Chamber)

  • These two are origin of most important classical herbal formula that are basis of Chinese and Japanese – Chinese Herbalism.

‘Pen T‘sao Jing Ji Zhu’ (Commentaries on the herbal classic) by Tao Hong Jing

730 herbs (6 categories)

  1. Stone (minirals)
  2. Grass and trees
  3. Insects and animals
  4. Fruit and veg 
  5. Grains 
  6. Named but un-used
  • Ancient Egypt
  1. Ebbers papyrus (1550 BC) [800 prescription,700 drugs]
  1. Edwin Smith Papyrus (1600 BC) [Surgical instruction and formulas for cosmetics]
  1. Kahun medical Papyrus (1900 BC) [Health of women , birthing instruction ]
  • Ancient India
  • Med prep of plant – Rigveda and Atharvaveda (3500-1500BC)  Developed Ayurveda
  • Ancient Greece and Rome
  • Hippocrates (460-370BC) – Father of medicine 
  • Aristotle (384-322BC) – Animal kingdom
  • Theophrastus (370- 287 BC) – Student of Aristotle
  •  Galen (B1 –AD200)- Method of preparation of plant and animal drug

Known as ‘ galemicals’ in his honour

  • Development of modern Pharmacognosy took place later during 1934-60
  • Development mainly due to following 4 events 
  1. Isolation of Penicillin (1928) – William Fleming
  2. Isolation of Reserpine from rawlfia wod road

↓

Hypotensive and tranquilizing properties

  1. Isolation of Vinca alkaloids- Vincristine – Leukarmic-  anticancer
  2. Isolation of Steroid hormone like progesterone
  • Important aspect of natural products that led to the modern development of drugs and Pharmaceuticals
  1. Isolation of phytochemicals:
  • Alkaloid from belladonna , erget , morphine etc
  1. SAR :
  • Hypotensive and tranquilizing action of reserpine are attributed to trimethoxy benzoic acid moiety.
  1. Drug from partial synthesis of natural products:
  • In ergetamine , by 9:10 hydrogenation , oxytocic activity is suppressed and spasmolytic activity increased
  1.  Natural products as models for synthesis of new drugs:
  • Morphine for potent analgesics
  • Atropine for spasmelytics
  1. Drugs of direct therapeutic uses:
  • Antibiotic, teroids, erget alkaloids and certain antitumor substances.
  1. Biosynthetic pathways:
  • Calvin’s cycle of photosynthesis 
  • Shikimic acid pathway of aromatic compounds .
  1. Pharmaceutical aids:
  • Acacia and tragacanth – binding and suspending agent
  • Sterculio and tragacanth – bulk laxative
  • Ishabgul and linseed – Demulcents
  • Saponin – detergent
  • Scope and development of cognosy
  • Pharmacognosy predominantly entails ‘ crude drugs ‘ of natural origin that are duly derived from 
    • Plant sources 
    • Animal sources 
    • Minerals sources
    • Their active chemical constituents.

These attributes to the ‘ Core subjects matter of pharmacognosy ‘

  • Crude drugs – not only therapeutic utility 
  • Used in cosmetic , textile , food and nutraceutical industries . 

1800 – 1850 BC – ‘ Apothecaries ‘

  • Stocking crude drugs for the preparation a host of useful products such as 
  • Herbal tea mixture
  • Various type of tincture
  • Extracts and juice invariably used for preparing
    • Medicinal drops
    • Syrups
    • Infusions
    • Ointments / liniments

1850 – 1900 BC –  Growth in fields of ‘ medicinal plant ‘

  • Phytochemists did isolation and characterization of pure ‘ active plant constituent ‘
  • These active components knocked out the crude drugs by semisynthetic/ synthetic medicines 
  • Herbal drug fate brighten gradually.

1900-2000 BC – Modern Pharnacognosist have better knowledge and understanding of 

  • Active constituents
  • Prominent therapeutic efficacy on human ailments
  • Both scientist and researchers are broadly exploring 
  1. Clanical plant sources
  2. Allied plant species that contains either identical or similar types of constituents.
  • Ongoing researches are 
    • Marine flora and fauna
    • Genetic engineering aspects
    • Tissue culture biotech

Futuristic growth – Anti-neoplastic profile

  • Hypoglycemic activity
  • Hepatoprotective profile
  • Hypotensive property
  • Anti-fertility activity
  • Anti-inflammatory profile
  • Anti-psychotics activity
  • General tonics ( rejuvenation phenomenon).