New technique to purify propolis

The healing properties of propolis - a mixture of resin and wax made by honey bees to seal and sterilise their hives - have been known for many years. But its use in medicine and food supplements has been limited because the sticky substance is not water soluble and has a strong, off-putting smell.

Now researchers at the University of Bradford's Centre for Pharmaceutical Engineering Science have developed a way of purifying propolis that retains its medicinal properties, but makes it dissolve in water and eliminates its pungent smell. The technique has already led to the development of a new mouth ulcer gel and opens the door to a huge range of other pharmaceutical and nutraceutical applications for the substance.

"Propolis is a complex chemical mix and a very useful natural product," explains Centre Director, Professor Anant Paradkar, who led the research. "Propolis has been shown to be anti-microbial, anti-fungal, a strong anti-oxidant, non-allergenic and can boost the immune system. It also promotes wound healing and has anaesthetic properties.

"There is a substantial market for propolis-based products - particularly in China, the USA and South Asia. The main stumbling block in developing products has been the solubility and odour issues, which our formulation overcomes."

Professor Paradkar's team has been developing the new technique to purify propolis in collaboration with natural medicine manufacturer, Nature's Laboratory. The researchers have helped the company develop a new propolis-based mouth ulcer gel, which has better anaesthetic, anti-microbial and anti-fungal properties than gels already on the market and is safe for use in children.

"A problem for mouth gels is that adhesion to the skin membrane inside the mouth is difficult - because of the nature of the surface, the gel can simply slide off," says Professor Paradkar. "As propolis retains some of its stickiness even in a water soluble formulation, when it is applied to specific areas in the mouth, it adheres more effectively."