Potent Antioxidant Properties of rolB-transformed Catharanthus roseus (L.) G. Don.

Abstract

Free radicals play an important role in pathological processes such as aging and developing cancer; hence, natural products inhibit free radical production, and can play an important role in preventing diseases. We aimed to evaluate the scavenging activity of free radicals, reducing power, inhibition of lipid peroxidation and malondialdehyde (MDA) formation, and the antioxidant composition ofrolB-transformed hairy roots and leaf callus ofCatharanthus roseus. Hairy roots of theCatharanthus roseuswere induced usingAgrobacterium rhizogenesstrain ATCC 15834 to transfer therolB gene. Polymerase chain reaction analysis was used to identify the presence of the gene in the transformed hairy roots. Folin-Ciocalteu reagent, aluminum chloride calorimetry and high performance liquid chromatography were used todetermine the content of total phenolic, flavonoid and gallic acid, respectively. To this end, we assayed the free radicals scavenging activity by 1-diphenyl-2-picrylhydrazyl (DPPH), reducing power, inhibition of lipid peroxidation and inhibition of malondialdehyde production. The results showed that phenolic, flavonoid, and gallic acid contents in the ethanol extract of the hairy roots were significantly higher (p ≤ 0.01) than those naturally found in the extracts of root, leaf, and leaf callus ofC. roseus. The hairy roots extract showed the lowest IC50for the inhibition of DPPH(•). Furthermore, the ethanol extract showed the best reducing power and had the highest potential to inhibit lipid peroxidation and to form the MDA.The transformed hairy roots can be considered a rich natural source of antioxidants.