Structurally diverse triterpenoid alkaloids from Buxus rugulosa.

Four new nortriterpenoid alkaloids, namely buxrugulines E-H (1-4), along with five known ones (5-9), were isolated from the twigs and leaves of Buxus rugulosa. Their structures were identified based on extensive NMR data and MS spectroscopic analyses. Our bioassays revealed that compounds 5, 6 and 8 exhibited potent cytotoxicity in vitro against MCF-7 cell lines, with IC50 values ranging from 6.70 to 11.00 µM, respectively.

Root-determined hypernodulation mutant of Lotus japonicus shows high-yielding characteristics.

Here we report the phenotypic characteristics of a novel hypernodulation mutant, Ljrdh1 (root-determined hypernodulation 1) of Lotus japonicus. At 12 weeks after rhizobial inoculation, there were no differences between the growth of Ljrdh1 and, wild-type. However, Ljrdh1 showed 2 to 3 times higher nitrogen-fixing activity, and seed and pod yields, were approximately 50% higher than the wild-type. This is the first report of a legume hypernodulation mutant showing normal growth and a high-yielding characteristic under optimal cultivation conditions.

A study of genetic structure of Stephania yunnanensis (Menispermaceae) by DALP.

Genetic diversity and genetic structure within and among ten populations of Stephania yunnanensis H. S. Lo and three populations of S. epigaea H. S. Lo from Yunnan province were evaluated by direct amplification of length polymorphism (DALP) markers. Five primer groups were screened, and a total of 287 DNA fragments were amplified, among which 266 were polymorphic, averaging 53.2 polymorphic bands per primer group in S. yunnanensis. The percentage of polymorphic bands of S. yunnanensis was 92.68% at the species level and 61.92% within the ten populations sampled. At the species level, the observed number of alleles (N (a)) was 1.9268 and the effective number of alleles (N (e)) was 1.5933; Nei's gene diversity (H) was 0.3414; Shannon's information index (I) was 0.5057. At the population level, N (a) = 1.6192, N (e) = 1.4001, H = 0.2298, and I = 0.3401. Total gene diversity of S. yunnanensis was 0.3419. Gene diversity within population was 0.2298, coefficient of gene differentiation was 0.3278, and estimated gene flow was 1.0254. The results indicated that the genetic differentiation was relatively higher among populations of S. yunnanensis. DALP markers were an informative and useful method for assaying genetic diversity and authenticating species of Stephania. These data could provide basic molecular evidence for establishing a reasonable strategy for protecting and exploiting the resource of S. yunnanensis.

[Effects of ganoderma lucidum spores on mitochondrial calcium ion and cytochrome C in epididymal cells of type 2 diabetes rats].

OBJECTIVE: To observe the effects of ganoderma lucidum spores (GLS) on mitochondrial calcium ion and cytochrome C in the epididymal cells of type 2 diabetes rats. METHODS: Fifty adolescent rats were randomly divided into a model group (n=20), a GLS group (n=20) and a control group (n=10). The animals of the former two groups were injected with 2% STZ via vena caudalis for one time to induce type 2 diabetes. Then the model group was given high-fat-sugar diet, the GLS group high-fat-sugar diet + GLS (250 mg/kg x d), and the control group normal diet + CA-citrate sodium buffer. The bilateral epididymides were obtained 10 weeks later and the contents of mitochondrial calcium and cytochrome C detected. RESULTS: Type 2 diabetes models were successfully constructed. The content of mitochondrial calcium in the epididymal cells was significantly higher in the model group ([3.279 +/- 0.502] mg/L) than in the control group ([2.606 +/- 0.048] mg/L, P < 0.01), with no significant difference between the GLS group ([2.693 +/- 0. 196] mg/L) and the control (P > 0.05). In the model group, the content of mitochondrial cytochrome C ([3.213 +/- 1.511] micromol/L) was significantly lower (P < 0.05) while that of cytoplasm cytochrome C ([2.484 +/- 0.661] micromol/L) significantly higher (P < 0.05) than in the control ([5.688 +/- 1.679] micromol/L and [1.574 +/- 0.329] micromol/L, respectively). In the GLS group, the content of mitochondrial cytochrome C ([5.258 +/- 1.560] micromol/L) was higher, with no significant difference (P > 0.05), and that of cytoplasm cytochrome C ([1.727 +/- 0.396] micromol/L) significantly lower than in the model group (P < 0.05), but the difference between the GLS and the control group was not significant (P > 0.05). CONCLUSION: With disequilibrium of calcium homeostasis and damage to mitochondria, there might be excessive apoptosis in the epididymal cells of type 2 diabetes rats. Ganoderma lucidum spores could protect epididymal cells and counteract their apoptosis in diabetic condition.

[Alteration of p53 gene during tree shrews' hepatocarcinogenesis].

OBJECTIVE: To detect the expression and variation of p53 gene during tree shrews' hepatocarcinogenesis induced by hepatitis B virus (HBV) and aflatoxin B1 (AFB1). METHODS: Tree shrews were divided into four groups: the tree shrews were infected with HBV and fed with AFB1 in group A, only infected with HBV in group B, fed with AFB1 alone in group C, and normal control in group D. All the tree shrews were performed liver biopsy every 15 weeks. The tissues of liver and tumor were detected by immunohistochemistry and molecular biotechnologies. RESULTS: (1) The incidence of hepatocellular carcinoma (HCC) in group A (66.7%) was higher than that in Group B and C (30%). HCC appearance in group A was earlier than that in group C (120.0 weeks +/-16.6 weeks vs 153.3 weeks +/-5.8 weeks, t = 3.336, P<0.01). (2) Mutated p53 protein was not found before the 75th week of the experiment in each group. (3) At the 105th week, the expression rates of mutated p53 protein were 78.6%, 60% and 71.4% in group A, B and C respectively, which were much higher than that (10%) in group D (x2 > or = 5.03, P<0.05). An abnormal band of p53 gene was detected in both group A and C. (4) The mutation points of p53 gene in liver cancer of tree shrew were at codon 275, 78 and 13. The nucleotide sequence and amino acids sequence of tree shrew's wild-type p53 showed 91.7% and 93.4% homology with those of human p53 respectively. CONCLUSIONS: There is a remarkable synergistic effect between HBV and AFB1 on HCC. Mutated p53 protein is expressed before HCC occurrence, which promotes the development and progress of HCC. HBV and AFB1 may synergistically induce p53 gene mutation.