Ex vivo inhibitory effect on tilapia LDL oxidation and hypolipidemia properties of Glycine tomentella root extract

Atorvastatin-loaded nanostructured lipid carriers (NLCs): strategy to overcome oral delivery drawbacks

Atorvastatin (AT) is a widely used lipid-regulating drug to reduce cholesterol and triglycerides. Its poor aqueous solubility and hepatic metabolism require development of drug delivery systems able to improve its solubility and bypass hepatic effect. For this purpose, atorvastatin nanostructured lipid carriers (AT-NLCs) were prepared and characterized. AT-NLCs were prepared by emulsification using high-speed homogenization followed by ultrasonication. The prepared NLCs showed particle size between 162.5 ± 12 and 865.55 ± 28 nm while zeta potential values varied between −34 ± 0.29 and −23 ± 0.36 mV. They also showed high encapsulation efficiency (>87%) and amorphous state of the drug in lipid matrix. Pharmacokinetic parameters of optimized formulation (NLC-1; composed of 2% Gelucire^® 43/01, 8% Capryol^® PGMC, 2% Pluronic^®F68 and 0.5% lecithin) revealed 3.6- and 2.1-fold increase in bioavailability as compared to atorvastatin suspension and commercial product (Lipitor^®), respectively. Administration of NLC-1 led to significant reduction (p < .05) in the rats’ serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and significant increase in high-density lipoprotein (HDL). This improvement was confirmed histologically by minimizing the associated hepatic steatosis. These investigations demonstrated the superiority of NLCs for improvement of oral bioavailability and in vivo performance of AT.

Antioxidants, anti-inflammatory, and antidiabetic effects of the aqueous extracts from Glycine species and its bioactive compounds

BACKGROUND

The aim of this study was to examine the possible antioxidant, anti-inflammatory, and antidiabetic effects of the aqueous extracts from three Glycine species. In HPLC analysis, the chromatograms of three Glycine species were established. Flavonoid-related compounds might be important bioactive compounds in Glycine species.

RESULTS

The results showed that the aqueous extract of Glycine tabacina (AGTa) had the strongest antioxidant activity compared with the other Glycine species extracts. We also found that AGTa had higher contents of total polyphenol compounds and flavonoids than the other extracts. We also have investigated the anti-inflammatory effects of the three Glycine species using lipopolysaccharide (LPS)-stimulated mouse macrophage (RAW264.7) ex vivo. When RAW264.7 macrophages were treated with different concentrations of three Glycine species together with LPS, a significant concentration-dependent inhibition of NO production was detected. The aqueous extract of Glycine max (AGM) had the strongest anti-inflammatory activity in comparison with the other Glycine species extracts. Western blotting revealed that three Glycine species blocked protein expression of iNOS and cyclooxygenase-2 (COX-2) in LPS-stimulated RAW264.7 macrophages, significantly. The antidiabetic activities of the three Glycine species were studied in vitro using α-glucosidase and aldose reductase (AR) inhibitory methods. AGTa had the highest inhibitory activities on α-glucosidase and aldose reductase, with IC₅₀ of 188.1 and 126.42 μg/mL, respectively. The bioactive compounds, genistein and daidzein, had high inhibitory activities on antioxidant, anti-inflammatory, α-glucosidase and aldose reductase.

CONCLUSIONS

These results suggest that Glycine species might be a good resource for future development of antioxidant, anti-inflammatory and antidiabetic heath foods.

Effects of replacing soybean meal with rubber seed meal on growth, antioxidant capacity, non-specific immune response, and resistance to Aeromonas hydrophila in tilapia (Oreochromis niloticus × O. aureus)

