Inhibitory effect of berberine on interleukin-2 secretion from PHA-treated lymphocytic Jurkat cells.

Berberine is an isoquinoline alkaloid isolated from herb plants, such as Cortex phellodendri (Huangbai) and Rhizoma coptidis (Huanglian). Huanglian and Huangbai have been used as "heat-removing" agents. In addition, berberine has been reported to exert anti-inflammatory effect both in vivo and in vitro, where mitogen-activated protein kinase (MAPK) and cyclooxygenase-2 (COX-2) expressions are critically implicated. We herein tested the hypothesis that berberine exerts an anti-inflammatory effect through MAPK and COX-2 signaling pathway in T-cell acute lymphoblastic leukemia (T-ALL). In Jurkat cells, we found that PHA exposure caused elevation on interleukin-2 (IL-2) production in a time-dependent manner. PHA-stimulated reactions were steeply suppressed by berberine, such as IL-2 mRNA expression and protein secretion. However, berberine did not exert any cytotoxic effect at doses of 40 µg/ml. In addition, the possible molecular mechanism of anti-inflammation effect of berberine could be the inhibition of PHA-evoked phosphorylation of p38, since c-Jun N-terminal kinases (JNK) and extracellular signal-regulated kinase (ERK) expressions did not alter. Consistent with above results, berberine inhibition on PHA-induced IL-2 secretion could be reversed by treatment of SB203580, a specific inhibitor of p38-MAPK. Interestingly, upregulation of PHA-induced COX-2 expression was also observed following berberine treatment of Jurkat cells. Furthermore, flow cytometry analysis showed berberine-induced cell cycle arrest at G1 phase after PHA stimulation and decreased percentage of G2/M phase. In conclusion, our study demonstrated that the anti-inflammatory effect of berberine largely potentially results from its ability to attenuate p38 MAPK expression, and does not exclude a positive action of berberine on cell cycle arrest. These results provide an innovative medicine strategy to against or treat T-ALL patients.

Effects of arginine supplementation on post-exercise metabolic responses.

This study investigated the effects of arginine supplementation on acute metabolic responses during recovery after a single bout of endurance exercise in trained athletes. Twelve healthy male judo athletes were randomly divided into two groups and performed a single bout of exercise at a speed estimated to correspond to 75%VO2max for 60 min, and then took either a placebo or arginine at 0.1 g/kg-wt. Blood samples of each athlete were collected before exercise, and 0, 15, 30, 45, 60, 90, 120 min after exercise, respectively. The experiment was repeated two weeks later, but treatments were exchanged for the two groups. The concentrations of glucose, insulin, free fatty acid (FFA), glycerol, lactate, ammonia, creatine kinase, and NOx (NO2(-) + NO3(-)) in blood were examined. No differences in the levels of glycerol, lactate, ammonia, creatine kinase, or NOx between the two groups were observed at any of the time points. However, the concentration of glucose was significantly higher in the arginine group as compared to that in the placebo group at the 15-min recovery point. The insulin concentration was also higher in the arginine group as compared to that in the placebo group at the 30-min recovery point. Furthermore, the free fatty acid levels at the 30, and 45-min recovery points were significantly lower in the arginine group compared to those in the placebo group. The results indicated that arginine supplementation during the exercise recovery period could increase glucose and insulin concentrations, and decrease FFA availability in the blood.

Biochemical and immunological studies of nucleocapsid proteins of severe acute respiratory syndrome and 229E human coronaviruses.

Severe acute respiratory syndrome (SARS) is a serious health threat and its early diagnosis is important for infection control and potential treatment of the disease. Diagnostic tools require rapid and accurate methods, of which a capture ELISA method may be useful. Toward this goal, we have prepared and characterized soluble full-length nucleocapsid proteins (N protein) from SARS and 229E human coronaviruses. N proteins form oligomers, mostly as dimers at low concentration. These two N proteins degrade rapidly upon storage and the major degraded N protein is the C-terminal fragment of amino acid (aa) 169-422. Taken together with other data, we suggest that N protein is a two-domain protein, with the N-terminal aa 50-150 as the RNA-binding domain and the C-terminal aa 169-422 as the dimerization domain. Polyclonal antibodies against the SARS N protein have been produced and the strong binding sites of the anti-nucleocapsid protein (NP) antibodies produced were mapped to aa 1-20, aa 150-170 and aa 390-410. These sites are generally consistent with those mapped by sera obtained from SARS patients. The SARS anti-NP antibody was able to clearly detect SARS virus grown in Vero E6 cells and did not cross-react with the NP from the human coronavirus 229E. We have predicted several antigenic sites (15-20 amino acids) of S, M and N proteins and produced antibodies against those peptides, some of which could be recognized by sera obtained from SARS patients. Antibodies against the NP peptides could detect the cognate N protein clearly. Further refinement of these antibodies, particularly large-scale production of monoclonal antibodies, could lead to the development of useful diagnostic kits for diseases associated with SARS and other human coronaviruses.