Phytochemical and biological study of phenolic components from Geoffroea decorticans stem bark / Estudio fitoquímico y biológico de los componentes fenólicos de la corteza de Geoffroea decorticans

The stem bark of Geoffroea decorticans (Gill.ex Hook. etArn.) Burk. was used medicinally to cure several skin affections; however, phytochemical and biological antecedents were not found. Analyses of purified methanolic extract from G. decorticans bark (PFGB), realized by silylation derivatization for GC/MS, C18-CC and HPLC followed by two-dimensional TLC and UV-Vis spectroscopy, allowed to characterize nine phenolic compounds, among these, two methoxy flavonoids. Antibacterial assays of PFGB showed the highest activity (MICs = 125 µg/mL) against Staphylococcus aureus (25923) and Enterococcus faecalis (29212) ATCC strains. Moreover, PFGB showed the highest intracellular antioxidant activity at low concentration (5 µg/mL), evaluated by using the fluorescent DA-H2DCF probe on lymphocyte culture; cytotoxic effects on lymphocytes activated or not by LPS were not observed, through Trypan Blue Exclusion and MTT colorimetric assays. The results obtained from the ethnomedicinal approach of this work contribute to the scientific validation of the vulnerary medicinal use of G. decorticans.

La corteza de Geoffroea decorticans (Gill.ex Hook. EtArn.) Burk. se utiliza con fines medicinales para curar diferentes afecciones de la piel; sin embargo, no encontramos antecedentes fitoquímicos y biológicos que validen las propiedades medicinales atribuidas. Analizamos el extracto metanólico purificado de corteza de G. decorticans (PFGB), por CG-EM de la muestra derivatizada por sililación, C18-CC y HPLC seguido de CCF bidimensional, y espectroscopia UV-Vis; estos métodos nos permitieron caracterizar nueve compuestos fenólicos, entre estos, dos metoxi-flavonoides. Los ensayos antibacterianos de PFGB mostraron mayor actividad (CIMs = 125 µg/mL) contra las cepas ATCC de Staphylococcus aureus (25923) y Enterococcus faecalis (29212). Además, PFGB evidenció la mayor actividad antioxidante intracelular a baja concentración(5 µg/mL), evaluada en cultivo de linfocitos, mediante el uso de sonda fluorescente DA-H2DCF; no se observaron efectos citotóxicos sobre linfocitos activados o no por LPS, a través de ensayos colorimétricos con MTT y test de exclusión con azul Tripán. Los resultados obtenidos del abordaje etnomedicinal de este trabajo, contribuyen con la validación científica del uso medicinal vulnerario de G. decorticans.

Study on antiviral activity and characteristic spectrum of phenolic fraction of Mentha haplocalyx / 中草药

Objective To explore the anti-influenza virus effect of phenolic fraction of Mentha haplocalyx in vitro, and to establish the HPLC characteristic spectrum of phenolic fraction of M. haplocalyx for its quality evaluation. Methods MTT method was used to detect the inhibitory effect of phenolic fraction of M. haplocalyx on influenza virus PR8 infecting MDCK cells in three ways, including adding drug firstly, adding drug and virus simultaneously and adding virus firstly. The characteristic spectrum of phenolic fraction samples of 12 batches of M. haplocalyx was established by HPLC method. The similarity of which was analyzed with Similarity Evaluation System for Chromatographic Fingerprint of Chinese Materia Medica (2.0 version). Results The phenolic fraction at 0.31—10 μg/mL showed antivirus PR8 activities in different degrees under three adding drug ways. Phenolic fraction of M. haplocalyx at six dilution concentrations displayed obvious antivirus PR8 effect under two adding drug ways including adding drug firstly and adding virus firstly, and virus inhibition rates of which were 14.17%—41.31% and 45.64%—87.48%, respectively. Total of 11 peaks were chosen as the common characteristic peaks of spectrum with the similarity degrees more than 0.9 of 12 batches of samples, which illustrated that different batches of phenolic fraction of M. haplocalyx were of high similarity. Conclusion Phenolic fraction of M. haplocalyx had better antiviral effect in vitro. The characteristic spectrum method established in this paper was simple, stable and reproducible, which could reflect the whole profile of phenolic fraction of M. haplocalyx and provide reference for quality control and efficacy stability of phenolic fraction of M. haplocalyx.

In vitro aldose reductase inhibitory potential of fractions isolated from Potentilla fulgens roots.

The present study was investigated to identify the active fraction of P. fulgens with aldose reductase (AR) inhibitory potential. AR is the rate limiting step of polyol pathway implicated in the onset of chronic complications of diabetes. In this study, kidney homogenates of normoglycemic and diabetic mice were used as a source of AR enzyme preparation for in vitro analysis. The Terpenoid/Phenolic (TP) fraction of P. fulgens had the lowest IC50 value (0.152 mg/ml) for AR than the other fractions. TP fraction was separated using thin layer chromatography (TLC) and separated TLC fractions were tested for their AR inhibitory activity. Among the TLC fractions, F-V had the lowest IC50 value (0.156 mg/ml) and was characterized further using High Performance Liquid Chromatography (HPLC), Infra-Red (IR) Spectroscopy and Mass Spectroscopy (MS). F-V showed absorption maxima at λ230 nm and λ280 nm. HPLC profile of this fraction showed the presence of one prominent peak with a retention time of 1.621. IR spectra of the prominent peak indicated the presence of aromatic group which is phenolic in nature. MS of the prominent peak showed m/z ratio of 458.8. The active fraction isolated from P. fulgens has been shown to inhibit AR in normoglycemic and diabetic mice.