Abstract:The black berry (Rubus fruticosus) and blue berry (Vaccinium corymbosum) contain bioactive polyphenols with reported anti-bacterial properties. This study sought to investigate the anti-bacterial, cartilage-protecting and anti-inflammatory effects of freeze-dried powder of polyphenolic-enriched berry by using a plate inhibition test, a minimum inhibitory concentration (MIC) test, and an in vitro bovine nasal explant cell culture model. Results showed that both gram-positive Bacillus subtilis and gram-negative Escherichia coli were inhibited by the freeze-dried powder. And a multiply antibiotic resistant bacterium Proteus mirabilis was also susceptive to berry freeze-dried powder. After a 20-day culture, the growth inhibition rate of Proteus mirabilis reached 50.43±0.00% and 68.05±3.00% in black berry and blue berry freeze-dried powder, respectively. Casein hydrolysis activity and gelatin zymography test indicated the protease activity significantly decreased to 50.02±0.30% and 66.00±5.00% in bovine nasal explant cell culture samples after black berry and blue berry freeze-dried powder were added. The release inhibition of glycosaminoglycan (GAG), which was a signal of inflammatory, was also found in according with protease inhibition by berry freeze-dried powder.
