One of my all-time favorite anti-microbial herb is the common thyme (Thymus vulgaris). Thyme and thyme again this small, low-growing herb (of which there are many varieties) has shown to pack a powerful punch in dissuading or eliminating viruses and obstinate bacteria. Before the use of antibiotics, thyme was the most extensively used surgical wash and dressing. It is most potent as an essential oil because of it’s concentrated thymol content.
Thymol is also found in oregano, cedar and horsemint and can be toxic in high doses, however, used correctly, I have seen it eliminate MSRA when nothing else did. Thyme leaves make a lovely tea that is excellent for colds and flu, indigestion and coughs and is safe for children. The fresh leaves or oil can also be used as a facial steam to open and protect the lungs and sinuses. To prevent illness spreading to other family members, use the oil of thyme in a room spray and counter-top wash and apply oil of thyme mixed in a little carrier oil or lotion to the bottoms of feet before going to bed.
Another favorite, less often used but treasured by Native Americans is Lomatium or Desert Parsley (Lomatium dissectum). It is a strong, resinous root that is taken as a decoction (boiled tea) or tincture when in risk of, or during illness. It is strongly antimicrobial with regards to flu, pneumonia and other upper respiratory diseases and was the primary herb that helped many Native Americans survive the Spanish flu. It alkalizes blood and reduces inflammation and tends to throw microbes and waste products out towards the skin, so is best used together with burdock root, hot baths and saunas.
For some people, the resins of the plant may irritate the skin, causing a rash, which will go away when you stop using the herb. As a tincture it is best combined with diaphoretic (sweat-producing) herbs like ginger or yarrow that assist natural detox. It is commonly found in formulas mixed with osha root, which often grows near it. Please note that this plant is threatened in some of its natural habitat, so buying cultivated versions is preferred.
A more recently popular anti-microbial herb in North America is andrographis (Andrographis paniculata), whose leaves and roots have been used for colds, flu and other feverish conditions in India (its native habitat) and Asia (where it has naturalized) for a long time. It is an extremely bitter herb, thus anti-inflammatory and has been effectively used for malaria, typhoid fever, lyme and cancerous tumors. It can impede viral entry into cells and reduces their ability to replicate.
Andrographis can be taken seasonally, but is not usually recommended for long-term use as it increases lymphocyte activity and can become too cooling for the spleen. It is a component of many Ayurvedic and Chinese formulas for treating acute (short-term) illness. Andrographis is incompatible with anti-coagulant drugs and contraindicated for women trying to become pregnant or those who are.