Enhancement of growth, antioxidative status, nonspecific immunity, and disease resistance in gibel carp (Carassius auratus) in response to dietary Flos populi extract.

This study investigated the effects of dietary Flos populi extract (FPE) on the growth, antioxidation capability, innate immune response, and disease resistance in gibel carp. A total of 480 fish were fed with five different diets containing 0, 0.5, 1.0, 1.5, or 2.0 g kg-1 FPE (designated as control, D0.5, D1.0, D1.5, or D2.0 groups) for 45 days. The fish were challenged with A. hydrophila after the feeding trial. Compared with the control, the feed efficiency (FE), weight gain (WG), final body weight (FBW), and specific growth rate (SGR) were significantly improved in groups D1.0 and D1.5. Dietary FPE significantly increased serum superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities, as well as glutathione (GSH) content. The contents of protein carbonyl (PCC) and malondialdehyde (MDA) in serum decreased significantly. Additionally, FPE supplementation in diets resulted in significant improvement in serum lysozyme (LZM) and myeloperoxidase (MPO) activities, as well as immunoglobulin M (IgM) and complement 3 (C3) concentrations. The hepatic antioxidant enzymes (CAT and SOD) activities increased, whereas content of MDA decreased in fish treated with dietary FPE than those of control both pre- and post-challenged. After 12 h-challenge, an obvious downregulation of hepatic Kelch-like-ECH-associated protein 1 (Keap1), splenic tumor necrosis factor-α (TNF-α), interleukin (IL)-8, IL-1ß, and toll-like receptor 2 (TLR2) mRNA levels was observed in fish treated with dietary FPE, whereas hepatic Nrf2 transcription level was upregulated compared to the control. Furthermore, compared to group D0.5, higher relative percent survival (RPS) was observed in gibel carp fed dietary 1.0-2.0 g/kg FPE. Our results reveal that FPE supplemented diet has a stimulatory effect on antioxidant capacity and nonspecific immune response, along with improved growth performance and enhanced resistance against A. hydrophila infection in juvenile gibel carp.

Flos populi (Male Inflorescence of Populus tomentosa Carrière) Aqueous Extract Suppresses Salmonella Pullorum Infection by Affecting T3SS-1.

Pullorum disease, caused by Salmonella Pullorum (S. Pullorum), is one of the most serious infectious diseases in the poultry industry. Flos populi is traditionally used in Eastern Asian countries to treat various intestinal diseases. However, the anti-infection mechanism of Flos populi is not very clear. In this study, we evaluated the anti-infective effects on S. Pullorum of Flos populi aqueous extract (FPAE) in chickens. FPAE significantly reduced S. Pullorum growth in vitro. At the cellular level, FPAE reduced S. Pullorum adhesion and invasion on DF-1 cells but did not affect its intracellular survival or replication in macrophages. Further investigation revealed that FPAE inhibited the transcription of T3SS-1 genes, which is the main virulence factor that mediates S. Pullorum adhesion and invasion in host cells. The results suggest that the anti-infective effect of FPAE likely occurs through the inhibition of S. Pullorum T3SS-1, thereby impairing its ability to adhere to and invade cells. Further, we evaluated its therapeutic effect on animal models (Jianghan domestic chickens) and found that FPAE reduced the bacterial loads in organs and decreased the mortality and weight loss of infected chickens. Our findings provide novel insights into the potential development of FPAE against S. Pullorum as an effective anti-virulence therapeutic substitute for antibiotics.

Antioxidant and anti-inflammatory constituents from Flos populi.

Investigation of the n-butanol extract of Flos populi led to the isolation of one new phenolic glycoside, 4'-hydroxybenzyl-2-hydroxybenzoate-1'-O-ß-D-glucopyranoside (1), together with twelve known compounds, which have been determined on the basis of spectroscopic analysis including UV, IR, HR-ESI-MS and 1D/2D NMR. The antioxidant capacity of all compounds were evaluated by ABTS radical-scavenging test and ferric reducing antioxidant power (FRAP) assay. And during a screening procedure for the anti-inflammatory activities among most compounds on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells, compound 13 exhibited remarkable inhibitory effects on nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1ß, suggesting that it might be a promising candidate as an anti-inflammatory agent.

Anti-inflammatory and analgesic activity of aqueous extract of Flos populi.

