The origin of methylglyoxal in New Zealand manuka (Leptospermum scoparium) honey.

Methylglyoxal in New Zealand manuka honey has been shown to originate from dihydroxyacetone, which is present in the nectar of manuka flowers in varying amounts. Manuka honey, which was freshly produced by bees, contained low levels of methylglyoxal and high levels of dihydroxyacetone. Storage of these honeys at 37 degrees C led to a decrease in the dihydroxyacetone content and a related increase in methylglyoxal. Addition of dihydroxyacetone to clover honey followed by incubation resulted in methylglyoxal levels similar to those found in manuka honey. Nectar washed from manuka flowers contained high levels of dihydroxyacetone and no detectable methylglyoxal.

The effects of long-term honey, sucrose or sugar-free diets on memory and anxiety in rats.

Sucrose is considered by many to be detrimental to health, giving rise to deterioration of the body associated with ageing. This study was undertaken to determine whether replacing sucrose in the diet long-term with honey that has a high antioxidant content could decrease deterioration in brain function during ageing. Forty-five 2-month old Sprague Dawley rats were fed ad libitum for 52 weeks on a powdered diet that was either sugar-free or contained 7.9% sucrose or 10% honey (which is the equivalent amount of sugar). Anxiety levels were assessed using an Elevated Plus Maze, whilst a Y maze and an Object Recognition task were used to assess memory. Locomotor activity was also measured using an Open Field task to ensure that differences in activity levels did not bias results in the other tasks. Anxiety generally decreased overall from 3 to 12 months, but the honey-fed rats showed significantly less anxiety at all stages of ageing compared with those fed sucrose. Honey-fed animals also displayed better spatial memory throughout the 12-month period: at 9 and 12 months a significantly greater proportion of honey-fed rats recognised the novel arm as the unvisited arm of the maze compared to rats on a sugar-free or sucrose-based diet. No significant differences among groups were observed in the Object Recognition task, and there appeared to be no differences in locomotor activity among groups at either 6 or 12 months. In conclusion, it appears that consumption of honey may reduce anxiety and improve spatial memory in middle age.

The effects of manuka honey on plaque and gingivitis: a pilot study.

UNLABELLED: Research has shown that manuka honey has superior antimicrobial properties that can be used with success in the treatment of wound healing, peptic ulcers and bacterial gastro-enteritis. Studies have already shown that manuka honey with a high antibacterial activity is likely to be non-cariogenic. The current pilot study investigated whether or not manuka honey with an antibacterial activity rated UMF 15 could be used to reduce dental plaque and clinical levels of gingivitis. A chewable "honey leather" was produced for this trial. Thirty volunteers were randomly allocated to chew or suck either the manuka honey product, or sugarless chewing gum, for 10 minutes, three times a day, after each meal. Plaque and gingival bleeding scores were recorded before and after the 21-day trial period. Analysis of the results indicated that there were statistically highly significant reductions in the mean plaque scores (0.99 reduced to 0.65; p=0.001), and the percentage of bleeding sites (48% reduced to 17%; p=0.001), in the manuka honey group, with no significant changes in the control group. CONCLUSION: These results suggest that there may be a potential therapeutic role for manuka honey confectionery in the treatment of gingivitis and periodontal disease.

Effects of stage of lactation and time of year on plasmin-derived proteolytic activity in bovine milk in New Zealand.

The objective of this study was to determine the effects of stage of lactation (SOL) and time of year on plasmin-derived proteolytic activity in the milk of pasture-fed dairy cows in New Zealand. Four herds of 20 Friesian cows were used, one herd calving in each of January, April, July and October. Cows grazed ryegrass/white clover pasture only, except during June (winter) when all cows received supplementary pasture silage. Milk samples were collected on four occasions during the year (spring, summer, autumn and winter) from each cow in milk, to give a total of three samples per cow (early, mid and late lactation; c. 30, 120 and 220 days after calving, respectively). Milk samples were analysed for plasmin-derived proteolytic activity. There was no effect of either SOL or time of year on plasmin activity and therefore yields of plasmin followed patterns in milk yield (highest in early lactation and in summer). There were effects of both SOL and time of year on plasminogen-derived and total plasmin plus plasminogen-derived activity, both of which were highest in late lactation and in spring. Changes in plasminogen-derived activity and total plasmin plus plasminogen-derived activity due to SOL were not only due to the decrease in milk yield associated with advancing lactation, because enzyme yields were also increased with advancing lactation. Similarly, effects of time of year on plasminogen-derived activity and total plasmin plus plasminogen-derived activity could not be attributed solely to concomitant changes in milk yield, and may be influenced by the variation in the quality and quantity of feed during the year inherent in a pasture-based dairy system. Effects of SOL on proteolytic activity were greater than, and independent of, effects of time of year.

Re-introducing honey in the management of wounds and ulcers - theory and practice.

Dressing wounds with honey, a standard practice in past times, went out of fashion when antibiotics came into use. Because antibiotic-resistant bacteria have become a widespread clinical problem, a renaissance in honey use has occurred. Laboratory studies and clinical trials have shown that honey is an effective broad-spectrum antibacterial agent that has no adverse effects on wound tissues. As well as having an antibacterial action, honey also provides rapid autolytic debridement, deodorizes wounds, and stimulates the growth of wound tissues to hasten healing and start the healing process in dormant wounds. Its anti-inflammatory activity rapidly reduces pain, edema, and exudate and minimizes hypertrophic scarring. It also provides a moist healing environment for wound tissues with no risk of maceration of surrounding skin and completely prevents adherence of dressings to the wound bed so no pain or tissue damage is associated with dressing changes. Using appropriate dressing practice overcomes potential messiness and handling problems.