Plumbagin from two Plumbago species inhibits the growth of stomach and breast cancer cell lines

Plumbagin is a potent natural molecule that is found in several plants, especially in the genus of Plumbago. For centuries, plants containing this substance have been used therapeutically for various ailments according to the Indian traditional system of medicine. The aims of this study were, firstly, to compare the effectiveness of two different extraction methods for the isolation of plumbagin and, secondly, to compare the anti-proliferative effects of plumbagin in both field grown and in vitro grown plants of Plumbago indica L. and Plumbago zeylanica L. Plumbagin was quantified from different parts, viz from the leaf, stem and root of both field and in vitro grown plants of Plumbago indica. Plumbagin was isolated using the serial maceration extraction method using methanol as solvent. Anti-proliferative activity of selected extracts was examined in both stomach cancer cell lines (AGS) and breast cancer cell lines (MDA-MB-231). Quantification of plumbagin was performed by reverse phase high performance liquid chromatography (HPLC). The leaves, stem and roots of the in vitro grown Plumbago indica yielded 70.98 mg g(-1), 22.45 mg g(-1)and 342.15 mg g(-1)of content, respectively. This was higher when compared to the field grown parts (28.87 mg g(-1), 11.54 mg g(-1) and 2687 mg g(-1)). We have demonstrated that different extraction methods have varied yield of plumbagin. The isolated compound was then tested for its anti-proliferative activity. Also, we have confirmed apoptotic medicated cell death by nucleus staining to detect cell death by the treatment of different type of extract of both Plumbago indica L. and Plumbago zeylanica L.