Salmonella typhimurium에 감염된 생쥐의 면역 반응에 Chlorella vulgaris 열수추출물이 미치는 영향

Abstract

The Salmonella species are an important group of pathogens that infect humans and animals by the oral route and cause a variety of disease syndromes. Salmonella typhimurium is one of Salmonella serovar that is the most frequent bacteria reported in humans and causes a human typhoid. Salmonella based food borne diseases are prevented by heating food before eating. In spite of that, food-borne disease remains a serious hazard because of increasing consumption of fresh-cut food. Fresh-cut products are usually eaten without heating, easily resulting in exposure to pathogenic bacteria specially Salmonella. Thus, to prevent food-borne diseases, alternative ways are needed. One of way is improving immune response. Chlorella vulgaris can effect a change in the immune system. Especially hot water extract of Chlorella vugaris is well known as a new type of biological response modifier, which enhances resistance against infection with various bacteria. It promotes some cytokines such as IL-12, IFN-γ and TNF-α that affect the immune response of bacteria-infected hosts. Balb/c mice were used in this study and infected with Salmonella typhimurium by oral route. The numbers of bacteria were measured from feces, mesenteric lymph nodes, spleen and liver, and cytokine expressions was measured from mesenteric lymph nodes. In the gourps that were infected Salmonella typhimurium, bacteria was detected in feces only at day 1 post-challenge and none was detected in the uninfected P-CON group. Specially in TR groups that fed with extract of Chlorella vulgaris before infection, showed bacteria higher than N-CON that fed without extract of Chlorella vulgaris. Extract of Chlorella vulgaris intake effect expression of IL-12 and IFN-γ and continuing extract of Chlorella vulgaris intake during Salmonella typhimurium infection may have been slightly more effective than providing it only during the week before infection. However TNF-α expression that showed decrease over time might effected by pathway of Salmonella typhimurium which causes reduce inflammation. In the present study, Chlorella showed some signs of enhancing immune response in a mouse host infected with a common result of food poisoning, Salmonella typhimurium. However further studies, perhaps on larger sample sizes are needed that examine effectiveness for one more week after infection. Hopefully this could help elucidating some of the findings in the present study that appeared to be inconsistent with our expectations, based on past research.