Antioxidative effects of glycoprotein isolated from Solanum nigrum L.
Glycoprotein from Solanum nigrum L. (SNL glycoprotein) was isolated and tested for antioxidative effects on oxygen free radicals using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The free radical scavenging activities of the SNL glycoprotein are optimal in acidic pH and up to 60 degrees C. However, it has minimal activities in the presence of EDTA, although such activities are not dependent on M(2+) ions (Ca(2+), Mn(2+), and Mg(2+)) in the presence of EDTA. Interestingly, when SNL glycoprotein was treated with deactivation agents (pronase E and NaIO(4)), the DPPH radical scavenging activity was decreased compared with the SNL glycoprotein treatment alone. The antioxidative effects of SNL glycoprotein on superoxide anion and hydroxyl radical under optimal conditions revealed that SNL glycoprotein has remarkable scavenging effects on both radicals, but exhibited slightly higher scavenging effects on superoxide anion generated by the enzymatic hypoxanthine/xanthine oxidase system than on hydroxyl radicals generated by the Fenton reaction. However, SNL glycoprotein was more effective against hydroxyl radials in cell cultures (NIH/3T3). Consequently, 20 microg/mL SNL glycoprotein has a scavenging ability against superoxide anion corresponding to that of ascorbic acid. On the other hand, its hydroxyl radical scavenging activity corresponds to 0.1 microg/mL catalase. From these results, we suggest that SNL glycoprotein has potent antioxidative potential.
Heo
Kyung-Sun
KS
Molecular Biochemistry Laboratory and Biodefensive Substances Group, Institute of Biotechnology, Chonnam National University, Kwangju, Korea.
Lim
Kye-Taek
KT
D016475:3T3 Cells / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004492:Edetic Acid / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D006834:Hydrazines / Q000737:chemistry; D006861:Hydrogen Peroxide; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical / Q000737:chemistry; D007501:Iron; D051379:Mice; D010851:Picrates; D010940:Plant Proteins / Q000737:chemistry*; D032324:Solanum nigrum / Q000737:chemistry*; D013481:Superoxides / Q000737:chemistry; D013696:Temperature
D000975:Antioxidants; D001713:Biphenyl Compounds; C045076:Fenton's reagent; D016166:Free Radical Scavengers; D006023:Glycoproteins; D006834:Hydrazines; D010851:Picrates; D010940:Plant Proteins; D013481:Superoxides; D017665:Hydroxyl Radical; D004492:Edetic Acid; D006861:Hydrogen Peroxide; C004931:1,1-diphenyl-2-picrylhydrazyl; D007501:Iron