Anti-oxidant and Anti-inflammatory Effects of Ethanol Extract from Polygala sibirica L. var megalopha Fr. on Lipopolysaccharide-Stimulated RAW264.7 Cells / 中国结合医学杂志

OBJECTIVE@#To investigate the anti-oxidant and anti-inflammatory effects of ethanol extract of Polygala sibirica L. var megalopha Fr. (EEP) on RAW264.7 mouse macrophages.@*METHODS@#RAW264.7 cells were pretreated with 0-200 µg/mL EEP or vehicle for 2 h prior to exposure to 1 µg/mL lipopolysaccharide (LPS) for 24 h. Nitric oxide (NO) and prostaglandin (PGE2) production were determined by Griess reagent and enzyme-linked immunosorbent assay (ELISA), respectively. The mRNA levels of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor α (TNF-α), interleukin-1beta (IL-1β), and IL-6 were determined using reverse transcription polymerase chain reaction (RT-PCR). Western blot assay was used to determine the protein expressions of iNOS, COX-2, phosphorylation of extracellular regulated protein kinases (ERK1/2), c-Jun N-terminal kinase (JNK), inhibitory subunit of nuclear factor Kappa B alpha (Iκ B-α) and p38. Immunofluorescence was used to observe the nuclear expression of nuclear factor-κ B p65 (NF-κ B p65). Additionally, the anti-oxidant potential of EEP was evaluated by reactive oxygen species (ROS) production and the activities of catalase (CAT) and superoxide dismutase (SOD). The 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl (OH), superoxide anion (O2-) radical and nitrite scavenging activity were also measured.@*RESULTS@#The total polyphenol and flavonoid contents of EEP were 23.50±2.16 mg gallic acid equivalent/100 g and 43.78±3.81 mg rutin equivalent/100 g. With EEP treatment (100 and 150 µg/mL), there was a notable decrease in NO and PGE2 production induced by LPS in RAW264.7 cells by downregulation of iNOS and COX-2 mRNA and protein expressions (P<0.01 or P<0.05). Furthermore, with EEP treatment (150 µg/mL), there was a decrease in the mRNA expression levels of TNF-α, IL-1β and IL-6, as well as in the phosphorylation of ERK, JNK and p38 mitogen-activated protein kinase (MAPK, P<0.01 or P<0.05), by blocking the nuclear translocation of NF-κ B p65 in LPS-stimulated cells. In addition, EEP (100 and 150 µg/mL) led to an increase in the anti-oxidant enzymes activity of SOD and CAT, with a concomitant decrease in ROS production (P<0.01 or P<0.05). EEP also indicated the DPPH, OH, O2- radical and nitrite scavenging activity.@*CONCLUSION@#EEP inhibited inflammatory responses in activated macrophages through blocking MAPK/NF-κ B pathway and protected against oxidative stress.

Apoptosis of HepG2 cells induced by Allium ascalonicum L. extract and its mechanism / 中国药学杂志

OBJECTIVE: To investigate the promotion of Allium ascalonicum L. extract (OE) on the apoptosis of human hepatic carcinoma cell line HepG2 and its mechanism. METHODS: Alamar blue assay was used for detecting the influence of OE on the proliferation of HepG2. The morphological changes of cells were observed under inverted microscope and Hoechst 33258 stainning. The cell apoptosis were detected by flow cytometry. Western blot and Caspase 3 activity kit were used to detect the protein expression in HepG2 cells treated with OE. Z-LEHD-FMK was used to validate the signal transduction pathway. RESULTS: OE inhibited the proliferation and induced the apoptosis of HepG2 cells in a dose-dependent manner. The expression of Bcl-2 and survivin was downreagulated in HepG2 cells treated with OE, and Bax, Bad, Apaf-1, p53 and Caspase 9 were upregulated. Besides, the Caspase 3 activity was significantly increased. Z-LEHD- FMK significantly inversed the cell viability of HepG2 cell inhibited by OE. CONCLUSION: These results confirm that onion extract induces the apoptosis of HepG2 through mitochondria-mediated pathway.