This study evaluated the effects of replacing soybean meal (SBM) with rubber seed meal (RSM) on growth, antioxidant capacity, non-specific immune response and resistance to Aeromonas hydrophila in tilapia (Oreochromis niloticus × Oreochromis aureus). Five experimental diets were formulated with 0 (control), 10, 20, 30, and 40% RSM replacing graded levels of SBM, respectively. Fish were fed one of the five experimental diets for eight weeks, and then challenged by A. hydrophila via intraperitoneal injection and kept for seven days. Dietary RSM inclusion level up to 30% did not affect the weight gain and daily growth coefficient, whereas these were depressed by a further inclusion. Fish fed diet with 40% RSM showed the lowest serum total antioxidant capacity, lysozyme, alternative complement pathway, respiratory burst and phagocytic activities. Dietary RSM inclusion gradually depressed the post-challenge survival rate, and that was significantly lower in fish fed diet with 40% RSM compared to fish fed the control diet. Conversely, the inclusion of RSM generally increased the serum total cholesterol level, the plasma alanine aminotransferase and aspartate aminotransferase activities, and these were significantly higher in fish fed diet with 40% RSM compared to fish fed the control diet. The results indicated that RSM can be included at level up to 30% in diet for tilapia without obvious adverse effects on the growth, antioxidant capacity, non-specific immune response and resistance to A. hydrophila infection, whereas these were depressed by a further inclusion.

Phenolic acids identified in sorghum distillery residue demonstrated antioxidative and anti-cold-stress properties in cultured tilapia, Oreochromis mossambicus

This study aimed to identify the bioactive compounds and evaluate the anti-cold-stress function of the sorghum distillery residue (SDR) using tilapia as an alternative animal model. The highest contents of water-soluble bioactive compounds in SDR were polyphenols, followed by tannins, anthocyanins, and flavonoids. SDR was extracted with double-distilled water, 95% ethanol, and ethyl acetate, separately. The ethanol extract (SDR-E) yielded the highest polyphenol content [15.03 mg/g of SDR dry weight (dw)], of which the EC50 value of R,R-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging efficiency was 0.56 ± 0.04 mg/mL. The SDR-E suppressed the oxidation of low-density lipoproteins (LDLs) more efficiently than that of other extracts. Tilapia fed a diet containing 3.6% SDR-E decreased accumulative mortality during cold stress, of 46.2%. The accumulative morality of the control was 92.9%. The phenolic acids identified in SDR included gallic acid (0.36 ± 0.08 mg/g of SDR dw), 3,4-dihydroxybenzoic acid (0.16 ± 0.12 mg/g of SDR dw), and 4-hydroxybenzoic acid (0.49 ± 0.23 mg/g of SDR dw). Diets supplemented with 0.5% 4-hydroxybenzoic acid fed to tilapia showed a lower mortality rate than that fed 1.0% 4-hydroxybenzoic acid, comparable to that of the tilapia fed 20% SDR. The latter showed lower mortality than that of the control. These results suggested that 4-hydroxybenzoic acid is one of the major anti-cold-stress compounds in SDR.

Dietary Aloe vera components' effects on cholesterol lowering and estrogenic responses in juvenile goldfish, Carassius auratus

Aloes are now considered a very interesting source of bioactive compounds among which phytosterols should play a major role. The present study is an attempt to investigate the hypocholesterolemic activity of Aloe vera associated with its impact on the reproductive status of juvenile goldfish. Therefore, the short- and long-term effects of feeding supplementary diet containing aloe components (20 mg aloe/g diet; 2%) on plasma lipids, plasma vitellogenin, and hepatic estrogen receptor α/β1 mRNA levels in goldfish were examined. Results of GC-MS for phytosterols show high abundance of β-sitosterol in freeze-dried powder of Aloe vera whole leaves. Moreover, a 2% aloe powder dietary supplement was not found estrogenic in juvenile goldfish after either 7- or 30-day treatment, but was consistent in plasma hypocholesterolemic effects following long-term exposure. The present data further support that plasma cholesterol modulation induced by phytosterols may not be related to estrogen-like activity.

