NEURO PROTECTIVE ACTIVITIES OF LACTOBACILLUS PLANTARUM HY-08 NEWLY ISOLATED FROM FERMENTED VEGETABLES

Background: To expand the availability of lactic acid bacterium as a new, safe and reliable bio resource, its neuro protective effects should be investigated. Methods: A lactic acid bacterium was isolated from traditional fermented vegetables and identified by 16S rRNA sequence analysis and a phylogenetic tree analysis. Its neuro protective activities were evaluated by the inhibition of producing Reactive Oxygen Species (ROS) and Ca 2+ ions in glutamate-induced HT 22 cells. Results: A rod-type lactic acid bacterium was first isolated from kimchi and named as Lactobacillus plantarum HY-08 [MG547899 registered in National Center for Biotechnology Information]. This new strain proved to grow well in a cheap and edible medium as 0.248 (1/h) of maximum specific growth and longer growth periods compared to other lactic acid bacteria, which is absolutely beneficial for industrial applications. This new strain also showed very high neuro protective effects in enhancing the growth of glutamate-induced HT22 cells up to 107.37% and in inhibiting the mitochondrial membrane potential of HT22 cells up to 101.65% when compared with those of commercially available Lactobacillus sp. (ATCC 8008). These neuro protective mechanisms were found to be caused by strong antioxidant activities of inhibiting the production of ROS and Ca 2+ ions in HT22 cells, possibly caused by high contents of unsaturated fatty acids, such as 13.2% of C16:1 and 33.2% of C18:1. These concentrations were higher than those in lactic acid bacteria. Conclusion: A newly isolated lactic acid bacterium, Lactobacillus plantarum HY-08 proved to have good neuro protective abilities responding to oxidative stress, and to be easily scaled-up for food industries because of their favorable growth characteristics.