Determination of phenolic compound total content and antioxidant activity of plant extracts of the Lamiaceae family

The research was conducted on the content of phenolic compounds and antioxidant activity of extracts of mint (Mentha longifolia), melissa (Melissa officinalis) and basil (Ocimum basilicum) plants grown on the territory of the National Scientific Laboratory for Collective Use of Sarsen Amanzholov East Kazakhstan University in a sharply continental climate with alternating artificial stressful situations (temperature rise, abundant watering, and lack of moisture). The quantitative indices of phenolic compounds were determined by the Folin-Chocalteu method, the antioxidant activity of extracts was determined by the ability of antioxidants to neutralize the stable radical DPPH. The analysis was performed on a BOYN BNUV-D830 AC220V/50Hz spectrophotometer. Calibration curves based on a standard gallic acid solution were constructed for each plant under study. A correlation was determined between the concentration of phenolic compounds and the antioxidant activity of extracts. It was revealed that the studied plants had pronounced antioxidant properties. The extracts of mint (Mentha longifolia), melissa (Melissa officinalis) and basil (Ocimum basilicum) demonstrated high activity in neutralizing free radicals which confirmed their potential as natural antioxidants. At the same time, each of the extracts had its own characteristics in terms of the level of antioxidant activity and concentration of phenolic substances. The data obtained may be used for the development of functional food products, phytopreparations, and cosmetics focused on the prevention of diseases associated with oxidative stress as well as to improve the quality of life. The research opens up prospects for the use of these plants in folk medicine and phytotherapy, as well as in the commercial production of environmentally friendly antioxidant supplements. The study confirms the need for further research to optimize the methods of extraction and evaluation of the biological activity of other plants.