Résumé
The present study was designed to determine the effects of Puer tea and green tea on blood glucose level. Male BALB/c mice were administered green tea extract (GTE) or Puer tea extract (PTE), either intragastrically or in their drinking water. The major components of these teas are epigallocatechin gallate (EGCG) and caffeine, respectively. Blood glucose measurement results showed that mice fed intragastrically or mice that drank GTE, PTE or caffeine showed significantly lower blood glucose levels compared to the control group. However, EGCG exhibited no influence on the blood glucose levels. When caffeine was eliminated from the GTE and PTE, the effect on the blood glucose levels was abolished, but the effect was recovered when caffeine was re-introduced into the extracts. Evaluation of hematological and biochemical indices at the time of the greatest caffeine-induced decrease in blood glucose levels showed that the effect of caffeine was specific. Microarray analyses were performed in 3T3-L1 preadipocytes and mature adipocytes treated with 0.1 mg · mL(-1) caffeine to identify factors that might be involved in the mechanisms underlying these effects. The results showed that few genes were changed after caffeine treatment in adipocytes, and of them only phospholipid transfer protein (PLTP) may be ralated to blood glucose. In conclusion, this study indicates that caffeine may be the key constituent of tea that decreases blood glucose levels, and it may be used to treat type 2 diabetes.
Sujets)
Animaux , Mâle , Souris , Cellules 3T3-L1 , Adipocytes , Métabolisme , Glycémie , Métabolisme , Caféine , Pharmacologie , Camellia sinensis , Chimie , Hypoglycémiants , Pharmacologie , Souris de lignée BALB C , Protéines de transfert des phospholipides , Métabolisme , Extraits de plantes , Pharmacologie , ThéRésumé
To construct Fv antibodies against H5N1 Avian influenza virus hemagglutinin,extracted mRNA from B lymphoblastoid cell lines secreting anti-HA antibodies was used and the VH and VL genes were amplified by RT-PCR and linked together by splicing overlap extension (SOE) with (Gly4 Ser)3 linker. The recombinant plasmid was then transformed to E. coli BL21(DE3) and sequence analysis indicated the total length of scFv was 714 bp and the expression of Fv was validated by PAGE and Western blot.