Investigation of antioxidant capacities of Melissa officinalis L. (lemon balm) plant produced by micropropagation in a temporary immersion bioreactor

The aim of this study is to determine the total phenolic, total flavonoid and antioxidant capacities of calluses obtained from the node parts of the Melissa officinalis L. plant using a temporary immersion biorector system under in vitro conditions. Callus development was achieved by adding a combination of different plant growth regulators into the prepared MS medium. The development of the node parts of the cultivated M. officinalis L. plant was monitored in air-conditioning rooms under 2500 lux fluorescent light at +22 °C in a 16-hour light and 8-hour dark environment. In the bioreactor system, 2-minute immersion and 2-minute aeration times were set at 30-minute intervals. M. officinalis L. plant explants were kept in culture for 2 weeks and subcultured twice. From the callus morphology, it was observed that the best callus development occurred at the concentrations of 1BAP+1 2,4-D mg/L and 1BAP+1,5 2,4-D mg/L. It was determined that the callus was dark green in color and had a hard structure. At the concentration of 1BAP+2 2,4-D mg/L, color development was observed as green-yellow and it was determined that the calli were fragile. In the combination of BAP and IAA, significant root and shoot development was observed, but no callus development was observed. It was observed that the calli that developed in the combination of BAP and picloram did not complete their development, turning brown in time and becoming softer and more fragile. Ethanol, methanol and HIP solvents were used in the study. When the highest activities of the extracts prepared with solvents in the ABTS radical scavenging method are compared, respectively; It was determined as Methanol > Ethanol > HIP extracts. In the DPPH radical scavenging method, when the highest activities of extracts prepared with solvents are compared, respectively; It was determined as Ethanol > Methanol > HIP extracts. This study aims to develop new generation tissue culture studies as an alternative to traditional tissue culture, and we believe that it will contribute to new studies.