Inhibition of cancer cells by using heat killed cells of Lactobacillus planetarum isolated from various food samples

Abstract

Lactobacillus plantarum bacteria was isolated from different food samples included banana, tomato, mandarin orange, and imported yogurt . Twenty three isoletes of Lactobacillus plantarum were obtained , and identi ed depending on selective medium MRS agar as well as phenotypic tests, microscopic tests and biochemical examinations . Antioxidant activity of crude bacterial isolates were tested . Results showed that the highest activity was belong to Lactobacillus plantarum isolated from imported yogurt )yR1( 47.12%, while the lower activity was belong to Lactobacillus plantarum isolated from mandarin orange )Mr3( 14.61%. compared with the industrial antioxidant )BHT( and α- tocopherol with activites of antioxidant was )82.70 and 73.96( % respectively. The cytotoxicity effect of the Heat killed )HK(of Lactoba- cillus plantarum on two of the cancer cells lines, human cervix uteri epitheloid carcinoma )Hela( and rat embryogenic broblast )REF( as normal cell line , were studied . In this study, six concentrations of )HK( cells which were )93.5, 187.5 , 375, 750,1500, 3000( mcg/ml. The results showed that all types of dead cells of lactobacillus plantarum which clear ef- fect on tumor cells differed depending on the degree of in uence For the )HK( cells, the highest percentage of inhibition for imported yogurt was 86.38 after 24 hours. While there was no effect of HK on )Rat Embroy Fibroblast( ofter exposure time 72h.