Anti-stress effects of Glycine tomentella Hayata in tilapia: inhibiting COX-2 expression and enhancing EPA synthesis in erythrocyte membrane and fish growth

The objective of this study was to elucidate the in vivo effects of the ethanol extract of wooly Glycine tomentella Hayata (GTE) root on tilapia to elucidate whether GTE has antistress activity. Tilapia as an animal model were fed with or without GTE, then injected with lipopolysaccharide (LPS) or ammonium chloride (NH(4)Cl). The tilapia were exposed to 100 mg/L of aqueous NH(4)Cl, and/or acute cold stress. Growth parameters of the tilapia were measured during the feeding trials. Tilapia injected with GTE (20 μg/g of fish), NH(4)Cl (100 μg/g of fish) and/or LPS (1 μg/g of fish) were then sampled 2 h poststimulation. GTE significantly inhibited cyclooxygenase-2 expression and hemoglobin (Hb) dimer formation (36 kDa). GTE also improved growth and blood viscosity and upregulated eicosapentaenoic acid content of erythrocytes. The in vivo results indicated that GTE (20 μg/g of fish) can be applied as a stress-tolerance enhancing agent for the aquaculture industry.

Glycine tomentella Hayata inhibits IL-1β and IL-6 production, inhibits MMP-9 activity, and enhances RAW264.7 macrophage clearance of apoptotic cells

Background

To assess the effects of Glycine tomentella Hayata (GTH), a traditional herbal medicine for treatment of rheumatic diseases on the expression of the proinflammatory cytokines and on the clearance of apoptotic cells by macrophages.

Methods

RAW264.7 cells were cultured with lipopolysaccharide (LPS) in the presence or absence of ethanol extract of GTH. The expression of proinflammatory cytokines IL-1β, IL-6, and TNF-α, and inducible nitric oxide synthase (iNOS) and transglutaminase 2 (TG2) were assayed by reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Matrix metalloproteinase (MMP)-2 and MMP-9 were assayed by gelatin zymography. For detecting uptake of apoptotic cells, RAW264.7 cells were cultured with carboxyfluorescein diacetate (CFDA)-stained apoptotic cells and assayed by flow cytometry.

Results

The major components of GTH analyzed by high-performance liquid chromatography (HPLC) chromatogram were daidzein (42.5%), epicatechin (28.8%), and naringin (9.4%).

GTH treatment inhibited the expression of proinflammatory cytokines IL-1β, IL-6 and MMP-9 but did not affect the expression of TNF-α and iNOS. GTH significantly enhanced the expression of TG2 and the clearance of apoptotic cells by RAW264.7 macrophages.

Conclusions

GTH inhibits proinflammatory cytokine secretion and MMP-9 activity, enhances apoptotic cell uptake and up-regulates TG2 expression. Our data show that GTH might have beneficial effects on rheumatic diseases.

Lipid-lowering and LDL-oxidation inhibitory effects of aqueous extract of freshwater clam (Corbicula fluminea)--using tilapia as an animal model

A previous study has demonstrated that tilapia able to exhibit hyperlipidemia and hypercholesterolemia is a good model for the evaluation of beneficial effects of nutraceuticals. In this study, tilapia were used to evaluate the in vitro and in vivo effects of a hot water extract (FC-HW) of freshwater clam (Corbicula fluminea). FC-HW prolonged the lag phase of Cu(2+)-induced human and tilapia LDL oxidation. The prolongation of the lag phase was concentration-dependent in human (r(2)= 0.94) and tilapia LDL (r(2)= 0.98). The antioxidative potential of FC-HW was 0.33% (on a weight basis) of Trolox, a positive control. Male tilapia (n= 24) were randomly divided into 2 groups and separately fed for 60 d with an isocaloric also isoprotein diet containing 2% (w/w) FC-HW or a control diet. Body length and body mass were significantly higher in fish fed FC-HW than those of the control group (P < 0.05). Total triacylglycerol, cholesterol, and LDL-C in plasma of the FC-HW group were significantly lower (-89.9%, -61.8%, and -54.5%, respectively), while plasma total antioxidant capacity of the FC-HW group was higher and the lag phase in Cu(2+)-induced LDL oxidation was longer than those of the control group (P < 0.05). FC-HW demonstrated hypolipidemia and hypocholesterolemia effects and inhibited human LDL oxidation in vitro and tilapia LDL both in vitro and ex vivo, indicative that FC-HW can be a potential nutraceutical to reduce the risk factors of atherosclerosis.