ABSTRACT:
Morinda citrifolia, commonly known as Noni or Indian Mulberry (Rubiaceae), is one of the traditional folk medicinal plants that have been used for over 2000 years in Polynesia and has been reported to have a broad range of therapeutic effects. In the present study, the antioxidant activity and cytotoxicity of methanolic extract of root suspension culture of Morinda citrifolia were evaluated. Antioxidant activity was evaluated by DPPH radical scavenging and reducing power assays whereas cytotoxicity was evaluated by MTT assay and Alamer Blue assay. The root suspension culture extract showed DPPH scavenging activity in a dose dependent manner with IC50 value of 92.5 ± 5.65 µg/ml. The root suspension extract had shown a significant cytotoxicity against mouse melanoma (B16) and human breast cancer (MCF-7) cell lines with IC50 values of 295 ± 14.14 µg/ml and 472.5 ± 17.67 µg/ml respectively. The phenolics and flavonoids were also evaluated quantitatively to study the effect of these compounds on antioxidant and antiproliferative activity of Morinda citrifolia. The levels of phenolics and flavonoids were 22.4 ± 0.28 mg/g and 218 ± 6.26 mg/g respectively. The above mentioned results shows that the high phenolic and flavonoid contents of the plant might be responsible for the observed potent antioxidants and significant antiproliferative activity of Morinda citrifolia root culture extracts.