Suberoylanilide Hydroxamic Acid, A Histone Deacetylase Inhibitor, Attenuates Postoperative Cognitive Dysfunction in Aging Mice

Postoperative cognitive dysfunction (POCD) is a recognized clinical entity characterized with cognitive deficits after anesthesia and surgery, especially in aged patients. Previous studies have shown that histone acetylation plays a key role in hippocampal synaptic plasticity and memory formation. However, its role in POCD remains to be determined. Here, we show that suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, attenuates POCD in aging Mice. After exposed to the laparotomy, a surgical procedure involving an incision into abdominal walls to examine the abdominal organs, 16- but not 3-month old male C57BL/6 mice developed obvious cognitive impairments in the test of long-term contextual fear conditioning. Intracerebroventricular (i.c.v.) injection of SAHA at the dose of (20 μg/2 μl) 3 hours before and daily after the laparotomy restored the laparotomy-induced reduction of hippocampal acetyl-H3 and acetyl-H4 levels and significantly attenuated the hippocampus-dependent long-term memory impairments in 16-month old mice. SAHA also reduced the expression of cleaved caspase-3, inducible nitric oxide synthase and N-methyl-D-aspartate receptor-calcium/calmodulin dependent kinase II pathway, and increased the expression of brain-derived neurotrophic factor, synapsin 1, and postsynaptic density 95. Taken together, our data suggest that the decrease of histone acetylation contributes to POCD and may serve as a target to improve the neurological outcome of POCD

Characterization and evaluation of antimicrobial and cytotoxic effects of Streptomyces sp. HUST012 isolated from medicinal plant Dracaena cochinchinensis Lour.

A highly potent secondary metabolite producing endophytic strain, Streptomyces sp. HUST012 was isolated from the stems of the medicinal plant Dracaena cochinchinensis Lour. Strain HUST012 showed antimicrobial and antitumor activities which were significantly much higher than those of dragon's blood extracted from D. cochinchinensis Lour. On further analysis, the strain was found to produce two metabolites, SPE-B11.8 (elucidated to be a novel metabolite (Z)-tridec-7-ene-1,2,13-tricarboxylic acid) and SPE-B5.4 (elucidated as Actinomycin-D). The Minimum Inhibitory Concentration values of SPE-B11.8 against a set of test bacterial organisms (Methicillin-resistant Staphylococcus epidermis ATCC 35984, Methicillin-resistant Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Klebsiella pneumoniae ATCC 13883) ranged between 15.63 and 62.5 µg/ml while that for SPE-B5.4 ranged between 0.04 and 2.24 µg/ml. The compound SPE-B11.8 showed cytotoxic effect at 41.63 and 29.54 µg/ml IC50 values against Hep-G2 and MCF-7 respectively, while the compound SPE-B5.4 exhibited stronger activities against them at 0.23 and 0.18 μg/ml IC50 values

Increased hippocampus–medial prefrontal cortex resting state functional connectivity and memory function after Tai Chi Chuan practice in elder adults

Previous studies provide evidence that aging is associated with the decline of memory function and alterations in the hippocampal function, including functional connectivity to the medial prefrontal cortex (mPFC). In this study, we investigated if longitudinal (12-week) Tai Chi Chuan and Baduanjin practice can improve memory function and modulate hippocampal resting-state functional connectivity (rs-FC). Memory function measurements and resting state functional Magnetic Resonance Imaging (rs-fMRI) were applied at the beginning and the end of the experiment. The results showed that 1) the memory quotient (MQ) measured by the Wechsler Memory Scale (WMS-CR) significantly increased after Tai Chi Chuan and Baduanjin practice as compared with the control group, and no significant difference was observed in MQ between the Tai Chi Chuan and Baduanjin groups; 2）rs-FC between the bilateral hippocampus and mPFC significantly increased in the Tai Chi Chuan group compared to the control group (also in the Baduanjin group compared to the control group, albeit at a lower threshold), and no significant difference between the Tai Chi Chuan and Baduanjin groups was observed; 3) rs-FC increases between the bilateral hippocampus and mPFC were significantly associated with corresponding memory function improvement across all subjects. Similar results were observed using the left or right hippocampus as seeds. Our results suggest that both Tai Chi Chuan and Baduanjin may be effective exercises to prevent memory decline during aging