COMPOUNDS FROM TROPIDIA CURCULIOIDES AS INDUCERS OF APOPTOSIS IN CANCER CELLS

Arunachal Pradesh (AP), the North-eastern state of India, is a natural habitat of 550 species of orchids including 37 species of medicinal importance. Though these plants are used extensively by locals for various ailments, very few scientific investigations have been conducted to establish their pharmacological potential. In the present study, we selected Tropidia curculioides, a relatively unexplored orchid to evaluate its cytotoxic potential. As any investigation has not been conducted to evaluate the cytotoxic potential of the extracts or compounds, we performed screening of the compounds, previously isolated by our group for cytotoxic activity against three cancer cells viz., MCF-7, A549, and SiHa cells. Interestingly, all three compounds exhibited IC₅₀ in the range of 30-50 µM. Further, we studied apoptosis inducing property and ROS mediated cell death with the most active compound. The result indicated that TcR-3, a gallic acid derivative possesses maximum activity with IC₅₀ of 34.26 µM against A549 cells. The cell proliferation assay and apoptosis-inducing property measured by flow cytometry indicated that the compound has comparable activity to that of standard drug doxorubicin. Further, it was capable of inducing ROS-mediated cell death against A549 cells. Cell cytotoxicity of the compound was well within the permissible limit. The present study identified TcR-3 as a chemopreventive agent which could further be investigated for target-based activity.