Abstract
Casticin (CTC), one of the major components of Vitex rotundifolia L., has been reported to exert significant beneficial pharmacological activities and can function as an antiprolactin, anticancer, anti‐inflammatory, neuroprotective, analgesic, and immunomodulatory agent. This study aimed at investigating whether the proapoptotic effects of CTC may be mediated through the abrogation of signal transducers and activators of transcription‐3 (STAT3) signaling pathway in a variety of human tumor cells. We found that CTC significantly decreased cell viability in a concentration‐dependent manner and suppressed cell proliferation in 786‐O, YD‐8, and HN‐9 cells. CTC also induced programmed cell death that was found to be mediated via caspase‐3 activation and induction of poly(ADP‐ribose) polymerase cleavage. Interestingly, CTC repressed both constitutive and interleukin‐6‐induced STAT3 activation in 786‐O and YD‐8 cells but only affected constitutive STAT3 phosphorylation in HN‐9 cells. Moreover, CTC could potentiate ionizing radiation–induced apoptotic effects leading to the downregulation of STAT3 activation and thus may be used in combination with radiation against diverse malignancies.
… 2 MATERIALS AND METHODS. 2.1 Reagents. CTC was purchased from
Biopurify Phytochemicals Ltd (Chengdu, Sichuan, China; Figure 1A). Stock
solution of CTC (100 mM) was prepared in dimethyl sulfoxide, stored at …
