Garlic Allium sativum |
Allicin, ajoene and diallyl sulfides |
Antibacterial and antifungal activity, with some antiviral and
antiparasitic effects reported in laboratory studies.
|
Extensive laboratory evidence, but insufficient clinical evidence
to use garlic as a treatment for established infections.
|
Tesfaye A. Revealing the therapeutic uses of garlic and its
potential for drug discovery. Scientific review.
|
| Berberine |
Berberine isoquinoline alkaloid |
May damage bacterial membranes, inhibit efflux pumps, interfere with
nucleic-acid and protein synthesis, and inhibit biofilm formation.
|
Strong preclinical evidence and limited indication-specific clinical
evidence. Poor oral bioavailability and drug interactions limit its
use as a general antimicrobial.
|
Berberine as a therapeutic alkaloid against ESKAPE and
multidrug-resistant bacteria: a comprehensive review.
|
Cranberry extract Vaccinium macrocarpon |
A-type proanthocyanidins |
Primarily reduces adhesion of uropathogenic bacteria, particularly
Escherichia coli, to urinary epithelial cells.
|
May reduce recurrent urinary tract infections in selected
populations. It is preventive rather than a reliable treatment for
an active UTI.
|
National Center for Complementary and Integrative Health:
Cranberry—Usefulness and Safety.
|
Probiotics
Lactobacillus, Bifidobacterium and
Saccharomyces boulardii
|
Live microorganisms; effects are strain-specific
|
Competitive exclusion of pathogens, production of bacteriocins,
inhibition of pathogen adhesion and restoration of microbiome
function.
|
Some human evidence for antibiotic-associated diarrhea and selected
gastrointestinal or vaginal indications. Results cannot be
generalized from one strain to another.
|
NIH Office of Dietary Supplements: Probiotics—Health Professional
Fact Sheet.
|
| Medical-grade honey / Manuka honey |
Methylglyoxal, hydrogen peroxide, defensin-1, organic acids and high
osmolarity
|
Broad topical antibacterial and antibiofilm activity; also supports
autolytic debridement and wound healing.
|
Clinically relevant primarily as a standardized, medical-grade
topical wound product. Ordinary food honey is not equivalent.
|
Jull AB et al. Honey as a topical treatment for wounds.
Cochrane systematic review.
|
Oregano oil Origanum vulgare |
Carvacrol and thymol |
Antibacterial, antifungal and antibiofilm activity, largely through
disruption of microbial membranes.
|
Strong laboratory activity, but inadequate human evidence for oral
treatment of infections. Concentrated oil can cause irritation.
|
Chemical composition, biological activity and potential uses of
oregano and oregano essential oil: a review.
|
Thyme Thymus vulgaris |
Thymol and carvacrol |
Antibacterial, antifungal and antibiofilm activity through membrane
damage and altered microbial permeability.
|
Better established as a constituent of topical antiseptic and
oral-care formulations than as an oral treatment for systemic
infection.
|
PubMed literature: thyme, thymol and antimicrobial activity.
|
Tea tree oil Melaleuca alternifolia |
Terpinen-4-ol and related monoterpenes |
Topical antibacterial and antifungal activity with some antiviral
laboratory activity.
|
Some clinical evidence for topical acne and fungal skin conditions.
Tea tree oil is toxic when swallowed and may cause contact
dermatitis.
|
Carson CF et al. Melaleuca alternifolia oil: a review of
antimicrobial and other medicinal properties.
|
Echinacea Echinacea species |
Alkamides, caffeic-acid derivatives, polysaccharides and
glycoproteins
|
Primarily immunomodulatory; relatively weak and inconsistent direct
antimicrobial activity.
|
Evidence for preventing or shortening respiratory infections is
inconsistent and preparation-dependent.
|
National Center for Complementary and Integrative Health:
Echinacea—Usefulness and Safety.
|
Elderberry Sambucus nigra |
Anthocyanins, flavonols and phenolic acids |
Antiviral effects have been reported in cell-culture and
preclinical studies, including interference with viral entry or
replication.
|
Small human trials have examined respiratory symptoms, but evidence
remains insufficient to establish treatment of influenza or other
viral infections.
|
National Center for Complementary and Integrative Health:
Elderberry.
|
Curcumin / turmeric Curcuma longa |
Curcumin and related curcuminoids |
Antibacterial, antifungal, antiviral and antibiofilm activity through
multiple membrane, enzyme and signalling effects.
|
Predominantly laboratory evidence. Poor aqueous solubility and low
systemic bioavailability are major clinical limitations.
|
Moghadamtousi SZ et al. A review on antibacterial, antiviral and
antifungal activity of curcumin.
|
Ginger Zingiber officinale |
Gingerols, shogaols and zingerone |
Antibacterial and antifungal activity, including possible inhibition
of microbial adhesion and biofilm formation.
|
Primarily laboratory evidence; there is little direct clinical
evidence that ginger supplements treat infections.
|
PubMed literature: ginger, gingerols and antimicrobial activity.
|
Clove Syzygium aromaticum |
Eugenol and eugenyl acetate |
Antibacterial, antifungal and local antiseptic activity, principally
through membrane and protein disruption.
