Significant effects of two pesticides on the bacteriostatic activity and antioxidant ability of green tea polyphenols
Abstract Background: Green tea polyphenols (GTPs) have good bacteriostatic activity and antioxidant capacity, yet pesticide pollutants in tea may affect their functionality. This study aims to explore the effects of pesticide pollutants on the bacteriostasis and antioxidant ability of GTPs.Results: The bacteriostatic activity of GTPs and two pesticides (acetamiprid (ACE), diquat dibromide (DIQ)) shows some certain time characteristics. Two pesticides can affect the bacteriostatic activity of GTPs. The bacteriostatic activity of GTPs is enhanced or weakened by the two pesticides with time lengthening, i.e. time-dependent synergism or antagonism. The bacteriostatic mechanisms of the three substances and their mixtures is produced by affecting cell morphology or destroying cell structure, and the long-term antagonism of the three substances is may due to the competition of action site. In addition, the two pesticides can greatly reduce the antioxidant capacity of GTPs. ACE reduces the free radical scavenging ability of GTPs by 14%~24% and DIQ reduces the free radical scavenging ability of GTPs by 39%~63% at the experimental concentration ratios.Conclusions: Two pesticides has significant effects on the bacteriostatic activity and antioxidant ability of GTPs.