Elaboration of approaches to standardizing love-in-a-mist (Nigella sativa) herb

Introduction. Love-in-a-mist (Nigellasativa L.) is a representative of the ranunculaceous family (Ranunculaceae). Nigellasativa L. is insufficiently studied as compared with other Nigella L. species, including wild fennel (Nigella damascena); however, it is a promising type of medicinal plant material, for which hepatoprotective, hypoglycemic, antioxidant, antibacterial, anthelmintic, and general healthimproving actions have been described. In addition to the use of the main raw material, such as the seeds of Nigella sativa L., of interest are its aboveground parts (herb) that have still been little studied and have not had a wide application in scientific medicine. Therefore, there is a need for pharmacognostic studies, followed by the development of regulatory documents confirming the identity and quality of this medicinal plant for promising raw materials. Objective: to develop a procedure for quantification determination of the amount of flavonoids in the Nigella sativa L. herb. Material and methods. The investigation object was the Nigella sativa L. herb harvested in July 2021 in the Ulyanovsk Region and in the Botanical Garden of the Samara Medical University. Direct and differential spectrophotometries were used to develop the procedure. Results. The optimal conditions were determined for quantification of the amount of flavonoids in the Nigella sativa L. herb; these were an extractant of 70% ethanol; a raw material-extractant ratio of 1:30; an extraction time of 45 min, and a raw material grinding size of 2 mm. Validation studies showed the validity of the developed procedure. Conclusion. The procedure was developed for quantification of the amount of flavonoids in the Nigella sativa L. herb, by using differential spectrophotometry at an analytical wavelength of 412 nm, calculated with reference to the standard sample (SS) - rutin. The content of the amount of flavonoids in the herb of the Nigella sativa L. cultivated in the Ulyanovsk and Samara Regions ranges 1.17 to 1.71%. The error of single determination at 95% confidence probability is ±4.17%.

Nigella sativa L, love-in-a-mist, Nigella sativa L, herb, standardization, flavonoids, spectrophotometry