Screening of anti-microbial, anti-biofilm activity, and cytotoxicity analysis of a designed polyherbal formulation against shigellosis

Background: Shigellosis is an infectious intestinal disease common in rural communities. In developing countries, shigellosis is caused predominantly by Shigella flexneri and has been determined as a major cause of morbidity and mortality. Objective: The study investigates the anti-biofilm, anti-microbial, and anti-shigellosis activity of a designed formulation. Materials and methods: The potential of the formulation against S. flexneri (MTCC 1457) was investigated using a well-diffusion assay. Further, the effect of the designed formulation on bacterial growth and biofilm formation was analyzed by the spectrophotometry method. Anti-quorum sensing activity was analyzed using Chromobacterium violaceum CV026, a bacterial strain. Finally, the cytotoxicity of the formulation was examined by using cell line and brine shrimp lethality assay. Results: The MIC value of the aqueous extract of the formulation was 2.4 mg ml(-1) and an inhibitory zone of 23 mm was observed. On the other side, the formulation significantly inhibited the bacterial growth, biofilm formation (23.78%), violacein inhibition (27.68%) at 0.6 mg ml(-1) concentration (did not significantly affect the growth curves) and was found non-toxic in cell assay and brine shrimp lethality assay. Conclusion: According to the result obtained, the designed formulation was found effective and non-toxic, so it can be used to treat shigellosis and Shigella-related infections. (C) 2021 The Authors. Published by Elsevier B.V. on behalf of Institute of Transdisciplinary Health Sciences and Technology and World Ayurveda Foundation.