Analysis of polyphenolic composition and stability of magistral preparation based on salviae officinalis folium

Kowalczyk A.;Wlodarczyk M.;Tuberoso C. I. G.;Fecka I.

2020-01-01

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Abstract

A magistral preparation based on the sage leaf decoction or infusion is one of the most popular herbal prescriptions prepared in pharmacies in Lower Silesia (Poland) for gargling in the case of pharyngitis or mouth infections. Other components of this preparation are boric acid, aluminum(III) acetotartrate or Burow's solution, and glycerol. The study aimed to investigate the polyphenolic composition and relations between herbal and chemical ingredients that are present in this mixture in comparison with the traditional aqueous galenic forms - infusion and decoction. The analysis was performed using high-performance liquid chromatography with diode-array detector (HPLC-DAD) and electrospray ionization mass spectrometry (ESI-MS) methods. The main polyphenolic ingredients of sage leaf were rosmarinic acid (RA) and luteolin 7-O-β-glucuronide. The RA predominance was observed in the infusion, decoction and magistral preparation. Comparing the contents of analyzed polyphenols, it was confirmed that their levels in the decoction were higher than in the infusion. Thus, the pharmacological activity of the examined magistral preparation results from the presence of boric acid, aluminum(III) salts and polyphenolic components of sage leaf hot water extract. The succeeding study showed that in the presence of excess salts of aluminum(III) and boric acid, sage polyphenols are partially soluble in an aqueous medium (mainly phenolic acids) and complexed as precipitated sediment (especially flavonoids). The aqueous solutions of this preparation obtained according to the recommendation are cloudy, which suggests limited solubility of the formed complexes. Therefore, the therapeutic activity should be associated with the presence of water-soluble caffeic acid esters like rosmarinic acid. The influence of luteolin glycosides coordination complexes is not evident. The obtained results also confirm the stability of the examined prescription formulation in the conditions of cold storage (4-6OC) within 7 days from its production.