[Limonoids from seeds of Azadirachta indica and their antibacterial activity].

Fifteen limonoids were isolated from 95% ethanol extracts of the dry seeds of neem( Azadirachta indica) by various column chromatography techniques including silica gel,Pharmadex LH-20 gel and ODS resin. Based on spectroscopic analysis,their structures were determined as nimbocinol( 1),17ß-hydroxynimbocinol( 2),1α,3α,7α-triacetylvilasinin( 3),7α-benzoyltrichilinin( 4),1,3-diacetyl-7-tigloyl-12-hydroxyvilasinin( 5),3-deacetylsalannin( 6),1-O-acetyl-1-detigloylsalannin( 7),2'( R),3'-dihydrosalannin( 8),2'( S),3'-dihydrosalannin( 9),2,3-dihydronimbolide( 10),6-homodesacetylnimbin( 11),gedunin( 12),7-deacetyl-7-epi-dihydrogedunin( 13),7-deacetoxy-7α-hydroxygedunin( 14) and nimbinene( 15). Compound 7 is a new natural product. 4,8,9,13 and 14 are isolated from the genus Azadirachta for the first time. Compound 2 showed inhibitory activity against Escherichia coli and Staphylococcus epidermidis,with MIC values of 32 and 128 mg·L~(-1),respectively. Compound 10 showed moderate inhibitory activity against S. epidermidis with a MIC value of 64 mg·L~(-1). Compound 11 inhibited the growth of E. coli and Pseudomonas aeruginosa,both with MIC values of 128 mg·L~(-1). Compound 15 exhibited inhibitory activity against P. aeruginosa,with a MIC value of128 mg·L~(-1).

[Limonoids from seeds of Azadirachta indica and their cytotoxic activity].

Eight limonoids were isolated from 95% ethanol extracts of neem(Azadirachta indica) seeds by various chromatographic methods. By comparison of their spectroscopic data with those reported in the literatures, these limonoids were determined as salannin(1), 1-detigloyl-1-isobutylsalannin(2), salannol-3-acetate(3), salannol(4), spirosendan(5), 1-detigloyloxy-3-deacetylsalannin-1-en-3-one(6), nimbin(7) and 6-deacetylnimbin(8). Compounds 2 and 5 were firstly isolated from this genus and 5 represented the only example of its type. And 6 is a new natural product. 6 showed inhibitory activity against HeLa and HL-60 cells, with IC50 of(21.61±4.37) and(27.33±5.74) µmol·L⁻¹, respectively. Both 7 and 8 mildly inhibited the growth of HeLa cells, with IC50 of (33.15±5.24) and (38.56±6.41) µmol·L⁻¹, respectively.

Relieving visceral hyperalgesia effect of Kangtai capsule and its potential mechanisms via modulating the 5-HT and NO level in vivo.

Kangtai capsule (KT) is one type of traditional Chinese medicine preparation derived from the proved recipe, which was frequently applied as an effective clinical treatment of IBS. However, there still lack the reasonable and all-round analytical approach and the scientific studies on its underlying mechanisms. Therefore, our study aimed to develop the novel method for evaluating its quality as well as to interpret the potential mechanisms. In our study, high performance liquid chromatography (HPLC) fingerprint was applied to provide a chemical profile of KT. The neonatal maternal separation (NMS) on Sprague-Dawley pups was employed to evaluate the therapeutic effect of KT by virtue of various parameters including visceral hyperalgesia, serum nitric oxide (NO) level, and tissue 5-hydroxytryptamine (5-HT) level. Consequently, a chromatographic condition, which was carried at 30°C with a flow rate of 0.5 ml/min on AQUA 3µ C18 column with mobile phase of acetonitrile and water-phosphoric acid (100:0.1, v/v), was established to give a common fingerprint chromatography under 254 nm with a similarity index of 0.963 within ten batches of KT samples. On the NMS model, KT markedly elevated the pain threshold of NMS rats. Furthermore, KT at three doses significantly decreased 5-HT content from distal colon of visceral hyperalgesia rats induced by NMS, while the significant decrease of 5-HT content in serum was only observed in the group with KT at high dose. However, compared with that in NMS rats without KT, there was no apparent difference of 5-HT level from brain issue in the rats with various doses. Besides, KT could substantially elevate the concentration of NO in the serum. The results showed our study developed the simple, rapid, accurate, reproducible qualitative and quantitative analysis by HPLC fingerprint for the quality control for KT. Data from the pharmacological investigation suggested that the curative effect of KT to the visceral hypersensitivity may be concerned with the level of 5-HT and NO in vivo, promising its potential in irritable bowel syndrome treatment.

