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.

Organ-specific distribution of chlorophyll-related compounds from dietary spinach in rabbits.

The distribution of chlorophyll-related compounds (CRCs) derived from dietary spinach was investigated in different organs the rabbits. The rabbits in the experimental group consumed 100 g of freeze-dried spinach powder after a 24 h fasting period and sacrificed 2, 4, 8, 12 and 24 h later and in the control group sacrificed after the 24 h fasting period. The main CRCs in the liver were found to be chlorophyll (Chl a) and b, chlorophyllide (Chlide) a and b, pheophytin (Phe) a and b and pheophorbide (Pho) a and b, which reached their peak values at 8 h post-feeding. The gallbladder contained mainly Chlide a and a', Pho a and a', Pho b and b', which peaked their values at 2 h post-feeding. Pho a and b were consistently observed in the blood and peaked at 12 h post-feeding. The earlier appearance of Chlide a', Pho a' and Pho b' in the gallbladder compared to the liver indicated that these CRCs were compartmentalized differently and might undergo the same type of vectorialized transport as characterized for the bile salts. Pho levels peaked later in the blood compared to the liver, suggesting that Pho might be released into the peripheral blood circulation from the liver. In conclusion, Chlide and Pho were the principal Chl metabolites in the rabbits. Our data may expand our understanding of the metabolism and biodistribution of CRCs in the human body. A number of biological functions, including anti-oxidation, anti-tumor and anti-aging have recently been attributed to CRCs, it will be interesting to explore, if the binding of Chlide and Pho to other nutrients or trace metal ions in the body mediate their biological functions.

Molecular epidemiology of HFMD-associated pathogen coxsackievirus A6 in Fujian Province, 2011-2013 / 病毒学报

In order to characterize the molecular epidemiology of HFMD-associated Coxsackievirus A6 (CVA6) in Fujian Province, a total of 1340 specimens from non-EV71 non-CVA16 HFMD patients were collected during 2011-2013. Isolated virus strains were identified and subtyped. Full-length coding regions for the VP1 gene of the predominant serotype CVA6 isolates were amplified and sequenced. Among the 375 non-EV71 non-CVA16 HFMD cases confirmed by virus isolation and molecular subtyping, 182 (48.5%) were found to be caused by CVA6, accounting for 7.9%, 16.2% and 39.6% HFMD-associated enteroviruses in FujianProvince during 2011, 2012, and 2013, respectively. Compared with general features observed in the HFMD epidemic, no difference in CVA6-specificity or severity rates was observed between geographical origins, gender, or age groups. Nucleotide sequence analyses of VP1 genes revealed high diversity levels of 16.2%-18.6% among CVA6 strains from Fujian Province, in contrast to the prototype CVA6 strain, and showed low levels of diversity in the amino acid sequences (4.3%-6.2%). Phylogenetic analysis also indicated that CVA6 isolates from Fujian Province were distinct from the prototype strain and other isolates from abroad; however, it was homologous to domestic strains, although the Fujian isolates clustered into multiple branches. These results suggested that significant changes in the pathogenic spectrum of HFMD in Fujian Province occurred during 2011-2013, as CVA6 was one of the predominant serotypes of HFMD. CVA6 isolates from Fujian Province were co-circulating and co-evolving with other domestic strains as multiple closely related CVA6 transmission chains were observed in Fujian Province overall and within each prefecture.