Gut bacterial nitroreductases play an important role in reduction of various nitroaromatic compounds to the corresponding N-nitroso compounds, hydroxylamines or aromatic amines, most of which are carcinogenic and mutagenic agents. Inhibition of gut nitroreductases has been recognized as an attractive approach for reducing mutagen metabolites in the colon, so as to prevent colon diseases. In this study, the inhibitory effects of 55 herbal medicines against Escherichia coli(E. coli) nitroreductase (EcNfsA) were examined. Compared with other herbal extracts, Syzygium aromaticum extract showed superior inhibitory potency toward EcNfsA mediated nitrofurazone reduction. Then, the inhibitory effects of 22 major constituents in Syzygium aromaticum against EcNfsA were evaluted. Compared with other tested natural compounds, ellagic acid, corilagin, betulinic acid, oleanic acid, ursolic acid, urolithin M5 and isorhamnetin were found with strong to moderate inhibitory effect against EcNfsA, with IC₅₀ values ranging from 0.67 to 28.98 mol·L^-1. Furthermore, the inhibition kinetic analysis and docking simulation demonstrated that ellagic acid and betulinic acid potently inhibited EcNfsA (K_i < 2 μmol·L ^-1) in a competitively inhibitory manner, which created strong interactions with the catalytic triad of EcNfsA. In summary, our findings provide new scientific basis for explaining the anti-mutagenic activity of Syzygium aromaticum, where some newly identified EcNfsA inhibitors can be used for developing novel agents to reduce the toxicity induced by bacterial nitroreductase.
Ellagic Acid/pharmacology* ; Escherichia coli ; Kinetics ; Nitroreductases/pharmacology* ; Plant Extracts/pharmacology* ; Syzygium

To study the effects of ellagic acid(EA)on inflammation and oxidative stress in mice with fatty liver disease induced by AKT gene transfection,the 20 female FVB mice were randomly divided into normal control group,model group and ellagic acid administration group(150,300 mg·kg~(-1)·d~(-1))(n=5).EA experimental groups and model group were using a high pressure into the tail vein transfection plasmid AKT.The next day,EA was started to administered continuously for 5 weeks after the AKT gene transfection,while the model group and the normal control group were given the same amount of saline.After the administration,the liver tissue and serum of mice were taken.HE and oil red O staining were using to observe the histopathological changes in liver;liver function to detect the serum and liver tissue as well as MDA and SOD levels;real-time quantitative PCR(RT-qPCR)was used to measure the mR-NA expression of NF-κB and TNF-α;Western blot and immunohistochemistry were used to measure the expression of NF-κB,TNF-αand COX-2 in liver tissue.RESULTS:: show that after AKT gene transfection,the model group had significant increase in the serum levels of AST,ALT,elevated the levels of MDA and decreased the levels of SOD in serum and liver tissue,aggravated histopathology degeneration and Liver inflammation,and significantly higher expression of NF-κB,TNF-α,IL-6,COX-2 and other inflammatory-related factors in liver tissue.EA administration group significant reductions in the serum levels of AST,ALT,and improved in hepatocyte fatty degeneration and liver inflammation,lower the levels of MDA and increased the levels of SOD in serum and liver tissue,and significant reductions in the expression of NF-κB,TNF-α,IL-6 and COX-2 in liver tissue.These results suggest that EA has obvious anti-inflammatory effect and inhibits oxidative stress and EA has a significant therapeutic effecton AKT gene inducing fatty liver,and the mechanism possibly by inhibiting inflammatory factors of NF-κB,TNF-α,IL-6,COX-2 and anti-oxidative stress-related.
Animals ; Ellagic Acid ; pharmacology ; Fatty Liver ; drug therapy ; genetics ; Female ; Inflammation ; drug therapy ; Mice ; Oxidative Stress ; Proto-Oncogene Proteins c-akt ; genetics ; Random Allocation ; Transfection

OBJECTIVE: To determine the biological activity of ellagic acid extracted from gallnut against nasopharyngeal carcinoma and its molecular mechanism. METHODS: Nasopharyngeal carcinoma 5-8F cells were treated with 2, 4, 6 μg/mL ellagic acid for 48 h in vitro. The cell proliferation and cell apoptosis were analyzed by MTT and Hoechst33258 stain. The cell cycle and protein expression were measured by flow cytometry and Western blot. RESULTS: Ellagic acid inhibited the proliferation of 5-8F cells. The inhibition rates were (29.35±4.95)%, (53.32 ±4.44)% and ( 61.75 + 6.93)%, respectively, with significant difference from the control group (P<0.01). S phase cells in the experimental groups were (25.47±0.74)%, (28.08±1.41)% and (35.49±0.66)%, respectively, with significant difference (P<0.01) from the control group (21.26±0.70)%. Cells in the experimental groups showed nuclear pyknosis, karyorrhexis and poptotic cell morphology. The expression of COX-2 and stathmin in 5-8F cells was down-regulated with increased drug concentration. CONCLUSION Ellagic acid extracted from gallnut has activity against nasopharyngeal carcinoma cells, and its mechanism may be related to down-regulated expression of COX-2 and stathmin.
Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cyclooxygenase 2 ; genetics ; metabolism ; Down-Regulation ; drug effects ; Ellagic Acid ; pharmacology ; Humans ; Nasopharyngeal Neoplasms ; pathology ; Plant Extracts ; pharmacology ; Stathmin ; genetics ; metabolism

OBJECTIVETo investigate the chemical constituents of the brach of Macaranga adenantha, and evaluate their TNF-alpha inhibitory activity.

METHODThe chemical conshifuents were isolated and purified by chromatographic methods. Structures of the compounds were identified by spectroscopic methods. The TNF-alpha secretion inhibitory activity of the mouse peritoneal macrophages was evaluated by MTT methods.

RESULTTen compounds were isolated and their structures were identified as: cleomiscosin A (1), cleomiscosin B (2), ellagic acid 4-O-alpha-D-rhamnopyranside (3), ellagic acid 4-O-beta-D-xylopyranoside (4), vanillic acid (5), (24R) -stigmast-4-en-3-one (6), (24R) -stigmast-3, 6-dione (7), (24R) -6beta-hydroxy-stigmast-4-en-3-one (8), daucosterol (9), beta-sitosteryl glucoside-6'-O-heptadecoicate (10). At a concentration of 10 micromol x L(-1), compounds 1, 3 and 4 showed inhibitory activity to TNF-alpha secretion of the mouse peritoneal macrophages with the inhibitory rates of 57.0%, 64.4%, and 57. 4%, respectively.

CONCLUSIONAll compounds were isolated from genus Macaranga for the first time. Compounds 1, 3, and 4 were active against TNF-alpha secretion of the mouse peritoneal macrophages.

Animals ; Cell Survival ; drug effects ; Coumarins ; chemistry ; isolation & purification ; pharmacology ; Ellagic Acid ; analogs & derivatives ; chemistry ; isolation & purification ; pharmacology ; Euphorbiaceae ; chemistry ; Macrophages, Peritoneal ; cytology ; drug effects ; secretion ; Mice ; Plant Stems ; chemistry ; Plants, Medicinal ; chemistry ; Tumor Necrosis Factor-alpha ; metabolism