Callus cultures of Thymus vulgaris and Trifolium pratense as a source of geroprotectors

Introduction. Geroprotectors are biologically active substances that inhibit the aging process. Many plant species are natural geroprotectors. For instance, Thymus vulgaris and Trifolium pratense are callus cultures with strong geroprotective properties. Study objects and methods. The present research featured T. vulgaris and T. pratense grown in vitro on various nutrient media. Their extracts were obtained by aqueous-alcoholic extraction using the following parameters: water-ethanol solvent Se = 30, 50, and 70 %; temperature Te = 30, 50, and 70°C; time τe = 2, 4, and 6 h. The quantitative and qualitative analysis was based on high-performance liquid mass spectrometry, gas mass spectrometry, and thin-layer chromatography. Results and discussion. The optimal extraction parameters for T. vulgaris were τe = 4 h, Te = 50°C, Se = 70 %, for T. pratense – τe = 6 h, Te = 70°C, Se = 70 %. The chromatography detected flavonoids, phenylpropanoids, simple phenols, higher fatty acids, mono- and sesquiterpenes, and aliphatic hydrocarbons. T. vulgaris appeared to have the highest content of thymol (23.580 ± 1.170 mg/mL); its thymol, apigenin, gallic, chlorogenic, and caffeic components demonstrated geroprotective properties. The extract of T. pratense possessed the highest rutin content (10.05 ± 0.35 mg/mL), and it owed its geroprotective characteristics to rutin, chlorogenic and p-coumaric acids. Conclusion. The callus cultures of T. vulgaris and T. pratense proved to be promising sources of geroprotective biologically active substances.