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Staged at the Hong Kong Science Museum from today (September 8) to January 7, 2007, the new Science News Corner exhibition – "Grapefruit forms bone?" – introduces the research findings of Dr Ricky WK Wong and Professor Bakr M Rabie, Faculty of Dentistry of the University of Hong Kong (HKU), on new bone formation from a non-toxic material – naringin.
The search for a non-toxic material to replace bone remains a big challenge for scientists. They found that bone morphogenetic proteins (BMPs), low molecular weight glycoproteins, are important regulators in bone formation during fracture repair. To discover small molecules that induce the generation of BMP-2 (one of the BMPs) and hence bone, HKU had conducted research on a Chinese herb, Gusuibu where naringin was discovered.
Gusuibu is used for treatment of bone fractures in Chinese medicine. In 2004, Dr Wong and Professor Rabie performed a study of Gusuibu by applying a collagen matrix carrier with Gusuibu extract to the parietal bone of rabbits. A total of 90% more new bone was present in defects grafted with Gusuibu-mixed collagen than those grafted with the collagen matrix carrier (control) alone. The bone inducing effect of Gusuibu was proven.
Naringin is a major flavonoid present in grapefruits and related citrus varieties. It causes the characteristic bitter taste in grapefruit. The flavonoids are polyphenolic compounds with antioxidant properties and widely exist in foods of plant or plant origin such as vegetables, fruit, tea and wine. Therefore, if naringin can be shown to increase bone formation, it may be a safe agent for bone induction.
Dr Wong and Professor Rabie have conducted several tests and experiments to examine the effect of naringin on bone cell activity in vitro and in animals, including "Cell Culture with UMR-106 Bone Cells", "Colourimetric Tetrazolium (MTT) Assay For Cell Viability and Acticity", "Cytoplasmic Total Protein Assay", and experiments on bone formation in rabbits. The results have shown that naringin could trigger the genes that form bones. In animal experiments, it increased the amount of new bone formation by four times compared with controls. It is also one of the few discoveries showing that plant substances can increase the growth of bone in animals.
Besides inducing bone formation, naringin has many other beneficial effects on humans. They include: protection against toxins in chemotherapy drugs and the environment; enhancing lipid metabolism and ethanol metabolism; reducing negative effects of ethanol intake; acting as a free radical scavenger and reducing cytotoxicity. Naringin also acts as an antioxidant and an anti-apoptotic; protects against carcinogenic matter and may reduce risk of atherosclerosis; it also significantly inhibits LDL oxidation. It is used in the treatment of gastric lesions, inhibits the Sindbis neurovirulent virus, reduces total cholesterol levels, protects plasma vitamin E levels, prevents hypercholesterolemia, and is anti-atherogenic.
The Science Museum is located at 2 Science Museum Road, Tsim Sha Tsui East, Kowloon. It is open from 1pm to 9pm from Monday to Friday and from 10am to 9pm on Saturdays, Sundays and public holidays. It is closed on Thursdays (except public holidays). Admission is $25, with a half-price concession applicable to full-time students, people with disabilities and senior citizens aged 60 or above. Admission is free on Wednesdays.
For enquiries, call 2732 3232 or visit the Science Museum's website at http://hk.science.museum for further information.
Ends/Friday, September 8, 2006
Issued at HKT 16:31
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