Analiza fitochemiczna gatunków Melilotus officinalis i Melilotus alba

Abstract

Introduction. All over the world, natural medicine uses species of the genus Melilotus due to their anti-inflammatory, anti-rheumatic, analgesic, spasmolytic, astringent, diuretic and anticoagulant effects. In the Polish Pharmacopoeia, only the yellow melilot herb (Meliloti herba) has a monograph. Aim. The research was aimed at a comparative analysis of the content of the sum of polyphenolic compounds, including the sum of flavonoids and phenolic acids, and antioxidant activity in water extracts of M. officinalis and M. alba herb and root. Material and methods. The research was carried out for two species of Melilotus officinalis and M. alba. The raw material was herb and melilot root, collected during flowering period from natural sites. In aqueous extracts from raw materials, the following methods were determined by colorimetric methods: the sum of polyphenolic compounds using the Folin-Ciocalteu reagent, the sum of phenolic acids using the Arnov reagent, the sum of flavonoids using the Christ-Müller method and the antioxidant activity using the 2,2-diphenyl-1-picryl-radical hydrazyl (DPPH). Results. Meliloti alba herb has a much higher content of polyphenols, including phenolic acids and flavonoids than M. officinalis. In the yellow sweet clover the sum of polyphenols in the samples ranged from 2.101 to 2.438%, while in the white sweet clover from 2.765 to 3.540%. The content of phenolic acids in the samples of yellow sweet clover herb was 0.617-0.766%, and in the samples of white sweet clover herb was 0.646-0.900%. The content of flavonoids in the samples of yellow sweet clover herb ranged from 0.748 to 0.975%, and in the case of white sweet clover herb it was at the level of 0.801-1.192%. The samples of the commercial yellow sweet clover herb had the lowest content of phenolic compounds; the sum of polyphenols was 1.579%, phenolic acids 0.361%, and flavonoids 0.441%. The determined content of total polyphenols in the roots of both melilot species was low and amounted to 0.450% in MORA1 and 0.362% in MARA2. Despite the lower content of polyphenolic compounds (2.438%), the yellow melilot showed higher antioxidant activity (IC50 = 4.35 mg/ml) compared to the white melilot herb (IC50 = 5.31) with a higher content of polyphenols (3.010%). Conclusions. A higher content of the sum of polyphenols as well as phenolic acids and flavonoids was found in the white melilot. In both the yellow and white sweet clover herb extract, significantly more polyphenolic compounds were determined compared to the content in their root extract.