Evaluation of in vitro antioxidant and Antityrosinase activities of Ixora coccinea Linn. Roots

Abstract

Ixora coccinea Linn. Commonly known as ‘vetchi’ is a flowering shrub of the Rubiaceae family used in the treatment of various ailments in the Ayurvedic system of medicines. This research aimed to study the qualitative phytochemistry and to determine the antioxidant and antityrosinase activities of Ixora coccinea roots. Phytochemical analysis indicated the presence of various plant bioactive metabolites in Ixora coccinea roots. Different solvent extracts were tested for their in vitro antioxidant potential using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and ferric ion-reducing power assay. The total phenolic content (TPC) of the extracts was determined by spectrophotometric methods. Methanolic and aqueous extracts of the roots were evaluated for antityrosinase activity by inhibitory potency of mushroom tyrosinase. The methanolic extracts of Ixora coccinea roots possessed the highest DPPH radical scavenging activity with an IC50 value of 26.88μg/ml compared with aqueous and ethyl acetate extracts. The estimation of total phenolic content revealed that methanolic extract has the maximum phenolic content and exhibited the highest ferric reducing power compared with the other two extracts. The methanolic extract of Ixora coccinea roots showed a comparable antioxidant activity with that of standard ascorbic acid and also exhibited potent tyrosinase inhibition with an IC50value of 120.03μg/ml using Kojic acid as a reference standard. The current study showed that the methanolic extract of Ixora coccinea roots have superior skin whitening and antioxidant activities and could be used as a potential source of natural ingredient for formulating cosmetic products.