Anti-listerial synergism of leaf essential oil of Metasequoia glyptostroboides with nisin in whole, low and skim milks

OBJECTIVE@#To examine the individual and synergistic anti-listerial effect of nisin and leaf essential oil of Metasequoia glyptostroboides (M. glyptostroboides) against one of the leading foodborne pathogens Listeria monocytogenes (L. monocytogenes) ATCC 19116 in milk samples.@*METHODS@#The whole (8%), low (1%) and skim (no fat content) milk samples were inoculated with L. monocytogenes ATCC 19116 along with leaf essential oil of M. glyptostroboides or nisin alone as well in combinations.@*RESULTS@#In this study, the leaf essential oil at the concentrations of 2% and 5% revealed strong anti-listerial effect against L. monocytogenes ATCC 19116 in all categories of milk samples. Nisin at the concentrations of 250 and 500 IU/mL displayed a strong inhibitory effect against ATCC 19116 as compared to the control group. Additionally, synergistic combinations of leaf essential oil (1%) and nisin (62.5, 125, 250 and 500 IU/mL) also had a remarkable anti-listerial synergism in all the tested milk samples including whole, low and skim milk after 14 days.@*CONCLUSIONS@#As a major finding, the leaf essential oil of M. glyptostroboides might be a useful candidate for using in food industry to control the growth of foodborne pathogenic bacteria as confirmed by its potent anti-listerial synergistic effect with nisin against L. monocytogenes ATCC 19116 in different milk samples.

Antioxidant, lipid peroxidation inhibition and free radical scavenging efficacy of a diterpenoid compound sugiol isolated from Metasequoia glyptostroboides

OBJECTIVE@#To investigate the antioxidant efficacy of a biologically active diterpenoid compound sugiol isolated from Metasequoia glyptostroboides (M. glyptostroboides) in various antioxidant models.@*METHODS@#An abietane type diterpenoid sugiol, isolated from ethyl acetate extract of M. glyptostroboides cones, was analyzed for its antioxidant efficacy as reducing power ability and lipid peroxidation inhibition as well as its ability to scavenge free radicals such as 1,1-diphenyl-2-picryl hydrazyl, nitric oxide, superoxide and hydroxyl radicals.@*RESULTS@#The sugiol showed significant and concentration-dependent antioxidant and free radical scavenging activities. Consequently, the sugiol exerted lipid peroxidation inhibitory effect by 76.5% as compared to α-tocopherol (80.13%) and butylated hydroxyanisole (76.59%). In addition, the sugiol had significant scavenging activities of 1,1-diphenyl-2-picryl hydrazyl, nitric oxide, superoxide and hydroxyl free radicals in a concentration-dependent manner by 78.83%, 72.42%, 72.99% and 85.04%, when compared to the standard compound ascorbic acid (81.69%, 74.62%, 73.00% and 73.79%) and α-tocopherol/butylated hydroxyanisole (84.09%, 78.61%, 74.45% and 70.02%), respectively.@*CONCLUSIONS@#These findings justify the biological and traditional uses of M. glyptostroboides or its secondary metabolites as confirmed by its promising antioxidant efficacy.

Inhibitory effects of total flavones of Metasequoia glyptostroboides on experimental cardiac hypertrophy and expression of c-Fos protein in ventricle / 中草药

To observe the effects of total flavones of Metasequoia glyptostroboides Hu et Cheng (TFM) on volume-overload cardiac hypertrophy and the expression of c-Fos protein in rat. Methods　Volume-overload cardiac hypertrophy of rat was induced by aortocaval shunts. The rats were given ig TFM (400, 40 and 4 mg/kg/d). c-Fos protein in the ventricles were measured by immunocytochemical study. Results　TFM at the above dosage decreased heart weight and contents of RNA and protein in the myocardium, inhibited the expression of c-Fos protein in the ventricles. Conclusion　TFM can prevent volume-overload cardiac hypertrophy in rats. The inhibitory effects on the expression of c-Fos protein may be its mechanism in the molecular level.

Effect of total flavones isolated from Metasequoia glyptostroboides on platelet aggregation and hemorrheological properties in rats and research of its mechanism / 中草药

Object To observe the effect of total flavones isolated from Metasequoia glyptostroboides Hu et Cheng (FMG) on platelet aggregation, 5 HT of release, content of NO in plasma and hemorrheological parameters in rats. Methods Platelet aggregation was quantified by turbidimetry, release of 5 HT was assayed by fluorescence technique, and content of NO in plasma was determined by spectrophotometry. Results Inhibition of platelet aggregation and release of 5 HT, increase of NO content in plasma, as well as decrease of whole blood viscosity, plasma viscosity, red cell electrophoresis time, red cell specific volume, red cell count and K value in ESR equation were observed in the acute blood stasis rat, thereby the rat's hemorrheological properties were improved. Conclusion FMG is able to inhibit the platelet aggregation and improve the hemorrheological parameters in acute blood stasis rat. The inhibition of release of 5 HT, increase of NO content in plasma and antagonistic action of Ca 2+ may be the mechanism of its actions.