Ever wondered what antibiotics are made of? How does little pills can relieve you of pain, headache, cold etc.
Before we get into this properly it is important to point out that basically all diseases are caused by microorganisms, the microorganism could be virus e.g HIV causing AIDS, bacteria e.g. mycobacterium tuberculosis causing Tuberculosis, protozoa e.g plasmodium falciparum causing malaria etc. These organisms find a way to penetrate our bodies and cause these diseases.
Before now antibiotics were made of substances secreted by these microorganisms themselves which are capable of inhibiting the growth of other microorganisms as in the cause of penicillium notatum which killed all other microorganisms surrounding it and is used in the production of the wonder drug Penicillin. However with the advent of technology it has become possible to wholly or partly synthesize substances that can inhibit disease causing microorganisms.
The definition of antibiotics can thus can rephrased as any substance produced by microorganisms or a similar product produced wholly or partly by chemical synthesis which in low concentrations can inhibit the growth of microorganisms.
While there are a lot of chemicals agents that can kill these organisms, not all are capable of killing them in a human or animal body without causing significant damage to the person, there are certain properties an agent must have before it can be used as an antibiotic,
- SELECTIVE TOXICITY: For a substance to be used as an antibiotic, it must selectively toxic meaning it has to exert high toxic effect on the disease causing microorganisms but little or no toxic effect on the host cells and tissues. This is the reason why antiseptics and disinfectants can not be used as antibiotics.
- MUST BE ABLE TO PENETRATE HOST CELLS: For a substance to be effective, it must be able to cross all barriers of the hosts cells and tissues to come in contact with the disease causing organisms , if this does not happen the substance cant be used as the disease causing organisms will continue to persist.
- MUST LEAVE THE HOST DEFENCE SYSTEM INTACT: Most substances destroys normal immune functions of the body such as phagocytosis, production of antibodies after their entry into the body, an antibiotic must leave the host defence mechanism intact upon completion of its work.