[Water holding characteristics of litters of typical forest in loess area of Western Shanxi Province, China]. / æ™‹è¥¿é»„åœŸåŒºå ¸åž‹æž—åˆ†æž¯è½ç‰©æŒæ°´ç‰¹æ€§.

It is of great significance to investigate the volume and water holding characteristics of litters for the accurate evaluation of forest water conservation function. With Pinus tabuliformis, Robinia pseudoacacia, Populus davidiana, Quercus wutaishanica and Platycladus orientalis as the research objects in the Loess Plateau of Western Shanxi Province, we analyzed the thickness of undecomposed layer and semi-decomposed layer, the volume of litter, and the relationship between the litter water-holding characteristics and the immersion time for different stands by the combination of sample survey and indoor immersion test. The results showed that the total thickness of litter layer was 4.06-5.12 cm, with the thickest layer in R. pseudoacacia forest and the thinnest in P. tabuliformis forest. The storage volume of litter was the largest in Q. wutaishanica (24.39 t·hm-2), followed by P. davidiana (23.64 t·hm-2), P. orientalis (22.51 t·hm-2), and R. pseudoacacia (22.48 t·hm-2), and the smallest in P. tabuliformis (20.42 t·hm-2). The volume in the undecomposed layer was less than that in the semi-decomposed layer. The maximum water holding of litter was 40.41-79.56 t·hm-2, with the highest of Q. wutaishanica and the lowest of P. tabuliformis. The effective interception rate of litter was 108%-188%. The changes of water capacity and water absorption rate of litter were most rapid in Q. wutaishanica, P. davidiana and R. pseudoacacia, and the changes were faster in the semi-decomposed layer than in the undecomposed layer. The water-holding capacity of litter in five forests was following an order of Q. wutaishanica>P. davidiana>R. pseudoacacia>P. orientalis>P. tabuliformis.

Structural characterization of three polysaccharides from the roots of Codonopsis pilosula and their immunomodulatory effects on RAW264.7 macrophages.

Three polysaccharides were isolated from the roots of Codonopsis pilosula by ion-exchange and gel-filtration chromatography. They were named RCNP, RCAP-1, and RCAP-2, and had apparent molecular weights of 1.14 × 104, 5.09 × 104, and 2.58 × 105, respectively. Their structures were characterized by HPGPC, chemical derivative analysis, GC-MS and NMR analyses. Results showed that RCNP contained arabinan and arabinogalactan regions. The arabinan region had a main chain comprising (1 → 5)-linked Araf residues, and the side chains branched at the O-3 position by the single Araf residues. The arabinogalactan region comprised alternating (1 → 4)-, (1 → 6)- or (1 → 3)-linked Galp along with small amounts of branches mainly at the O-3 position of the (1 → 6)-linked Galp or O-6 position of the (1 → 3)-linked Galp residues by terminally linked Araf residues. RCAP-1 and RCAP-2 were highly methyl-esterified pectin-type polysaccharides with long homogalacturonan regions interrupted by a short rhamnogalacturonan I (RG-I) region. The side chains of the RG-I region consisted of (1 → 2)-linked Rha residues attached to the position O-4 of rhamnose. Their degrees of methyl-esterification were approximately 60.6% and 68.1%, respectively. Bioactivity tests showed that RCAP-1 and RCAP-2 exerted a significant immunostimulatory effect based on NO production from RAW264.7 macrophages. These results suggested that these two pectin-type polysaccharides were potential immunostimulation agents.

Ginsenoside Rd attenuates mitochondrial permeability transition and cytochrome C release in isolated spinal cord mitochondria: involvement of kinase-mediated pathways.

Ginsenoside Rd (Rd), one of the main active ingredients in Panax ginseng, has multifunctional activity via different mechanisms and neuroprotective effects that are exerted probably via its antioxidant or free radical scavenger action. However, the effects of Rd on spinal cord mitochondrial dysfunction and underlying mechanisms are still obscure. In this study, we sought to investigate the in vitro effects of Rd on mitochondrial integrity and redox balance in isolated spinal cord mitochondria. We verified that Ca2+ dissipated the membrane potential, provoked mitochondrial swelling and decreased NAD(P)H matrix content, which were all attenuated by Rd pretreatment in a dose-dependent manner. In contrast, Rd was not able to inhibit Ca2+ induced mitochondrial hydrogen peroxide generation. The results of Western blot showed that Rd significantly increased the expression of p-Akt and p-ERK, but had no effects on phosphorylation of PKC and p38. In addition, Rd treatment significantly attenuated Ca2+ induced cytochrome c release, which was partly reversed by antagonists of Akt and ERK, but not p-38 inhibitor. The effects of bisindolylmaleimide, a PKC inhibitor, on Rd-induced inhibition of cytochrome c release seem to be at the level of its own detrimental activity on mitochondrial function. Furthermore, we also found that pretreatment with Rd in vivo (10 and 50 mg/kg) protected spinal cord mitochondria against Ca2+ induced mitochondrial membrane potential dissipation and cytochrome c release. It is concluded that Rd regulate mitochondrial permeability transition pore formation and cytochrome c release through protein kinases dependent mechanism involving activation of intramitochondrial Akt and ERK pathways.