Search

Background Koelreuteria henryi Dummer is an indigenous plant in Taiwan. The species has been used in traditional folk medicine for the promotion of liver functions and for treating malaria and urethritis. The present study investigated the antioxidant activity of the flower extract of Koelreuteria henryi Dummer. The extraction conditions were optimized by the contents of total phenolic acids and total flavonoids, and antioxidant activity assays. Moreover, an in vitro study for investigating antioxidant activity of K. henryi flower extract was demonstrated by hydrogen peroxide (H2O2)-induced apoptosis. Results K. henryi flower extracted for 150 min showed high contents of total phenolic acids and total flavonoids. In an in vitro model, L929 cells were pretreated with K. henryi flower extract, and then treated with H2O2 to induce oxidative damage. Results demonstrated that H2O2-induced apoptosis was inhibited by the treatment of 200 μg/ml K. henryi flower extract through the mitochondria-mediated pathway and mitogen-activated protein kinase (MAPK) pathway. The caspase 8/9 activity and expression of p-p38 and pERK were repressed by K. henryi flower extract. In addition, the prevention of H2O2-induced apoptosis by K. henryi flower extract activated the nuclear factor-erythroid 2-related factor (Nrf2) stress response pathway to transcript heme oxygenase 1 (HO-1). Also, K. henryi flower extract prevented H2O2-induced apoptosis through HO-1 production, as evident by the use of HO-1 inhibitor. Conclusions The present study demonstrated that K. henryi flower extract could inhibit the H2O2-induced apoptosis in L929 cells through the activation of the Nrf2/HO-1 pathway. How to cite: Tsai WC, Chang HC, Yin HY, et al. The protective ability and cellular mechanism of Koelreuteria henryi Dummer flower extract against hydrogen peroxide-induced cellular oxidative damage. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.07.006 .

Background Taraxacum species (commonly known as dandelion) used as herbal medicine have been reported to exhibit an antiproliferative effect on hepatoma cells and antitumor activity in non-small-cell lung cancer cells. Although several investigations have demonstrated the safety of Taraxacum officinale, the safety of tissue-cultured plants of T. formosanum has not been assessed so far. Therefore, the present study examines the safety of the water extract of the entire plant of tissue cultured T. formosanum based on acute and subacute toxicity tests in rats, as well as the Ames tests. Results No death or toxicity symptoms were observed in the acute and subacute tests. The results of the acute test revealed that the LD50 (50% of lethal dose) value of the T. formosanum water extract for rats exceeded 5 g/kg bw. No abnormal changes in the body weight, weekly food consumption, organ weight, or hematological, biochemical, and morphological parameters were observed in the subacute toxicity test. Thus, the no observed adverse effect level (NOAEL) of T. formosanum water extract was estimated to be higher than 2.0 g/kg. Finally, the results of the Ames test revealed that T. formosanum water extract was not genotoxic at any tested concentration to any of five Salmonella strains. Conclusions The water extract of tissue-cultured T. formosanum was non-toxic to rats in acute and subacute tests and exhibited no genotoxicity to five Salmonella strains. How to cite: Tsai WC, Chang HC, Tseng YH, et al. Toxicity evaluation of water extract of tissue-cultured Taraxacum formosanum by acute, subacute administration, and Ames test. Electron J Biotechnol 2020;45. https://doi.org/10.1016/j.ejbt.2020.04.001

Ara h2 is a major peanut allergen that induces rashes, vomiting, diarrhea, and anaphylactic shock. Since peanut is a major source in producing edible oils globally, Ara h2 residues can be present in various edible oils. In this work, an immunomagnetic nanoparticle-based lateral flow assay for identifying Ara h2 in edible oils is developed. This assay exhibits high sensitivity with a visual detection limit of 0.1 mg/kg Ara h2 in oil, and favorable specificity in differentiating peanut from seeds and nuts. The calculated CV values of intra- and inter-assay were 6.73–10.21% and 4.75–8.57%, respectively, indicating high reproducibility. In an analysis of 26 oil products, Ara h2 was detected in two peanut oils as 0.122 ± 0.026 mg/kg and 0.247 ± 0.027 mg/kg. The entire method takes 5 h, including a 3.5-h sample preparation. Hence, this method has the potential to be an effective way to screen edible oils for Ara h2.

This study describes an immunomagnetic nanoparticle (IMNP)-based lateral flow assay (LFA) for detecting the major peanut allergen Ara h 1. We developed a clearly specific method in identifying peanut from ten other seeds and nuts, and a good visual limit of detection (vLOD) of 0.01 μg/mL Ara h 1 in PBS. PBS that contains 1 M NaCl and 2% Tween 20 was determined to be the optimal extraction buffer for isolating Ara h 1 from cookie, milk and chocolate with vLOD values of 0.5 μg/g, 0.5 μg/mL, and 1 μg/g, respectively. Forty two processed foods were simultaneously analyzed using this method and an AOAC-approved ELISA kit. The specificity and sensitivity of this assay were thus determined to be 100 and 95%, respectively. This new IMNP-based LFA has potential as a rapid tool for screening processed foods for Ara h 1 residues.

In this study, a liposomal nanovesicle was applied as a nanocarrier of ginseng extract (GE) to enhance the intracellular antioxidant activity of GE. The optimal condition of preparing GE liposomal nanovesicle (GELN) was prepared by tagging with 3.0 mol% of polyethenyl glycol (PEG3.0) followed by homogenisation at 15,000 psi for 5 min to reduce its diameter to ∼150 nm. PEG3.0-GELN encapsulated the most ginsenosides (234.1 ± 13.9 mg/g) with a higher reducing power than GELNs tagged with lower amounts of PEG (0–1.5 mol%). After treatment with PEG3.0-GELN (20 μg ginsenoside/ml), the % increase in mitochondrial membrane potential (ΔΨ) of H 2 O 2 -damaged cells rose 20.9% and the % decrease in apoptosis increased 12.4%, compared with those treated with GE. Therefore, this investigation proved that utilising liposomal nanovesicles to encapsulate GE can effectively suppress the depolarisation of ΔΨ and thus enhance the survival rate of H 2 O 2 -damaged cells.