scholarly journals Optimized Extraction of Polysaccharides from Bergenia emeiensis Rhizome, Their Antioxidant Ability and Protection of Cells from Acrylamide-induced Cell Death

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 976 ◽  
Author(s):  
Chen Zeng ◽  
Shiling Feng

Bergeniaemeiensis is a traditional herb in Chinese folk medicine. Most related studies are focused on the bioactivity of bergenin, neglecting other bioactive compounds. In our previous work, polysaccharides were identified in B. emeiensis rhizome. To evaluate the extraction process and the antioxidant ability of these polysaccharides, a response surface method and antioxidant assays were applied. The results showed that the yield of polysaccharides was highly affected by extraction time, followed by temperature and solvent-to-sample ratio. Under the optimal conditions (43 °C, 30 min and 21 mL/g), the yield was 158.34 ± 0.98 mg/g. After removing other impurities, the purity of the polysaccharides from B. emeiensis (PBE) was 95.97 ± 0.92%. The infrared spectrum showed that PBE had a typical polysaccharide structure. Further investigations exhibited the PBE could scavenge well DPPH and ABTS free radicals and chelate Fe2+, showing an excellent antioxidant capacity. In addition, PBE also enhanced the cell viability of HEK 239T and Hep G2 cells under acrylamide-exposure conditions, exhibiting great protection against the damage induced by acrylamide. Therefore, PBE can be considered a potential natural antioxidant candidate for use in the pharmaceutical industry as a health product.

Food Research ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 2224-2232
Author(s):  
R. Wahyuni ◽  
W. Wignyanto ◽  
S. Wijana ◽  
S. Sucipto

Moringa oleifera contains high nutritional and bioactive compounds that have the potential as a source of antioxidants. The main objective of this study was to obtain optimal conditions in the extraction process of Moringa leaf, maintain protein and antioxidant activity, and reduce tannin. It is carried out through the response surface method which consists of two factors. The first factor (X1) was the extraction temperature (°C) which contains three levels, namely 70, 80, and 90°C. The second factor (X2) was time (mins) consisting of three levels, namely 5, 10, and 15 mins. The parameters in this study were total protein, antioxidant activity, and total tannin. The results revealed that the optimum condition for Moringa leaf extraction is found to be temperature 80.54°C and a time of 12.19 mins. In that treatment, the total protein is 17.4594%, antioxidant activity is up to 10.2629 µg/mL, and tannin is 7.853% with the desirability of 0.792 or 79.2%.


1993 ◽  
Vol 70 (02) ◽  
pp. 273-280 ◽  
Author(s):  
Janos Kappelmayer ◽  
Satya P Kunapuli ◽  
Edward G Wyshock ◽  
Robert W Colman

SummaryWe demonstrate that in addition to possessing binding sites for intact factor V (FV), unstimulated peripheral blood monocytes also express activated factor V (FVa) on their surfaces. FVa was identified on the monocyte surface by monoclonal antibody B38 recognizing FVa light chain and by human oligoclonal antibodies H1 (to FVa light chain) and H2 (to FVa heavy chain) using immunofluorescence microscopy and flow cytometry. On Western blots, partially cleaved FV could be identified as a 220 kDa band in lysates of monocytes. In addition to surface expression of FVa, monocytes also contain intracellular FV as detected only after permeabilization by Triton X-100 by monoclonal antibody B10 directed specifically to the Cl domain not present in FVa. We sought to determine whether the presence of FV in peripheral blood monocytes is a result of de novo synthesis.Using in situ hybridization, no FV mRNA could be detected in monocytes, while in parallel control studies, factor V mRNA was detectable in Hep G2 cells and CD18 mRNA in monocytes. In addition, using reverse transcriptase and the polymerase chain reaction, no FV mRNA was detected in mononuclear cells or in U937 cells, but mRNA for factor V was present in Hep G2 cells using the same techniques. These data suggest that FV is present in human monocytes, presumably acquired by binding of plasma FV, and that the presence of this critical coagulation factor is not due to de novo synthesis.


