Induction of Apoptosis by Methanolic Extract of Rubia Cordifolia Linn in HEp-2 Cell Line is Mediated by Reactive Oxygen Species

Rubia cordifolia Linn, which belongs to the Rubiaceae family, is a well-known herb used in Ayurvedic medicine.In the present study, we investigated the influence of a methanolic extract (RC) on the induction of apoptosisin HEp-2 (human laryngeal carcinoma) cell line, as evidenced by cytotoxicity, morphological changes andmodification in the levels of pro-oxidants. Inhibition of cell proliferation and lactate dehydrogenase (LDH) releaseincreased in a time and dose-dependent manner. Further, reduced glutathione (GSH), glutathione transferase(GST) and protein levels decreased and lipid peroxidation increased significantly on RC treatment in a dosedependent manner when compared to controls. Based on the results we determined the optimal dose as 30mg/ml and the apoptotic effect of RC extract (30 mg/ml) on HEp-2 cells was confirmed by fluorescent microscopyand transmission electron microscopy (TEM) based on morphological and ultrastructural changes. RC extractsuppressed the proliferation of HEp-2 oral cancer cells inducing apoptotic cell death in vitro. These results pointto potential of RC extract as an agent for the treatment of laryngeal squamous cell carcinoma.