Integrating metabolomics and network pharmacology to assess the effects of quercetin on lung inflammatory injury induced by human respiratory syncytial virus.

Quercetin (QR) has significant anti-respiratory syncytial virus (RSV) effects. However, its therapeutic mechanism has not been thoroughly explored. In this study, a lung inflammatory injury model caused by RSV was established in mice. Untargeted lung tissue metabolomics was used to identify differential metabolites and metabolic pathways. Network pharmacology was used to predict potential therapeutic targets of QR and analyze biological functions and pathways modulated by QR. By overlapping the results of the metabolomics and the network pharmacology analyses, the common targets of QR that were likely to be involved in the amelioration of RSV-induced lung inflammatory injury by QR were identified. Metabolomics analysis identified 52 differential metabolites and 244 corresponding targets, while network pharmacology analysis identified 126 potential targets of QR. By intersecting these 244 targets with the 126 targets, hypoxanthine-guanine phosphoribosyltransferase (HPRT1), thymidine phosphorylase (TYMP), lactoperoxidase (LPO), myeloperoxidase (MPO), and cytochrome P450 19A1 (CYP19A1) were identified as the common targets. The key targets, HPRT1, TYMP, LPO, and MPO, were components of purine metabolic pathways. The present study demonstrated that QR effectively ameliorated RSV-induced lung inflammatory injury in the established mouse model. Combining metabolomics and network pharmacology showed that the anti-RSV effect of QR was closely associated with purine metabolism pathways.

Aqueous two-phase extraction combined with chromatography: new strategies for preparative separation and purification of capsaicin from capsicum oleoresin.

Capsaicin was preparatively separated and purified from capsicum oleoresin with a new method combined with aqueous two-phase extraction (ATPE) and chromatography. Screening experiments of ATPE systems containing salts and hydrophilic alcohols showed that potassium carbonate/ethanol system was the most suitable system for capsaicin recovery among the systems considered. Response surface methodology was used to determine an optimized aqueous two-phase system for the extraction of capsaicin from capsaicin oleoresin. In a 20 % (w/w) ethanol/22.3 % (w/w) potassium carbonate system, 85.4 % of the capsaicin was recovered in the top ethanol-rich phase while most oil and capsanthin ester were removed in the interphase. The capsaicinoid extract was then subjected to two chromatographic steps using D101 macroporous resin and inexpensive SKP-10-4300 reverse-phase resin first applied for the purification of capsaicin. After simple optimization of loading/elution conditions for D101 macroporous resin chromatography and SKP-10-4300 reverse-phase resin chromatography, the purities of capsaicin were improved from 7 to 85 %. In the two chromatography processes, the recoveries of capsaicin were 93 and 80 % respectively; the productivities of capsaicin were 1.86 and 4.2 (g capsaicin/L resin) per day respectively. It is worth mentioning that a by-product of capsaicin production was also obtained with a high purity (90 %).