[Efficacy of tianmaixiaoke tablets in the treatment of newly diagnosed type 2 diabetes mellitus in China].

OBJECTIVE: To explore the efficacy and influencing factors of chromium picolinate (tianmaixiaoke tablet) in the treatment of newly diagnosed type 2 diabetes mellitus in China. METHODS: A total of 84 outpatients with newly diagnosed type 2 diabetes mellitus visiting 4 hospitals in Beijing were randomly divided into two equal groups: study group receiving tianmaixiaoke tablet 240 mg bid for 24 weeks (n = 42) and control group sitagliptin 100 mg qd for 24 weeks (n = 42). The levels of fasting plasma glucose (FPG), plasma glucose 2 h after meal (PG2 h) and glycated hemoglobin (HbA1c) were detected before and 24 weeks after treatment. The serum levels of chromium and insulin were detected. RESULTS: Study was completed in 76 patients. The serum level of chromium was significantly lower in the diabetes group than in the normal group at baseline ((56 ± 28) µg/L vs (112 ± 21) µg/L, P = 0.00). At 24 weeks after treatment, the levels of HbA1c, FPG and PG2 h decreased while the serum level of chromium increased significantly in both groups. There were 11 patients with changed HbA1c from baseline (ΔHbA1c) ≥ 1% in the study group. At 24 weeks after treatment, HbA1c decreased by 1.61% (from 8.38% ± 0.72% to 6.77% ± 0.62%) and serum level of chromium increased by 35.14 µg/L in the ΔHbA1c ≥ 1% group with a low baseline serum level of chromium ((36.2 ± 18.0) µg/L). Both study group and control group were divided into three subgroups according to baseline serum level of chromium. ΔHbA1c reduced with the increase in baseline serum level of chromium in study group, while in control group, ΔHbA1c was unrelated with baseline serum level of chromium. At 24 weeks after treatment, insulin resistance index (HOMA-IR) reduced, ß cell function index (HOMA-ß) and insulinogenic index (IGI) increased in both groups. Multiple linear regression showed that the variables significantly associated with ΔHbA1c were baseline HbA1c and the baseline serum level of chromium. CONCLUSIONS: Chromium is commonly deficient in the newly diagnosed type 2 diabetics in China. HbA1c decreases and serum chromium increases significantly after chromium supplementation in the patients with a low baseline serum level of chromium.

Colorectal cancer cell growth inhibition by linoleic acid is related to fatty acid composition changes.

Polyunsaturated fatty acids (PUFAs) possess anti-cancer action both in vitro and in vivo. In the present study, we detected cell viability with methyl thiazolyl tetrazolium (MTT) assay and cell membrane permeability with propidium iodide (PI) fluorescence dyeing, and calculated cell membrane fluidity change as fluorescence anisotropy. Fatty acid content in cells was measured by gas chromatography/mass spectroscopy (GC/MS), and the relationship between fatty acid composition and cell viability was studied. We observed that n-6 PUFA linoleic acid (LA) inhibited tumor cell growth at high concentrations (≥300 µmol/L), while low concentrations (100-200 µmol/L) seemed to promote cell proliferation. Analyses of cell membrane permeability, cell membrane fluidity, and cell fatty acid composition suggested that the anti-cancer action of LA could be related to changes in the ratio of n-6 to n-3 PUFAs. We observed that pre-incubation of cancer cells with 100 µmol/L LA for 24 h enhanced cell sensitivity to the cytotoxic action of LA, whereas undifferentiated cell line LoVo seemed to have a distinct path in LA-induced death. These results showed that one of the mechanisms by which supplementation of LA induces cancer cell death could be altering the ratio of n-6/n-3 PUFAs, and this may be related to cell differentiation status.