ETHNOPHARMACOLOGICAL RELEVANCE: Flos populi is an important traditional Chinese medicine prepared from the male inflorescence of Populus tomentosa Carr. or Populus canadensis Moench (Salicaceae family). Flos populi is mainly used for the treatment of various inflammatory diseases and anti diarrhea in East Asian countries. The objective of this study was to investigate the anti-inflammatory and analgesic properties of the aqueous extract of Flos populi (FPAE). MATERIALS AND METHODS: Cotton pellets-induced granuloma, carrageenan-induced paw oedema, arachidonic acid-induced right ear oedema and xylene-induced ear oedema were used to assess anti-inflammatory activity of FPAE and analgesic activity was evaluated by hot plate test, acetic acid-induced abdominal writhing test and formalin test. RESULTS: FPAE produced significant dose-response anti-inflammatory activity against cotton pellets-induced granuloma. FPAE at dosages of 50, 100 and 200 mg/kg bw. significantly reduced carrageenan-induced paw edema by 48.84% (P<0.05), 54.95% (P<0.05), and 62.05% (P<0.05) at 5h after carrageenan injection, respectively. FPAE significantly (P<0.05) reduced the ear oedema induced by arachidonic acid and peaked at the dose of 200 mg/kg bw. (40.78%). A significant (P<0.05) dose dependent inhibition of xylene-induced oedema was produced by FPAE and peaked at the highest dose of 200 mg/kg bw. (23.95%). FPAE (50, 100 and 200 mg/kg bw.) produced significant dose-response analgesic activity in the hot-plate test. However, the low percentage inhibition (<50%) suggests that it is not a centrally acting analgesic. Extract at dosages of 50, 100 and 200 mg/kg bw., p.o. significantly reduced acetic acid-induced writhing by 39.6% (P<0.05), 45.4% (P<0.05), and 51.8% (P<0.05), respectively. The extract also caused marked dose-dependent inhibition of formalin-induced pain in the second phase (P<0.05). CONCLUSION: The findings in this study suggest that the aqueous extract of Flos populi possesses anti-inflammatory and analgesic activities. These results may support the fact that this plant is used traditionally to cure inflammatory diseases.

Hypolipidaemic and antioxidant properties of ethanol extract from Flos populi.

This study was undertaken to evaluate antihyperlipidaemic and in vitro antioxidant activity of ethanolic extract of Flos populi (EFP). The results demonstrated that EFP contains 78.5% flavonoids and 10.4% phenolics, and it exhibited free radical-scavenging activity on 2,2-diphenyl-picrylhydrazyl (IC50 36.40 ± 0.62 µg/mL) and high reducing power (EC50 206.32 ± 1.6l µg/mL) under in vitro chemical assays. And irrespective of prophylactic administration or remedial administration, in high fat diet-induced hyperlipidaemic mice, oral treatment with EFP produced a decrease in the levels of serum total cholesterol, triglycerides, low-density lipoprotein-cholesterol and increase in high-density lipoprotein-cholesterol. In a word, in high fat diet-fed hyperlipidaemic mice, EFP (100, 200 and 400 mg/kg) significantly altered the plasma lipid levels to near normal. These results support a potential effect of EFP in cardiovascular disease.

Adsorption/desorption characteristics and enrichment of quercetin, luteolin and apigenin from Flos populi using macroporous resin

Abstract In this study, the adsorption/desorption characteristics of quercetin, luteolin and apigenin from Flos populi extract (Populus tomentosa Carrière, Salicaceae) on twelve macroporous resins (NKA-9, HPD-600, HPD-826, HPD-750, HPD-400, DM-130, AB-8, SP-825, X-5, D-101, HPD-100, HPD-200) were evaluated. Both high adsorption and desorption capacities of quercetin, luteolin and apigenin from Flos populi extract on SP-825 resin indicated that SP-825 resin was appropriate and its data were well fitted to the Langmuir and Freundlich isotherms. To get the optimal separation process, the influences of factors such as flow rates, loading sample volumes, concentrations of desorption solution were further investigated. Column packed with SP-825 resin was used to perform dynamic adsorption and desorption experiments. After one round of treatment, the contents of quercetin, luteolin and apigenin in the final products were 3.75-fold, 3.67-fold and 3.54-fold increased with recovery yields of 87.25, 85.19 and 82.22%, respectively. The results showed that the preparative enrichment of quercetin, luteolin and apigenin was available via adsorption and desorption on SP-825 resin. This method is a promising basis for the large-scale preparation of quercetin, luteolin and apigenin from Flos populi.

Enrichment and purification of total flavonoids from Flos Populi extracts with macroporous resins and evaluation of antioxidant activities in vitro.

Enrichment and purification of total flavonoids from Flos Populi extracts were studied using five macroporous resins. The static tests indicated that NKA-9 resin was appropriate and its adsorption data were well fitted to the Langmuir and Freundlich isotherms. To optimize the separation process, dynamic adsorption and desorption tests were carried out. The optimal adsorption parameters were initial concentrations in sample solution of 7.64mg/mL, pH of 5.0, sample loading amount of 2.3BV, flow rate of 2BV/h, temperature of 25°C. The optimal desorption parameters were deionized water and 20% ethanol each 5BV, then 60% ethanol of 10 BV, flow rate of 2BV/h. After one run treatment with NKA-9 resin, the content of total flavonoids in the product increased from 11.38% to 53.41%, and the recovery yield was 82.24%. The results showed that NKA-9 resin revealed a good ability to enrichment total flavonoids from Flos Populi, and the method can be referenced for the enrichment of total flavonoids from other materials. The antioxidant activities of the purified flavonoids were further evaluated in vitro. It showed that the DPPH radical scavenging increased from 59.46% to 82.63% at different concentrations (0.06-0.14mg/mL). At different concentrations (0.6-1.4mg/mL), the hydroxyl radical scavenging increased from 35.39% to 74.12%. Moreover, the reducing ability and total oxidant capacity appeared to be dose-dependent of flavonoids. It indicated that the purified flavonoids can be used as a source of potential antioxidant.