contribution of medicinal plants in modern medicine

WELCOMETo Our Presentation

Our Presentation Topic Is:

“Contribution of Medicinal PlantsIn Modern Medicine”

Name Of Our Group Members:

Md. Wahid Al Rashid

StudentB.Pharm (Hons.)

Department of Pharmacy Stamford University

Bangladesh

Afroza Nasrin

StudentB.Pharm (Hons.)

Department of Pharmacy Stamford University

Bangladesh

Medicinal Plants: Definition

All plants that have therapeutic properties or exert beneficial pharmacological effects on the animal body are generally designated as medicinal plants.

Medicinal plants contain substances which are also precursors for synthesis of useful drugs.

Modern Medicine: Definition

The term ‘medicine’ refers to a preparation containing one or more drugs or therapeutic agents which is used in the treatment, cure and reduction of the severity, seriousness, or pain of various diseases and external or internal injuries of man and other animals.

The preparation may also contain substances other than the drugs.

By the phrase ‘modern medicine’, it is referred to those medicinal preparations which are produced scientifically by using modern technology and it is known - how and which are in current use in the modern Pharmacopoeias for the care and management of diseases.

Medicinal plants In Modern Medicine:

At the present time, substances from plants

are used in the following main ways in modern medical treatment:

Directly as source of active pharmaceutical agents – either as single purified drugs, for example , morphine (extracted from the opium poppy Papaver somniferum) or in advanced extract from often in admixtures with other ingredients, for example, senna extract from Cassia senna.

As blue-prints for the manufacture of synthetic

drugs of a similar structure, for example the plant alkaloid cocaine extracted from Erythroxylum coca which has provided the chemical structure for the synthesis of procaine and other related anaesthetics.

As tools to help us understand physiological and pharmacological mechanisms, especially in drug development and testing.

Medicinal plants are used in a variety of dosage forms as- powders, pastes, juices, infusions, decoctions--medicinal preparations.

Important examples of natural drugs:

Isolation of the natural analgesic drug morphine from the latex of Papaver somniferum capsules (Opium) in 1804 is probably the first most important example of natural drugs which plants have directly contributed to modern medicine.

Isolation of other important plant-derived drugs of modern medicine rapidly followed and many useful drugs have since been discovered and introduced into modern medicine. Drugs like caffeiene from Thea sinensis (1819), quinine from Cinchona spp. (1820) and colchicines from Colchicum autumnale (1820) constitute some examples of such early drugs.

The list of the plant-derived medicinal substances

occurring in modern medicine is very long now. About 100 such drugs of defined structures are in common

use today throughout the world and about half of them are accepted as useful drugs in the industrialized countries.

These include drugs like atropine, colchicine, digitoxin, L-

dopa, emetine, ephedrine, ergotamine, hyoscine, hyoscyamine, morphine, quinidine, quinine, rescinnamine, reserpine, sennosides, vinblastine, vincristine, etc.

In addition to these, there are other

plant-derived chemical substances of known structures that are used as drugs or necessary components of many modern medicinal preparations. These include camphor capsaicin, eucalyptol, menthol, minor cardiac glycosides, various volatile oils etc. These are only a few examples of vast number of drugs that are derived from plants.

Some Medicinal plants

Aloe Vera Datura

Neem Senna

History of using medicinal plants

Since diseases, decay and death have always co-existed with life, the early man had to think about disease and its treatment at the dawn of human intellect. Thus the human race started using plants as a means of treatment of disease and injuries from the early days of civilization on the earth and in its long journey from ancient time to modern age the human race has successfully used plants and plant products as effective therapeutic tools for fighting against diseases and various other health hazards.

Man was well aware of the medicinal

properties of many plants growing around him more than five thousand years ago. The earliest mention of the medicinal use of plants is found in the Rig Veda (4500 – 1600 BC), which reported that the Indo-Aryans used the Soma plant as a medicinal agent.

