High tetramethylpyrazine production by the endophytic bacterial Bacillus subtilis isolated from the traditional medicinal plant Ligusticum chuanxiong Hort.

Tetramethylpyrazine (TMP) with significant protective effects on cardiovascular is the active ingredient of traditional Chinese medicine Rhizoma Chuanxiong (RC). However, many studies have reported the low content of TMP in RC. The endophytes of medicinal plants have the biosynthetic potential to produce the same or similar active metabolites as the host, while few reports were conducted to explore the endophytic bacteria of Ligusticum chuanxiong Hort. and its productive capacity for the important ingredient TMP. The present paper focuses on the isolation and identification of TMP producing endophytic bacteria from RC. In this study, the endophytic bacteria were isolated from the rhizome of Ligusticum chuanxiong Hort. (Umbelliferae). Yeast extract peptone glucose medium (YP) was used for fermentation medium (37 °C, 220 rpm agitation, 144 h). GC and GC/MS were performed to determine and verify the product, the fermentation characteristics were investigated. Morphological observation, physiological and biochemical indexes combining with 16S rRNA sequence analysis were carried out to identify the endophytic bacteria. As a result, five strains of endophytic Bacillus subtilis were firstly isolated and identified from RC, named as LB3, LB3-2-1, LB6-2, LB4, LB5 respectively. All five strains of endophytic B. subtilis produced TMP, while LB5 had the highest production of 10.69 g/L at the 144 h fermentation. This work demonstrates the fact that the endophytic B. subtilis of RC can produce a high level of TMP, indicating the endophytic B. subtilis might play a role in the accumulation of TMP during the growth period of RC.

Glucagon-like peptide-1 protects hippocampal neurons against advanced glycation end product-induced tau hyperphosphorylation.

We have previously demonstrated that glucagon-like peptide-1 (GLP-1) receptor agonist ameliorated neurodegenerative changes in rat models of diabetes-related Alzheimer's disease (AD), and protected neurons from glucose toxicity in vitro. Herein, we investigated the effects of GLP-1 receptor mediates on cell toxicity and tau hyperphosphorylation induced by advanced glycation end products (AGEs), which are associated with glucose toxicity, and the molecular mechanism in PC12 cells and the primary hippocampal neurons. Our study demonstrated that the similar protection effects of GLP-1 existed in PC12 cells treated with glucose-bovine serum albumin (BSA) in hyperglycemic conditions or with glycoaldehyde-BSA alone. Additionally, glucose-BSA alone did not induce significant cytotoxicity in PC12 cells, but resulted in tau hyperphosphorylation in primary hippocampal neurons in 24h. And we found that GLP-1 could reduce cell tau phosphorylation induced by high glucose or glucose-BSA. Furthermore, our data in the present study suggested that GLP-1 regulated tau phosphorylation induced by AGEs through a signaling pathway involving glycogen synthase kinase 3ß (GSK-3ß), similarly to the GSK-3ß inhibitor, lithium chloride. Our findings suggest that GLP-1 can protect neurons from diabetes-associated AGE insults in vitro, and provide new evidence for a potential therapeutic value of GLP-1 receptor agonist in the treatment of AD especially diabetes-related AD.

["Effort index"--estimating abilities of respiratory muscles].

This paper analyzes the actual values of FEV1 and MBC in 240 normal subjects, 147 patients with COPD and 85 cases of cancer tumors, and shows that the actual values of MBC in both COPD patients and cancerous cases are much lower than the calculated values from FEV1. The authors believe that the ratio between the actual values of MBC and its calculated values may be used to reflect the strengths or abilities of the respiratory muscles efforted, called "Effort Index". The formula of MBC calculated from FEV1 is based on the linear regression equation formulated from the actual values of FEV1 and MBC in 240 normal subjects (aged 16-80 yrs). The "Effort Index" is equal to the actual value of MBC/the calculated value of MBC. The "Effort Index" in 240 normal subjects is 1.00 +/- 0.14 (M +/- SD), in mild, moderate and severe cases of COPD being 0.907, 0.807 and 0.626 respectively, and in markedly wasted cancer cases, 0.861 +/- 0.130. The results show that the formula of MBC calculated from FEV1 is useful only for the subjects with normal respiratory muscular abilities; while in COPD patients and markedly emaciated cancerous cases, owing to the chronically tired-out or exhausted respiratory muscular strength, the actual values of MBC are actually lower than those calculated from FEV1, hence the decreased "Effort Index".

[Replacement of helium by argon in the measurement of the carbon monoxide diffusing capacity of the lung].

Carbon monoxide diffusing capacity of the lung (DLco) of 118 normal subjects and 48 patients was measured by using three different gas mixtures respectively: (1) 10% He, 0.3% CO, 21% O2 and the remainder N2; (2) 10% Ar, 0.3% CO, 21% O2 and the remainder N2; (3) 10% He, 10% Ar, 0.3% CO, 21% O2 and the remainder N2. The results were extremely close with each other, value was 0.99 (P less than 0.0005). These results indicate for the first time that the much cheaper and easy-available gas-argon can be used instead of the very expensive helium for measurement of DLco.