| As a major component of the Earth's ecosystem, plants are closely related to human life.They provide not only human essential substances (saccharides, lipids and proteins), but also a large number of secondary metabolites for humans. In addition to regulating the growth and development of plants themselves, these compounds also play an irreplaceable role in plant protection and human health care and other fields. It, exploring from the plant with high agricultural activity of compound or using plant-derived pesticides makes it possible to replace high risk chemical pesticides. At the same time, the diseases caused by human pathogens has brought great pressure to human health and social economy, and it is a feasible and effective way to study and develop antimicrobial agents based on natural products. In addition, plant secondary metabolites protect the body. A major mechanism of secondary metabolites is to remove free radicals in the body, to maintain the body's redox homeostasis.Therefore, the study of natural bacteria with strong ability to inhibit bacteria and antioxidant capacity of human health care has great practical value. For this purpose, this paper studies the the genus inhibitory activity of plant or human pathogenic bacterium and tracking the active ingredients of Capparidaecae family Capparis zeylanica Linn (CZ). In this paper,based on the research activity of CZ, we continue to expand the scope of its activity, such as its free radical scavenging activity in vitro. Also based on wild-type yeast (WT) of Saccharomyces cerevisiae BY4741 (MATa, his3, leu2, met15, ura3) and its homologous Sod1, Ctt1, Gsh1, Gtt1 and Gtt2 gene-deficient strains, we assessed the in vivo antioxidant activity of CZ. Results were as follows:(1) Evaluating the free radical scavenging activity of CZ through the DPPH, ABTS,and free radicals such as hydroxyl radicals in vitro experimental. Results showed that IC50 of CZ sample solution to scavenging DPPH free radical was approximately between 0.1-0.2 mg/mL. The effect of scavenging DPPH free radical was lower than the control of its Vitamin C (VC) and 2,6-di-tert-butyl-p-cresol (BHT). The scavenging rate of CZ sample at a concentration of 0.1 mg/mL on hydroxyl radical scavenging was around 37% (similar to 0.1 mg/mL BHT), much higher than the equivalent concentration of VC solution (16%). When the CZ concentration raised to 0.5 mg/mL, the hydroxyl radical scavenging for around 63%,much higher than the VC (42%). Thus, CZ has a strong scavenging capacity for hydroxyl radical. However, the ABTS radical scavenging rate and reducing capacity of CZ samples were less effective.(2) Assessment of the in vivo antioxidant activity of CZ extracted through AB-8 of macroporous adsorption resin, based on wild-type Yeast Saccharomyces cerevisiae BY4741(MATa, his3, leu2, met15 and ura3) and its homologous gene-deficient strains Sod1, Ctt1,Gsh1, Gtt1 and Gtt2. CZ samples solution showed strong antioxidant activity in yeast model.After the CZ sample pretreatment, the tolerance of WT-type yeast cells stressed with H2O2,CCl4, and CdSO4 improved significantly. Continues to analysis the effects on gene deficient type strains, we found CZ samples cannot obviously improve tolerance of the Gtt1 type yeast to H2O2 and CCl4 and the Gtt2 type yeast to CdSO4, which meant this Gttl gene may has an important role in improve the tolerance of yeast cell to H2O2 and CCl4 and Gtt2 gene may matter in weakening Cd2+ toxicity in yeasts. The results of determination of lipid peroxidation and intracellular ROS content showed that CZ samples play an antioxidant,which may function though inhibiting yeast cell membrane-lipid peroxidation and decreasing intracellular ROS level.(3) Active components of CZ extracted through percolation method. The plant pathogen inhibition test found the active ingredients are in the chloroform extraction phase. The inhibition rate of most the strains of petroleum ether and n-butyl alcohol extracts were less than 5%, and chloroform extracts of strains tested for the inhibition was between 10%-30%,but still far below the rate of methyl ether ring h-pyrazole kresoxim-methyl (0.5 mg/mL) to these 5 species of plant pathogen inhibition. The inhibition rates of Chloroform extracts on Fusarium fungus, alternaria fungi and grape canker bacteria of 2 days were 13.01%, 18.77%and 12.4%. And the inhibition rate of Colletotrichum gloeosporioides Penz and Bipolaris cactivora (Petrak) Alcorn (tropical pathogens) of 2 days were 23.51% and 29.76%,respectively, far more effective than on three non-tropical fungi.(4) The inhibitory activity of the ethanol extracts of CZ to the three common foodborne pathogens was tested by the filter paper method. The results showed that there was no inhibitory effect on the Gram-positive bacteria (Staphylococcus aureus) at the low concentration (10 mg/mL), while the two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) showed a certain inhibitory effect (9.7±1.1 mm and 9.3±0.41 mm,respectively). With the increase of the concentration, the CZ samples showed inhibitory activity against each strain of bacteria, and it was not completely positive correlation. When the concentration was increased to 200 mg/mL, the inhibitory zone diameters of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa to CZ were 15.4 ±2.5 mm,20.6 ± 2.7 mm and 21.2 ±0.9 mm,respectively. With the same concentration, the control sample potassium sorbate showed better inhibition effects to each strain of bacteria. |
PDF Full Text Request