[Neuroprotective effect of ginsenoside Rb-1 on a rat model of Alzheimer's disease].

Objective: To investigate the protective mechanism of ginsenoside Rb-1 on the brain in a rat model of Alzheimer's disease. Methods: Fifty-six male Sprague-Dawley rats were randomly divided into control group, model group, low-dose Rb-1 group (Rb-1: 25 mg•kg(-1)•d(-1)) and high-dose Rb-1 group (Rb-1:50 mg•kg(-1)•d(-1)). Morris water maze was designed to observe the changes of learning and memory ability in rats. Flow cytometry was used to detect the apoptosis of hippocampal neurons. Immunohistochemistry and Western blot were employed to detect the expression levels of apoptosis-related genes (p53, Bax, cytochrome C (Cyto C), Caspase-3 and caspase-9) and anti-oxidative stress-associated genes (nuclear Factor-E2-related factor 2 (Nrf2), kelch-like ECH-associated protein 1 (keap-1), heme oxygenase 1(HO-1) and NADPH quinone dehydrogenase 1 (NQO1)).The activities of catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were detected by relevant kits. ANOVA and Tukey-Kramer test were used for statistical analysis. Results: The learning and memory ability of rats in the model group was lower than that of the control group (P<0.01).The learning and memory ability of rats in the high-dose Rb-1 treatment group was significantly higher than that of the model group [(80±8) s vs (100±11) s, t=5.390, P<0.01]. The expression levels of apoptosis-related genes (p53, Bax, Cyto C, caspase-3 and caspase-9) in the model group were significantly higher than those in the control group (P<0.01), while the expression levels of these genes in low-dose and high-dose Rb-1 groups were significantly lower than those of the model group (P<0.01). The expression levels of Nrf2, HO-1 and NQO1 genes in the model group were significantly lower than those in the control group (P<0.05), while the expression of these genes in low-dose and high-dose Rb-1 groupswere significantly higher than those of the model group (P<0.01). The activities of CAT, GSH-Px and SOD in the model group were lower than those in the control group (P<0.01), however the activities of CAT, GSH-Px and SOD in low-dose and high-dose Rb-1 groups were higher than those of model group (P<0.05). Conclusions: Both low-dose and high-dose Rb-1 have protective effect on memory and cognitive function of Alzheimer's disease rats by reducing the damage and apoptosis of hippocampal neurons, down-regulating the expression levels of p53, Bax, Cyto C, caspase-3 and caspase-9, up-regulating the expression of Nrf2, HO-1 and NQO1 genes, and increasing the activities of CAT, GSH-Px and SOD. Moreover, the protective effect of Rb-1 on rat brain may be dose-dependent.

Effects of beta-glucanase and xylanase supplementation on gastrointestinal digestive enzyme activities of weaned piglets fed a barley-based diet.

The effects of supplementing a barley-based diet for weaned piglets withexogenous beta-glucanase and xylanase on gastrointestinal digestiveenzyme activities were investigated. Thirty-six cross-bred weaned pigletswere randomly assigned to two groups with three pens based on sexand mass. Each group was fed on the diet based on barley with or withoutadded beta-glucanase and xylanase (0.15%) for a 4-week period. Theresults showed that enzyme supplementation improved growth performanceof piglets significantly (p < 0.05), but had no effect (p = 0.091)on average daily feed intake. The results also showed that supplementationof beta-glucanase and xylanase had no effect on pepsin activity in gastriccontents but slightly decreased (p = 0.092) the pepsin activity ingastric mucosa. Meanwhile, no effect of enzyme supplementation ontrypsin activity in duodenal contents was observed. However, the activitiesof amylase and lipase in duodenal contents were significantly(p < 0.05) decreased, whereas the activities of maltase, sucrase andgamma-glutamyl transpeptidase (gamma-GT) in jejunal and ileal mucosa wereenhanced significantly (p < 0.05). The improvement of disaccharidaseand gamma-GT activity may be attributed to the positive impacts of exogenousenzymes on digestion and absorption of the nutrients. In conclusion,the current results indicated that supplementation with enzymes in barley-based diets could improve the growth performance of piglets,decrease the activities of amylase and lipase in duodenal contents andincrease the activities of disaccharidase and gamma-GT in jejunal and ilealmucosa.

