Polarographic determination of berberine in the presence of H(2)O(2) in medicinal plants.

The mechanism of the parallel catalytic wave of berberine in the presence of H(2)O(2) was studied. The results showed that the reduction process of the C[double bond]N bond of berberine was two successive one-electron transfers, in which an intermediate free radical was involved. When H(2)O(2) was present, it oxidized the free radical to the original C[double bond]N bond, producing the parallel catalytic wave of berberine. In Na(2)B(4)O(7)-Na(2)CO(3) (pH 9.4, 0.08 M)-H(2)O(2)(4 mM) supporting electrolyte, the peak current of the catalytic wave was linear to the berberine concentration in the range of 1.0 x 10(-8)-3.0 x 10(-7) M. The limit of detection was 7.0 x 10(-9) M. The catalytic wave can be applied to direct determination of berberine in medicinal plant Coptis chinensis Franch, after sufficiently diluting the water extraction without preliminary separation.

[An experimental study on inhibitory effect of Chinese medicine tai-bao on antisperm antibody].

OBJECTIVE: To investigate whether Chinese medicine Tai-bao could inhibit antisperm antibody in experimental mice. METHODS: The experimental immunoinfertility mice were due to antisperm antibody induced by injection of human sperm membrane antigens. The experimental immuno-infertile mice used in the present study were divided into four groups including Tai-bao high dose group (46.8 g.kg-1.d-1), Tai-bao low dose group (31.2 g.kg-1.d-1), prednisone group and normal saline group. The enzyme linked immune sorbent assay (ELISA) and microcytotoxic assay were used for detection of antisperm antibody. The change of levels of antisperm antibody before and after treatment, pregnant rate, and the number of implantation were investigated in tested mice. RESULTS: The pregnant rates in normal saline group, prednisone group, Tai-bao high dose group and low dose were 38.89%, 47.06%, 70.00% and 75.00% respectively. The rate of pregnancy in Tai-bao low dose group was significantly higher as compared with normal saline group (P < 0.05). The rate of implantation in Tai-bao low dose group was significantly higher than that in prednisone group (P < 0.05). The results of detection of the cytotoxic antibody to sperm showed that cytotoxic percentages in Tai-bao high dose group (63.0 +/- 10.3%) and prednisone group (56.3 +/- 13.7%) were significantly lower (P < 0.05 and P < 0.01) than that in normal saline group (72.84 +/- 5.05%). CONCLUSION: Chinese medicine Tai-bao possesses regulatory effect on reproductive immune function, inhibitory effect on antisperm cytotoxic antibody, and promoting effect on pregnancy.

Regulation of rat hypothalamic preprogrowth hormone-releasing factor messenger ribonucleic acid by dietary protein.

To further evaluate nutrient regulation of GRF synthesis, we measured hypothalamic preproGRF messenger (m) RNA in food-deprived rats refed diets varying in nutrient composition by nuclease protection analysis. Adult male Sprague-Dawley rats were allowed free access to food (Fed), food deprived for 72 h (72-h FD), or 72 h FD then refed for 72 h with either a normal (NF) diet or isocaloric diets containing no protein (PF), carbohydrate (CF), or fat (FF). Seventy-two-hour FD rats displayed the expected 80% reduction in hypothalamic preproGRF mRNA. Upon refeeding, levels were normalized in rats refed NF, CF, or FF diets. In contrast, preproGRF mRNA in rats refed a PF diet was similar to that in 72-h FD rats. Rats refed a PF diet failed to gain weight and consumed less food than animals refed NF, CF, or FF diets. However, the lack of the GRF response to the PF diet was due to protein deprivation rather than caloric restriction, since hypothalamic preproGRF mRNA returned to 66% of Fed values in rats refed an equivalent amount (grams per day) of a NF diet. In 72-h FD rats refed isocaloric diets containing 4%, 8%, or 12% protein, preproGRF mRNA was restored to Fed values in a protein concentration-dependent manner being completely restored by the 12% diet. A lack of dietary protein was sufficient to regulate hypothalamic preproGRF mRNA since feeding rats a PF diet without prior food deprivation resulted in 70% reduction in preproGRF mRNA, whereas CF and FF diets were without effect. These data indicate that decreased hypothalamic preproGRF mRNA expression in 72-h FD rats occurs as a result of dietary protein deprivation.