Effect of low dosage of chito-oligosaccharide supplementation on intestinal morphology, immune response, antioxidant capacity, and barrier function in weaned piglets.

This study was conducted to determine the effect of dietary supplementation of a low dose of chito-oligosaccharide (COS) on intestinal morphology, immune response, antioxidant capacity, and barrier function in weaned piglets. A total of 120 weaned pigs (21 d of age; 7.86 ± 0.22 kg average BW) were randomly assigned (6 pens/diet; 10 pigs/pen) to 2 dietary treatments consisting of a basal diet (negative control) or the basal diet supplemented with COS (30 mg/kg) for a 14-d period. Six randomly selected piglets from each treatment were killed for blood and tissue sampling. No significant differences were observed in ADG, ADFI, and G:F between treatment and the control group. Piglets fed the COS-supplemented diet had greater ( < 0.05) stomach pH than those fed the control diet on d 14 postweaning. Dietary supplementation with COS reduced villus height ( < 0.05) and villus height:crypt depth ( < 0.05) in the ileum. Dietary COS supplementation tended to reduce villus height in the duodenum ( = 0.065) and jejunum ( = 0.058). There was no effect on crypt depth in the intestinal segments of treatment group. Piglets fed the COS-supplemented diet increased ( < 0.05) the number of intraepithelial lymphocytes in duodenum or jejunum and goblet cells of ileum. However, COS decreased ( < 0.05) the number of intraepithelial lymphocytes in ileum of weaned piglets. The concentrations of IL-10 (duodenum, jejunum, and ileum) and secretory immunoglobulin (SIgA; duodenum and ileum) were higher in piglets fed the COS-supplemented diet compared with control ( < 0.05). Dietary COS supplementation reduced ( < 0.05) the concentration of total antioxidant capacity and superoxide dismutase of the jejunum or ileum. The mRNA expression of occludin in the ileum and ZO-1 in jejunum and ileum had a significant change in piglets fed the COS-supplemented diet compared with the control group ( < 0.05). In conclusion, these results indicated that dietary COS supplementation at 30 mg/kg had no effects on promoting growth performance and tended to reduce villus height in the duodenum or jejunum of weaned piglets. The results further showed that supplemental COS at this level may cause an immune and oxidative stress response in small intestine and have compromised the intestinal barrier integrity in weaned piglets. The research will provide guidance on the low dosage of COS supplementation on weaning pigs.

Trichosanthin, an extract of Trichosanthes kirilowii, effectively prevents acute rejection of major histocompatibility complex-mismatched mouse skin allograft.

Trichosanthin is an active component extracted from the root tuber of the Chinese medicinal herb Trichosanthes kirilowii. Trichosanthin has abortifacient, anti-tumor, anti-HIV, and immunoregulatory functions. In the current study, we explored its potential effect on allograft rejection in a murine skin transplantation model across a fully mismatched major histocompatibility complex. It was found that treatment of recipient mice with trichosanthin (0.25 or 1 mg/kg, IP) significantly delayed allograft rejection. T cells that originated from recipients treated with trichosanthin were restimulated with donor-specific splenocytes showed a significantly reduced response compared with that of control recipients. In line with these results, the mRNA levels for interleukin (IL)-2 and interferon-gamma were decreased and the levels of IL-4 and IL-10 were increased in splenic T cells originating from trichosanthin-treated recipients. These results indicated that trichosanthin may have potential therapeutic value for transplantation rejection and other inflammatory diseases.

Effect of dietary methylmercury and seleno-methionine on Sacramento splittail larvae.

The effects of methylmercury (MeHg) and selenium (Se) contamination on food webs in the San Francisco Estuary have received considerable attention during the past decade. However, knowledge of their effects on native fishes of California is lacking. This study investigated the interactive effects of dietary MeHg and seleno-methionine (SeMet) on Sacramento splittail (Pogonichthys macrolepidotus) larvae. Twelve diets containing increasing levels of SeMet (0.64, 8.2 and 35.0 microg Se g(-1) diet) and MeHg (0.01, 0.13, 4.7 and 11.7 microg Hg g(-1) diet) were fed to 21-day post-hatch larvae for 4 weeks in 2-L beakers at 25 degrees C. Fish were fed twice a day at a feeding rate of 40, 30, 25 and 20% of body weight during the 1st, 2nd, 3rd and 4th week, respectively. At the end of week 4, no significant difference (P>0.05) was observed among treatments for mortality, body length or weight, and condition factor. Bioaccumulation of Hg and Se responded positively and significantly (P<0.05) to their dietary concentrations. The molar ratio of Se/Hg in diets was linearly correlated to the ratio of Se/Hg in fish. Dietary Se inhibited Hg accumulation, which was negatively correlated to the dietary Se/Hg ratio. Histopathological examination revealed severe gill anomaly and liver glycogen depletion in fish fed the 11.7 microg Hg g(-1) diet. Liver glycogen depletion and kidney tubular dilation were found in larvae fed the 11.7 microg Hg and 11.7 microg Hg+35 microg Se g(-1) diets. In conclusion, dietary Hg enhanced Se accumulation but dietary Se inhibited Hg accumulation in splittail. Dietary Se showed a protective effect in fish fed the high MeHg diet. This protection was related to the dietary Se/Hg ratio, which is a more reliable criterion for evaluating the interactive effect between Se and Hg in splittail.

