Effects of manual loading on calcitonin gene-related peptide and nerve growth factor in rats with chronic low back pain / 中国骨伤

OBJECTIVE@#To observe the analgesic effect of manipulation loading on chronic low back pain (CLBP) model rats and the expression of inflammatory factors in psoas major muscle tissue, and to explore the improvement of manipulation on local inflammatory microenvironment.@*METHODS@#Thirty two SPF male SD rats weighing 340-360g were randomly divided into blank group, sham operation group, chronic low back pain model group and treatment group, with 8 rats in each group. In the model group, L@*RESULTS@#There was no significant difference in PWT and PWL between the blank group and the sham operation group after modeling (@*CONCLUSION@#Local massage loading has analgesic effect on CLBP rats, at the same time, it can inhibit the content of CGRP and NGF in psoas muscle tissue of CLBP rats, and improve the local inflammatory microenvironment.

Oral acute toxicity of (+)-usnic acid in mice and its cytotoxicity in rat cardiac fibroblasts / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the oral acute toxicity of of (+)-usnic acid in mice and assess its cytotoxicity in rat cardiac fibroblasts.</p><p><b>METHODS</b>The mice with acute poisoning of (+)-usnic acid at different doses by oral administration were observed for toxic manifestations, and the LD(50) was determined. The survival time and survival rate of the mice receiving different doses of (+)-usnic acid were observed. Cultured rat cardiac fibroblasts were inoculated with different concentrations of (+)-usnic acid, and the cell growth inhibition rate was estimated and the IC(50) determined using MTT assay.</p><p><b>RESULTS</b>Higher dose of (+)-usnic acid resulted in more obvious symptoms of poisoning and shorter survival time of the mice. The LD(50) of (+)-usnic acid in mice by oral administration was 388 mg/kg. The manifestations of poisoning such as apathism, pilomotor, chill, dyspnea, torpidity and anorexia was observed. Rat cardiac fibroblasts incubated with (+)-usnic acid showed obvious growth inhibition, which was positively correlated to the dose of (+)-usnic acid, and high dose of (+)-usnic acid caused severe cell injuries. The IC(50) of (+)-usnic acid in rat cardiac fibroblasts was 322 microg/ml.</p><p><b>CONCLUSION</b>(+)-usnic acid is a natural compound of low toxicity in mice, and low to medium dose of (+)-usnic acid dose not produce obvious cytotoxicity.</p>