Natural Antibiotics

Generally, the term "natural antibiotics" refers to those substances with antibacterial activity that derive from plants.
In fact, natural antibiotics are not only derived from plants, but also from fungi, bacteria and animals.

Antibiotics are substances used to fight bacterial infections and can have bacteriostatic (i.e. inhibit bacterial growth) or bactericidal (i.e. are able to kill bacteria) action.

Antibiotics produced by fungi

The kingdom of fungi - better known as the kingdom of fungi - includes many organisms, from the smallest and simplest ones (such as yeasts and molds) to the most complex and large ones (such as the fungi that are part of our diet).
The main natural antibiotics produced by fungi are listed below.

Penicillins

The first penicillin - la penicillin G - was discovered by Alexander Fleming in 1929 and became the progenitor of the great penicillin family.
Penicillin G is a metabolic product of the fungus Penicillium notatum (now known as Penicillium chrysogenum).

During his studies, Fleming noticed that a bacterial culture plate was contaminated with a mold and that inside that same plate the growth of bacteria was strongly inhibited. The subsequent studies that were carried out led to the identification and isolation of the penicillin G.
From that moment on, research in this field received a great boost, leading to the synthesis of new penicillins with improved characteristics.
Penicillins are bactericidal antibiotics.
Benzylpenicillin, oxacillin, cloxacillin, nafcillin, ampicillin, amoxicillin, bacampicillin and carbenicillin belong to this class of drugs.

Cephalosporins

The discovery of the first cephalosporin - the cephalosporin C - took place in Italy thanks to the doctor Giuseppe Brotzu.
Cephalosporin C derives from the fungus Cephalosporium acremonium (now known as Acremonium chrysogenum) and is the progenitor of the cephalosporin family.
Cephalosporins are bactericidal antibiotics.
Cefapyrin, cefalexin, cefuroxime, cefotetan, cefaclor, cefixime and ceftibuten belong to this category.

Antibiotics produced by bacteria

Some antibiotics of natural origin have been isolated from bacterial cultures, in particular from actinomycetes (Gram-positive bacteria). The classes of drugs that originate from bacteria are listed below.

Carbapenems

Carbapenems are bacteriostatic antibiotics. The progenitor of this class of drugs is the thienamycin, which was first isolated from actinomycete Streptomyces cattleya.
Imipenem and meropenem belong to this category.

Tetracyclines

Tetracyclines are a set of bacteriostatic compounds obtained from actinomycetes bacteria belonging to the genus Streptomyces. In particular, the first tetracycline to be discovered - the chlortetracycline - was obtained from crops ofStreptomyces aureofaciens.
Tetracycline, demeclocycline, oxytetracycline, minocycline and doxycycline belong to this family.

Aminoglycoside antibiotics

Aminoglycoside antibiotics are bactericidal compounds. There streptomycin (the progenitor) was discovered by the biologist Selman Abraham Waksman in 1952, who isolated it from actinomycete cultures Streptomyces griseus.
Neomycin, kanamycin and gentamicin belong to this family of drugs.

Macrolides

Macrolide antibiotics can have both bacteriostatic and bactericidal activity, depending on the concentration of the drug and the microorganism to be countered.
The progenitor of this family of antibiotics is the "erythromycin, obtained from cultures of Streptomyces erythraeus.
Clarithromycin and azithromycin also belong to this family.

Chloramphenicol

Chloramphenicol is a bacteriostatic antibiotic that can become bactericidal at very high concentrations.
It was first isolated from bacterial cultures of Streptomyces venezuelae.

Vancomycin

Vancomycin is an antibiotic obtained by fermenting the bacterium Amicolatopsis orientalis.

Daptomycin

Daptomycin is a bactericidal antibiotic obtained from the bacterium Streptomyces roseosporus.

Antibiotics produced by the human body

The ability to synthesize antibiotic substances belongs to almost all living beings, including man.
The white blood cells of the human organism produce some substances with antimicrobial action, among which thedefensin and thecathelicidins.
The destruction of pathogens by the human immune system is mainly entrusted to some leukocytes (white blood cells), in particular, to macrophages, neutrophils and cytotoxic T lymphocytes. These cells are able to ingest and digest pathogens through the secretion of strongly oxidizing substances. Numerous enzymes also contribute to this action, such as lactoferrin, lysozyme, collagenase and elastase.
Then there are peptides with antimicrobial action, such as the same defensins and cathelicidins and the protein inducing bacterial permeability.
Defensins and cathelicidins are an integral part of the innate (non-specific) immune system; they belong to the class ofantimicrobial peptides (AMPS) and boast a "broad spectrum antimicrobial action. In fact, they are mainly active against Gram-positive and Gram-negative bacteria, but also have a certain antiviral, antifungal, antiparasitic and antitumor activity.
In addition to the direct antimicrobial activity - generally carried out by creating pores in the bacterial membrane - defensins and cathelicidins are able to enhance the immune response by stimulating the intervention of leukocytes.
The defensins and cathelicidins are packed inside the neutrophil granules: the defensins are found inside the primary granules, while the cathelicidins are found in the secondary granules.

Plant-produced antibiotics

Some types of plants are capable of producing antibacterial substances, even if they have a much lower activity than that possessed by antibiotics deriving from fungi and bacteria.
Furthermore, it is good to remember that the antibacterial substances contained in these plants can interfere with any pharmacological treatments already in progress.
Plants also contain other compounds that could be potentially dangerous for the individual.
Therefore, before using herbal or homeopathic remedies, it is good to consult your doctor and ask your pharmacist for advice.

Garlic (Allium sativum)

Inside the garlic there is a particular substance - allicin - which is endowed with antibacterial properties. Furthermore, allicin also has antifungal, antiviral, anti-inflammatory and analgesic properties.
The use of garlic in folk medicine is very ancient and documented, especially as regards the treatment of infections and the prevention of atherosclerosis and hypertension.

Cinnamon (Cinnamomum zeylanicum)

Cinnamon has antimicrobial and eupeptic properties (facilitates digestion).
It was once used for the treatment of gastrointestinal diseases, bacterial cystitis, vaginitis and infections of the oral cavity.

Onion (Allium cepa)

Onion contains sulfur substances with antibiotic properties. Furthermore, it is also endowed with anti-inflammatory activity and seems useful in the prevention of atherosclerosis.

Echinacea (Echinacea)

In reality, echinacea does not produce a real substance with antibacterial action, but has adaptogenic and immunostimulating properties that make it useful in the adjuvant treatment of respiratory and lower urinary tract infections.

Eucalyptus (Eucalyptus globulus)

Eucalyptus essence - in addition to boasting mucolytic and expectorant properties - is also endowed with antibacterial properties. Therefore, it can be useful as an antiseptic in case of pharyngitis, bronchitis, ear infections and adenitis.

Hydraste (Hydrastis canadensis)

Hydraste contains a substance called berberine. This substance has antibacterial properties and may also be useful in the treatment of relapses from Candida albicans.

Propolis

Propolis is a resinous material that is produced by bees following the processing of the waxy-rubbery substances that cover the flower buds.
Propolis is used by bees to cement the cells of the hive. It is used thanks to its bacteriostatic, bactericidal, antifungal and antiviral properties

Essential oils

Essential oils (or essences, or volatile oils) are made up of a mixture of highly volatile substances and are characterized by an intense odor. For this reason, the components of essential oils are also called "aromatic".
Essential oils can be made up of variable mixtures of substances, such as terpenes, alcohols, aldehydes, ketones and esters.
Essential oils extracted from certain types of plants boast antibacterial properties. Among these plants, we remember: