Effects of maize rotation on the physicochemical properties and microbial communities of American ginseng cultivated soil.

The production of American ginseng (Panax quinquefolius L.) is severely limited by the replant disorders in China. Crop rotation with maize might reduce the replant problems, but little information is available on the effect of maize rotation on soil cultivated with ginseng. In this study, we analyzed nutrients, phenolic acids, and microbial communities in soils from the fields with continuous maize, mono-culture ginseng, and 1-, 3-, and 5-year maize rotation after ginseng. Pot experiments were also conducted to evaluate the performance of replanting ginseng in these soils. The results showed that Mn, Cu, and 5 phenolic acids in ginseng-cultivated soil were significantly decreased by maize rotation. A 5-year maize rotation significantly increased the relative abundance of beneficial soil bacteria, such as Arthrobacter, rather than decreasing the abundances of potential pathogenic genera. Clustering analysis revealed that the physicochemical properties and microbial communities of 3- and 5-year maize rotation soil were more similar to CM than to G soil. The biomass of replanted ginseng root was improved, and root disease was reduced over 3 years of maize rotation. Overall, the results showed that at least a 3-year maize rotation is needed to overcome the replant failure of American ginseng.

An independent study of the preclinical efficacy of C2-8 in the R6/2 transgenic mouse model of Huntington's disease.

BACKGROUND: C2-8 is a small molecule inhibitor of polyglutamine aggregation and can reduce photoreceptor neurodegeneration in a Drosophila model of Huntington's disease (HD). Further preclinical studies have shown that oral administration of C2-8 in R6/2 HD transgenic mice can penetrate into the brain, reduce mHTT-exon1 aggregation, improve motor performance and diminish striatal neuron atrophy. OBJECTIVE: In this independent preclinical study, we aimed to evaluate the pharmacokinetic properties and therapeutic efficacy of C2-8 intraperitoneal (IP) delivery in the R6/2 HD mouse. METHODS: R6/2 mice were IP injected with low dose C2-8 (10 mg/kg), high dose C2-8 (20 mg/kg), or vehicle twice daily from 3 weeks to 3 months old. Longitudinal behavioral tests (accelerating Rotarod and wire-hang) were performed to evaluate the motor deficits, and neuropathology was measured by unbiased stereology. RESULTS: We confirmed that the compound has good blood-brain-barrier penetration after acute or sub-chronic intraperitoneal delivery. Chronic treatment with C2-8 in R6/2 mice results in a significant reduction of nuclear mHTT aggregate volume in the brains, replicating a key finding of C2-8 as a polyglutamine aggregation inhibitor in vivo. However, by comparing HD mice with C2-8 treatment to those with vehicle treatment, we were unable to demonstrate significant amelioration of motor deficits using Rotarod and wire-hang tests. Moreover, we did not observe improvement in the striatal neurodegenerative pathology, as measured by brain weight, striatal volume, and striatal neuron volume in the C2-8 treated R6/2 mice. CONCLUSIONS: Our study supports the practice of independent preclinical studies for novel molecules in HD therapeutic development and suggests that the use of alternative delivery strategies and full-length HD mouse models are likely needed to further assess whether the aggregate-inhibiting properties of C2-8 can be consistently translated into a preclinical benefit in HD mice.

[Effects of berberine on expression of hepatocyte nuclear factor 4alpha and glucokinase activity in mouse primary hepatocytes].

OBJECTIVE: To observe the expression of hepatocyte nuclear factor 4alpha (HNF4alpha) and the activity of key enzyme glucokinase (GK) in glucose metabolism, and further to investigate the possible mechanism of berberine in treating type 2 diabetes. METHOD: Mouse primary hepatocytes were isolated by an improved single two-step perfusion method. The murine hepatocytes were cultured and incubated with berberine (0, 1, 3, 10, 30, 100 micromol x L(-1)) and 1 mmol x L(-1) metformin for 24 h respectively. The mRNA expression of HNF4alpha were quantified by RT-PCR and the protein expression of HNF4alpha were quantified by Western-blot. And the activity of GK were detected with enzyme kinetics method. RESULT: As compared with the negative control group, at a certain concentration range, the expression of HNF4alpha mRNA and protein and the activity of GK were promoted by berberine. Both of them reached the top at the concentration of 30 micromol x L(-1) (P<0.01). But the metformin made no difference with the negative control group on the expression of HNF4alpha and the activity of GK. CONCLUSION: It is suggested that the effects of berberine on improving glucose metabolism can be mechanically associated with its up-regulating the HNF4a expression and inducing the activity of hepatic glucokinase.

[Effects of Huanglian Jiedu Decoction on phosphatidylinositol-3-kinase expression in target tissues of type 2 diabetic rats].

OBJECTIVE: To observe the effects of Huanglian Jiedu Decoction (HLJDD), a traditional Chinese compound herbal medicine, on p85 mRNA and protein expressions of phosphatidylinositol-3-kinase (PI-3K) in target tissues (skeletal muscular and adipose tissues) in rats with type 2 diabetes mellitus (T2DM) and to investigate the molecular mechanism of HLJDD in treating T2DM. METHODS: The male Wistar rats were injected with streptozotocin (STZ) 30 mg/kg through tail vein, and fed with high-fat and high-caloric diets to induce T2DM. Then the rats were randomly divided into untreated group, aspirin-treated group and HLJDD group, and treated correspondingly. Meanwhile, a group of normal animals without any treatment was set up for normal control group. Ten weeks later, serum fasting blood glucose (FBG), serum fasting insulin (FINS) and oral glucose tolerance test (OGTT) were routinely determined. The expressions of PI-3K p85 mRNA and protein in skeletal muscle and adipose tissue were determined with RT-PCR and Western blotting before and after insulin treatment. RESULTS: Compared with the untreated group, the FBG and OGTT levels in T2DM rats treated with HLJDD decreased significantly (P<0.05). The FINS in HLJDD group was lower than that in the normal control group (P<0.05), but was not significantly different from that in the untreated group. The PI-3K p85 mRNA and protein expressions in HLJDD group obviously increased, as compared with those in the untreated group. CONCLUSION: The effect of HLJDD in treating T2DM was probably associated with its improvement of PI-3K p85 mRNA and protein expressions in skeletal muscle and adipose tissue of the T2DM rats.