A Novel Approach for Measurement of Total Reactive Oxidant Species (ROS) In Vivo by A Fluorometric Method

Abstract

Six healthy participants were given a single dose of 100 mg of CoffeeBerry® whole coffee fruit extract containing high levels of antioxidants to verify an acute effect of the treatment on ROS serum level. Blood samples were collected at 0 min, 60 min, 120 min and 180 min for subsequent measurements of serum ROS level using dihydrorhodamine 6G (DHR6G) as a fluorescent probe. The nonfluorescent DHR6G, after being oxidized by ROS present in serum samples, became rhodamine 6G (R6G) and emitted fluorescence. By quantifying R6G specific fluorescence, we were able to measure the ROS concentration. DHR 6G is indiscriminate to various free radicals (FR) found in the human body, thus DHR 6G can be very useful in quantifying total ROS in vivo. Our data indicated that five participants responded to the intake of CoffeeBerry® whole coffee fruit extract by significant decrease of ROS concentrations in vivo. Collected results are promising and indicating that DHR6G-based method could be reliable and efficacious to measure acute serum ROS changes in response to single dose treatment with antioxidant products. Therefore further clinical validation of this test is justified.

Decrease of free radical concentrations in humans following consumption of a high antioxidant capacity natural product

“…In our previous study, we first demonstrated the use of DHR6G as a fluorometric assay for ROS in vivo (Nemzer et al. ). The theory behind using DHR6G is that nonfluorescent DHR6G will emit fluorescence after being oxidized by ROS.…”