Medicinal Drugs from Biodiversity

Status of Philippine Biodiversity

• high species diversity and high endemicity

  • archipelagic country (patchwork of islands)

  • tropical location of country (tropical biome)

  • extensive area of rainforest

Threats in Biodiversity

Why is there a decline?

1. hunting

2. used as pets or food

3. habitat destruction

4. species restricted to one or two islands (example: tarsiers)

5. climate change

6. medicine (overexploitation)

7. religious rites

Pharmacology

• study of history, sources, physical and chemical properties of drugs

• ways in which drugs affect the living systems

Two Main Branches of Pharmacology

1. Pharmacokinetics

2. Pharmacodynamics

Pharmacodynamics

• biological and physiological effects of drugs

• drugs’ mechanisms of action

  what the drug does to the body

Classification of Drugs’ Effect

1. Medicinal

2. Poisonous

3. Psychoactive

Pharmacokinetics

• what the body does to the drug

• drug’s journey in your body

4 Steps in Pharmacokinetics

ADME

1. Absorption: How the drug gets into your bloodstream.

2. Distribution: How the drug spreads to different parts of your body

3. Metabolism (or Biotransformation): How the body breaks down the drug

4. Excretion: How the body gets rid of the drug

Drug Administration

1. Oral

2. Enteral (medications that are administered into the gastrointestinal tract)

3. Rectal

4. Inhalation

5. Intramuscular Injection (using the deltoid muscle)

6. Subcutaneous injection (tissue layer beneath the skin)

7. Transdermal (usually patches applied to the skin)

Drug Tests

identifies the presence of: methamphetamine, cannabinoids, or THC (tetrahydrocannabinol)

Pharmacotherapeutics

• how drugs may be best used in treatment of illness

• what’s the best drug and the right dose?

Pharmacognosy

• where drugs come from

• drugs derived from herbal and natural drug sources

• studying compositions of natural substances to gain knowledge for developing synthetic versions

Executive Order 247

balance the potential benefits of using Philippine biodiversity with the need to protect it and share the profits fairly

Toxicology

study of poisons and poisonings

History of Pharmacology

Ancient Egypt: listed 700 remedies for ailments

First Century: Dioscorides prepared De Materia Medica which classified 600 plants for medicinal purposes

Sources of Drugs

1. Natural

2. Semisynthetic

3. Synthetic

Drug Uses

1. Symptomatic treatment

2. Prevention

3. Diagnostic drugs

4. Curative

5. Health maintenance

6. Contraception

Principles of Drug Action

1. Agonist effect

2. Antagonistic effect

3. Adverse drug effect

4. Therapeutic effect

Agonist effect

describes a drug's ability to bind to a receptor in the body and activate it, triggering a response that is similar to the body's own natural substances

example: morphine binds to opioid receptors in the brain, reducing pain

Antagonistic Effect

drug's ability to bind to a receptor and block it, preventing the body's natural substances (or other drugs) from activating the receptor

example: Naloxone is used to reverse the effects of opioid overdose

Adverse Effect

unwanted effect of the drug, also known as side effects

Therapeutic Effect

positive effect of the drug

Drugs from plants

1. Medicinal

2. Poisonous

3. Psychoactive

examples of drugs from plants

CCSSTTVDAOM

1. Caffeine

2. Cocaine

3. Silymarin

4. Scopolamine

5. Tetrahydrocannabinol

6. Theobromine

7. Vinblastine

8. Digixon/Digitoxin

9. Arecoline

10. Opium

11. Morphine

Poisonous plants

1. chrysanthemum

2. piscicide (Derris elitica)

Drugs from microorganisms

1. antimalaria

2. replication inhibitors on HSP 90

3. antibiotics

4. anti-inflammatory

5. apoptosis inhibiting compounds

6. anti-cell proliferating agent

7. cell lysis

drugs from marine organisms

1. Fucoidan extract

2. Portuguese man-o-war

3. Shell-less gastropods

4. Shells from crustaceans

newly discovered drugs

1. Ara-C

2. Bryostatin

3. Ecteinascidin

4. Descodermolide

5. Halichondrin B

6. Conus toxin

Ara-C (Cytarabine)

• anticancer drug to treat acute myelocytic lymphoma

• isolated from a shallow-water sponges

Bryostatin

• Anticancer and immune modulating agent

• Action: activation of protein kinase C mediation cell signalling pathways

Ecteinascidin

• Ascidian Ecteinascidia turbinata

• Treatment for ovarian cancer

Descodermolide

• From sponge Discodermia

• Potent immunosuppressive

• Inhibits cell proliferation by interfering microtubule network assembly

Halichondrin B

• Sponge Lissodendoryx

• like the action of Descodermolide

Conus toxin

• Conus spp.

• Bioactive compounds for poison, tranquilizer, muscle relaxant

• Interfering nerve conduction

Cocaine

• local anesthesia

• Erythroxylum coca

Digoxin / Digitoxin

• cardiotonic

• stain

• Digitalis purpurea (Lady’s glove)

Scopolamine

• sedation

• psychoactive drug

• Datura spp.

Silymarin

• antihepatotoxic (prevents liver disease)

• Silybum marianum (milk thistle)

• some found in bitter gourd

Tetrahydrocannabinol

• diuretic

• decrease ocular tension

• Cannabis sativa

Opium

• staying awake

• vasodilation

• Papaver somniferum

Theobromine

• diuretic

• vasodilator

• Theobroma cacao

Vinblastine

• antitumor

• antileukemic

• Catharanthus roseus (rosy periwinkle)

Arecoline

• anti-helminthic

• Areca catechu

• masticated

Caffeine

• CNS stimulator

• mimics neurotransmitter response

• cardiovascular response

Morphine

• analgesic

• eye dilator

• antispasmodic

• Papaver somniferum