A large number of plants now known to contain important medicine agents were known to the Babylonians around 3000 BC. The use of many plants were recorded as far back as in 1500 BC.

The first Chinese Pharmacopoeia

containing a list of 135 different plant medicines with their uses and methods of preparation appeared around 1122 BC. More than 400 recipes of plant medicine used in Greek system of medicine were described by Hippocrates around 400 BC. These are the starting materials from which modern medicine gradually evolved to reach the present state of its development.

As therapeutic use of plants continued with the

progress of civilization and development of human knowledge,

-scientists tried to hard to isolate different chemical constituents from plants,

- put them to biological and pharmacological tests and thus have been able to identify and isolate therapeutically active compounds,

which have been used to prepare modern medicines.

Drugs of plant origin used in modern medicine:

Drug Actions/Clinical Uses Plant Source

Caffeine CNS stimulant Camellia sinensis

Cocaine Local anaesthetic Erythroxylum coca

Codeine Analgesic, anti-tussive Papaver somniferum

L-Dopa Anti-parkinsonism Mucuna spDigitalin Cardio tonic Digitalis purpurea

Digitoxin Cardiotonic Digitalis purpurea

Digoxin Cardiotonic Digitalis purpurea

Drug Actions/Clinical Uses Plant Source

Emetine Amoebicide, emetic Cephaelis ipecacuanha

Ephedrine Sympathomimetic, antihistamine

Ephedra sinica

Morphine Analgesic Papaver somniferum

Nicotine Insecticide Nicotiana tabacum

Quinidine Anti-arrhythmic Cinchona ledgeriana

Quinine Antimalarial, antipyretic Cinchona ledgeriana

Drug Actions/Clinical Uses Plant Source

Rescinnamine

Antihypertensive, tranquillizer

Rauvolfia serpentina

Reserpine Antihypertensive, tranquillizer

Rauvolfia serpentina

Sennosides A, B

Laxative Cassia species

Vinblastine Antitumor, Antileukemic agent

Catharanthus roseus

Vincristine Antitumor, Antileukemic agent

Catharanthus roseus

Contribution of plant-derived drugs in modern

world: Although with the advent of synthetic

drugs the use and procurement of plant-derived drugs have declined to a large extent, a large number of drugs of modern medicine are obtained from plant sources. As more data become available from phytochemical analysis and pharmacological screening of medicinal plants, the number of plant-derived drugs of modern medicine is increasing everyday.

How prominently plant-derived drugs still feature in

modern medicine can be assessed from the following facts:

-In the US, in 1980 alone, the consumer paid 8 billion Dollars for prescription drugs in which the active ingredients are still derived from plants.

- 47% of some 300 million new prescriptions written by physicians in America in 1961 contained, as one or more active ingredients, a drug of natural origin.

- About 33% of the drugs produced in the developed countries are derived from plants.

- More than 47% of all drugs used in Russia are obtained from botanical sources.

- If microbes are added, 60% of the modern medicinal products are of natural origin.

Not only had that, according to some generous

estimates, almost 80% of the present day medicines are directly or indirectly obtained from plants. Surprisingly, this large quantity of modern drugs comes from less than 15% of the plants which are known to have been investigated pharmacologically, out of the estimated 500,000 species of higher plants growing on the earth.

Thus, it is apparent that whatever progress science might have made in the field of medicine over the years, plants still remain the primary source of supply of many important drugs used in modern medicine.

Indeed, the potential of obtaining new drugs from

plant sources is so great that thousands of substances of plant origin are now being studied for activity against such formidable foes as heart disease, cancer and AIDS. This type of study is sure to bring fruitful results, because of the fact that the plant kingdom represents a virtually untapped reservoir of new chemical compounds, many extraordinarily dynamic, some providing novel bases on which the synthetic chemist may build even more interesting structures.

In this way modern medicine will continue to

be enriched by the introduction of newer and more potent drugs from plant sources.

Thank you