Antioxidant and cytotoxic activities and phytochemical screening of four Philippine medicinal plants

Abstract

The crude methanol extracts of four Philippine medicinal plants namely Brucea amarissima (Lour.) Merr. Bark, Intsia bijuga (Coebr.) O. Kuntze, Laportea meyeniana Warb, and Pipturus arborescens (Link) C.B. Rob leaves were examined for their antioxidant (radical scavenging) activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, and cytotoxicity using brine shrimp lethality assay (BSLA). LC50 values for BSLA ranged from 37.7 to 89.5 µg/ml, with B. amarissima having the lowest value and therefore the most potent, and L. meyeniana having the highest value. EC50 values for DPPH radical scavenging activity ranged from 343 to 1846 µg/ml, with B. amarissima and I. bijuga having the lowest and highest values, respectively. Phytochemical screening revealed the presence of flavonoids, tannins, triterpenes, steroids, anthraquinones, anthrones, flavonoid glycosides, and coumarins, which could be responsible for the bioactivities shown by these plants.   Key words: Philippine medicinal plants, DPPH radical scavenging activity, brine shrimp lethality assay, phytochemical screening.