Effect of Psidium cattleianum leaf extract on Streptococcus mutans viability, protein expression and acid production.

Plants naturally produce secondary metabolites that can be used as antimicrobials. The aim of this study was to assess the effects of Psidium cattleianum leaf extract on Streptococcus mutans. The extract (100%) was obtained by decoction of 100 g of leaves in 600 ml of deionized water. To assess killing, S. mutans biofilms were treated with water (negative control) or various extract dilutions [100, 50, 25% (v/v) in water] for 5 or 60 min. To evaluate the effect on protein expression, biofilms were exposed to water or 1.6% (v/v) extract for 120 min, proteins were extracted and submitted to 2-dimensional difference gel electrophoresis. Differentially expressed proteins were identified by mass spectrometry. The effect of 1.6% (v/v) extract on acid production was determined by pH measurements and compared to a water control. Viability was similar after 5 min of treatment with the 100% extract or 60 min with the 50% extract (about 0.03% survival). There were no differences in viability between the biofilms exposed to the 25 or 50% extract after 60 min of treatment (about 0.02% survival). Treatment with the 1.6% extract significantly changed protein expression. The abundance of 24 spots was decreased compared to water (p < 0.05). The extract significantly inhibited acid production (p < 0.05). It is concluded that P. cattleianum leaf extract kills S. mutans grown in biofilms when applied at high concentrations. At low concentrations it inhibits S. mutans acid production and reduces the expression of proteins involved in general metabolism, glycolysis and lactic acid production.

Ovine metabolism of saponins: evaluation of a method for estimating the ovine uptake of steroidal saponins from Narthecium ossifragum.

A sheep was dosed three times per day over six consecutive days with 70 g Narthecium ossifragum, and once on the seventh day with 70 g N. ossifragum. Additionally, it was dosed once on days 1-7 with 20 mg of [20,23,23-2H3]sarsasapogenin. After 7 days, the sheep was killed and GC-MS analysis of the free and conjugated sapogenin content in bile, urine, rumen, duodenum, jejunum, colon and rectum samples collected from the sheep, faecal samples collected on days 4-7, and dosed plant material was performed. The N. ossifragum contained mainly sarsasapogenin and smilagenin. Only neglible levels of deuterium-labelled sarsasapogenins were detected in the samples from the animal. Ingested saponins were quickly hydrolysed in the rumen to free sapogenins and, in part, epimerized at C-3 to afford episapogenins. The absorption of free sapogenins appeared to occur in the jejunum. The concentration of sapogenins in faeces reached a plateau 108 h after dosing started.

[Antitumor activities of 4 derivatives of artemisic acid and artemisinin B in vitro].

The cytotoxicities of 2 derivatives of artemisinin B and 2 derivatives of artemisic acid (designated as Compound A, B, C, and D) were investigated, using trypan blue dye exclusion test and colony-forming units assay. At the concentration of 5 micrograms.ml-1, the inhibition rates of these 4 compounds against murine leukemia cell line P388 were > 85%. When tested against human hepatoma cell line SMMC-7721 at 25 micrograms.ml-1, the inhibition rates of Compound A, B, C, and D were found to be 92.3%, 96.9%, 84%, and 82.1%, respectively, and 27%, 8%, 37.8%, 1.7% against normal human embryonic lung cell line WI-38, respectively. These 4 compounds all showed an inhibition rate of 100% against human gastric cancer cell line SGC-7901 at 50 micrograms.ml-1.

[Derivatives of arteannuin B with antileukemia activity].

Arteannuin B (I) was converted to hydroxy lactones (VII, VIII) by a mixture of formic acid and sulfuric acid. Compound VI and Compound VII both showed activity against leukemia P 388 cell in vitro. The rate of growth inhibition were 97.5% and 11.8% for (VI) and 80% and 52.6% for (VII) at the concentration of 10 and 1 micrograms/ml respectively. It seems that the antileukemia activity of 6-membered lactone is higher than that of 5-membered and the methylene group is necessary for the antileukemia activity.