Antioxidant studies of citric acid and citrus fruits towards paraquat by cyclic voltammetry: An antidote of paraquat poisoning.

Voltammetric parameters are studied to confirm the antioxidant activity of citric acid towards reduced form of methyl viologen dication (1, 1'-dimethyl-4, 4'-bipyridinium, MV 2+, also known as paraquat). In this study the kinetics of the reaction of citric acid with reduced form of methyl viologen is also reported. Out of two oxidative peaks (i.e. MVo to MV+˖ and MV+˖ to MV+2) the first peak is almost removed after interaction with citric acid. Shifting in second cathodic peak potential is also obvious and possibility of citric acid to scavenge or making adduct with paraquat is identified. Some real samples (fruit juices) as a rich source of citric acid are also studied. This study presents a simple, relevant and fast voltammetric method by which quick quantitation and monitoring of antioxidant/ scavenging activity of food, herbs and other spices towards paraquat poisoning is possible. It may constitute a new wave of treatment or therapy for the disease caused by paraquat.