Isoflavonoids isolated from plants have been confirmed to fight osteoporosis and promote bone health. However, few studies have been conducted to describe the anti-osteoporosis activity of botanical flavonone. Based on the experimental outcomes, we demonstrated the ability of naringin to fight osteoporosis in vitro. We developed a retinoic acid-induced osteoporosis model of rats to assess whether naringin has similar bioactivity against osteoporosis in vitro. After a 14-day supplement of retinoic acid to induce osteoporosis, SD rats were administered naringin. A blood test showed that naringin-treated rats experienced significantly lower activity of serum alkaline phosphatase and had higher femur bone mineral density, compared to untreated rats. All three dosages of naringin improved the decrease in bone weight coefficient, the length and the diameter of the bone, the content of bone ash, calcium, and phosphorus content induced by retinoic acid. The data of histomorphological metrology of naringin groups showed no difference as compared to normal control rats. These outcomes suggest that naringin offer a potential in the management of osteoporosis in vitro.

Diet and nutrition have substantial impact on reducing the incidence of diabetes mellitus, where oxidative stress is an important etiopathological factor. The combined protective role of low dose of naringin (15 mg kg(-1)) and vitamin C (25 mg kg(-1)) and high dose of naringin (30 mg kg(-1)) and vitamin C (50 mg kg(-1)) on streptozotocin (STZ)-induced toxicity was studied in male Wistar rats. To induce type II diabetes mellitus, rats were injected with STZ intraperitoneally at a dose of 45 mg kg(-1) body weight. STZ-induced diabetic rats showed significant increase in blood glucose, water intake, food intake and glycated hemoglobin and significant decrease in plasma insulin, total hemoglobin, body weight and liver glycogen. Diabetic rats also showed significant decrease in the activity of hexokinase and significant increase in the activities of glucose-6-phosphatase and fructose-1,6-bisphosphatase in liver and kidney. The levels of plasma thiobarbituric acid reactive substances, lipid hydroperoxides and vitamin E were elevated while the level of reduced glutathione was decreased in diabetic rats. Glycoprotein components such as hexose, hexosamine, fucose and sialic acid were increased in plasma, liver and kidney of diabetic rats. Oral administration of high doses of naringin (30 mg kg(-1)) and vitamin C (50 mg kg(-1)) to diabetic rats for a period of 21 days normalized all the above-mentioned biochemical parameters. The effect exerted by naringin (30 mg kg(-1)) and vitamin C (50 mg kg(-1)) was similar to the effect exerted by insulin (6 units kg(-1)). Thus, our study shows the antihyperglycemic and antioxidant effects of naringin and vitamin C in STZ-induced type II diabetes mellitus in rats. Copyright 2008 John Wiley & Sons, Ltd.

Naringin is a flavonoid that is commonly found in grapefruits. The objective of this study was to evaluate the effects of naringin on the growth of periodontal pathogens such as A. actinomycetemcomitans and P. gingivalis in vitro. For comparison, the effects of naringin on several oral microbes were also studied. Different concentrations of naringin solution were added to calibrated suspensions of A. actinomycetemcomitans and P. gingivalis. All the suspensions were incubated for 3, 6 and 24 h in an anaerobic chamber at 37 degrees C. At each time point, selected dilutions from each culture broth were plated on blood agar plates. Colonies recovered on blood agar were visually counted on days 3 and 5, respectively. A. actinomycetemcomitans showed a significant decrease (p < 0.05) in viable counts after 3 h when naringin was added at baseline. P. gingivalis also showed a marked growth reduction in the presence of naringin, and no colony forming units could be observed after 24 h. Naringin also had an inhibitory effect against all bacteria and yeasts tested. The results suggest that naringin possesses significant antimicrobial properties on periodontal pathogens in vitro. It also has an inhibitory effect on some common oral microorganisms in low concentrations.