Inhibitory Effects of Secoiridoids from the Roots of Gentiana straminea on Stimulus‐induced Superoxide Generation, Phosphorylation and Translocation of Cytosolic Compounds to Plasma Membrane in Human Neutrophils

Abstract

Gentiana straminea Maxim. has been used widely as a traditional Chinese medicine for the treatment of rheumarthritis, icterepatitis, constipation, pain and hypertension. Five secoiridoids, gentiopicroside (GTP), 6'-O-(2-hydroxy-3-O-β-D-glucopyranosyl-benzoyl)-sweroside (HGBS), 6'-O-β-D-glucosylgentiopicroside (GGTP), sweroside (SW) and swertiamarin (STM) were isolated from the roots of G. straminea. The effect of these secoiridoids on stimulus-induced superoxide generation in human neutrophils was assayed by measuring the reduction of ferricytochrome c. Tyrosyl or serine/threonine phosphorylation of neutrophil proteins, and translocation of the cytosolic compounds to the cell membrane were also investigated using specific monoclonal antibodies. The five secoiridoids used in the present experiment suppressed N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced superoxide generation in a concentration dependent manner. GTP and HGBS also suppressed phorbol 12-myristate 13-acetate (PMA) and arachidonic acid (AA)-induced superoxide generation. However, the other three secoiridoids showed no effect on PMA- and AA-induced superoxide generation. fMLP-, PMA- and AA-induced tyrosyl or serine/threonine phosphorylation and translocation of the cytosolic proteins to the cell membrane were suppressed in parallel with the suppression of the stimulus-induced superoxide generation.

Screening of Antioxidant Activity of Gentian Lutea Root and Its Application in Oil-in-Water Emulsions

“…[ 2 , 3 ]. Furthermore, a substantial number of studies have demonstrated the effect of the secoiridoid group on the scavenging function to generate free radicals [ 7 , 13 , 48 ]. Wei et al .…”

“…Wei et al . [ 13 ] reported that five secoiridoids, including gentiopicroside, sweroside, swertiamarin and sweroside, did not show any scavenging ability towards free radicals by in vitro DPPH assay. However, taking into account their report, it was desirable to explore more individual extracted compounds by isolating the compounds followed by a biochemical assay, such as ABTS radical, to measure their activity.…”

“…Furthermore, xanthone, and its derivatives, are phenolic compounds with antioxidant properties which have attracted much attention recently [ 12 ]. There are few reports that have investigated the radical scavenging activities of secoiridoid-glycosides using DPPH assay [ 7 , 13 ], although some authors have measured total antioxidant capacity of G. Lutea but without sufficient assessment of individual antioxidants [ 10 , 14 ]. However, the observation of antioxidant activity of G. Lutea extract towards lipid oxidation has not been fully determined.…”

Characterization of metabolites of sweroside in rat urine using ultra-high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry and NMR spectroscopy

“…Sweroside, a natural iridoid compound, is a main active component of Swertia pseudochinensis Hara which has been used to treat jaundice and diarrhea in clinics in Asia . Sweroside has been extensively studied and demonstrated for possessing various bioactivities, including wound healing, cell neuritogenic activity, antioxidation and typically concerned in the treatment of hepatobiliary disorders . Pre‐clinical experiments in rats have shown that the administration of sweroside prior to that of the carbon tetrachloride effectively protects against carbon tetrachloride‐induced liver injury .…”

Chemical and Genetic Comparative Analysis of Gentiana crassicaulis and Gentiana macrophylla

“…Radix Gentianae Macrophyllae, also referred to as Qinjiao, is a well‐known herbal medicine widely distributed in P. R. China, Kazakhstan, Mongolia, and the Russian Federation. It has been frequently used for the treatment of rheumatic arthritis, inflammation, pain, and hepatitis . As to the plant origin, Qinjiao are originated from four perennial medicinal plants from the genus Gentiana (Gentianaceae) recorded in Chinese Pharmacopeia , including Gentiana crassicaulis Duthie ex Burk ., Gentiana macrophylla Pall ., Gentiana straminea Maxim ., and Gentiana dahurica Fisch .…”