A novel immobilized cholinesterase for on-site screening of organophosphate and carbamate compounds

Acetylcholinesterase was physically adsorbed on polyvinylpyrrolidone K30 to prepare a novel immobilized cholinesterase, which was described for the first time. The immobilized enzyme was tested for its reactivity, enzyme activity stability, the solubility, the influence of pH and buffer, and characteristic reactivity with inhibitors, e.g., organophosphate and carbamate compounds. The result revealed that the immobilized cholinesterase held its original activity in solution, stable enough, easy to dissolve for convenient operation, and this immobilized cholinesterase could be well used for rapid, on-site screening of organophosphate and carbamate compounds, together with a portable pesticide analyzer.     

Effects of Chinese traditional medicine-selected recipe Q0409 on ability of learning and memory in SAM-P/8 mice

AIM: To investigate the effects of Chinese traditional medicine-selected recipe Q0409 on the ability of learning and memory in SAM-P/8 mice. METHODS: Total 91 mice (4-month-old SAM-P/8 mice, SAM-R/1 mice and Kunming mice) were used in the study, in which the male and female animals were labeled separately. According to the performance of Morris water maze test, the mice were divided into 5 groups randomly. The mice were fed with different drugs or distilled water for 60 d (from 4 months to 6 months). The mice were fed with the drugs from 61 d to 65 d, and 1 h later each time, the Morris water maze test was carried out. After this Morris test were finished at 65 d, the mice were killed immediately and their hippocampal tissues were isolated. Half of the hippocampal tissues were added with precooled normal saline and made into 10% (g/mL) homogenate for detecting the protein content and acetyl cholinesterase (AChE) activity. The other half was fixed with 4% paraformaldehyde and embedded with paraffin for immunohistochemical staining of amyloid β-protein (Aβ). RESULTS: Compared with model group, the results of navigation training and spatial probe training in Morris water maze test were significantly improved (P<0.05), and the activity of AChE in the hippocampal homogenate was significantly decreased (P<0.05) in Q0409 treatment group. No difference in Q0409 group was observed compared with control group and positive drug (huperzine A) group. Immunohistochemical staining showed no typical "senile plaques" in the male mice of Q0409 group, while there was shallower and smaller brown staining in the hippocampus of the female mice of Q0409 group. The positive area of Aβ deposition decreased in the CA1 area of hippocampal tissues in Q0409 group. These results were similar to those in positive drug group. CONCLUSION: Q0409 improves the ability of learning and memory in SAM-P/8 mice, which is related to the inhibition of AChE activity and the reduction of Aβ protein deposition in the hippocampus. The effects is similar to those of huperzine A.     

Bioactive Compounds from Macroalgae in the New Millennium: Implications for Neurodegenerative Diseases

Marine environment has proven to be a rich source of structurally diverse and complex compounds exhibiting numerous interesting biological effects. Macroalgae are currently being explored as novel and sustainable sources of bioactive compounds for both pharmaceutical and nutraceutical applications. Given the increasing prevalence of different forms of dementia, researchers have been focusing their attention on the discovery and development of new compounds from macroalgae for potential application in neuroprotection. Neuroprotection involves multiple and complex mechanisms, which are deeply related. Therefore, compounds exerting neuroprotective effects through different pathways could present viable approaches in the management of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. In fact, several studies had already provided promising insights into the neuroprotective effects of a series of compounds isolated from different macroalgae species. This review will focus on compounds from macroalgae that exhibit neuroprotective effects and their potential application to treat and/or prevent neurodegenerative diseases.