Author(s):  
Sara Díaz ◽  
Antonio N. Benítez ◽  
Sara Ramírez-Bolaños ◽  
Lidia Robaina ◽  
Zaida Ortega

AbstractThe aim of this work is the optimization of phenolic compound extraction from three by-products of banana crops (rachis, discarded banana, and banana’s pseudostem pulp), as a way to valorize them through a green extraction process. The influence of the temperature and aqueous ethanol concentration (Et-OH) on extract properties (total phenol content (TPC) and antioxidant activity) was firstly analyzed. 78 ℃ and ethanol concentrations close to 50% yielded the best results for the three materials. The equations obtained by the response surface methodology gave a satisfactory description of the experimental data, allowing optimizing the extraction conditions. Under optimized conditions, time influence was then assessed, although this parameter seemed not influence results. Among the three by-products, rachis extract (60% Et-OH, 78 ℃, and 30 min) presented the highest TPC (796 mg gallic acid/100 g of dried material) and antioxidant activity (6.51 mg Trolox equivalents/g of dried material), followed by discarded banana, and pseudostem pulp. Under the optimal conditions, experiments were performed at a larger scale, allowing to determine the extraction yields (EY) and to characterize the extracts. The highest EY was obtained for the rachis (26%), but the extract with the highest activity was obtained for discarded banana (50% Et-OH, 78 ℃, and 60 min), which presented a TPC of 27.26 mg/g extract corresponding to 54.59 mg Trolox equivalents/g extract. This study contributes to the valorization of banana crops residues as a source of polyphenolic compounds with bioactive functions that can be extracted under economic extraction conditions. Graphical abstract


1989 ◽  
Vol 16 (4) ◽  
pp. 344-352
Author(s):  
Paul J. Dierickx

Glutamic acid (GA) content was measured in cultured Hep G2 cells, after treatment of the cells with test compounds. The results with 37 chemicals were compared with their respective rabbit eye irritation data, of which 17 were determined according to the OECD test, and the other 20 in range-finding studies. The chemicals were mainly organic solvents (alcohols, esters, amines, acids and others). The xenobiotics were applied to the cells for 4 hours at 5 different concentrations. The cells were then incubated for 15 minutes with tritiated GA. GA uptake inhibition was measured by liquid scintillation counting, and the results were expressed as the GI50 value, which is the concentration of test compound required to induce a 50% reduction in GA uptake. A linear correlation coefficient r = 0.66 was found between the log GI50 and the mean corneal opacity scores. This value is comparable to that obtained in total protein and uridine uptake inhibition studies. However, r = 0.81 was found when the log GI50 was compared with range-finding scores, indicating that a closer relationship exists between cytotoxicity and the latter.


1984 ◽  
Vol 259 (24) ◽  
pp. 15556-15563 ◽  
Author(s):  
J I Gordon ◽  
H F Sims ◽  
C Edelstein ◽  
A M Scanu ◽  
A W Strauss
Keyword(s):  
Hep G2 ◽  

1988 ◽  
Vol 16 (1) ◽  
pp. 16-22
Author(s):  
Marina Marinovich ◽  
Jose L. Lorenzo ◽  
Liliana M. Flaminio ◽  
Agnese Granata ◽  
Corrado L. Galli

The hepatotoxicity of carbon tetrachloride (CC14) was evaluated in vitro in freshly isolated rat hepatocytes and in the human hepatoma cell line, Hep G2. Toxicity was assessed by the leakage of cytosolic enzymes (lactate dehydrogenase and aspartate aminotransferase) and cell viability (trypan blue exclusion). The established human cells were less sensitive to CCl4-induced injury; higher doses of the toxic agent and longer incubation times were necessary to elicit cell damage. Micromolar concentrations of prostaglandin E2 significantly decreased enzyme leakage in both Hep G2 cells and rat hepatocytes challenged with CC14; a stable derivative of prostacyclin (ZK 36374) was ineffective. These results suggest that human hepatoma Hep G2 cells may represent a valid alternative to isolated rat hepatocytes for an initial approach to the in vitro evaluation of cell toxicity.


1990 ◽  
Vol 17 (4) ◽  
pp. 325-333
Author(s):  
Paul J. Dierickx ◽  
Virginia C. Gordon

The neutral red uptake inhibition assay and the EYTEX™ system were investigated as alternative methods for the assessment of eye irritation, determined according to the EEC protocol. The 17 test chemicals used were mainly organic solvents. The xenobiotics were applied to Hep G2 cells for 24 hours at different concentrations. Neutral red uptake inhibition was then measured. The results are expressed as the NI50 value, which is the concentration of test compound required to induce a 50% reduction in neutral red uptake. The same chemicals were also tested as coded samples by the EYTEX™ test according to the manufacturer's directions. A nearly identical quantitative correlation was found for both in vitro methods with corneal opacity scores: r = 0.84 for EYTEX™ scores and r = 0.83 for log NI50, expressed in μg/ml. Whilst these correlations are certainly not perfect, it is clear that both in vitro methods can be used as valuable prescreening methods.


1992 ◽  
Vol 267 (31) ◽  
pp. 22630-22638 ◽  
Author(s):  
S Furukawa ◽  
N Sakata ◽  
H.N. Ginsberg ◽  
J.L. Dixon

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