Investigation of the Antimicrobial Activity of Biologically Active Substances Extracted from the Callus Cell Cultures of Rheum cordatum Losinsk and Rheum tataricum L. Plants (Family Polygonaceae) using Fourier infrared Spectroscopy to Analyze the Chemical Composition and Identify Active Compounds

The increasing demand for novel antimicrobial agents has led to interest in plant-derived bioactive substances (BAS). This study focuses on the establishment of callus cultures from Rheum cordatum Losinsk. and Rheum tataricum L. under in vitro conditions and the evaluation of the antimicrobial properties of BAS synthesized in these callus cells. Callus cultures were induced from leaf and stem explants using Murashige-Skoog nutrient medium supplemented with 2,4-D (0.1mg/L) and BAP (0.01mg/L). Callus formation frequency was recorded for both species, and green plant regeneration from R. cordatum calluses was observed. Antimicrobial activity was assessed by testing callus-derived extracts against various microorganisms, including gram-positive Staphylococcus aureus 6538 and Salmonella abony NTCC 6017, gram-negative Escherichia coli NTCC 8439 and Klebsiella pneumonia 700603, and the yeast-like fungus Candida albicans R50. Callus induction was successfully achieved in both species, with formation frequencies of 60±6% for R. cordatum and 72±8% for R. tataricum. Extracts from R. tataricum callus cultures exhibited antimicrobial activity against S. aureus, E. coli, and K. pneumoniae. R. cordatum callus extracts showed moderate effects on these microorganisms. The results highlight the significant potential of callus-derived rhubarb extracts in addressing bacterial and fungal pathogens. The study demonstrates the efficacy of Murashige-Skoog medium supplemented with 2,4-D and BAP in promoting callus induction and growth in rhubarb species. Extracts from rhubarb callus tissues represent significant potential in developing new antimicrobial agents effective against a wide range of pathogens, including bacterial and fungal infections. Future studies will focus on the regeneration of plants from callus cultures and the detailed pharmacological profiling of their BAS.