ABSTRACT
AIM: To investigate the effect of Chinese propolis on the activity of phosphatidylcholine-specific phospholipase C (PC-PLC) and the expression of Toll-like receptor 4 (TLR4) in LPS-treated vascular endothelial cells (VECs). METHODS: Confluent VECs were stimulated with LPS at the concentration of 100 μg/L in the presence of 0.5% fetal bovine serum. The cells were treated with Chinese propolis at the concentration of 12.5 mg/L for 12 h and 24 h. The viability of VECs and the level of nitric oxide (NO) were detected by sulforhodamine B (SRB) assay and chemical method, respectively. The activity of PC-PLC was measured using L-α-phosphatidylcholine as substrate. The protein levels of TLR4, nuclear factor-Κb p65 (NF-Κb p65) and p53 were determined by Western blotting. The level of intracellular reactive oxygen species (ROS) was examined using a fluorescent probe, 2',7'-dichlorodihydrofluorescin (DCHF). For the measurement of mitochondrial membrane potential, the fluorescent dye JC-1 was used. RESULTS: Treatment with Chinese propolis for 24 h had no effect on the viability of VECs. However, the levels of NO and ROS were significantly decreased by Chinese propolis. PC-PLC activity and NF-Κb p65 expression were significantly depressed by Chinese propolis treated for 12 h, and the expression of TLR4 and p53 were dramatically decreased by Chinese propolis treated for 12 and 24 h. No effect of Chinese propolis on mitochondrial membrane potential was observed. CONCLUSION: Chinese propolis depresses the activity of PC-PLC and the expression of TLR4, and then inhibits the downstream signal molecules such as NF-Κb p65, p53, ROS and NO in VECs.
ABSTRACT
AIM: To study the effect of propolis on the expression of CD54 and activation of NF-?B p65 in lung tissue of acute lung injury (ALI) rats. METHODS: 40 male Wistar rats were divided into 5 groups: normal control, model control, dectancyl group, water soluble derivative of propolis (WSP) group and ethanol extracted propolis (EEP) group. ALI animal model was performed by oleic acid and LPS twice attack. The pathologic slice was observed with light microscope and the NF-?B p65 activity and CD54 expression were tested by immunohistochemistry (SABC and SP). RESULTS: Both EEP and WSP antagonized the lung edema, decreased the inflammation and inhibited the expression of CD54 and activation of NF-?B p65. CONCLUSION: The increase in the expression of CD54 and the activation of NF-?B p65 in the lung tissues of ALI were involved in the formation of ALI. Propolis ameliorated the lung damage, which maybe related to the inhibition of CD54 expression and NF-?B p65 activation.
ABSTRACT
Objective: To investigate the anti-inflammatory effect and the possible mechanism of water and ethanol extracts of propolis. Method: Forty male Wistar rats were divided into 5 groups: normal group, model group, medicine groups, two groups treated with water and ethanol extracts of propolis. The acute pleurisy model was established by injecting carrageenan. The effects of propolis on acute pleurisy was studied by counting leukocytes, measuring the content of MDA, lysozyme and activity of SOD in serum and the content of NO, protein and PGE2 in pleural effusion. Results: The propolis solutions extracted by water and ethanol presented obvious effect on inflammation. It could antagonize the purulent pleurisy, reduce the number of leukocytes and the content of MDA, lysozyme and activity of SOD in serum and the contents of NO, protein and PGE2 and decrease the inflammation. Conclusion: Propolis displays anti-inflammatory effects by decreasing the action of NO and PGE2 and preventing the activation of protein kinase.