Microscopical characteristics, phytochemical investigation and biological activities of different Lysimachia species growing in Vietnam

Several species of the genus Lysimachia L. (Primulaceae) are well known in folk medicine, but very few studies have been conducted on them. The aim of our study was to investigate the microscopical characteristics and chemical composition of Lysimachia insignis Hemsl., L. decurrens G. Forst., and L. congestra Hemsl. as well as to evaluate some biological activities of their methanol extracts. The transverse sections of stem and powder characteristics of the three Lysimachia species shared some similarities. Also, some differences were indicated. The chemical investigation of three aforesaid species including the preliminary phytochemical screening, the quantification of the total polyphenol content and total flavonoid content, as well as the determination of metabolites. The phytochemical screening showed the presence of flavonoids, saponins, tannins and sterols in all the three species. On the other hand, coumarins were detected in L. insignis while anthranoids were present in L. decurrens and L. congestiflora. The total polyphenol content and the total flavonoid content of the aforesaid species were determined by the spectrometric method. The metabolite profiling approach of three species was performed by LC-Q ToF-HRMS and HPTLC. The methanol extract of L. insignis showed a weak inhibitory effect on NO production (I% = 57.4 at the concentration of 100 ptg/m1) while the extract of L. decurrens exhibited moderate anti-oxidant activity in vitro (SC% = 62.5 at the concentration of 100 F.g/mL).