Abstract:
Cancer is one of the most common causes of death in the developed world, with one-third of people diagnosed with
cancer during their lifetime. Oral cancer commonly occurs involving the buccal mucosa (cheeks), tongue, floor of the
mouth and lip. It is one of the most devastating and disfiguring of malignancies. Morinda citrifolia L., commonly known
as ‘noni’, belongs to the Rubiaceae family. It is native to the Pacific islands, Hawaii, Caribbean, Asia and Australia.
The plant displays broad curative effects in pharmacological studies. Damnacanthal (DAM) and Nordamnacanthal
(NDAM), anthraquinone compounds isolated from the roots of Morinda citrifolia L., has been used for the treatment
of several chronic diseases including cancer. The objectives of this study were to evaluate cytotoxicity, morphological
changes, cell death mode (apoptosis/necrosis), and cell migration induced by DAM and NDAM on the most common
type of oral cancer, oral squamous cell carcinoma (OSCC)cells. Anti-proliferative effects of these compounds against
OSCC cell lines were determined by MTT assay. The mode of cell death was analysed by phase contrast and fluorescent
microscopy as well as flow cytometry. In addition, cell migration was assessed. The results showed that DAM and
NDAM exerted cytotoxicity against OSCC cells with IC50 values of 1.9 to >30 μg/ml after 72 h treatment. Maximum
growth inhibition among the tested cell lines for both compounds was observed in H400 cells, and thus it was selected
for further study. The study demonstrated inhibition of H400 OSCC cell proliferation, marked apoptotic morphological
changes, induction of early apoptosis, and inhibition of cell migration by DAM and NDAM. Therefore, this information
suggests that these compounds from noni have potential for used as anti tumor agents for oral cancer therapy.