Comparative studies for screening of bioactive constituents from various parts of Incarvillea emodi

A comparative study was performed on various parts (shoots, roots and flowers) of Incarvillea emodi. The alcoholic extracts of different parts were fractionated with solvents of different polarity and studied for the determination of total polyphenol content and total antioxidant potential. Furthermore, we have isolated major iridoid glucosides from the dried flowers of I. emodi followed by the comparative cytotoxicity studies of these iridoids against five different human cancer cell lines. The results have demonstrated that ethyl acetate fraction of all parts have higher phenolic content (167.87-294.31 mg/g as gallic acid equivalent) and higher total antioxidant potential (252.95-384.64 mg/g as trolox equivalent). The results of in vitro cytotoxicity studies have indicated that boschnaloside (2) possesses promising anticancer potential against three human cancer cell lines, THP-1, A-549 and PC-3, which belong to leukaemia, lung and prostate cancers, respectively, while plantarenaloside (1) expressed relevant cytotoxic activity against THP-1 cell lines of leukaemia.