Father of Chemotherapy
It was during 1870s when Ehrlich started his research career, he searched for chemicals that could destroy infectious microbes without causing damage their host and originated the term ‘chemotherapy’ to express the type of drug he was searching for. Later, Ehrlich begun to study an arsenic compound called Atoxyl. This compound is known to destroy syphilis but it’s a toxic for human consumption. In 1905, after countless researching and brewing hundreds of slight variations of Atoxyl chemical, Ehrlich and a Japanese student made their 606th brew of an arcenobenzene compound which they observed it for 2 years. After their observation Sahachiro Hata, the Japanese student, injected their chemical No. 606 into a rabbit, host to syphilitic ulcer. The next day, Hata found there was no live spirochetes on the animal’s ulcer and within few weeks, the ulcers was completely healed. Following their discovery, Ehrlich tested their drug on mice, guinea pigs and many more rabbits and the outcomes their results were all positive. (Hadley. 2009).
Ehrlich then sends 65 thousand free samples of their drug, marketed under the name Salvarsan, known as the first modern chemotherapy agent, to doctors all over the world. The drug became a success in a flash around the world which made Ehrlich won Nobel Prize in Physiology or Medicine in 1908. In present day, due to his achievements and contributions Ehrlich is known as the father of chemotherapy. (Hadley. 2009).
“Receptors, located on both the cell surface and within the cell, are macromolecules and the molecular targets through which drugs produces their beneficial effects in various disease states. (Williams M. 2006)”. Cellular biochemical processes such as; protein phosphorylation, ion conductance, enzymatic activity and DNA transcription, are regulated directly or indirectly by Activated receptors. Ligands are molecules that bind to a receptor. There are many forms to ligands and receptors, however they share one common relationship: they come in closely matched pairs, with a specific receptor matching just one or few specific ligands, vice-versa.
There are two types of receptors; Intracellular receptor and Cell-surface receptors.
Intracellular receptors are protein receptors which are found within the cell, generally in the nucleus or the cytoplasm. In order for the ligands of intracellular receptor to cross the plasma membrane and reach their receptors, the need to be small in size and hydrophobic.
“Cell-surface receptors are membrane-anchored proteins that bind to ligands on the outside surface of the cell. (Khanacadamy. 2016)”. The crossing the plasma membrane is not required by the ligand in this form signaling so, molecules such as hydrophilic or large molecules may act as ligands.
One particular drug that targets the cell-surface receptor is, penicillin. In 1928, Alexander Fleming, inspired by the discoveries of Ehrlich, made his own discovery which was penicillin. Penicillin is a type of antibiotic that is originated from Penicillium fungi. The main objective of penicillin is to destroy bacteria. Penicillin attacks bacteria through the penicillin binding protein that are on the cell-surface of the bacteria. It affects the synthesis of peptidoglycan on cell wall of the bacteria. A bacterium needs its rigid peptidoglycan on its cell wall to withstand and maintain the osmotic pressure to prevent lyse. However, penicillin prevents the cross-linking of peptidoglycan properly in its final stage of cell wall synthesis and weakens its cell wall which causes an unbalanced osmotic pressure and makes the bacterium to lyse. Since human cells does not contain peptidoglycan, penicillin is selectively virulent and does not harms the host when consumed.
Even though penicillin is one of the miracle cures, it does have its own share of side effects. The side effects are the observed commonly are gastrointestinal effect and hypersensitivity reactions. One example of an antibiotic that is under the group of penicillin called Amoxicillin. It is one of the most commonly consumed antibiotic and marketed under the name Agumentin. Amoxicillin is a bactericidal, however it does have its side effects such as, Gastrointestinal; diarrhea, nausea, abdominal pain and few others
Hypersensitivity; skin rashes, pruritus, angioedema and few others.
Doctors can prescribe medications, depending to the person’s health issue, to counteract this side effects so that it can me consumed safely.
“Pharmacogenomics is the study of how genes affect a person’s response to drugs. This relatively new field combines pharmacology (the science of drugs) and genomics (the study of genes) to acquire efficient, safe medications and doses that will be personalized to a person’s genetic structure (NIH. 2018)”. Drugs that are out in world are currently available for ‘one size fits all’, which sometimes does not work similarly for everyone. Predicting beneficial medication for a person can be very difficult as some experiences negative side effects or some does not respond to the medication at all. “Due to that researchers are studying how inherited differences in gene alter the body’s response to medication. This differences will be accounted to foresee whether a medication will be competent for a specific person (NIH. 2018)”.
At present, pharmacogenomics is still in its beginning stage and the use of it currently limited as drugs are generally prescribed on a general fundamental, such as according to an individual’s height and weight, instead of their genome. Researchers are currently researching on the potentiality of variation in the single nucleotide polymorphisms (SNPs), which determines a drug response of an individual. Having the profiles of SNP variation can facilitate prescribed medication that is tailored specifically for an individual. With this treatment will be more efficient and the risk of negative side effects will be reduced.