CYTOTOXIC BIOACTIVE COMPOUNDS FROM CALOTROPIS GIGANTEA STEM BARK

Abstract

<p><strong>Objective: </strong>The present study deals with the cytotoxic activity of n-hexane and ethyl acetate extracts of <em>Calotropis gigantea</em> L. stem bark and its fractions such as A, B, C, D and E fractions on murine leukemia cell line P388.</p><p><strong>Methods: </strong>The crude extracts of <em>C. gigantea</em> stem bark were prepared using n-hexane and ethyl acetate solvents. The plant extracts were subjected to vacuum liquid chromatography followed by TLC. According to the similarity of stain patterns, the fractions were combined. The extracts and its combined fractions were then subjected for the phytochemical test. Cytotoxic activity of those extracts and its combined fractions were tested using MTT assay. Fraction D was subjected to gravity column chromatography followed by TLC. Then, fractions A, B, and D2 were crystallized and subjected to GC-MS.</p><p><strong>Results: </strong>The qualitative screening of n-hexane extract of <em>Calotropis gigantea</em> L. stem bark for secondary metabolites showed the presence of terpenoid, flavonoids, phenolics and coumarins. While the ethyl acetate extract contained phenolics, steroids, flavonoids, saponins and coumarins compounds. IC<sub>50 </sub>values for n-hexane extract and E fraction are 76.29 µg/ml and 18.48 µg/ml, respectively. In the ethyl acetate extract and C fraction obtained IC<sub>50</sub> values 57.05 µg/ml and 52.58 µg/ml.</p><p><strong>Conclusion: </strong>Cytotoxic activity from E fraction of n-hexane extract of <em>C. gigantea</em> stem bark is the most potent and containing flavonoids, phenolics and coumarins. The main components from several compounds of n-hexane extract of <em>C. gigantea</em> are germacrane-A, (-)-globulol, urs-12-ene and veridiflorol. </p>