Optimized and comparative antioxidant assays and its applications in herbal and synthetic drug analysis as an antioxidants.

Drug development in the recent times often relies on use of natural and synthetic drugs that are promising candidates as therapeutic agents for prevention of diseases and disorders. They possess different chemical structures with wide range of therapeutic activities. Many natural and synthetic drugs act as antioxidant agents in various metabolic processes. Increasing epidemiological, clinical and experimental studies have shown that intake of antioxidants drugs provide protection against various disorders and diseases related to oxidative stress. The factors responsible for this oxidative stress are mainly free radicals, reactive nitrogen species (RNS) and reactive oxygen species (ROS). The antioxidant drugs act as free radical scavenging, reducing and metal chelating substances; Antioxidants also show inhibition of various metabolic enzymes and factors responsible for inflammation. The present paper reviews different In vitro assays for determination of antioxidant activities (Table 1). The basic assays include DDPH assay, OH Scavenging assay, Reducing activity assay, TEAC assay, FCR assay, PRTC assay, ABTS assay, FRAP assay, ORAC assay, Ferric thiocynate assay, TRAP assay, Chemiluminescence assay, NBT assay, CUPRAC Assay.