Antimicrobial plants

The vast majority of antibiotics used in modern medicine are or have been produced by microorganisms, yeasts or fungi, which belong to the vegetable kingdom. Higher plants mainly produce antimicrobials as a defense mechanism against infections or these substances are constituents of cellular metabolism.

Differentiation of antimicrobial activity in antiseptic, antibacterial, bactericidal, bacteriostatic, antifungal, fungicide, antiviral, virus, will not be done in this entry, just the mention of plants that have shown such activity. I left out of this first communication a large quantity of plants with lesser use in the Latin world.

As expected, besides a long list of plants with antimicrobial activity, a number of chemical compounds responsible for this activity are involved as well. Alkaloids, coumarins, simple phenols, flavones, quinones and tannins are the most common.

ACACIA (Acacia farnesiana, nilotica)

Leaves and fruits

Antibacterial properties of some species of acacia are due to its tannin content in concordance with the extracts concentration.

GARLIC (Allium sativum)

The bulb is used.

Its antibacterial activity has been attributed to a sulfur amino acid, the aliin, with antimicrobial and antioxidant properties. There are a lot of medicinal products prepared from garlic bulbs (bulbs generally dried or aged). In powder, tinctures and so on.

Bardana (Arctium lappa)

This plant is a bit obsolete though its antimycotic properties deserves further studies, at least for nails fungus. I use to prepare an alcoholic extract of fresh roots from 2 years old plants harvested after the plant produce seeds.

LARGE INDIAN CRESS (Tropaeolum majus)

Leaves and flowers are used.

It has antibiotic properties due to their isotianate (sulfur and glucotropoline) content with proven effectiveness against several common bacteria. It is used at external and internal route (in respiratory and urinary systems).

CUMIN (Cuminum ciminum)

Aerial parts.

Cumin essential oil has a strong antifungal activity against several fungi of medical importance.

EUCALYPTUS (Eucalyptus globulus and other sp).

Mature leaves from older branches.

The essential oils are very active due to their eucalyptol content , which gives the characteristic aroma and is used as of the respiratory tract and urinary tract antiseptic. It has proven effective against certain fungi. Its external use is highly recommended as an antiseptic, however internal use must be undertaken with caution.

JACARANDA (Jacaranda mimosaefolia)

Fruits

Glutamic acid, and fixed oils that provide antimicrobial properties both in internal and external use. Its use in foodstuffs preservation is considered.

LICHENS (Cetraria islandica and others)

Many of them owe their antifungal and bacteriotatic properties to their usnic and vulpinic acids content.

MARCELA or MACELA (Achyroclyne satureoides)

The flowers are used.

Hydroalcoholic extract has a proven antiviral activity. Plant is little known worldwide but widely used in the Amazon area and at the south of South America.

YARROW (Achillea millefolium)

Aerial parts are used.

The alcoholic extract has a significant antiviral activity. It is also used locally to cure wounds. Its healing properties have been well known since ancient times.

WALNUT (Juglans regia)

Bark

Bark extracts have shown antimicrobial activity. Scientific publications do not mention active ingredients, but activity against staphylococci, Candida, colibacilar, pseudomonas and other microorganisms.

OREGANO (Origanum vulgare)

Aerial parts

Aqueous and alcoholic extracts and essential oils have powerful antimicrobial activity. Bacteria, fungi and viruses are effectively controlled.

The usual manufacture of aqueous extracts (obtained by decoction) and the alcoholic extracts (obtained by maceration in absolute alcohol or alcohol 96 °), permits a home made elaboration.

GRAPEFRUIT (Citrus paradise)

Extracts of this plant is touted as highly effective against a large number of microorganisms. So far I have found no publications that prove it.

I have seen only one study in which, after damaging the shell of the fruit, an antifungal compound is produced, but is not present in the healthy fruits.

PINE (Pinus silvestris)

The active ingredients are extracted mainly from the needles, leaves and young branches.

The essential oil with several compounds of antiseptic activity is used externally and in the airways (the turpentine is partially responsible for this activity). Has been recommended for urinary tract infections, although there are plants with greater effect and greater safety. The pinosilvina has antifungal activity.

THYME (Thymus vulgaris)

Leaves and flowers.

The essencial oils, the aqueous and alcoholic extracts, containing phenol, thymol and carvacrol, have a powerful antiseptic and antimicrobial activity. Its antiviral activity is widely known, as its antifungal activity, although this requires very frequent applications, probably more than 6 times a day.

When boiling their aerial parts a characteristic aroma of phenols and derivatives, very similar to cloroxilenol (in these regions Espadol).

This antiviral activity with its astringent effect, the presence of tannins, make it a required component of herpes simple medications.

CAT'S CLAW (Uncaria tormentosa)

Roots or rhizome.

Alcoholic or hydroalcoholic extracts are potent antivirals, whereas the aqueous extracts are used as immune enhancers. This is a plant that has proven effective in enhancing the immune system for treatment of different ailments.