Platelet phospholipid n-3 PUFA negatively associated with plasma homocysteine in middle-aged and geriatric hyperlipaemia patients.

Studies showed that increased dietary intake of n-3 polyunsaturated fatty acids (PUFA) has a cardiovascular beneficial effect. Increased plasma phospholipid (PL) docosahexaenoic acid (22:6n-3) is associated with decreased plasma homocysteine (Hcy). The aim of this study was to investigate the relationship between platelet PL fatty acid and plasma Hcy in middle-aged and geriatric hyperlipaemia patients (50 males, 31 females) and 65 healthy subjects (43 males, 22 females) in Hangzhou, China. Plasma Hcy demonstrated significant positive correlation with adrenic acid (22:4n-6) (r = 0.188, P = 0.018) and negative correlation with 22:6n-3 (r = -0.277, P = 0.001) and the ratio of n-3/n-6 (r = -0.231, P = 0.003) in sex-, age- and BMI-controlled partial correlation analysis. The present results suggest that increased ratio of n-3/n-6 PUFA in platelet PL is associated with decreased thrombotic risks such as plasma Hcy in middle-aged and geriatric hyperlipaemia patients in Hangzhou.

[The tissue culture of medicinal plant Trichosanthes kirilowii and its protein analysis].

We reported preliminary results of rapid propagation, callus induction and regeneration of Trichosanthes Kirilowii, and its protein analysis. Pre-existing meristerms regenerate shoots very rapidly when grown on MS medium containing 0.5 or 1.0 mg/L 6-BA; calli could be induced from leaf sections when put on MS medium containing 4.0 mg/L 6-BA + 0.2 mg/L IAA; shoots regenerated successfully 30 days after calli induction and the differentiation ratio was one shoot out of every four leaf sections; and all shoots gave rise to roots after removing onto MS medium containing 0.1 mg/L NAA and 100% survived when transplanted into soil. Very excitingly, these plants produced small tubers in one month, where satisfactory expression of TCS protein was detected by Western blot analysis.

[Mechanism of anti-inflammatory action of Huanglian Jiedu decoction a traditional Chinese prescription].

OBJECTIVE: To elucidate the mechanism of anti-inflammatory action of Huanglian Jiedu Decoction (HJD). METHODS: An acute inflammatory air-pouch was established in mice by s.c. injecting air and 1% carrageenan. A mouse endotoxeamia induced by lipopolysaccharide was also used. Splenocyte proliferation was quantified with 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetery. NO2- concentration was examined by a Griess reagent and interleukin-1 activity was evaluated in thymocyte proliferation. RESULTS: HJD significantly inhibited the leukocyte infiltration and PGE2 production in the mouse air-pouch model. In the in vitro assay, HJD significantly inhibited concanavalin A(Con A)-induced transformation of spleen cells isolated from the endotoxeamia mice, but did not influence that from the normal mice. HJD did not affact Con A-induced interleukin-2 production in splenocytes in either normal or endotoxeamia mice. HJD remarkably reduced interleukin-1 and NO production in peritoneal macrophages elicited by lipopol ysaccharide. CONCLUSION: HJD displays an anti-inflammatory effect mainly through inhibiting the production of inflammatory cytokines including IL-1, NO and PGE2.

Velvet antler polypeptides promoted proliferation of chondrocytes and osteoblast precursors and fracture healing.

