The evolution of medicine from sorcery to gene therapy – The Star Online

In ancient times, humans did not at first regard death and disease as natural phenomena; they were regarded as supernatural in origin.

They might be the result of a spell cast upon the victim by some enemy or the work of an offended god.

Drilling holes 2.5 to 5cm across in the skull known as trephination was one method practised to provide the evil spirit a means of escape.

Hypnosis, magic and religion also played a large part in the medicine practised by prehistoric human society.

This was accompanied by incantations, dancing, grimaces etc, hence practitioners were also called witch doctors or sorcerers.

The transition from magic to science was a gradual process that lasted over centuries.

There are illustrations of the usage of opium, mandrake plants or alcohol to decrease pain and for surgical procedures like the amputation of a limb.

Making a patient unconscious by hitting them on the head (and giving them a concussion) was another method that sometimes had lethal consequences.

Moving forward, plant products were widely used in folk medicine, and indeed, are still used in many parts of the world today.

As a matter of fact, some modern drugs have their origins in plants, e.g. aspirin from willow bark, digoxin from foxgloves, morphine from opium poppies and quinine from Chicona bark.

Beginnings of a science

The works of the Greek Father of Medicine Hippocrates (460-375 BCE) mark the beginning of diseases being considered a natural, rather than a supernatural, phenomenon.

The first vaccination occurred in the late 18th century, when English physician Edward Jenner (1749-1823) discovered that a person became protected from smallpox when they were inoculated with pus from a cowpox lesion.

Perhaps the most spectacular advancement of the 19th century was the discovery that diseases were caused by minute living organisms.

The usage of antiseptics by French chemist and microbiologist Louis Pasteur (1822-95) and British surgeon Joseph Lister (1827-1912) dramatically reduced infections and deaths after surgical procedures.

At the beginning of the 20th century, German physician Paul Ehrlich (1854-1915) discovered the lethal effects of arsenic on the microorganism responsible for syphilis.

This success inaugurated the antibiotics era, and was followed by the accidental discovery of sulphonamides and penicillin.

Gene-based therapy is the latest advancement in modern-day medicine. AFP

Lock and key

At this point, all these discoveries were made via observations of the patients; the doctors and scientists then did not know how exactly any of these medicines acted inside the human body.

With technological advancements in the field of microscopy, it was discovered that medicines specifically bind to a particular protein on the bodys cells and cause their effect.

These proteins are known as receptors and are potential targets for drugs.

Each receptor binds to one unique ligand (chemical compounds present in our body), just like a lock and key.

Only the correct key (ligand) can fit into the keyhole of the lock (receptor).

Upon the binding of the ligand to the receptor, a chain of signalling reactions will trigger the cells response.

This response can vary depending on the organ and the type of cell.

For example, in the stomach, it could be gastric secretion from the parietal cells to digest food, while in blood vessels, it could be constriction of the smooth muscle cells to increase blood pressure, and so on.

That is also how medicines act on our cells.

The chemical structure of a medicine is designed to selectively bind to a receptor, producing a desirable effect to cure or control a disease.

In type 2 diabetes, for example, there is insufficient insulin produced by the pancreas, resulting in an unhealthily high glucose level in the blood.

Anti-diabetic medicine (e.g. gliclazide) acts on the beta cells of the pancreas and increases its insulin release.

This increased amount of insulin elevates the use of glucose by peripheral tissues and reduces blood glucose levels.

Gene effect

We also came to know about biological units we inherit from both our parents known as genes, which are made up of DNA (deoxyribonucleic acid) that reside in the nucleus of our cells.

Genes are responsible for our looks, height, skin colour and body functions, as well as our resistance to or predisposition for certain diseases.

It is now a reality that each one of us can have our genetic makeup analysed if we so wish.

This can provide information to doctors on how our bodies respond to certain medications, allowing them to see which medications are effective and which ones should be avoided to decrease adverse effects.

Genetic differences between humans (caused by natural mutations) can result in slightly altered proteins, which may in turn be more or less active.

If the altered protein is involved in metabolising a particular medicine, this may affect the levels of the medicine in the body, and thus influence how the patient responds to the medicine.

This understanding has helped doctors realise why some people react differently to certain medicines.

In personalised medicine, doctors modify the dosage of the medicine or substitute it with a different one, according to the genetic makeup of the patient for optimal treatment effects.

It is now also possible to treat or cure genetic disorders diseases caused by genetic abnormalities that affect the normal functioning of the body by replacing the defective gene with a healthy copy, or knocking out the defective gene.

Known as gene therapy, this method of treatment is advancing rapidly and may become the primary form of treatment, rather than drugs or surgery, in the not-so-far-away future.

Associate Professor Dr Kumaraswamy Kademane and Dr Irma Izani Mohamad Isa are with Perdana University Graduate School of Medicines Pharmacology Unit. This article is courtesy of Perdana University, which is celebrating their 10th anniversary this year. For more information, email starhealth@thestar.com.my. The information provided is for educational and communication purposes only and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the readers own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.

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The evolution of medicine from sorcery to gene therapy - The Star Online