Chromatographic Analysis and Anti-Oxidative Property of Naoxinqing Tablet, a Proprietary Preparation of Diospyros Kaki Leaves

Abstract

The Naoxinqing (NXQ) tablet is a standardised proprietary herbal product containing an extract of persimmon leaves (Diospyros kaki) for the management of cardio- and cerebrovascular diseases. Although previous reports suggested that the efficacy of NXQ is at least partly mediated by its anti-oxidative property, the anti-oxidative effect of the major components of NXQ has not been studied systematically. For quality control purposes, only analytical methods limited to 3 marker analytes have been reported, the extent to which the other components affect efficacy has not been explored. In this study, we developed an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC MS/MS) method for the identification of seven analytes (kaempferol-3-O-glucoside (astragalin), quercetin-3-O-galactoside (hypericin), quercetin-3-O-glucoside (isoquercitin), kaempferol, 3,4-dihydroxybenzoic acid (protocatechuic acid), and furan-2-carboxylic acid (pyromucic acid) and quercetin) in the NXQ. This is the first method reported and validated for the quantification of the seven major secondary metabolites in NXQ. The results for the quantified analytes were then compared in 15 different batches of NXQ. The variation observed in the seven components highlights the need to quantify key bioactive components to ensure product consistency. Radical scavenging activity and abundance was used to rank the analytes. The anti-oxidative effects of NXQ were examined using cultured human vascular endothelial cells (EA.hy926). Corrected 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) activity results revealed that quercetin and kaempferol have the strongest anti-oxidant capacity in the extract. Both quercetin and kaempferol significantly inhibited the hydrogen peroxide (H2O2)-induced EA.hy926 cell injury and intracellular reactive oxygen species (ROS) generation. In conclusion, we established and validated an UPLC-MS/MC method for the analysis of major bioactive components in the NXQ and demonstrated that its anti-oxidative property may play a critical role in cerebrovascular protection.

Insecticidal Activities of Atriplex halimus L., Salvia rosmarinus Spenn. and Cuminum cyminum L. against Dactylopius opuntiae (Cockerell) under Laboratory and Greenhouse Conditions

“…Finally, a compound was putatively annotated when it has been previously reported from either the studied plant or one of the species of the genus [ 18 , 20 , 27 , 28 , 29 ] and its MS characteristics matched with fragmentation patterns listed above. The other compounds were annotated by comparison of their respective MS characteristics with reported MS data in the literature [ 30 , 31 , 32 , 33 ].…”

Persimmon Leaves: Nutritional, Pharmaceutical, and Industrial Potential—A Review

“…NXQ prepared from PL is used for the management of cardio- and cerebrovascular diseases, and its composition was investigated using UPLC coupled with a tandem MS [ 42 ]. Seven compounds, specifically kaempferol-3- O -glucoside (astragalin), quercetin-3- O -glucoside (isoquercitin), quercetin-3- O -galactoside (hypericin), kaempferol, quercetin, pyromucic acid, and protocatechuic acid were identified in the NXQ.…”

“…Results suggested that harvest time and variety were important factors for antioxidant activity, mainly those harvested in months with higher ambient temperature, sunshine duration, and solar radiation. Moreover, Kazzem et al [ 42 ] determined the antioxidant activity of NXQ tablets prepared from PL. It was found that flavonoids, mainly quercetin and kaempferol, showed strong DPPH radical scavenging activity and inhibited the H 2 O 2 -induced human vascular endothelial (EA.hy926) cell injury and intracellular ROS generation.…”

Separation, identification, and fingerprinting of antioxidant components in persimmon (Diospyros kaki) leaves by offline two‐dimensional liquid chromatography with electrochemical detection and tandem mass spectrometry

“…Among them, phenolic acids such as gallic acid, caffeic acid, chlorogenic acid, and cinnamic acid, and flavonoids such as kaempferol-3-Oglucoside, isoquercitrin, quercetin, hyperoside, and rutin, are present in persimmon leaves [8]. At present, there is no effective assay to evaluate the content of these phenolics comprehensively, and the existing studies only determine a small amount of those compounds [9,10]. Therefore, the contribution of different compounds to antioxidant activity is still unclear.…”