Honey Suppresses Mutagenic Pathways in E.Coli

Encouraging news for beekeepers worldwide harvesting monofloral honeys... Encouraging news for hospitals worldwide with antibiotic-resistant Escherichia coli...

Suppression of Error Prone Pathway is Responsible for Antimutagenic Activity of Honey

Food and Chemical Toxicology, 2012, Jan 14

Honey, both unifloral (Syzygiumcumuni) and bifloral, demonstrated strong antimutagenicity against physical (UV, γ) and chemical (Ethylmethane sulfonate) mutagens as ascertained by rpoB/RifR and Ames tests.

The effect of honey was evaluated in radiation (UV or γ) exposed E. coli cells for SOS response, a well known error prone repair pathway known to significantly contribute to mutagenicity by quantifying LexA repressor level, measuring cell filamentation frequency, and prophage induction by SIVET (Selectable – In - Vivo Expression Technology) assay. LexA was almost completely degraded, phenotypically long filamentous cells (∼30 μm) were formed, and SIVET induction frequency was increased in radiation exposed E. coli cultures, however these changes were significantly inhibited in presence of honey confirming its strong antimutagenic nature. Further, rpoB/RifR mutation frequency upon UV exposure in E. coli recA- cells was found to be negligible, whereas, E. coliumuC- and umuD- knockouts showed comparatively higher mutation frequency. Honey did not show any effect on mutagenesis in these knockouts, indicating the SOS dependence of the observed mutagenesis.

Honey was also found to suppress EMS induced mutagenesis but through SOS independent mechanism.

Phenolics present in honey were found to be one of the important factors contributing to the antimutagenicity of honey.

Highlights:

• Pollen analysis indicated commercial Indian honey as unifloral and bifloral.
• It showed broad spectrum antimutagenicity by Ames and E .colirpoB/RifR tests.
• Honey suppressed E. coli SOS response, an error-prone repair process.
• Error-prone repair is one of the major causes of mutagenesis.
• Honey inhibited LexA degradation, cell filamentation and prophage induction.

Cuban Monofloral Honey Shows High Antioxidant Activity

We need more studies on the advantages of monofloral honeys. This is precisely what was done for Manuka Honey and we now see its worldwide acceptance into main stream medical and veterinary usage...

Radical-Scavenging Activity, Protective Effect Against Lipid Peroxidation and Mineral Contents of Monofloral Cuban Honeys

Plant Foods Human Nutrition, 2012 Jan 3

Several monofloral Cuban honeys were analyzed to determine their free radical-scavenging activity and from this the total antioxidant content was estimated. The protective effect against lipid peroxidation in an in vitro model of rat liver homogenates was evaluated and, lastly, the mineral content of the honeys, which can be related to the maintenance of intracellular oxidative balance, was determined.

The scavenging capacities against hydroxyl and superoxide radicals were determined using the spin-trapping technique and the hypoxanthine/xanthine oxidase assay, respectively. Lipid peroxidation was evaluated through the production of TBARS and hydroperoxides. All honeys tested showed potential antioxidant activity with Linen vine displaying the highest scavenging capacity towards the DPPH, hydroxyl and superoxide radicals, while the least efficient was Christmas vine honey. Honeys also inhibited, in a concentration-dependent mode, lipid peroxidation in rat liver homogenates, with Linen vine resulting the best while the least effective was Christmas vine honey.

The ability to scavenge free radicals and protect against lipid peroxidation may contribute to the ability of certain Cuban honeys to help in preventing/reducing some inflammatory diseases in which oxidative stress is involved. A total of eight minerals were identified and quantified as follows: cadmium, chromium, copper, nickel, iron, manganese, lead, and zinc. Minerals found in higher concentrations were iron, zinc and manganese.

Mexican Honeys Prove Antioxidant, Antibacterial Action

It's reassuring to see Mexican researchers contributing to the body of science confirming the antibacterial and antioxidant properties in honey. Nutritionally speaking, I've often found Mexican Honey to be very flavorful, aromatic and with lots of tropical notes.  

Quality Parameters and Antioxidant and Antibacterial Properties of Some Mexican Honeys

J Food Science, 2011 Dec 2

A total of 14 Mexican honeys were screened for quality parameters including color, moisture, proline, and acidity. Antioxidant properties of complete honey and its methanolic extracts were evaluated by the DPPH, ABTS, and FRAP assays. In addition, the antimicrobial activity of complete honeys against Bacillus cereus ATCC 10876, Listeria monocytogenes Scott A, Salmonella Typhimurium ATCC 14028, and Sthapylococcus aureus ATCC 6538 was determined.

Most of honeys analyzed showed values within quality parameters established by the Codex Alimentarius Commission in 2001. Eucalyptus flower honey and orange blossom honey showed the highest phenolic contents and antioxidant capacity. Bell flower, orange blossom, and eucalyptus flower honeys inhibited the growth of the 4 evaluated microorganisms. The remaining honeys affected at least 1 of the estimated growth parameters (increased lag phase, decreased growth rate, and/or maximum population density). Microorganism sensitivity to the antimicrobial activity of honeys followed the order B. cereus; L. monocytogenes; Salmonella Typhimurium; S. aureus.

The monofloral honey samples from orange blossoms, and eucalyptus flowers demonstrated to be good sources of antioxidant and antimicrobial compounds. All the Mexican honey samples examined proved to be good sources of antioxidants and antimicrobial agents that might serve to maintain health and protect against several diseases. 

Practical Application: 

The results of the study showed that Mexican honeys display good quality parameters and antioxidant and antimicrobial activities. Mexican honey can be used as an additive in the food industry to increase the nutraceutical value of products.