The protective ability and cellular mechanism of Koelreuteria henryi Dummer flower extract against hydrogen peroxide-induced cellular oxidative damage

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.

Toxicity evaluation of water extract of tissue-cultured Taraxacum formosanum by acute, subacute administration, and Ames test

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.

Rapidly detecting major peanut allergen-Ara h2 in edible oils using a new immunomagnetic nanoparticle-based lateral flow assay.

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 ±â€¯0.026 mg/kg and 0.247 ±â€¯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.

Application of gamma irradiation in ginseng for both photodegradation of pesticide pentachloronitrobenzene and microbial decontamination.

This study investigates the feasibility of using gamma irradiation for photodegradation of a common residual fungicide, pentachloronitrobenzene (PCNB), in ginseng, and for microbial decontamination. American ginseng, Panax quinquefolius, was subjected to gamma irradiation. PCNB residues were analyzed by gas chromatography with electron capture detection and mass spectrometry. Eighty percent of PCNB (100 ppm) in a methanol aqueous solution was degraded by 5 kGy irradiation, and the primary degradation product was pentachloroaniline. Furthermore, contaminated PCNB (3.7 ppm) in ginseng were reduced to 0.2 ppm after 20 kGy irradiation. The IC(50) for treatment of Sclerotium rolfsii with 20 kGy irradiated PCNB was about 2.7 times higher than that for treatment with unirradiated PCNB. The survival rate of mouse fibroblast L929 cells treated with 20 kGy irradiated PCNB was about 12.9% higher than that of L929 cells treated with unirradiated PCNB. Additionally, after 20 kGy irradiation, less than 5% reduction of contents of ginsenoside Rb1 and Re were observed, and amounts of ginsenosides Rc, Rd, and Rg1 were not reduced significantly. The minimal gamma dose for microbial decontamination was 10 kGy. Therefore, gamma irradiation can be used for both PCNB photodegradation and microbial decontamination of ginseng without obvious loses of ginsenoside contents.

Evaluation of nanofabricated ginseng extract powders.

The objective of this study is to investigate the nano-fabrication method for ginseng extract powders (GEPs) and detect the differences in physical and chemical properties, and cytotoxicity of GEPs before and after fabrication. White ginseng was used as the raw material to produce the GEPs (Sample A). After grinding, the GEPs passed a 40-mesh sieve (particle size < 105 microm) and was named as Sample B. The residue (particle size > 105 microm) was named as Sample C. Samples A and B were used for nanofabrication though the use of a high-energy ball mill. Sample B was ground for 3 hr (Sample D) and 1 hr (Sample E), while Sample A was ground for 3 hr (Sample F) and 1 hr (Sample G). Nanoparticles of GEPs with ranges of 300 nm approximately 1 microm and 500 nm approximately 3 microm were produced. The heavy metal content (As, Cd, Co, Cu, Fe, Hg, Mn, Ni, Pb, Se and W) of Samples A-G were all under the maximum residue limit. Sample C contained a higher amount of yellow crystal material and had the highest ginsenoside contents and antioxidant capacity. There were enrichments of ginsenosides (approximately 1.3 fold) and antioxidant capacities (approximately 1.6 fold) in Sample C compared to Sample A. Moreover, after nano-fabrication, the antioxidant capacity was not changed significantly. However, the cellular growth enhancement ability was increased significantly. Samples F and G had the higher cellular growth enhancement ability and improved the cellular growth of L929 cells about 1.3 times as compared to Sample A. In future studies, Sample C will be used for nanofabrication in order to enhance the curative efficiency of ginseng.