In previous studies we have observed that several polyphenolic molecules can inhibit growth and induce the synthesis of differentiation markers in colon cancer cells. In the present work we have sought to determine if similar activity can be observed with methanolic and ethanolic extracts from okra and drumstick. In okra, phenolic molecules and antioxidant activity were associated primarily with the seeds, whereas in drumstick the seeds had lower concentrations of phenolics and antioxidant activity than skin, pulp and seed coat. In studies with okra extracts we have concentrated on the effects of seed extracts because they were generally most inhibitory for cell proliferation as judged by protein yield, thymidine incorporation into DNA and tetrazolium salt reduction. With extracts from drumstick the greatest inhibition of growth was generally with seed coat extracts but anomalous results were obtained in assays of tetrazolium salt reduction. Inhibition was greater at low concentrations but at high concentrations the apparent effect was reversed. Studies in the absence of cells showed that a component of the drumstick seed-coat extract reacted directly to reduce the tetrazolium salt. Comparison with other parts of the drumstick indicated that this reduction was much greater with the seed coat extract. Small effects on colon cancer cell differentiation have been seen with extracts of okra seed and with pulp and seed extract from drumstick as judged by induction of alkaline phosphatase activity. In the case of okra seed extracts this effect was additive with the action of butyrate. Okra and drumstick have had a role in traditional medicine and the present data are encouraging for further studies on potential cancer chemopreventive action.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5439. doi:1538-7445.AM2012-5439