In vitro evaluation of antimicrobial activity and measuring its antigenic specific immune response in mice model studies: Allium cepa

Abstract

Allium cepa (onion; Liliaceae family), herbaceous annual plant and reported Sulphur based amino acids with many minerals including vitamins. Inspite of various medicinal uses of this plant as food and also showed various beneficial effects. The antimicrobial activity of aqueous extract from Allium cepa (onion bulb) was evaluated against bacterial strains using disc diffusion method. In contrast, inflammatory response or inhibition of T cell antigenic response was evaluated using typhoid vaccine and swine flu vaccine in Swiss mice. These studies were conducted according to ethical guidelines and determining T cell proliferation including estimation of cytokines from cell culture supernatant and also measuring its hemolytic activity. The results showed that aqueous extract show the highest inhibition rate against Pseudomonas aeruginosa and Salmonella enteritidis. In mice model studies, aqueous extract at higher doses showed inhibition in antigen specific T cell proliferation and also declining in the level of IFN-gamma production but enhancement in IL-4 production. In addition, aqueous extract at higher concentration does not showed any hemolytic activity. Overall, this study provides evidence for the presence of secondary metabolites in aqueous extract that probably interferes with bacterial growth (antimicrobial) and also declining in antigenic specific proliferation (i.e. anti-inflammatory) which would prevent and inhibit initiation and progression of many diseases.