A novel alternative spliced variant of neutrophil gelatinase-associated lipocalin receptor in oesophageal carcinoma cells.

Recent studies suggest that NGAL (neutrophil gelatinase-associated lipocalin) is a novel iron transporter with functions distinct from that of transferrin and mediates a new iron-delivery pathway. To get a better understanding of NGAL function in oesophageal carcinoma, we analysed the expression of NGAL receptors in oesophageal carcinoma cells and identified a novel spliced variant designated NgalR-3. When expressed in a heterologous system, the protein produced from this novel spliced variant exhibits the biochemical characteristics of interaction and co-localization with NGAL protein in vivo. This new finding suggests that NgalR-3 may act as a potential NGAL receptor and play a role in NGAL-mediated iron transport in oesophageal carcinoma.

[Protective effects of shenmai injection on the delayed injury of the cerebral neurons in rat induced by intracerebral hemorrhage].

OBJECTIVE: To observe protective effects of Shenmai (SM) injection on the delayed injury of the cerebral neurons in rat with intracerebral hemorrhage. METHOD: Rosenberg models of intracerebral hemorrhage was established and the effects of SM injection on the pathologic changes in neuronal structure, mitochondria-DNA(mtDNA)deletion, C-myc gene and expression PDGF-A gene in hippocampal CA1 areas, were investigated. RESULT: SM injection inhibited the apoptosis of pyramidal cells in the hippocampal CA1 areas, and decreased the degree of mtDNA deletion in the neurons in the injured area. SM injection had no effect on gene expression of C-myc at initial stage a intracerebral hemorrhage, but significantiy decreased the level of PDGF-A mRNA and prolonged the time of its expression. CONCLUSION: SM injection might attenuate the delayed injury induced by intracerebral hemorrhage via regulating the expression of PDGF.

[Influence of dosage on cell biocompatibility of hydroxyapatite/tricalcium phosphate].

OBJECTIVE: To investigate the influence of different dose levels of hydroxyapatite/tricalcium phosphate (HA/TCP) on the proliferation and alkaline phosphatase (ALP) activity of rabbit osteoblasts. METHODS: Three different dose levels of HA/TCP (10%, 40%, 70%) were co-cultivated with rabbit osteoblasts respectively. The proliferation and ALP expression capacity of osteoblasts were examined with MTT method and enzyme histochemistry once every 24 hours until 5 days. Three control groups of other materials were treated and examined in the same way: rabbit osteoblasts as normal control; polyvinylchloride as positive control; titanium alloy as negative control. RESULTS: There was remarkable time-effect relationship in the proliferation of osteoblasts. Ten percent HA/TCP did not affect osteoblasts growth while 40% HA/TCP could slow the cell growth rate down though time-effect relationship still existed. The proliferation of osteoblasts stagnated when co-cultivated with 70% HA/TCP. On the other hand, 10% HA/TCP could cause reversible damage on ALP activity of osteoblasts, whereas when the dose was 40%, and the cultivation lasted 6 days the damage was irreversible. Three different dose levels of titanium alloy (10%, 40%, 70%) had no effect on the proliferation or ALP activity of osteoblasts. CONCLUSION: Dosage is an important factor affecting the biocompatibility evaluation of biomaterial. It suggests that dose choosing should be more specified upon each individual biomaterial. It also indicates that ALP may be a good supplementary index of the cell compatibility of material.