|
Relevant mainly to topical, food-preservation and dental
applications. Evidence for systemic infection treatment is
insufficient.
|
PubMed literature: clove, eugenol and antimicrobial activity.
|
Cinnamon Cinnamomum species |
Cinnamaldehyde, eugenol and cinnamic acid derivatives |
Antibacterial, antifungal and antibiofilm activity; may alter
microbial membranes and quorum-sensing pathways.
|
Predominantly laboratory evidence. Cassia cinnamon can contribute
substantial coumarin exposure when consumed in concentrated amounts.
|
PubMed literature: cinnamon, cinnamaldehyde and antimicrobial
activity.
|
Neem Azadirachta indica |
Nimbidin, nimbin, nimbolide, azadirachtin and other limonoids |
Antibacterial, antifungal, antiparasitic and antibiofilm effects have
been reported.
|
Some topical and dental research exists, but systemic clinical
evidence is inadequate. Oral neem preparations have important safety
concerns.
|
PubMed literature: Azadirachta indica and antimicrobial activity.
|
Black seed Nigella sativa |
Thymoquinone, thymohydroquinone and related volatile compounds |
Antibacterial, antifungal, antiparasitic and possible antiviral
activity.
|
Considerable laboratory research but limited, heterogeneous clinical
evidence for infectious diseases.
|
PubMed literature: Nigella sativa, thymoquinone and antimicrobial
activity.
|
Green tea extract Camellia sinensis |
Epigallocatechin gallate (EGCG) and other catechins |
Antibacterial, antiviral and antibiofilm activity; may damage
membranes, inhibit microbial enzymes and enhance some antibiotics.
|
Some localized oral-health evidence, but limited evidence for
treating systemic infections. Concentrated extracts may cause liver
injury in susceptible individuals.
|
PubMed literature: EGCG, green tea and antimicrobial activity.
|
Licorice root Glycyrrhiza species |
Glycyrrhizin, glycyrrhetinic acid, liquiritigenin and other
flavonoids
|
Antiviral, antibacterial and antifungal effects have been reported
in laboratory and preclinical studies.
|
Limited clinical antimicrobial evidence. Glycyrrhizin can cause
hypertension, hypokalemia, fluid retention and clinically important
drug interactions.
|
National Center for Complementary and Integrative Health:
Licorice Root.
|
Andrographis Andrographis paniculata |
Andrographolide and related diterpenoid lactones |
Immunomodulatory, anti-inflammatory and possible antiviral or
antibacterial activity.
|
Some evidence for modest symptom reduction in uncomplicated
respiratory infections, but this does not establish direct pathogen
eradication.
|
PubMed literature: Andrographis and respiratory infections.
|
| Pelargonium sidoides |
Proanthocyanidins, phenolic acids and oxygenated coumarin derivatives
|
Possible antiviral, antibacterial anti-adhesive and
immunomodulatory activity.
|
Some human evidence for modest symptom improvement in acute
bronchitis and selected respiratory infections. It is not a
substitute for antibiotics when bacterial treatment is indicated.
|
Timmer A et al. Pelargonium sidoides extract for acute respiratory
tract infections. Cochrane systematic review.
|
Monolaurin Glycerol monolaurate |
Monolaurin, a monoester derived from lauric acid |
May disrupt lipid membranes and interfere with signalling or
virulence in certain bacteria and enveloped viruses.
|
Predominantly laboratory and animal evidence. There is insufficient
clinical evidence to recommend oral monolaurin for infections.
|
PubMed literature: glycerol monolaurate and antimicrobial
activity.
|
| Caprylic acid |
Octanoic acid, an eight-carbon medium-chain fatty acid |
Antifungal and membrane-disrupting activity, particularly against
Candida species, has been reported in vitro.
|
Insufficient human evidence for treating candidiasis or systemic
fungal infection. Marketing claims commonly exceed the evidence.
|
PubMed literature: caprylic acid and Candida.
|
Olive leaf extract Olea europaea |
Oleuropein, hydroxytyrosol and elenolic-acid derivatives |
Antibacterial, antiviral and antifungal activity has been observed
in laboratory studies.
|
Preliminary evidence only; clinical trials have not established it
as a treatment for infectious disease.
|
PubMed literature: olive leaf, oleuropein and antimicrobial
activity.
|
Goldenseal Hydrastis canadensis |
Hydrastine, canadine and berberine |
Extracts and individual alkaloids show antibacterial activity in
laboratory studies.
|
There is no good clinical evidence that goldenseal treats human
infections. Product composition, absorption and drug interactions
are important limitations.
|
National Center for Complementary and Integrative Health:
Goldenseal.
|
Sweet wormwood / artemisinin
Artemisia annua
|
Artemisinin and related sesquiterpene lactones |
Artemisinin derivatives are potent antimalarial agents. Additional
antibacterial, antiviral and antiparasitic effects are being studied.
|
Artemisinin-based combination therapies are established medicines,
not ordinary supplements. Herbal preparations should not replace
standardized malaria treatment because dose variability can promote
treatment failure and resistance.
|
World Health Organization: Guidelines for malaria.
|