AIM: To study the effects of velvet antler (VA) total polypeptides (VATP) and VA polypeptides, VAP-A, VAP-B, and VAP-C on proliferation of chondrocytes and osteoblast precusors. METHODS: Chondrocytes (rabbit and human fetus) and osteoblast precusors (chick embryo) were incubated in the culture medium containing VATP or VAP-A, VAP-B, and VAP-C. [3H]TdR incorporation into DNA was measured. Fracture healing-promoting action of VATP was determined in rats. RESULTS: VATP 50-200 mg.L-1 and VAP-B 12.5, 25, and 50 mg.L-1 showed most marked proliferation-promoting activity for rabbit costed chondrocytes and increased incorporation of [3H]TdR from (73 +/- 9) Bq (control group) to (272 +/- 55), (327 +/- 38), and (415 +/- 32) Bq, respectively (P < 0.01). The activity of VAP-A was weaker than that of VAP-B, and VAP-C had no activity. VATP 10 and 20 mg.kg-1 by local injection into the cross-section fracture area accelerated healing of radial fracture. The healing rate of VATP-treated group was higher (75%) than that of control group (25%) (P < 0.05). CONCLUSION: VATP accelerated fracture healing by stimulating proliferation of chondrocytes and osteoblast precursors.

Comparison of parenteral nutrition supplemented with L-glutamine or glutamine dipeptides.

Although glutamine is an important fuel used by the intestinal mucosa and other visceral organs, it is not present in any commercially available parenteral amino acid solution. To compare the effects of L-glutamine with glutamine dipeptides, we studied the effects of each in 8 dogs and 60 Wistar rats. In the dog study, three amino acid solutions were compared: standard commercial amino acid solution (control), alanine-glutamine dipeptide-enriched solution (glutamine 3.4%), and glycine-glutamine dipeptide-enriched solution (glutamine 3.6%). Arterial and venous samples were collected to compare the effects of the three solutions on skeletal muscle amino acid exchange. In the rat study, two studies were undertaken: group 1 rats underwent only central venous catheterization; group 2 rats underwent central venous catheterization and a 50% intestinal resection. Within each group, three different solutions were infused: standard amino acid solution (control), glutamine-enriched (1.5% glutamine) solution, or glutamine dipeptide-enriched (1% glutamine) solution. After 7 days of parenteral nutrition, samples of gut, blood, and muscle were collected for determination of mucosal thickness, villus area, serum amino acid profile, liver and renal function tests, and muscle composition. When glutamine or glutamine-dipeptide solutions were administered, the dogs showed increasing serum glutamine concentrations and enhanced glutamine uptake across the hind leg muscle. Similarly, both groups of rats demonstrated significant differences in serum glutamine levels, nitrogen balance, intestinal mucosa thickness, and villus area. We conclude that both glutamine and glutamine-dipeptide infusions increase serum glutamine concentrations and result in regional tissue effects. Both exerted similar metabolic effects with no apparent complications.

Increased sarcolemmal membrane permeability of cardiac muscle cells in rats fed grains cultivated in a Keshan disease endemic area: a study with horseradish peroxidase as a tracer.

The alteration of sarcolemmal membrane permeability of cardiac muscle cells in rats fed grain from a Keshan disease (KD) endemic area was studied with horseradish peroxidase (HRP) as a tracer. Weanling male rats were divided at random into three groups and fed the following three diets, respectively, for 3 months: a diet with grain from a KD endemic area (Group A), a diet with grain from a KD nonendemic area (Group B), and standard laboratory chow (Group C). At the end of the experiment, HRP was injected intravenously and localized in the ventricular myocardium by light microscopy. The experimental results showed that the percentage of cardiac muscle cells containing HRP reaction product in rats fed grain from the KD endemic area was significantly greater than that in rats fed grain from nonendemic area and standard laboratory chow. This suggests that the sarcolemmal membrane permeability of cardiac muscle cells in rats of Group A was markedly increased. The distribution of cardiac muscle cells with increased sarcolemmal membrane permeability was similar to that seen in the myocardium of KD patients. The present study suggests that the abnormal membrane permeability of cardiac muscle cells may play an important role in the pathogenesis of myocardial necrosis in KD.