Category:Antimicrobial herbs

An antimicrobial herb is a plant medicine with documented activity against bacteria, fungi, viruses, or parasites. The category covers the broad-spectrum traditional antimicrobials (garlic, oregano, thyme, goldenseal), the antifungal-prominent herbs (tea tree, oregano, neem, pau d'arco), the antiviral-active herbs (elderberry, olive leaf, lemon balm for herpes simplex), and the antiparasitic-active herbs (wormwood, black walnut hull, pumpkin seed, the Artemisia annua of artemisinin fame).

The foundational antimicrobial herb in Western practice is garlic (Allium sativum), whose allicin and the related thiosulfinates produce broad-spectrum antibacterial, antifungal, and modest antiviral activity in vitro. The clinical use of crushed garlic for infection long predates the introduction of penicillin; the Russian wartime use of garlic as "Russian penicillin" in the Second World War, when antibiotic supplies failed, is documented. Oregano oil (Origanum vulgare), with its carvacrol and thymol content, has substantial in-vitro antimicrobial activity and a substantial herbal-supplement market for upper-respiratory and gastrointestinal infection. Goldenseal (Hydrastis canadensis), the Native American and Eclectic medicine containing the berberine and hydrastine alkaloids, has broad antimicrobial activity through DNA-binding and inhibition of microbial efflux pumps; conservation concern (United Plant Savers At-Risk) is substantial. The related berberine-containing Oregon grape (Mahonia aquifolium) and Chinese coptis (Coptis chinensis) extend the berberine-based antimicrobial tradition. Thyme (Thymus vulgaris) and the related oregano share thymol-mediated activity. Olive leaf (Olea europaea), with its oleuropein content, has Mediterranean traditional antiviral use.

The antifungal-prominent herbs include tea tree oil (Melaleuca alternifolia), the standard herbal antifungal for tinea and minor skin infection; pau d'arco (Tabebuia impetiginosa) for Candida overgrowth in traditional South American practice; neem (Azadirachta indica) for tropical fungal and bacterial skin infection; undecylenic acid from castor oil for topical antifungal use; and black walnut hull (Juglans nigra).

The antiviral-active herbs (cross-listed under antivirals where pharmaceutical-grade use applies) include lemon balm (Melissa officinalis) topical cream for herpes labialis (substantial Cochrane evidence), elderberry for influenza, licorice (Glycyrrhiza glabra) for selected viral indications, and the pharmaceutical-derivative artemisinin (from Artemisia annua).

Garlic (Allium sativum), oregano (Origanum vulgare), thyme (Thymus vulgaris), goldenseal (Hydrastis canadensis), Oregon grape (Mahonia aquifolium), Chinese coptis (Coptis chinensis), olive leaf (Olea europaea), tea tree (Melaleuca alternifolia), pau d'arco (Tabebuia impetiginosa), neem (Azadirachta indica), wormwood (Artemisia absinthium), sweet wormwood (Artemisia annua), black walnut hull (Juglans nigra), pumpkin seed (Cucurbita pepo; antiparasitic), cloves (Syzygium aromaticum), cinnamon (Cinnamomum verum), grapefruit seed extract, propolis (bee-derived plant resin), the antimicrobial peppermint and eucalyptus essential oils, and elderberry, lemon balm, and licorice (cross-listed for antiviral indications).

The boundary of this category is "herb whose principal or important indication is antimicrobial." The pharmaceutical anti-infectives (antibacterials, antifungals, antivirals, antiparasitics) are listed under their primary umbrellas; the herbal interest is in adjunctive use, in prevention, and in selected indications where evidence-grade herbal options exist. Several herbs in this category have evidence of resistance-pressure modulation and synergy with pharmaceutical antibacterials, with active research interest. The historical antiseptics derived from herbal sources (Listerine from thymol and menthol; tincture of iodine; carbolic acid from phenol) are listed under antiseptics.

This category page is an encyclopedia article about its subject. The actual index of herbs belonging to the category is generated automatically by the wiki engine, from category-membership declarations on the individual herb pages, and appears at the foot of the page below the references.