Antibacterial Scientific Literature
- Perry et al. 36,18 showed inhibition of the Gram-positive bacteria Bacilus subtillis and the fungi Trichophyton mentagrophytes was only strongly associated with East Cape sourced Manuka oil.
- Porter et al. 27 found a direct correlation with MBC (Minimal Bactericidal Concentration) antibacterial properties to a number of pathogens (including MRSA bacterium) was associated with the separated polar triketone rich fraction/portion of the oil.
|Organism||Manuka Oil (Whole Oil)||Manuka Oil (Non-polar fraction)||Manuka Oil (Polar fraction)|
|Staphylococcus aureus (MRSA)||0.0195||1.25||0.0195|
- Kim and Rhee 38 studied the whole Manuka oil and β-triketone fraction against a vast array of MRSA and other multi-resistant bacteria. They showed the pure oil was effective against these Gram-positive bacteria and the β-triketone fraction was 2-3 fold better. They also discovered synergistic effects when used with some antibiotics.
- Harkenthal et al. 42 compared results for TTO, Cajuput, Niaouli, Manuka, Kanuka, and Eucalyptus oils, finding both TTO & Manuka gave excellent results with high triketone Manuka oil effective at Gram-positive bacterium while TTO effective at Gram-negative bacterium. They also found Manuka oil very effective against Gram-positive antibiotic resistant staphylococcus species (see table below).
|Organism (Antibiotic Resistant Staphylococcus)||Manuka Oil (MIC, % v/v)||TTO (MIC, % v/v)|
- Lis-Bachin et al. 43,39 have done extensive pharmacological and antimicrobial studies of Manuka, Kanuka, TTO and some of their major individual monoterpene & sesquiterpene constituents.
- Christoph et al.41  showed the synergistic effects of LEMA® oil against S. aureus.
- Takarada et al. [2004, 2005]44,45 tested Manuka oil, TTO, Eucalyptus oil, Lavandula oil, Romarinus oil against 14 oral pathogens that can cause systemic diseases and bad breath (oral halitosis). Their MIC results showed that Manuka oil exhibited the strongest antibacterial activity against these bacteria and that at 0.2% or lower they had little effect on human cells.
- Maddocks-Jenning et al. 46 found Manuka & Kanuka oil can potentially help with radiation induced mucositis (mouth ulcers).
- Jeong et al. 47 showed that high β-triketone Manuka oil inhibits the growth of difficult to control intestinal bacteria.
- Sulaiman Alnaimat [2011, PhD thesis]48 tested Manuka oil against Gram-positive bacteria including MRSA, Mycobacterium phlei and Bacilus subtilis giving MICs of 0.03% (v/v) and 0.25% against Staphylococcus epidermidis. Kill assays on MRSA with Manuka oil at a concentration of 1.5% (v/v) were successful in killing >1000 CFU ml-1 within 8 hours.
- Song et al. 49 has recently showed that the β-triketone rich East Cape Chemotype Manuka oil of New Zealand has excellent activity against challenging to treat antibiotic resistant bacteria involved in skin and ear infections of dogs.
- Courtney 28. Antimicrobial Composition Comprising Leptospermum scoparium and Melaleuca alternifolia oils. This patent describes the antibacterial properties of a broad spectrum oil called LEMA® oil.
- Cotton 50. Compositions and Dressings for the Treatment of Wounds. This patent uses Manuka oil in conjunction with Manuka honey for wound dressings.
- Harcourt 51. Antimicrobial Composition and its Method of Use. Manuka & TTO used with a galloyl moiety for synergistic effects.
Antifungal Scientific literature
- Perry et al. 36,18 showed inhibition of the fungi Trichophyton mentagrophytes was strongly associated with only East Cape Chemotype Manuka oil.
- Kim and Rhee 38 showed fungicidal effects of the whole Manuka oil and β-triketone fraction against a number of fungal strains.
- Lis-Bachin et al. 43 showed Manuka was much more effective than Kanuka on a number of common fungal/mold strains (Aspergillus niger, Aspergillus ochraceus and Fusarium culmorum).
- Sing & Chittenden [2010, Scion NZ]52 demonstrated the efficacy of East Cape Manuka oil and it's purified β-triketones (99.7%) extract for controlling allergen forming wood fungal molds commonly found in damp dwellings. They found that both these oils hindered the growth of Penicillium corylophilum, significantly hindered the growth of Alternaria alternata and virtually eliminated the growth of Cladosporium herbarum.